BIOLOGY
OF
REPRODUCTION
13,
Fine
50-60
(1975)
Structure
of the Rabbit
Vas Deferens
J.
CHARLES Department School
of
and
Vasectomy
FLICKINGER
of Anatomy, Medicine,
Epididymis
after
University
of
Charlottesville,
Virginia,
Virginia
22901
ABSTRACT Adult male rabbits were subjected to Several portions of the epididymis and microscopes at intervals up to 9 months
either vas after
bilateral deferens operation.
vasectomy or a bilateral sham operation. were studied with the light and electron In vasectomized rabbits, the epididymis
and proximal vas deferent were distended with sperm and expanded progressively from 2 weeks through 4 months after vasectomy. This expansion continued in one rabbit killed at 6 months and in one killed 9 months after vasectomy. However, in the remaining 3 rabbits killed 6 or 9 months after vasectomy, the epididymidis and vas deferens were less distended than in other vasectomized animals, and in 2 of these there was evidence that sperm escaped the male duct system and underwent phagocytosis in a spermatic granuloma in the surrounding connective tissue. Despite the distention, the epithelium of the epididymis and vas deferens of vasectomized rabbits remained columnar. The epithelium also continued to be functionally active as indicated by the persistence of the characteristic complement of cellular organdIes, including vacuoles and lysosomes thought to be involved in absorption and smooth endoplasmic reticulum that may be involved in secretion. The epithelium of the cauda epididymidis and proximal part of the vas deferens in both vasectomized and sham-operated animals fixed 2 to 6 months after operation was highly folded and had many apical cytoplasmic projections. The origin of this change is unknown, but it may be related to seasonal variations in activity of the epithelium.
1972a,
INTRODUCTION The
widespread
male
of interest
in
on
of
standing remains
the
a
yet
that
Second,
are
vasectomy,
clinical
in
what
changes?
systemic
possibly
tomy,
is
the testis
Another
by
and
are
retained
and
Howards,
impression research,
studies
are
vasec-
at
differences
in
der,
1973a,
1972,
least
response
types
can be gained from so far as ultrastructural is that there are species to vasectomy (Alexan-
b; Kubota,
1969;
March
Received
December
18,
vasectomy
In male
50
it
and 1965;
animals
Ohri, Segal,
duct
(Horan,
such
as
system
or
Johnson
1973;
indi-
considerations
from be treated after
many
will it principles mass
a given animal with exceptional accumulation
from
the
age or or other within a often vary
response,
the
These
only
present
the
study,
reproductive
The
male
duct
large
expansion
Quick,
1974.
species
prove of
of
species
of and
possible response
apparently
to to diver-
detail.
gent
Flickinger,
from
appar-
same
Jhaver
their
1975).
experiments the general
of
discern
1975. 10,
the al.,
from
within
vasectomy.
Accepted
et
escape
Perhaps information
caution.
immunologic
that
concerned,
(cf.
of
that generalizations on vasectomy
detailed
One
rat Kar
individual
particulars
sperm
cate study
means. recent
the
whether
after
there of
on
and
1972b; Plaut, 1973; Sackler 1973, 1974), perhaps as
Neaves,
experiment
in
question
is whether
as the 1962;
1973;
given
of
vasectomy? the
consequences
mediated
of
fate
results
Flickinger,
al.,
investi-
differing
the result of using animals of different strain, varying operative procedures, technical differences. Furthermore,
are
the extent
are
1972;
different
obtained
contradictory
et
effects organs
after
significance,
deleterious
following
the
what
alternations
these
the
about
produced
if so,
of
great
are
are
operation
reproductive
First,
there
the
particular,
male
and,
significance of
the
resolved.
sperm
of
under-
However,
also
of animal such 1960; Smith,
has
species,
1973).
have
ently
the
information of
questions on
of
effects
variety
In
fundamental
not
the
consequences
incomplete.
vasectomy
greatly
valuable
in
as a means increased
vasectomy
has
Although obtained
two
of
research
operation. been
use
contraception
b,
gators
rabbit
system
1924).
we
tract
was
was
examined rabbit chosen because
known
after Thus
have
of
vasectomy the
the
to
be capable (Moore
rabbit appeared
the after the of and
favor-
RABBIT
EPIDIDYMIS
AND
able for determining the response of the epithehum of the epididymis and vas deferens to progressively lumen. In was
accumulating addition, an
to determine
after vasectomy. sperm tosis
sperm objective
the fate of sperm Mechanisms
the study
produced
for the disposal of
might include the following: 1) phagocyof sperm by epithelium of the epididymis
and
2)
vas deferens;
through
the
sperm tions
in the in the
migration
epithelium
of
and
epithelium
and
phagocytes
phagocytosis
lumen, possibly duct epithelium;
and dissolution of sperm male ducts with uptake the
within the
of
of
following altera3) degeneration
in the lumen of the of soluble material by
4)
rupture
of
the
duct
system ma and
with formation phagocytosis
outside system. epididymis
the confines of the male reproductive The histology and ultrastructure of the and vas deferens of vasectomized
(Fhickinger,
AND
vasectomy or a bilateral sham operation performed on 25 young adult male Dutch-belted rabbits. The animals were obtained from the Arrow Rabbit Farm, Statesville, N.C., and each weighed Bilateral
approximately 2 kg. The animals were anaesthetized with intravenous pentobarbital, and the operation was performed through a vertical midline abdominal incision. In the vasectomized animals, the vas deferent on each side was ligated doubly with 2-0 black silk and was divided between the ligatures approximately 2-3
from
the termination
vessels
lying
on
the
of the vas deferens. The surface
of
the
vas
included
case of the animals that received a sham operation, ligatures were passed around each vas deferens, but they were then withdrawn without ligation. The rabbits were maintained in the university vivarium at a temperature of 70 to 72 F with a cycle of 12 h light and 12 h darkness. The animals Purina
in the
had
constant
fixed
ligature.
access
In the
to
water
and
were
for 2 h at room temperaglutaraldehyde in 0.1 M 7.3 or in a combination of
paraformaldehyde, glutaraldehyde, and picric acid (Ito and Karnovsky, 1968). The specimens were postfixed in 1 percent OsO4 in 0.1M cacodylate buffer at pH 7.3
for 1 h, dehydrated in a graded series of ethanols followed by propylene oxide, and embedded in Araldite. Sections 1 thick for light microscopy were stained with 0.5 percent toluidine blue in 0.5 percent sodium borate. Thin sections showing silverto pale gold interference colors were cut with a diamond knife, stained with lead citrate (Reynolds, 1963), and examined with a Philips EM-300 electron microscope. In addition, the entire testis, epididymis, and proximal part of the vas deferens from one side of some animals killed 4, 6, or 9 months after vasectomy were fixed en bloc in Bouin’s fluid, embedded in paraffin and serially
sectioned
General
for
light
microscopy.
Observations
The
proximal
fed
rabbit chow. Four animals were not studied morphologically because they died during the course of the experiment. Two of these had acquired a hair ball (tricobezoar) in the stomach and two died from undetermined causes. In none of the animals that died was there any evidence at autopsy that the death was attributable to an abnormality of the reproductive system. Two vasectomized animals and one sham-operated rabbit were killed at intervals of 2 weeks and 1, 2, 4, and 6 months after the operation. Three vasectomized and 3 sham-operated rabbits were killed 9 months after the operation. Three normal rabbits were also studied. Each animal was killed by intravenous injection of an overdose of pentobarbital. Samples of the caput and cauda epididymidis and
part of the vas deferens
the cauda epididymidis rabbits were distended
animals up to 4 months rabbit killed at 6 months months,
this
However, generally
progressive
and
vas
6
months
9 months
after
killed
after
killed and
proximal but
animals content other
after vasectomy. In one and in one killed at 9 distention
three rabbits were impressive increase
epididymis
mis
and
of the vasectomized with a viscous light
sperm suspension. These organs inprogressively in size in the vasectomized
normal
deferens
were gently separated from the vas so they would not be
were
either 5 percent buffer at pH
yellow creased
METHODS
was
blood
vas deferens
ture in cacodylate
51
RESULTS
1975).
MATERIALS
cm
the
DEFERENS
of a spermatic granuloof sperm by macrophages
rabbits are described in this paper while the structure of the testis is considered in a separate publication
VAS
less
continued.
exceptions in the size
deferens.
In
and
in
1 of 2 of
vasectomy,
vas distended
2 rabbits 3 animals
the
deferens
were
than
to this of the
epididylarger
than
in vasectomized
killed at earlier intervals, and their was clearer and less viscous than in the vasectomized
rabbits. In the rabbit killed
6 months after vasectomy, a soft yellow material of rubbery consistency was present between the epididymis and the testis. Histological study (Fig.
1)
sperm
that this material
showed
and
macrophages,
which
consisted
contained
of
many
ingested sperm and large lysosomes (Fig. 2). In one of the animals killed 9 months after vasectomy, similar yellow material found near the epididymis also contained numerous macrophages laden with large lysosomes. In another rabbit and
mis
killed connective
appeared
normal
and
9 months
vasectomy,
around
the
abnormal, having
but in this case we suspected presence histological
after
tissue
means.
a
being
yellowish
caput
the
firmer
than
discoloration,
are unable to confirm of extravasated sperm None
of
fat
epididy-
the
rabbits
the by
devel-
52
FLICKINGER
I..
FIG. 1. Light micrograph vasectomy. There are numerous which contain ingested sperm
of
a portion of a spermatic sperm (5) in the center of and dense bodies. X450.
the
granuloma granuloma,
from a rabbit surrounded
by
killed 6 months after phagocytic cells (P),
FIG. 2. An electron micrograph of a part of a phagocytic cellfrom the spermatic granuloma illustrated in Fig. The cytoplasm contains dense sperm heads (H), sperm tails(T), and large lysosomes (L) with polymorphous interiors. X 16,000. 1.
RABBIT
oped ligated
EPIDIDYMIS
AND
a cyst or granuloma around the proximal end of the vas deferens, as is common in
vasectomized rats (Flickinger, 1972a). Sperm were present in large numbers sections and
of the
lumen
the middle
midis
(Glover
animals,
and
in the mal
they
rabbits.
were
or
segment
ductuli
of
epididymidis
were
present
absent
the
origin
from
caput
efferentes.
known
exceptionally deferens
were
A
were
1971)
much
present and
in the
lumen
efferentes
luminal
contents
deferens
of all the rabbits. In paraffin
in
scattered the
the
cytoplasmic
other
rabbits.
and
the
of
of
un-
1971). The epithelium of the was very tall with an undulating
of the and
the vas
the
epididymis
apical surface, of the lumen the in
smooth
profile,
cells small
epithelial
sections
sperm, but only very were involved and no
increase in their numbers with time after either operation was observed. The rabbit killed 6 months after vasectomy which
FIG.
sperm
3.
rabbit, which are numerous,
A
were
portion contains especially
found
outside
of
organelles
Blocks of the caput epididymidis samples of both the initial and middle
uniform
in
epithelium
all
than
in
Epididymidis
segment
to contain of sperm
the
system appeared atrophdiminished in height and
fewer
of the ductuli efferentes of both vasectomized and sham-operated rabbits, some of these round appeared numbers
animal
the male duct the cells were
ini-
the
among
epididymis
Caput
smaller of
cells
of
this
exception to the descripand ultrastructure of the and vas deferens that
proxi-
in
round
In
parts of ic, since any
vasectomized
ductuli
of
contained
epididymidis few
the only histology the epididymis
the
follows.
numerous
of profiles
of
of all the and
53
was
tion
parts
epididy-
DEFERENS
system
in
epididymidis
of the caput
baa
the
Sperm
cauda
Nicander,
cauda
of
numbers tial
segment and
distended part
of the
VAS
the
duct
of the supranuclear cytoplasm rough and smooth endoplasmic in the middle segment of the
(Glover
and
columnar
cells
epithelial so
the
stereocihia
were
The caput
to
the
filled much In the middle were
more
surface
shorter,
many
vacuoles. The lumen in the middle larger than in the initial segment many
profile
cells
apical
contained
Nicander,
initial segment
and long stereocilia in plastic sections. height
included segments
had
and
a
the
cytoplasmic segment was and contained
sperm.
principal
cells of both
epididymidis
in
regions
of the
rabbits
were
normal
of a principal cell in the csput epididymidis of a normal reticulum and caput epididymis.
a large Golgi X 21,000.
apparatus
(G).
Vacuoles
(V)
54
FLICKINGER
characterized
many
by
surface, smooth
microvilli
on
a large supranuclear endoplasmic reticulum
tubular form, endoplasmic vesicles were
Golgi
the
apical
lysosomes
apparatus, mainly of
with a
branes,
and basal and perinuclear rough reticulum. Smooth and coated present in the apical cytoplasm
of
uoles
had
low
to
the
a content
vasectomized
the of
normal
endoplasmic
with
occupied
FIG.
trating
4.
the
nizable
parts
cluding
some
4),
much
A
which
portion
basal
portion
of sperm membranous
of
of the
content,
are
not
material.
of
detectable X 16,000.
cell
identifica-
caput
in these
the and
Dense
endoplasmic
were
lysosomes
supranuclear numerous
rough
apparatus, and abunreticulum in the form and whorls of memand
perinuclear
microvilli
projected
comcytointo
The cauda epididymidis of vasectomized rabbits and sham-operated animals killed 2 weeks and 1 month after operation resembled
The
the
of
the shape
the lumen.
from
numerous
scattered
cisternae. in
plasm,
and
cytoplasm.
7) contained
mon
to large bodies
with
type
cells of the epithelium of the of normal rabbits (Figs. 5
branous
cytoplasm
in size
the
Epididymidis
appara-
char-
Golgi
mem-
Recognizable
permitted cells.
smooth
the
of
instances
organdIes epithelial
reticulum, a large Golgi dant smooth endoplasmic of closely packed tubules
epithelium
of a cell
identify
and
ranged
a cell’s
to
in favorable
The columnar cauda epididymidis
identified
of a micrometer
but
remaining of columnar
Cauda of
epididy-
morphologically
(Fig.
tenths
material.
sham-operated
a large
content
masses
of
amount
features
in
granular
caput
a flocculent
structures
as Iysosomes that
and
polymorphous
regions,
difficult
and tion
in some
including
prominent
vacuoles
numerous
the
rabbits,
reticulum
Particularly
a few
and
epithelium of the ultrastructural
retained
were
small
a
and
involved,
vac-
material and
density
contained
The
was
material.
acteristic
tus.
3).
flocculent
electron
also
both
In
animals,
(Fig.
of
moderate
cases they membranous
midis
epididymis
a dense
parts of sperm were sought in them but were not detected. In some cases, so much of the cytoplasm was occupied by lysosomes that it
and larger vacuoles and lysosomes were present deeper in the cells. The vesicles and vacuoles were most numerous in samples of the middle segment
had homogenous
epididymidis
structures lysosomes-like
of a rabbit
morphologically figures,
9 months resembling
which
contain
after
vasectomy,
lysosomes a dense
(L). substance
illusRecogin-
RABBIT
EPIDIDYMIS
AND
VAS
DEFERENS
.
55
I 7
4.
FIG.
Light micrograph
5.
of a
midis
normal
smooth, curving
of the cauda epididy-
rabbit.
The
epithelium
has
a
profile. X430.
FIG. 6. Light micrograph midis
of
a
epithelium
rabbit
4
of the cauda epididy-
months
is highly
folded
after and
vasectomy.
the
apical
The surface
is
Sham-operated animals killed 2 to 6 months after operation had a similar appearance. X430. irregular.
that
of
and
6
normal
changes
but
epididymidis
apical
surfaces
in
only
the
2, 4,
following in
cells
ani-
epithelium
highly
of
the
folded.
had
vas deferens
vasecto-
sham-operated
the was
of
killed, the
not also
specimens
most
cauda
rabbits
operation,
observed
rabbits, In
In
after
were
mized mals.
rabbits.
months
very
The irregular
contours (Fig. 6) and there were many long projections of the apical ends of the cells into the lumen. These projections contained virtually all
of
the
usual
cytoplasmic
organdIes
(Fig.
8), and smooth
their most endoplasmic
bodies,
and
differed
in their larger size and their content
many smaller
prominent reticulum,
dense
lysosomes.
cytoplasmic apical
frequently
seen
deferens a fixation
organdIes
“blebs” in
contents were multivesicular The
projections
from
the
of cytoplasm
the
many
that
are
and
vas
epididymidis
and are thought by some artefact (e.g. Nicander,
of
to represent 1970). These
features were less prominent in animals killed 9 months after operation than in the 2 to 6 month specimens. In some samples from vasectomized rabbits, close apposition between apical projections of epithelial cells and within Proximal The
the
lumen Vas
was
these sperm
observed.
of the proximal
rabbits resembled
cauda epididymidis ing folding of the and
many
of the same rabbits, exhibitepithelium, apical projections
lysosomes.
These
to pronounced
the epididymis, but they than in the epididymis.
Vas
The deferens
part
of
were
in
Distal
initial
features
noticeable closest
the
that of
In vasectomized and it was similar to the
the
vas
most
deferens
were
less
Deferens
epithelium formed
extending
from
given cross deferens was
of the distal part of the vas many long gland-like crypts the
oval epithelium-lined central distal
main portion
similar
to
the
main
lumen.
Thus,
in a
section, the lumen of the vas represented in several circular to profiles in addition
to the
lumen. The epithelial contained organelles
cells of qualitatively
proximal
vas deferens,
part
of the
the
but in general the cells of the distal part were not as large and cytoplasmic organdIes such as smooth
endoplasmic
reticulum
were
not
as
abundant as in their proximal counterparts. The most striking feature of the distal part of the vas deferens in all the specimens was the great
Deferens
epithelium
in normal
the cauda epididymidis. sham-operated animals,
part of the
variability
in
the
height
of
the
epithelial
cells.
56
FLICKINGER
7. Electron micrograph of a principal cell from the cauda epididymidis of a normal rabbit, (T) and flattened Iamellae (A) of smooth endoplasmic reticulum, a large Golgi apparatus lysosomes (L), and microvilli (M) on the apical surface. X20,000. FIG.
tubules
illustrating (C),
dense
RABBIT
.1-
EPIDIDYMIS
AND
VAS
DEFERENS
57
-
8. Parts of several epithelial cells in the cauda epididymidis of a rabbit prepared 2 months after vasecThe apical surface of the epithelium is irregular and has long processes containing cytoplasmic organdIes such as smooth endoplasmic reticulum (5), mitochondria, and multivesicular bodies (B). Lysosomes (L) are numerous. M, microvilli on the apical cell surface. X 18,000. FIG.
tomy.
FLICKINGER
58
In some regions they were columnar, but in other areas they were much shorter cuboidal or even squamous cells. Differences between vasectomized were
and not
sham-operated
or
normal
rabbits
detected.
In
most
of
normal
in and
cently
the
been
the
and
rabbits,
in
shown
of
(Johnson
size
the
comparison
that
hamster
Howards, pressure
and
might
be
increase
in
expected atrophy
the has
epididymal epithelium been described (Kothari
vas
but in the present rabbit epididymis height resembled operated rabbits. As judged and
part
the wall, prominent
the
in the caput tomy. Since vasectomized
the
size
and
of
epi-
seems
this
likely
rather region.
than
that
fluid
sperm
Numerous
were
fluid
the absorptive
Changes epithelium proximal
the
trated
materials
and
of
the
absorption
the
and ab-
multivesicular
less
fluid
lysosomes of more here
in this concen-
as compared
steroids
in been
(Hamil-
composition has indicated
rabbits
of the after may
cells. effect
one
of that
epithelium
is not
vasectomy, be affected
although (Jones,
These changes of vasectomy,
possibility
seasonal
is that
variations
duct epithelium. All during the summer,
in the and the of the projecappeared but when
in the
the rabbits and the
the
changes
activity
of the
were purchased normal rabbits
were killed and operations were performed on the remaining rabbits at this time. Samples prepared 4 to 6 months after operation in which the changes were most extensive were thus fall
all and
tance when
taken winter in
vasectomy, tion of
system vasectomy.
the that
regard
emphasized
rabbits sperm
the lumen components
animals such as
to vasectomy. within the male
duct
up to 6 months after in at least 2 and possibly
killed 6 appeared
to to
sperm
was
no
9 months have escaped accumulated
longer
able
after the until
to accomo-
increased volume and the epididymis The large numbers of lysosomes
epithelium and
during the event, our the impor-
been for examinathese variations
rabbits
Perhaps
system
some
it not
all rabbits However,
system. duct
killed any
In
such as sham-operated the effects of procedures
been attributed accumulated
in
3 of 5 vasectomy the
this
since had sham-operated
might have Sperm
duct
from animals months.
of controls studying
midis
nature
the
2 to 6 months after operation of the cauda epididymidis vas deferens included folding and formation of long apical
but
reflect
ens (Friend and Farquhar, 1967), and these functions appeared to continue in these regions also after vasectomy. Perhaps the dense and reflects
in
tions of epithelial at first to be an
date the ruptured.
region
of
of
impaired function
bodies and lysosomes have a role in absorption and intracellular digestion in the cauda epididymidis (Nicander, 1970) and proximal vas defer-
polymorphous
synthesis
capacity
seriously secretory
experience
epididymidis continued after vasecthe content of the vacuoles in animals was mainly a fine floccuit
the Study
vasec-
reticulum has
clear,
The large numbers of in the middle segment suggests that absorption
especially rabbits
in
after
endoplasmic vas deferens
and
1971).
continue
both of a
of
principal cells of have been implifrom
which
smooth
of
epididy-
of
and vas deferens after vasectomy.
materials
the
they were seen also in sham-operated animals it became apparent that the cause must lie elsewhere. The basis for these observations is not
of the the
implicated
epithelium
dogs 1973),
morphology organelles,
1965).
materials in
lining Flattening
in vasectomized and Mishra,
intracellular
absorption
material,
soluble
in which tissue,
pressure
epithelial
abundant vacuoles in the rabbit caput epididymidis in
of the
in a thinning
deferens.
abundance in
1973).
(Morris, S., This expanalso
of the epididymis a high level of activity
lumen (Nicander, these vacuoles in vasectomized
the
study the epithelium of the remained columnar and its that of normal and sham-
by their
thelium retained
sorbed
proximal
of the
and
in
In vasectomized
result
possibly
re-
The
reticulum
nature,
epididymal
vasectomy
intra-luminal
to
epididymis
lent
after
and most
the
cated
pressure
in the
and
The the
the
has
epididymidis.
since epididymis
ton,
both
It
progressively thinner personal communication).
sion
cells
with
rises 1975).
the
vas deferincreased
animals.
vas deferens increases smooth muscle is the becomes 1975,
rabbits
part of the sperm and
sham-operated
epididymis
caput endoplasmic
mis and in the vas deferens suggests that regions have additional functions, perhaps tomy, the
vasectomized
and proximal distended with
progressively
the
smooth
secretory DISCUSSION
epididymis ens were
with
of the the
proximal
sperm
may
with by
when recognizable in the epididymal
caput
and vas
also
subsequent the epithelial parts and
have
cauda deferens
suggest
degenerated uptake cells.
of sperm were vasal epithelium,
in
epididyin
of their However, sought none
RABBIT
were
observed.
of
intact
This sperm
epididymis
or vas
disposal
of
appeared
indicates by
to
was
A
of
not
few
sperm
in
cells
were
in
ductules, but were extremely
small, and frequency
these cells were in sham-operated
gration of duct system of sperm
phagocytes into the lumen of the did not seem important in disposal after vasectomy. In addition, we
were
unable
tion
or
to recognize
atrophy
might
be
duct
of
system
and male
of
were
worth may
occur
after
vasectomy,
in
isms ple,
of sperm phagocytosis
and near
in the lumen of the rete testis
some have
of
tion).
(1972)
Alexander’s
ly pertinent studies have comparable phagocytosis
the
reported 1973;
the
sperm
at
other
longer
8 years
rabbits 12 S., personal
in this context dealt with animals length of time. of
sperm
by
are
a
it
is apparent
that
the
epididymis
proximal of much
vas deferens of the rabbit greater expansion as sperm
the
deferens killed
proximal
in almost within
one
ligated all the
month
after
to
in
and
of even
vasectomy
the
epididymis Alexander, Hooker system
very little, to escape
and
and either
(Smith, 1973a; Gilmore,
is more
as a result sperm the vas deferens
vas
(Flickduct exsoon or the
1962; Flickinger, 1972a; Kwart and Coffey, 1973; 1972). The rabbit duct
distensible
and
undergoes
the outside by
of a spermatic end of
the
the
of the duct macrophages
proximal
epididymis
has
of other Howards,
species 1975)
also
been
(Horan, including
and Morris, 1973). In addition, rabbit there were indications
has
recently
reported
in the compo-
observations
epididymis. Section 7:
tion for
System.
eds.),
(R.
described
in the
of the vas deferens 41/2 months after
but
there
was
absorption hum
lumen. duct
of or
of
infiltration
system
with in
the of
Subsequently,
mas occurred to my.
present
formation rabbits
Disten-
epididymidis was observed, evidence
epididymal
of
into
the
the
excurrent
of sperm 8 months
of epithe-
macrophages
rupture
E. B.
Physiosimilar
article.
histological by
and
American that are
and cauda vasectomy
no sperm
of PhysioVol. V. Male
0. Greep
pp. 303-3 17, Washington]
Society,
those
In “Handbook Endocrinology,
granuloafter
vasec-
ACKNOWLEDGMENTS
in those
inger, 1972a). This suggests that the male system of the rat is relatively non-distensible, the epididymis and proximal vas deferens pand begin
in the logy”,
logical
In vasectowas observed end
animals,
is
imposed
some sperm might disintegrate with subsequent uptake of their by the epithelium of the epididymis.
are capable accumulate
for 6 to 9 months after vasectomy. mized rats a spermatic granuloma
and
Reproductive
since few other maintained for a In this instance,
1972a),
or
(Schmidt
Astwood,
mon-
cells
of
vasectomized rabbits [Bedford, J. M. (1975) Maturation, transport, and fate of spermatozoa
especial-
mononuclear
differences
around
in a variety Johnson and rat
number conjecture
tissue. Formation
Bedford
tubules in
on
vasectomy
the
reach
deferens
both
small this
on
months after communica-
observations
after
if
are phagocytosed either
vas
that lumen nents
the lumen of the efferent ductules was observed. In comparing these results in the rabbit with previous observations on the rat (Flickinger,
around
in
mechan-
seminiferous been observed
and
men
the
the
differences in distensibility of and vas deferens, sperm of both
in connective
which
of
despite
the apparent epididymis
system
additional
rabbit and
then
is by
but
on suggest
rupture and no means
may
evidence
because
species ultimately
disposal may operate. For examof sperm within the rete testis
small proportion vasectomy (Morris, to
the
epididymis
The
involved,
granuloma
outside that
conclusive
the
but the observations for 6 to 9 months
the
escape.
by
when the
located
emphasizing
intervals
up
observed,
ultimately
of
Instead,
was
59
for months, vasectomized
correct,
of degenera-
invasion
DEFERENS
animals
equal mi-
epithelium,
phagocytes.
changes
keys
areas
precede
sperm
the phagocytes duct system. It seems
duct
to by
phagocytosis
any
the
thought
observed with animals.Thus
that
sperm
that
observed
VAS
pansion animals
the
important
round
of the efferent sperm involved
AND
phagocytosis
epithelium
deferens
contain
paraffin sections the numbers of
that
the
sperm.
EPIDIDYMIS
ex-
The author is indebted for technical assistance to Miss Sharon Odum. This research was supported by contract (NO1-HD-1-2506) with the Center for Population Research, National Institute of Child Health and
Human
Development. REFERENCES
Alexander, N. J. (1972). Vasectomy: long term effects in the rhesus monkey. J. Reprod. Fertil. 31, 399-406. Alexander, N. J. (1973a). Ultrastructural changes in rat epididymis after vasectomy. Z. Zellforsch. 136, 177-182. Alexander, N. J. (1973b). Autoimmune hypospermatogenesis in vasectomized guinea pigs. Contraception 8, 147-164.
FLICKINGER
60
Flickinger, C. J. (1972a). Alterations in the fine structure of the rat epididymis after vasectomy. Anat. Rec. 173, 277-300. Flickinger, C. J. (1972b). Ultrastructure of the rat testis after vasectomy. Anat. Rec. 174, 477-494. Flickinger, C. J. (1973). Regional variations in endoplasmic reticulum in the vas deferent of normal and vasectomized rats. Anat. Rec. 176, 205-224. Friend, D. S., and Farquhar, M. G. (1967). Functions of coated vesicles during protein absorption in the rat vas deferens. J. Cell Biol. 35, 357-376. Clover, T. D., and Nicander, L. (1971). Some aspects of structure and function in the mammalian epididymis. J. Reprod. Fertil. Suppl. 13, 39-50. Hamilton, D. W. (1971). Steroid function in the mammalian epididymis. J. Reprod. Fert. Suppl. 13,
89-97.
Hooker, R. H., and Gilmore, of the vasa deferentia with silastic medical
D. P. (1972). of the male adhesive. Int.
Obstruction and rabbit J. Fertil. 17,
rat
14-16.
Horan, A. H. (1973). The pathogenesis of hydrotestis after ligation of the vas deferent: a study in several species. J. Urol. 110, 317-321. Howards, S. S., Micropuncture
Ito,
Miller, and
S., and Johnson, microanalytical
A. studies
(1975). of the
effect of vasectomy
on the rat testisand epididy-
mis. Fertil. Steril. S., and Karnovsky,
20-28. M. J. (1968).
26:
Formaldehyde-
glutaraldehyde fixatives containing pounds. J. Cell. Biol. 39, 168A.
trinitro
com-
Johnson, A. L., and Howards, S. S. (1975). Intratubular pressure in the testis and epididymis before and after vasectomy. Amer. J. Physiol. 228: 556-564. Jhaver, P. S., and Ohri, B. B. (1960). The history of
experimental Int. Jones,
Coll. R.
and clinical work
Surg.
(1973).
33,
on vasectomy.
482-486.
Epididymal
function
mized rabbit. J. Reprod. Fertil.36, Kar,
A. B., Chandra, Long-term effect itary system of 381
J.
in the
vasecto-
the testis after vasectomy in rats and men. Jap. J. Urol. 60, 373-397. Kwart, A. M., and Coffey, D. S. (1973). Sperm granulomas: an adverse effect on vasectomy. J. Urol. 110, 416-422. Moore, C. R., and Quick, W. J. (1924). Properties of the gonads as controllers of somatic and psychical characteristics. VII. Vasectomy in the rabbit. Am. J. Anat. 34, 317-336. Neaves, W. B. (1973). Permeability of Sertoli tight junctions to lanthanum after ligation of ducrus deferens and ductuli efferentes. J. Cell Biol. 59, 559-572. Neaves, W. B. (1974). The rat testis after vasectomy. J. Reprod. Fertil. 40, 39-44. Nicander, L. (1965). An electron microscopical study of absorbing cells in the posterior caput epididymidis of rabbits. Z. Zellforsch. 66, 829-847. Nicander, L. (1970). Morphological evidence of secretion and absorption in the epididymis. In “Morphological Aspects of Andrology.” (A. F. Holstein and E. Horstman, eds.), Vol. 1, pp. 121-124, Grosse Verlag, Berlin. Plaut, S. M. (1975). Testicular morphology in rats vasectomized as adults. Science 181, 554-555. Reynolds, E. S. (1963). The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol. 17, 208-21 2. Sackler, A. M., Weltman, A. S., Pandhi, V., and Schwartz, R. (1973). Gonadal effects of vasectomy and vasoligation. Science 179, 293-295. Schmidt, S. S., and Morris, R. R. (1973). Spermatic granuloma: The complication of vasectomy. Fertil. Steril. 24, 941-947. Segal, R. J. (1972). Effect of vasoligation of 14-dayold and 21-day-old rats on spermatogenesis. Fertil. 17, 3 3-34. Smith, G. (1962). The effects of ligation efferentia and vasectomy on testicular the
199-202.
H., and Kamboj, V. P. (1965). of vasectomy on the gonad-piturats. Acta Biol. Med. Germ. 15,
adult
rat.
J. Endocr.
RECOMMENDED
23,
Int. of the function
J.
vasa in
385-399.
REVIEWS
-385.
Karnovsky, hyde electron Kothari, L. changes my. Int. Kubota, R.
M. J. (1965). A formaldehyde-giutaraldefixative of high osmolality for
use
in
microscopy. J. Cell Biol. 27, 137A. K. and Mishra, P. (1973). Histochemical in the testis and epididymis after vasectoJ. Fertil. 18, 119-125. (1969). Electron microscopic studies on
Hamilton, In
D. W. (1972). The mammalian epididymis. “Reproductive Biology.” (H. Balm and S. Glassner, edt.), pp. 268-337, Exerpta Medica, Amsterdam. Clover, T. D., and Nicander, L. (1971). Some aspects of structure and function in the mammalian epididymis. J. Reprod. Fertil., Suppl. 13, 39-50.
OF
REPRODUCTION
13,
Fine
50-60
(1975)
Structure
of the Rabbit
Vas Deferens
J.
CHARLES Department School
of
and
Vasectomy
FLICKINGER
of Anatomy, Medicine,
Epididymis
after
University
of
Charlottesville,
Virginia,
Virginia
22901
ABSTRACT Adult male rabbits were subjected to Several portions of the epididymis and microscopes at intervals up to 9 months
either vas after
bilateral deferens operation.
vasectomy or a bilateral sham operation. were studied with the light and electron In vasectomized rabbits, the epididymis
and proximal vas deferent were distended with sperm and expanded progressively from 2 weeks through 4 months after vasectomy. This expansion continued in one rabbit killed at 6 months and in one killed 9 months after vasectomy. However, in the remaining 3 rabbits killed 6 or 9 months after vasectomy, the epididymidis and vas deferens were less distended than in other vasectomized animals, and in 2 of these there was evidence that sperm escaped the male duct system and underwent phagocytosis in a spermatic granuloma in the surrounding connective tissue. Despite the distention, the epithelium of the epididymis and vas deferens of vasectomized rabbits remained columnar. The epithelium also continued to be functionally active as indicated by the persistence of the characteristic complement of cellular organdIes, including vacuoles and lysosomes thought to be involved in absorption and smooth endoplasmic reticulum that may be involved in secretion. The epithelium of the cauda epididymidis and proximal part of the vas deferens in both vasectomized and sham-operated animals fixed 2 to 6 months after operation was highly folded and had many apical cytoplasmic projections. The origin of this change is unknown, but it may be related to seasonal variations in activity of the epithelium.
1972a,
INTRODUCTION The
widespread
male
of interest
in
on
of
standing remains
the
a
yet
that
Second,
are
vasectomy,
clinical
in
what
changes?
systemic
possibly
tomy,
is
the testis
Another
by
and
are
retained
and
Howards,
impression research,
studies
are
vasec-
at
differences
in
der,
1973a,
1972,
least
response
types
can be gained from so far as ultrastructural is that there are species to vasectomy (Alexan-
b; Kubota,
1969;
March
Received
December
18,
vasectomy
In male
50
it
and 1965;
animals
Ohri, Segal,
duct
(Horan,
such
as
system
or
Johnson
1973;
indi-
considerations
from be treated after
many
will it principles mass
a given animal with exceptional accumulation
from
the
age or or other within a often vary
response,
the
These
only
present
the
study,
reproductive
The
male
duct
large
expansion
Quick,
1974.
species
prove of
of
species
of and
possible response
apparently
to to diver-
detail.
gent
Flickinger,
from
appar-
same
Jhaver
their
1975).
experiments the general
of
discern
1975. 10,
the al.,
from
within
vasectomy.
Accepted
et
escape
Perhaps information
caution.
immunologic
that
concerned,
(cf.
of
that generalizations on vasectomy
detailed
One
rat Kar
individual
particulars
sperm
cate study
means. recent
the
whether
after
there of
on
and
1972b; Plaut, 1973; Sackler 1973, 1974), perhaps as
Neaves,
experiment
in
question
is whether
as the 1962;
1973;
given
of
vasectomy? the
consequences
mediated
of
fate
results
Flickinger,
al.,
investi-
differing
the result of using animals of different strain, varying operative procedures, technical differences. Furthermore,
are
the extent
are
1972;
different
obtained
contradictory
et
effects organs
after
significance,
deleterious
following
the
what
alternations
these
the
about
produced
if so,
of
great
are
are
operation
reproductive
First,
there
the
particular,
male
and,
significance of
the
resolved.
sperm
of
under-
However,
also
of animal such 1960; Smith,
has
species,
1973).
have
ently
the
information of
questions on
of
effects
variety
In
fundamental
not
the
consequences
incomplete.
vasectomy
greatly
valuable
in
as a means increased
vasectomy
has
Although obtained
two
of
research
operation. been
use
contraception
b,
gators
rabbit
system
1924).
we
tract
was
was
examined rabbit chosen because
known
after Thus
have
of
vasectomy the
the
to
be capable (Moore
rabbit appeared
the after the of and
favor-
RABBIT
EPIDIDYMIS
AND
able for determining the response of the epithehum of the epididymis and vas deferens to progressively lumen. In was
accumulating addition, an
to determine
after vasectomy. sperm tosis
sperm objective
the fate of sperm Mechanisms
the study
produced
for the disposal of
might include the following: 1) phagocyof sperm by epithelium of the epididymis
and
2)
vas deferens;
through
the
sperm tions
in the in the
migration
epithelium
of
and
epithelium
and
phagocytes
phagocytosis
lumen, possibly duct epithelium;
and dissolution of sperm male ducts with uptake the
within the
of
of
following altera3) degeneration
in the lumen of the of soluble material by
4)
rupture
of
the
duct
system ma and
with formation phagocytosis
outside system. epididymis
the confines of the male reproductive The histology and ultrastructure of the and vas deferens of vasectomized
(Fhickinger,
AND
vasectomy or a bilateral sham operation performed on 25 young adult male Dutch-belted rabbits. The animals were obtained from the Arrow Rabbit Farm, Statesville, N.C., and each weighed Bilateral
approximately 2 kg. The animals were anaesthetized with intravenous pentobarbital, and the operation was performed through a vertical midline abdominal incision. In the vasectomized animals, the vas deferent on each side was ligated doubly with 2-0 black silk and was divided between the ligatures approximately 2-3
from
the termination
vessels
lying
on
the
of the vas deferens. The surface
of
the
vas
included
case of the animals that received a sham operation, ligatures were passed around each vas deferens, but they were then withdrawn without ligation. The rabbits were maintained in the university vivarium at a temperature of 70 to 72 F with a cycle of 12 h light and 12 h darkness. The animals Purina
in the
had
constant
fixed
ligature.
access
In the
to
water
and
were
for 2 h at room temperaglutaraldehyde in 0.1 M 7.3 or in a combination of
paraformaldehyde, glutaraldehyde, and picric acid (Ito and Karnovsky, 1968). The specimens were postfixed in 1 percent OsO4 in 0.1M cacodylate buffer at pH 7.3
for 1 h, dehydrated in a graded series of ethanols followed by propylene oxide, and embedded in Araldite. Sections 1 thick for light microscopy were stained with 0.5 percent toluidine blue in 0.5 percent sodium borate. Thin sections showing silverto pale gold interference colors were cut with a diamond knife, stained with lead citrate (Reynolds, 1963), and examined with a Philips EM-300 electron microscope. In addition, the entire testis, epididymis, and proximal part of the vas deferens from one side of some animals killed 4, 6, or 9 months after vasectomy were fixed en bloc in Bouin’s fluid, embedded in paraffin and serially
sectioned
General
for
light
microscopy.
Observations
The
proximal
fed
rabbit chow. Four animals were not studied morphologically because they died during the course of the experiment. Two of these had acquired a hair ball (tricobezoar) in the stomach and two died from undetermined causes. In none of the animals that died was there any evidence at autopsy that the death was attributable to an abnormality of the reproductive system. Two vasectomized animals and one sham-operated rabbit were killed at intervals of 2 weeks and 1, 2, 4, and 6 months after the operation. Three vasectomized and 3 sham-operated rabbits were killed 9 months after the operation. Three normal rabbits were also studied. Each animal was killed by intravenous injection of an overdose of pentobarbital. Samples of the caput and cauda epididymidis and
part of the vas deferens
the cauda epididymidis rabbits were distended
animals up to 4 months rabbit killed at 6 months months,
this
However, generally
progressive
and
vas
6
months
9 months
after
killed
after
killed and
proximal but
animals content other
after vasectomy. In one and in one killed at 9 distention
three rabbits were impressive increase
epididymis
mis
and
of the vasectomized with a viscous light
sperm suspension. These organs inprogressively in size in the vasectomized
normal
deferens
were gently separated from the vas so they would not be
were
either 5 percent buffer at pH
yellow creased
METHODS
was
blood
vas deferens
ture in cacodylate
51
RESULTS
1975).
MATERIALS
cm
the
DEFERENS
of a spermatic granuloof sperm by macrophages
rabbits are described in this paper while the structure of the testis is considered in a separate publication
VAS
less
continued.
exceptions in the size
deferens.
In
and
in
1 of 2 of
vasectomy,
vas distended
2 rabbits 3 animals
the
deferens
were
than
to this of the
epididylarger
than
in vasectomized
killed at earlier intervals, and their was clearer and less viscous than in the vasectomized
rabbits. In the rabbit killed
6 months after vasectomy, a soft yellow material of rubbery consistency was present between the epididymis and the testis. Histological study (Fig.
1)
sperm
that this material
showed
and
macrophages,
which
consisted
contained
of
many
ingested sperm and large lysosomes (Fig. 2). In one of the animals killed 9 months after vasectomy, similar yellow material found near the epididymis also contained numerous macrophages laden with large lysosomes. In another rabbit and
mis
killed connective
appeared
normal
and
9 months
vasectomy,
around
the
abnormal, having
but in this case we suspected presence histological
after
tissue
means.
a
being
yellowish
caput
the
firmer
than
discoloration,
are unable to confirm of extravasated sperm None
of
fat
epididy-
the
rabbits
the by
devel-
52
FLICKINGER
I..
FIG. 1. Light micrograph vasectomy. There are numerous which contain ingested sperm
of
a portion of a spermatic sperm (5) in the center of and dense bodies. X450.
the
granuloma granuloma,
from a rabbit surrounded
by
killed 6 months after phagocytic cells (P),
FIG. 2. An electron micrograph of a part of a phagocytic cellfrom the spermatic granuloma illustrated in Fig. The cytoplasm contains dense sperm heads (H), sperm tails(T), and large lysosomes (L) with polymorphous interiors. X 16,000. 1.
RABBIT
oped ligated
EPIDIDYMIS
AND
a cyst or granuloma around the proximal end of the vas deferens, as is common in
vasectomized rats (Flickinger, 1972a). Sperm were present in large numbers sections and
of the
lumen
the middle
midis
(Glover
animals,
and
in the mal
they
rabbits.
were
or
segment
ductuli
of
epididymidis
were
present
absent
the
origin
from
caput
efferentes.
known
exceptionally deferens
were
A
were
1971)
much
present and
in the
lumen
efferentes
luminal
contents
deferens
of all the rabbits. In paraffin
in
scattered the
the
cytoplasmic
other
rabbits.
and
the
of
of
un-
1971). The epithelium of the was very tall with an undulating
of the and
the vas
the
epididymis
apical surface, of the lumen the in
smooth
profile,
cells small
epithelial
sections
sperm, but only very were involved and no
increase in their numbers with time after either operation was observed. The rabbit killed 6 months after vasectomy which
FIG.
sperm
3.
rabbit, which are numerous,
A
were
portion contains especially
found
outside
of
organelles
Blocks of the caput epididymidis samples of both the initial and middle
uniform
in
epithelium
all
than
in
Epididymidis
segment
to contain of sperm
the
system appeared atrophdiminished in height and
fewer
of the ductuli efferentes of both vasectomized and sham-operated rabbits, some of these round appeared numbers
animal
the male duct the cells were
ini-
the
among
epididymis
Caput
smaller of
cells
of
this
exception to the descripand ultrastructure of the and vas deferens that
proxi-
in
round
In
parts of ic, since any
vasectomized
ductuli
of
contained
epididymidis few
the only histology the epididymis
the
follows.
numerous
of profiles
of
of all the and
53
was
tion
parts
epididy-
DEFERENS
system
in
epididymidis
of the caput
baa
the
Sperm
cauda
Nicander,
cauda
of
numbers tial
segment and
distended part
of the
VAS
the
duct
of the supranuclear cytoplasm rough and smooth endoplasmic in the middle segment of the
(Glover
and
columnar
cells
epithelial so
the
stereocihia
were
The caput
to
the
filled much In the middle were
more
surface
shorter,
many
vacuoles. The lumen in the middle larger than in the initial segment many
profile
cells
apical
contained
Nicander,
initial segment
and long stereocilia in plastic sections. height
included segments
had
and
a
the
cytoplasmic segment was and contained
sperm.
principal
cells of both
epididymidis
in
regions
of the
rabbits
were
normal
of a principal cell in the csput epididymidis of a normal reticulum and caput epididymis.
a large Golgi X 21,000.
apparatus
(G).
Vacuoles
(V)
54
FLICKINGER
characterized
many
by
surface, smooth
microvilli
on
a large supranuclear endoplasmic reticulum
tubular form, endoplasmic vesicles were
Golgi
the
apical
lysosomes
apparatus, mainly of
with a
branes,
and basal and perinuclear rough reticulum. Smooth and coated present in the apical cytoplasm
of
uoles
had
low
to
the
a content
vasectomized
the of
normal
endoplasmic
with
occupied
FIG.
trating
4.
the
nizable
parts
cluding
some
4),
much
A
which
portion
basal
portion
of sperm membranous
of
of the
content,
are
not
material.
of
detectable X 16,000.
cell
identifica-
caput
in these
the and
Dense
endoplasmic
were
lysosomes
supranuclear numerous
rough
apparatus, and abunreticulum in the form and whorls of memand
perinuclear
microvilli
projected
comcytointo
The cauda epididymidis of vasectomized rabbits and sham-operated animals killed 2 weeks and 1 month after operation resembled
The
the
of
the shape
the lumen.
from
numerous
scattered
cisternae. in
plasm,
and
cytoplasm.
7) contained
mon
to large bodies
with
type
cells of the epithelium of the of normal rabbits (Figs. 5
branous
cytoplasm
in size
the
Epididymidis
appara-
char-
Golgi
mem-
Recognizable
permitted cells.
smooth
the
of
instances
organdIes epithelial
reticulum, a large Golgi dant smooth endoplasmic of closely packed tubules
epithelium
of a cell
identify
and
ranged
a cell’s
to
in favorable
The columnar cauda epididymidis
identified
of a micrometer
but
remaining of columnar
Cauda of
epididy-
morphologically
(Fig.
tenths
material.
sham-operated
a large
content
masses
of
amount
features
in
granular
caput
a flocculent
structures
as Iysosomes that
and
polymorphous
regions,
difficult
and tion
in some
including
prominent
vacuoles
numerous
the
rabbits,
reticulum
Particularly
a few
and
epithelium of the ultrastructural
retained
were
small
a
and
involved,
vac-
material and
density
contained
The
was
material.
acteristic
tus.
3).
flocculent
electron
also
both
In
animals,
(Fig.
of
moderate
cases they membranous
midis
epididymis
a dense
parts of sperm were sought in them but were not detected. In some cases, so much of the cytoplasm was occupied by lysosomes that it
and larger vacuoles and lysosomes were present deeper in the cells. The vesicles and vacuoles were most numerous in samples of the middle segment
had homogenous
epididymidis
structures lysosomes-like
of a rabbit
morphologically figures,
9 months resembling
which
contain
after
vasectomy,
lysosomes a dense
(L). substance
illusRecogin-
RABBIT
EPIDIDYMIS
AND
VAS
DEFERENS
.
55
I 7
4.
FIG.
Light micrograph
5.
of a
midis
normal
smooth, curving
of the cauda epididy-
rabbit.
The
epithelium
has
a
profile. X430.
FIG. 6. Light micrograph midis
of
a
epithelium
rabbit
4
of the cauda epididy-
months
is highly
folded
after and
vasectomy.
the
apical
The surface
is
Sham-operated animals killed 2 to 6 months after operation had a similar appearance. X430. irregular.
that
of
and
6
normal
changes
but
epididymidis
apical
surfaces
in
only
the
2, 4,
following in
cells
ani-
epithelium
highly
of
the
folded.
had
vas deferens
vasecto-
sham-operated
the was
of
killed, the
not also
specimens
most
cauda
rabbits
operation,
observed
rabbits, In
In
after
were
mized mals.
rabbits.
months
very
The irregular
contours (Fig. 6) and there were many long projections of the apical ends of the cells into the lumen. These projections contained virtually all
of
the
usual
cytoplasmic
organdIes
(Fig.
8), and smooth
their most endoplasmic
bodies,
and
differed
in their larger size and their content
many smaller
prominent reticulum,
dense
lysosomes.
cytoplasmic apical
frequently
seen
deferens a fixation
organdIes
“blebs” in
contents were multivesicular The
projections
from
the
of cytoplasm
the
many
that
are
and
vas
epididymidis
and are thought by some artefact (e.g. Nicander,
of
to represent 1970). These
features were less prominent in animals killed 9 months after operation than in the 2 to 6 month specimens. In some samples from vasectomized rabbits, close apposition between apical projections of epithelial cells and within Proximal The
the
lumen Vas
was
these sperm
observed.
of the proximal
rabbits resembled
cauda epididymidis ing folding of the and
many
of the same rabbits, exhibitepithelium, apical projections
lysosomes.
These
to pronounced
the epididymis, but they than in the epididymis.
Vas
The deferens
part
of
were
in
Distal
initial
features
noticeable closest
the
that of
In vasectomized and it was similar to the
the
vas
most
deferens
were
less
Deferens
epithelium formed
extending
from
given cross deferens was
of the distal part of the vas many long gland-like crypts the
oval epithelium-lined central distal
main portion
similar
to
the
main
lumen.
Thus,
in a
section, the lumen of the vas represented in several circular to profiles in addition
to the
lumen. The epithelial contained organelles
cells of qualitatively
proximal
vas deferens,
part
of the
the
but in general the cells of the distal part were not as large and cytoplasmic organdIes such as smooth
endoplasmic
reticulum
were
not
as
abundant as in their proximal counterparts. The most striking feature of the distal part of the vas deferens in all the specimens was the great
Deferens
epithelium
in normal
the cauda epididymidis. sham-operated animals,
part of the
variability
in
the
height
of
the
epithelial
cells.
56
FLICKINGER
7. Electron micrograph of a principal cell from the cauda epididymidis of a normal rabbit, (T) and flattened Iamellae (A) of smooth endoplasmic reticulum, a large Golgi apparatus lysosomes (L), and microvilli (M) on the apical surface. X20,000. FIG.
tubules
illustrating (C),
dense
RABBIT
.1-
EPIDIDYMIS
AND
VAS
DEFERENS
57
-
8. Parts of several epithelial cells in the cauda epididymidis of a rabbit prepared 2 months after vasecThe apical surface of the epithelium is irregular and has long processes containing cytoplasmic organdIes such as smooth endoplasmic reticulum (5), mitochondria, and multivesicular bodies (B). Lysosomes (L) are numerous. M, microvilli on the apical cell surface. X 18,000. FIG.
tomy.
FLICKINGER
58
In some regions they were columnar, but in other areas they were much shorter cuboidal or even squamous cells. Differences between vasectomized were
and not
sham-operated
or
normal
rabbits
detected.
In
most
of
normal
in and
cently
the
been
the
and
rabbits,
in
shown
of
(Johnson
size
the
comparison
that
hamster
Howards, pressure
and
might
be
increase
in
expected atrophy
the has
epididymal epithelium been described (Kothari
vas
but in the present rabbit epididymis height resembled operated rabbits. As judged and
part
the wall, prominent
the
in the caput tomy. Since vasectomized
the
size
and
of
epi-
seems
this
likely
rather region.
than
that
fluid
sperm
Numerous
were
fluid
the absorptive
Changes epithelium proximal
the
trated
materials
and
of
the
absorption
the
and ab-
multivesicular
less
fluid
lysosomes of more here
in this concen-
as compared
steroids
in been
(Hamil-
composition has indicated
rabbits
of the after may
cells. effect
one
of that
epithelium
is not
vasectomy, be affected
although (Jones,
These changes of vasectomy,
possibility
seasonal
is that
variations
duct epithelium. All during the summer,
in the and the of the projecappeared but when
in the
the rabbits and the
the
changes
activity
of the
were purchased normal rabbits
were killed and operations were performed on the remaining rabbits at this time. Samples prepared 4 to 6 months after operation in which the changes were most extensive were thus fall
all and
tance when
taken winter in
vasectomy, tion of
system vasectomy.
the that
regard
emphasized
rabbits sperm
the lumen components
animals such as
to vasectomy. within the male
duct
up to 6 months after in at least 2 and possibly
killed 6 appeared
to to
sperm
was
no
9 months have escaped accumulated
longer
able
after the until
to accomo-
increased volume and the epididymis The large numbers of lysosomes
epithelium and
during the event, our the impor-
been for examinathese variations
rabbits
Perhaps
system
some
it not
all rabbits However,
system. duct
killed any
In
such as sham-operated the effects of procedures
been attributed accumulated
in
3 of 5 vasectomy the
this
since had sham-operated
might have Sperm
duct
from animals months.
of controls studying
midis
nature
the
2 to 6 months after operation of the cauda epididymidis vas deferens included folding and formation of long apical
but
reflect
ens (Friend and Farquhar, 1967), and these functions appeared to continue in these regions also after vasectomy. Perhaps the dense and reflects
in
tions of epithelial at first to be an
date the ruptured.
region
of
of
impaired function
bodies and lysosomes have a role in absorption and intracellular digestion in the cauda epididymidis (Nicander, 1970) and proximal vas defer-
polymorphous
synthesis
capacity
seriously secretory
experience
epididymidis continued after vasecthe content of the vacuoles in animals was mainly a fine floccuit
the Study
vasec-
reticulum has
clear,
The large numbers of in the middle segment suggests that absorption
especially rabbits
in
after
endoplasmic vas deferens
and
1971).
continue
both of a
of
principal cells of have been implifrom
which
smooth
of
epididy-
of
and vas deferens after vasectomy.
materials
the
they were seen also in sham-operated animals it became apparent that the cause must lie elsewhere. The basis for these observations is not
of the the
implicated
epithelium
dogs 1973),
morphology organelles,
1965).
materials in
lining Flattening
in vasectomized and Mishra,
intracellular
absorption
material,
soluble
in which tissue,
pressure
epithelial
abundant vacuoles in the rabbit caput epididymidis in
of the
in a thinning
deferens.
abundance in
1973).
(Morris, S., This expanalso
of the epididymis a high level of activity
lumen (Nicander, these vacuoles in vasectomized
the
study the epithelium of the remained columnar and its that of normal and sham-
by their
thelium retained
sorbed
proximal
of the
and
in
In vasectomized
result
possibly
re-
The
reticulum
nature,
epididymal
vasectomy
intra-luminal
to
epididymis
lent
after
and most
the
cated
pressure
in the
and
The the
the
has
epididymidis.
since epididymis
ton,
both
It
progressively thinner personal communication).
sion
cells
with
rises 1975).
the
vas deferincreased
animals.
vas deferens increases smooth muscle is the becomes 1975,
rabbits
part of the sperm and
sham-operated
epididymis
caput endoplasmic
mis and in the vas deferens suggests that regions have additional functions, perhaps tomy, the
vasectomized
and proximal distended with
progressively
the
smooth
secretory DISCUSSION
epididymis ens were
with
of the the
proximal
sperm
may
with by
when recognizable in the epididymal
caput
and vas
also
subsequent the epithelial parts and
have
cauda deferens
suggest
degenerated uptake cells.
of sperm were vasal epithelium,
in
epididyin
of their However, sought none
RABBIT
were
observed.
of
intact
This sperm
epididymis
or vas
disposal
of
appeared
indicates by
to
was
A
of
not
few
sperm
in
cells
were
in
ductules, but were extremely
small, and frequency
these cells were in sham-operated
gration of duct system of sperm
phagocytes into the lumen of the did not seem important in disposal after vasectomy. In addition, we
were
unable
tion
or
to recognize
atrophy
might
be
duct
of
system
and male
of
were
worth may
occur
after
vasectomy,
in
isms ple,
of sperm phagocytosis
and near
in the lumen of the rete testis
some have
of
tion).
(1972)
Alexander’s
ly pertinent studies have comparable phagocytosis
the
reported 1973;
the
sperm
at
other
longer
8 years
rabbits 12 S., personal
in this context dealt with animals length of time. of
sperm
by
are
a
it
is apparent
that
the
epididymis
proximal of much
vas deferens of the rabbit greater expansion as sperm
the
deferens killed
proximal
in almost within
one
ligated all the
month
after
to
in
and
of even
vasectomy
the
epididymis Alexander, Hooker system
very little, to escape
and
and either
(Smith, 1973a; Gilmore,
is more
as a result sperm the vas deferens
vas
(Flickduct exsoon or the
1962; Flickinger, 1972a; Kwart and Coffey, 1973; 1972). The rabbit duct
distensible
and
undergoes
the outside by
of a spermatic end of
the
the
of the duct macrophages
proximal
epididymis
has
of other Howards,
species 1975)
also
been
(Horan, including
and Morris, 1973). In addition, rabbit there were indications
has
recently
reported
in the compo-
observations
epididymis. Section 7:
tion for
System.
eds.),
(R.
described
in the
of the vas deferens 41/2 months after
but
there
was
absorption hum
lumen. duct
of or
of
infiltration
system
with in
the of
Subsequently,
mas occurred to my.
present
formation rabbits
Disten-
epididymidis was observed, evidence
epididymal
of
into
the
the
excurrent
of sperm 8 months
of epithe-
macrophages
rupture
E. B.
Physiosimilar
article.
histological by
and
American that are
and cauda vasectomy
no sperm
of PhysioVol. V. Male
0. Greep
pp. 303-3 17, Washington]
Society,
those
In “Handbook Endocrinology,
granuloafter
vasec-
ACKNOWLEDGMENTS
in those
inger, 1972a). This suggests that the male system of the rat is relatively non-distensible, the epididymis and proximal vas deferens pand begin
in the logy”,
logical
In vasectowas observed end
animals,
is
imposed
some sperm might disintegrate with subsequent uptake of their by the epithelium of the epididymis.
are capable accumulate
for 6 to 9 months after vasectomy. mized rats a spermatic granuloma
and
Reproductive
since few other maintained for a In this instance,
1972a),
or
(Schmidt
Astwood,
mon-
cells
of
vasectomized rabbits [Bedford, J. M. (1975) Maturation, transport, and fate of spermatozoa
especial-
mononuclear
differences
around
in a variety Johnson and rat
number conjecture
tissue. Formation
Bedford
tubules in
on
vasectomy
the
reach
deferens
both
small this
on
months after communica-
observations
after
if
are phagocytosed either
vas
that lumen nents
the lumen of the efferent ductules was observed. In comparing these results in the rabbit with previous observations on the rat (Flickinger,
around
in
mechan-
seminiferous been observed
and
men
the
the
differences in distensibility of and vas deferens, sperm of both
in connective
which
of
despite
the apparent epididymis
system
additional
rabbit and
then
is by
but
on suggest
rupture and no means
may
evidence
because
species ultimately
disposal may operate. For examof sperm within the rete testis
small proportion vasectomy (Morris, to
the
epididymis
The
involved,
granuloma
outside that
conclusive
the
but the observations for 6 to 9 months
the
escape.
by
when the
located
emphasizing
intervals
up
observed,
ultimately
of
Instead,
was
59
for months, vasectomized
correct,
of degenera-
invasion
DEFERENS
animals
equal mi-
epithelium,
phagocytes.
changes
keys
areas
precede
sperm
the phagocytes duct system. It seems
duct
to by
phagocytosis
any
the
thought
observed with animals.Thus
that
sperm
that
observed
VAS
pansion animals
the
important
round
of the efferent sperm involved
AND
phagocytosis
epithelium
deferens
contain
paraffin sections the numbers of
that
the
sperm.
EPIDIDYMIS
ex-
The author is indebted for technical assistance to Miss Sharon Odum. This research was supported by contract (NO1-HD-1-2506) with the Center for Population Research, National Institute of Child Health and
Human
Development. REFERENCES
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FLICKINGER
60
Flickinger, C. J. (1972a). Alterations in the fine structure of the rat epididymis after vasectomy. Anat. Rec. 173, 277-300. Flickinger, C. J. (1972b). Ultrastructure of the rat testis after vasectomy. Anat. Rec. 174, 477-494. Flickinger, C. J. (1973). Regional variations in endoplasmic reticulum in the vas deferent of normal and vasectomized rats. Anat. Rec. 176, 205-224. Friend, D. S., and Farquhar, M. G. (1967). Functions of coated vesicles during protein absorption in the rat vas deferens. J. Cell Biol. 35, 357-376. Clover, T. D., and Nicander, L. (1971). Some aspects of structure and function in the mammalian epididymis. J. Reprod. Fertil. Suppl. 13, 39-50. Hamilton, D. W. (1971). Steroid function in the mammalian epididymis. J. Reprod. Fert. Suppl. 13,
89-97.
Hooker, R. H., and Gilmore, of the vasa deferentia with silastic medical
D. P. (1972). of the male adhesive. Int.
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14-16.
Horan, A. H. (1973). The pathogenesis of hydrotestis after ligation of the vas deferent: a study in several species. J. Urol. 110, 317-321. Howards, S. S., Micropuncture
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(1975). of the
effect of vasectomy
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Johnson, A. L., and Howards, S. S. (1975). Intratubular pressure in the testis and epididymis before and after vasectomy. Amer. J. Physiol. 228: 556-564. Jhaver, P. S., and Ohri, B. B. (1960). The history of
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