Longitudinal changes of manganese-dependent dismutase and other indexes of manganese and iron status in women13 Cindy
D Davis
JL
The superoxide
ABSTRACF
dependent has
and
not
been
MnSOD
We
longitudinally
and other
in 47 women during received one of four manganese, or both
supplementation MnSOD activity baseline
Greger
effect of dietary factors on manganesedismutase (MnSOD) activity in humans
studied.
activity
indices
evaluated
ofmanganese
a 124-d supplementation treatments: placebo, mineral supplements
retention
changes
in
and iron status 60
study. Subjects mg iron, 1 5 mg daily. Manganese
resulted in significant increases in lymphocyte and serum manganese concentrations from
values
but
no changes
in urinary
manganese
indices
demonstrated
of iron
that
status.
with serum manganese exposure in humans. KEY
MnSOD
activity
can
be
used
manganese, changes
superoxide
in nutritional
dismutase,
status,
manganese
ferritin,
Subjects
and study
Forty-seven
dismutase
nogenesis
(EC
chemical
(3), to protect
iron,
transferrin,
1 . 1 5. 1 .) has been shown (1, 2) and radiation-induced
to protect carci-
reprofusion injury (4), and to inhibit inflammation (5). Several dietary factors alter the activity of the mitochondrial form (manganese-dependent) of superoxide dismutase (MnSOD). MnSOD activity is depressed in the tissues of ingestion ofhigh
fatty
acids
has also been
rodents
(6).
activity
However,
in humans
Although pecially
cells against
manganese-deficient amounts ofiron
the
found the
has
not
practical
in bone,
(9),
limited
work
that
young
women
recognized
been
done
by
Nutrition
Food
in their ingestion
of manganese
been
typically
and
(10) would
dietary
factors
were
Board
in
es-
of the
species
National
Research
lymphocytes. Furthermore, we hypothesized ofiron supplements would further depress
that regular manganese
l992;55:747-52.
Printed
in USA.
activity
in response
to diet
healthy,
nonsmoking
participated
1 cm
tall
in this
and
weighed
I 24-d 59.6
females study. ±
aged
The
1.2 kg. All
blinded
manner
to one
of four
treatments.
elemental
1 19 d, the subjects
manganese
amino
acid
bound
that rats retained acid
chelate
to protein
chelate
was
82.3%
chosen
more
of manganese
rather
hydrosylates. because
manganese than
The Ashmead
when
manganese
man(17)
fed an chlo-
© 1992 American
Downloaded from https://academic.oup.com/ajcn/article-abstract/55/3/747/4715211 by guest on 30 March 2018
1
From
the
Department
of
Nutritional
ofAgricultural
Sciences,
University
and Life Sciences,
of
University
of Wisconsin-Madison, project #2633, NIH grants ROl-DK41940 and MOl-RR03186 from the General Clinical Research Center Program of the National Center for Research Resources. 3 Address reprint requests to JL Greger, Department of Nutritional Sciences, 1415 Linden Drive, Madison, WI 53706. ReceivedJuly 10, 1991. Accepted for publication September 19, 1991.
the estimated mg) recommended of MnSOD
Nuir
maximal
±
Wisconsin, Madison. 2 Supported by the College
hypothesized
activity
Am J C/in
have less than
(2-5
MnSOD
MnSOD
less than
consume
intake
animal We
165
in a doubly
observed
activity on
deficiency,
in several
in humans.
because
consumed one ofthe following supplements at dinner daily: 1) placebo (prepared to look like the other supplements), 2) 60 mg Fe as ferrous fumarate (Approved Pharmaceutical Corp, Syracuse, NY), 3) 15 mg Mn as an amino acid-chelated manganese supplement (Laser Co. Crown Point, IN), or 4) both the iron and manganese supplements daily. The manganese supplement was a nonspecific formulation of
studied.
has
daily
the
been
have who
MnSOD
of dietary
women
design
y (1 ± SE)
ganese-amino
(6-8). Moreover, vs polyunsaturated
to decrease
effect effects
safe and adequate Council
rodents or saturated
and
apparently
± 0.5
assigned
both
young
subjects gave informed consent after a full explanation of the study, which was approved by the University of WisconsinMadison Committee on the Use of Human Subjects. After an initial 5-d baseline period, subjects were randomly
Introduction
against
among
Methods
For the next
Superoxide
activity
retention
subjects
oral contraceptives
cells
MnSOD
would not be observed during the short duration oftypical metabolic balance studies (ie, 10-30 d) (13-16). Hence, we longitudinally evaluated manganese and iron utilization of young women receiving manganese and/or iron supplements for 1 19 d.
23.9
concentrations to monitor manganese Am J Clin Nutr 1992;55:747-52.
WORDS
longitudinal
Oral
lymphocyte
and
rats fed very high amount ofiron (1 1) or injected with iron (12) retained less oforal doses ofMn-54 than those animals fed normal amounts of iron. We also hypothesized that changes in
excretion
contraceptive use and the stage of the menstrual cycle did not confound the use of lymphocyte MnSOD activity or serum manganese to monitor manganese status, but fat intake affected both indices. This work or in any
superoxide
Society
for Clinical
Nutrition
747
748
DAVIS
TABLE
AND
GREGER
I
Baseline (day supplemented
1) values for indexes of manganese with manganese and/or iron
status
in women S S
Treatment
Serum
Mnt
Urine
Lymphocyte MnSOD
Mn
C S
C
nmo//L
U/gprotein
.5 0
Mn(n= 11) Fe(n= 12) Mn + Fe (n = 1 1) Placebo(n=
nmo//d
17.3±2.0’
18.7± 10.6 15.4±
I 3)
I ± SE. t Values in a column
10.6±
1.9
1.74 ±0.14
6.5±
1.0
2.02 ±0.17
2.3 1.3
1.94 ± 0.21 1.72 ±0.12
1.8’ ±
0.6”
1 1.5 9.1
19b
± ±
C
.o C
S 0
5 C
*
nificantly
different,
S
without
P < 0.05
a common
superscript
letter are sig-
C.)
(ANOVA). 25
ride. The amount of manganese in the supplement (15 mg) was the minimum amount that we could find in commercially available, single supplements, ie, not multivitamins. Supplements were counted beforehand and given to subjects in five batches
during
the bottles were counted on average, consumed the 1 l9-d period. There the
four
the
study.
The
supplements
remaining
when the bottles were returned. 1 17 ± 0.3 ( ± SE) supplements were no differences in compliance
in
Subjects, during among
treatments.
Subjects were instructed to continue their usual exercise patbirth-control methods, and dietary regime. None of the subjects consumed vitamin or mineral supplements, laxatives, fiber supplements, or medications for chronic conditions in the month before or during the study; 45% used oral contraceptive agents. The oral contraceptives used contained between 0.03 and 0.035 mg ethinyl estradiol. tern,
Sample
collection
Blood days
samples
were
1 , 25, 60, 89, and
drawn
from
124. Day
fasted
1 samples
(
8 h) subjects
on
50
75
Time 2. Changes
FIG
supplemented (n
=
12);A,
in urinary
manganese
100
125
(days) excretion
overtime
in 47 women 0, Fe
with manganese and/or iron. (n = 1 1) 0, Mn; Mn + Fe (n = 11);U, placebo (n = 13).1 ± SE.
determinations plements until
subjects did not begin taking the sup5. Special syringes (Sarstedt Monovette, Sarstedt, Arlington Heights, IL) were used for serum collection to reduce trace element contamination. Vacutainer tubes (Becton Dickinson and Co, Rutherford, NJ) were used for plasma collection. Lymphocytes were isolated from fresh whole blood on a Ficoll-Hypaque density medium (Histopaque-1077, Sigma, St Louis). Cells were suspended in 0.5 mL phosphate-buffered saline, sonicated for 10 s, and stored at -70 #{176}C. Subjects collected all oftheir urine in acid-washed plastic containers on days 2-4, 22-24, 57-59, 86-88, and 121-123; 3-d because
day
were used for baseline
U
S a) 0 C
S
0
S
C S
E.. 1 Es
.2
;,o. OE
SC C S a)
C
C S
S
S
.C
C S
C.)
.C C.)
Time
(days) Time
FIG 1 . Changes in serum manganese women supplemented with manganese O,Fe(n=l2);A,Mn+Fe(n=ll);U,placebo(n=l3).i±SE. *P < 0.05 compared with placebo at compared with placebo at same time with placebo at same time point. Time P < 0.0001.
concentrations and/or iron.
over time (n
=
(days)
in 47
1 1) 0, Mn;
same time point; tP < 0.01 point; tP < 0.0001 compared effect was significant overall,
Downloaded from https://academic.oup.com/ajcn/article-abstract/55/3/747/4715211 by guest on 30 March 2018
FIG
3. Changes
in lymphocyte
MnSOD
activity
overtime
in 47 women
supplemented with manganese and/or iron. (n = I 1) 0, Mn; 0, Fe (n = 12); A, Mn + Fe (n = 1 1); U, placebo (n = 13). 1 ± SE. P < 0.05 compared with placebo at same time point. tP < 0.01 compared with placebo at same time point. Time effect was significant overall, P
The
53%
from
serum
manganese
subjects
dif-
of man-
fat. Subjects less
diets.
offat They
suggests
lym-
in humans. In addition, serum manganese has been accurately measured only in the past few years because of methodological problems (23). We found that both lymphocyte MnSOD activity and serum manganese concentrations were sensitive to moderate dietary supplementation. Accurate ways to assess
manganese
status
are
important
be-
of the potential for both manganese deficiency and manganese toxicity in human subjects. Americans, especially women, are believed to consume less than the estimated safe and adequate daily dietary intake of manganese (10, 24). Several investigators have hypothesized that less than optimal manganese intake may be related to degenerative bone changes (9, 25) and altered pancreatic function (9, 26). Although manganese toxicity has been documented in industrial settings (27, 28), the potential health cause
effects
of long-term
dienyl
manganese
continuous tricarbonyl,
exposure
to methylcyclopenta-
a replacement
for lead
are unknown (29). Perhaps lymphocyte MnSOD serum manganese concentrations will be useful exposure
in gasoline,
activity with in monitoring
to manganese.
four
intake had
that
the
the
energy
from
fat.
The
ganese
quintended
ferrin
highest
forms
small response oflymphocyte MnSOD activity to manganese supplementation and the long time required for significant changes to be observed (89 d) in this study suggest that manganese intake ofthese healthy young women approximated their requirements. The increased lymphocyte MnSOD activity with time indicates increased manganese exposure, not necessarily improved nutritional status. Moreover, a variety of factors inducing oxidative stress, ie, exposure to hyperbaric oxygen (30), ozone (3 1), ethanol (32), or diets rich in polyunsaturated fatty acids (6), have also been demonstrated to increase levels of MnSOD activity in laboratory animals. Similarly, in this study women who consumed < 30% oftheir energy from fat had lower MnSOD activity than did individuals consuming > 31% of their intake when fat, is high deserves Our observations
and serum
in the other
quintile
This
how
subjects into the following 30% of calories from fat, 31-
and lower
intakes.
con-
consume
indicators
significantly
did
National
to determine
had
in the lowest
of
0% to con-
adults
should
ofcalories
37%
0.05 (ANOVA).