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).