Endocrinol. Japon.

Possible

1979, 26 (3), 399-409

Role

of Brain Norepinephrine Hypophyseal Adrenal

in the Hypothalamic System

TOMONARIOISHI Department of Bioclimatology and Medicine, Research Institute Balneotherapeutics, Kyushu University, Beppu874, Japan

of

Synopsis Intracisternalinjection of bethanidine in rats decreasedbrain norepinephrineturnover without affectingits endogenouslevel, and increasedboth cardiac norepinephrine turnoverlandserum corticosteronelevel. A negativecorrelationwas observedbetween brain norepinephrine turnover rate and serum corticosterone level. On the other hand, when cardiac norepinephrine turnover was suppressedby intraperitoneal injection of bethanidine, serum corticosteronedid not changesignificantly. Next, ether inhalation was added after intracisternal injection of bethanidine. Then, serum corticosteroneincreasedmore evenwhen brain norepinephrineturnoverwas suppressed only slightly. These data may indicatethat serum corticosteroneincreasesby selective decrease in brain norepinephrine turnover via the humoral route; from the hypothalamus down to the adrenal cortex. Inversely,intracisternal injection of corticosteroneincreasedbrain norepinephrine turnover. These results suggest that brain norepinephrine may play an inhibitory role in the tonic regulation of CRF-ACTH secretion in the higher center than the hypothalamusand there may be a closed-loopfeedbacksystembetweenbrain norepinephrine and serum corticosterone. Brain catecholamines, including epinephrine, dopamine and serotonin, regional neuronal distributions in the

norshow brain

1950; Vogt, 1954; Amin et al., (Holtz, 1954; Montagu, 1957; DahlstrOm and Fuxe, 1964; Anden et al., 1966; Iversen, 1967). On the basis of the intracellular localization, the synthetic and catabolic system and the releasing mechanism of the catecholamines onto the lower neurons, it is suggested that the amines may function as central neurotransmitters (Vogt, 1954 and 1959; Bertler and Rosengren, 1959). Indeed, a number of studies have reported that brain catecholamines may play an important role in the central regulation of Received

December

26, 1978.

many physiological functions such as blood pressure (McCubbin et al., 1960; Share and Melville, 1963), mood or affect (Everett and Wiegand, 1962; Schildkraut, 1965), pituitary functions (Sawyer et al., 1947; Fuxe, 1964; Coppola et al., 1965) and body temperature (Brodie and Shore, 1957; Feldberg and Myers, 1965). Brain norepinephrine has also been suggested to be a higher component in the tonic and phasic regulation of the hypothalamic hypophyseal adrenal system. However, there are many controversial results. Some studies suggested the stimulatory effect of brain norepinephrine on ACTH secretion (EndrOczi et al., 1963; Krieger and Krieger, 1964; Naumenko, 1967; Bhargava et al., 1972), while others the inhibitory role (Maickel et al.,

Endocrinol. June 1979

OISHI

400 1961;

Giuliani

Ganong,

et

1967;

al.,

1969a

and

Cohen

and

1969;

Van

1966

;

Lorenzen

Bhattacharya b;

Van

Ganong, Loon

et

and

Loon

et

1969;

Steiner

at

Preziosi,

On

the

not

1972;

only

other

find

hand,

any

some

and

al.,

in

1974).

investigators

correlation

epinephrine

et

the

the

ACTH

brain

secretion

1967;

Carr al.,

Kumeda

et

Ito ly

and

1973;

et

al.,

stressed

the

rather

the

brain

b)

importance of

have of

the

studying

than

the

static

level

in

analyzing

catecholamine

over

was

a a

of

its

Determination

role

of

tration

to

The

present

investigate

study

the

norepinephrine

was

relation

costerone

level

carried

and

after

out

between

turnover

serum

intracisternal

were

brain

bethanidine,

through

a

the

specific

three

does

not

barrier

of

the

release

brain

cortex, the

method

The

brain

pass

and

is

sympathetic

without

bellar

a

and

content Green,

(Boura

lowering

1963).

intracisternal brain

et

al.,

the

1962;

Moreover,

injection

of

norepinephrine

the

Boura effect

corticosterone

turnover

was

anesthesia in4.9%.

animals

the

were

inturn-

injection.

of

inferior

of on

was

also

expected

ex-

supposedly

the

was time

and

discarded.

of

The

of

of

the

the

the

dorsal

into

border brain

hypo-

caudal

pons

and

Cushman,

one

kept

was

medulla

1957). were

of stem

thalamus,

the

cereorigin

dividing

caudal

the

They

anterior at

rostral

while

to (1972).

along

further

at

consist

(Pellegrino

bellum

with

(Fig.1).

composed

longata

at

subparts

midbrain

according

laterally

caudally

into

cerebral

Schanberg

rostrally

nerves,

to and

plate;

colliculi,

and

divided

stems and

separated

colliculi

thalamus

glass

Ito

superior

caudal

at10:00. and

brain

by

cervical and

decapitation

ice-cold

caudal

was

and

concen-

removed

an

and

stem

the1st

norepinephrine

by

reported

peduncles

rostral

nor-

brain

on

rostral

was

amine

U.S.A.)

norepinephrine

after

immediately

portions

cortiinjection

which

blood-brain

inhibitor

epinephrine

drug

rate

injection.

dissolved

Brain

sacrificed

was

commissure

of

the

ether

Control

the

at05:00.

turnover

Co., light

1.0or5.0ƒÊg

of

Rats

neurotransThe

mitter.

its

Chemical

vehicle.

at

after

under

estimated1hr

al.(1967).

weight

and

solution. the

achieved

et

body

determined5hr

of0.2,

with

was

turn-

phase

as

dose

jected

the

catecholamine

the

rate after

intraperitoneally of

(Sigma

animals.

studied24hr

Schanberg

injected

body while

turnover

injection of

intracisternally

ethanol-saline

control its

were

method

were

anes-

rats,

the

concentration

injected

previous-

heart

was

heart

ether of

and

either4or20mg/kg

the

at

and

the

Corticosterone

1974;

1974).

phase

endogenous

Kaplanski

Hiroshige,

in

Intracisternal to

light

experimental

injected

the

Norepinephrine

(Smelik,

1968;

and

al.(1976a

dynamic over

Moore, Abe

and

injection.

of

the

concentration

Bethanidine

in

et

was

brain

dose

nor-

under

either0.4or2.0mg/kg n

vehicle

according

could

between

of

Norepinephrine

al.,

Scapagnini

Scapagnini

dose

at10:00

the

and

intracisternally

the

weight

1969; et

injected

thesia

Marks,

al.,

al., 1971;

was

and

Japon.

ob-

The frozen

cereuntil

assay.

amined.

Materials

Experimental Male Wistar throughout obtained

and

Methods

animals rats, weighing150-200g,

these experiments. from the Animal

versity. Prior to in groups of5and ordinary ditioned

the

experiment, were bred

food and water chamber at24•}2•Ž

were

The Center,

ad

they for2

animals Kyushu

used were Uni-

were housed weeks with

libitum in an with illumination

air-confrom

06:00to18:00.

Administration

of

drugs

Fig.1.•@

Bethanidine (bethanidine sulphate, N-benzylN'N"-dimethylguanidine sulphate; Burroughs We

of

llcome

ed.

Co.,

England)

solved

in20ill

of0.9%

saline

Schematic the

caudal

rat, brain

illustration including stem.

of

cerebral The

each cortex,

cerebellum

brain

portion

rostral was

discard-

and

Vol.26,

No.3

Brain

BRAIN

samples

ice-cold0.4N

oxide

at

the

of

wet

Then, weight

fluorometrically

in

described

by

minor

The

added

to

Estimation

of

The calculated

of

according

the

to

tritium

fraction

tracer

dose

Neff,

for

removed the

and

chloric

counted

Scintillation by of

ml

of

The was

rate 1/hr)

The

slope

half-life

to

be

according of (T1/2,

the to

the

the

decline

hr)

and

indicates tissue).

the

The

rate in

of

the

the

heart.

significance

of

coefficients

parallel),

the

Student's

(that

data

t test

were

at

the

is,

difference-

whether

analyzed

the

the

statistically

Computer

Center

of

University.

labeled

was

number

of

samples

costerone

centrifuged.

frozen

and

stored

from

together was

on

with

a

to

day.

the the

modifications

Theat -20•Ž

experiment

same by

according slight

single

the

determined

assay

level

and

promptly

serum

corticosterone

collected

were-

Serum

competitive

protein

method

of

(Oishi

corti-

et

Murphy

al.,

1977).

to Effect

of

intracisternal

injection

of

be-

thanidine Intracisternal

of

the

dose

injection of

of

bethanidine

at

no

significant

either0.4or2.0mg/kg

caused

changes

concentration

of

in

the

norepinephrine

three

brain

portions-

coefficient, least to rate

Effect

serum

was

Results

scin-

calculation

of

turnover

was

(1967)

norepinephrine for

used

of blood

counting

of

rats

(Table1),

squares.

calculate

the

(ng/g/hr):

intracisternal

norepinephrine

(No.)

the

of3H-NE

the

regression

Kyushu

and6.0g

(regression

Table1.•@

(ng/g

described.

from

analysis

binding

toluene,

average

method

the

with

Co.,

eluate

of

gave

decline

the

re-

fraction

already

radioactivity

(Liquid

This

monoethylether and

of

quickly

per-

Aloka

alumina

transformed

constant

was

radioactivity

LSC-673, the

5

eluted

counter

of1,000ml

of

as

estimated

of

at10:00. 5or9hr

heart

norepinephrine

acid

the

saline

decapitation2, the

the

was

turnover with5ƒÊCi

of0.9%

by

estimating

analyzed

quickly

of0.05N

solution.

consisted

activity

of

are

All

by

i.e.

was

The

Type

logarithmically

.5ml

eluted

rate

serum

of25%. specific

be

Trunk

For

used,

brain

scintillation

glycol

norepinephrine

and

Determination

in20pl

sacrificed

were

scintillation

ethylene

perchloric

were

injection.

portions

of

toluene

were

above.

liquid

a

and

rats

with5ml

5-diphenyloxazole,

efficiencies

k,

a

solution

of2,

three

adding0.5ml a

tillation

the

described

in

k

steady

specific Costa

3H-NE

the

The

Spectrometer,

Japan) 10ml

as

the

norepinephrine.

intravenously

sacrificed

0.05N

using

of

cardiac

injection,

to

lines

norepi-

1966;

15rats

into

where

[NE]

endogenous

injected in0

moved

between

decline

brain

of

They

fraction

acid

was

al.,

after

divided

the

anesthesia,

time-point.

norepinephrine

the

For

from

England,

ether

group,

each

were

after

Statistical

injection

et

at10:00.

experimental

k,

and

(3H-NE)(The

3or5hr

animals

of

They

was

kinetics

the

with4ƒÊCi

saline

decapitation2,

600

light

intracisternally

every

in

rate=[NE]

half-life of

were dissolved

decline

and

Amersham,

Under

of0.9%

state level

(Brodie

1970).

injected

steady

401

turnover

T1/2the

concentration

turnover

turnover

intracisternal

activity5.8Ci/mmol)

Hita-

norepinephrine

activity

Centre,

a

norepinephrine

of l-7-3H-norepinephrine

Radiochemical

in

MPF-4,

for

brain

the

after

with

was92•}4%.

norepinephrine

specific

nephrine

rate

and

slope,

Rats 3H-NE

method

read

norepinephrine

rate

endogenous

of

was

homogenates

brain

turnover

the (1971)

(Model

recovery

the

Estimation in

determined

to

Fluorescence

Japan).

standard

was

Gordon

spectrophotometer

Ltd.,

is

of0.05N

according and

SECRETION

T1/2=0.693/k

state

content

sample

duplicate

modifications.

the

the

ACTH

aluminum

with5ml

Shellenberger

fluorescence

on

norepinephrine of

was

Norepinephrine fluid

eluted

acid.

of

homogenate

supernatant

pH7.8and

AND

in5volumes The

for30min.

from

perchloric

chi

acid.

at28,000g

absorbed

ng/g

homogenized

perchloric

centrifuged was

were

NOREPINEPHRINE

but

it

turnover

dose-dependently

portions;

the

injection

of

bethanidine

decreased

norepinephrine in

initial

specific

on

all activity

brain

level

and

i.c.

the

intracisternal

injection.

Values

are

means•}SEM.

three was.

402 Table2.•@

Turnover

of

injection

(No.) *

indicates

P