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Title
Aspects of cardiomyopathy are exacerbated by elevated dietary
fat in copper-restricted rats.
Author
Jalili T; Medeiros DM; Wildman RE
Address
Department of Human Nutrition and Food Management' Ohio State
University' Columbus 43210' USA.
Source
J Nutr, 126(4):807-16 1996 Apr
Abstract
The obJective of this study was to determine if a high fat diet
having a 2:1 saturated-polyunsaturated fatty acid ratio exacerbates
signs of copper deficiency. Male weanling Long-Evans rats were
randomly placed into one of the following treatment groups: adequate
copper low fat or deficient copper high fat. The levels of fat
used were 31 or 12% of daily energy' and copper concentrations
were 94.5 micromol/kg and <15.8 micromol/kg in the copper-adequate
and copper-deficient diets' respectively. Cardiac hypertrophy
as well as lower liver copper levels and superoxide dismutase
activity were observed in both groups of copper-deficient rats.
Irrespective of copper level' consumption of the high fat diet
resulted in the thickening of the interventricular septum and
left ventricular free wall. Electrocardiograms revealed that
the copper-deficient high fat diet led to a significantly smaller
QT interval compared with all other groups. Significantly greater
S-wave voltage due to copper deficiency was observed. Significantly
lower heart cytochrome c oxidase (CCO) activity was found in
the copper-deficient groups with the copper deficient high fat
group showing the lowest activity. Western blots of the cardiac
non-myofibrillar fraction demonstrated lower amounts of CCO nuclear
encoded peptides in the copper-deficient groups' with the least
amount seen in the copper-deficient high fat treatment. These
data suggest that a high level of dietary fat exacerbates some
of the signs of copper deficiency.
Title
Antioxidant defense system in lung of male and female rats: interactions
with alcohol' copper' and type of dietary carbohydrate.
Author
Fields M; Lewis CG; Lure MD
Address
Beltsville Human Nutrition Research Center' US Department of
Agriculture' Agricultural Research Service' MD 20705' USA.
Source
Metabolism, 45(1):49-56 1996 Jan
Abstract
Male and female rats were used to investigate the effects of
type of dietary carbohydrate (CHO)' copper' and ethanol consumption
on lung antioxidant enzyme activities and levels of phosphorylated
compounds in whole blood. copper-deficient female rats exhibited
a greater degree of copper deficiency than males' as assessed
by hepatic copper concentration and hepatic copper superoxide
dismutase (CuSOD) activity. However' copper-deficient male rats
fed fructose-containing diets exhibited greater growth retardation'
anemia' and heart hypertrophy than females consuming the same
diets and males fed starch. In addition' one of 10 copper-deficient
male rats that ate a fructose-based diet and drank water and
one of 10 copper-deficient male rats that ate a starch-based
diet and drank ethanol died. copper-deficient' starch-fed males
exhibited the highest activities of glutathione peroxidase (GSH-Px)
and catalase as compared with fructose-fed rats. Ethanol consumption
elevated the activities of GSH-Px and catalase. copper-deficient
female rats exhibited higher catalase but lower GSH-Px activities
than males. It is suggested that in copper deficiency' the ability
to increase antioxidant enzyme activities in rats consuming starch
is greater than in rats consuming fructose. Rats fed starch are
provided with a greater degree of protection against oxidative
damage than rats fed fructose. In addition' polyphosphorylated
compounds in blood were reduced in copper-deficient male rats
that consumed fructose-based diets. This may impair supply of
oxygen to tissues.
Title
Defects of copper deficiency in rats are modified by dietary
treatments that affect glycation.
Author
Saari JT; Bode AM; Dahlen GM
Address
U.S. Department of Agriculture' Agricultural Research Service'
Grand Forks Human Nutrition Research Center' ND' USA.
Source
J Nutr, 125(12):2925-34 1995 Dec
Abstract
We examined the hypothesis that nonenzymatic glycosylatin of
proteins (glycation) contributes to the defects of copper deficiency.
We studied copper-adequate and -deficient rats while altering
two factors known to affect glycation: type of dietary carbohydrate
and amount of food intake. copper deficiency caused cardiac enlargement
and anemia' decreased erythrocyte osmotic fragility' enhanced
heart lipid peroxidation' increased the percentage of glycated
hemoglobin (Hb A1) and reduced staining of lens crystallins on
SDS-PAGE gels (suggestive of glycation). Increasing dietary sucrose
reduced organ copper concentration' exacerbated the rise in Hb
A1 and worsened the anemia caused by copper deficiency. Food
restriction ameliorated heart and erythrocyte defects' reduced
the percentage of glycated hemoglobin and heart peroxidation
and also improved heart and liver copper status in copper-deficient
rats. These findings indicate that copper deficiency enhances
glycation and that sucrose may exacerbate some defects of copper
deficiency by enhancing glycation. Inhibition of defects of copper
deficiency by food restriction suggests that glycation and/or
peroxidation may contribute to those defects.
Title
Antioxidant enzyme gene transcription in copper-deficient rat
liver.
Author
Lai CC; Huang WH; Klevay LM; Gunning WT 3rd; Chiu TH
Address
Department of Pharmacology' Medical College of Ohio' Toledo 43699-0008'
USA.
Source
Free Radic Biol Med, 21(2):233-40 1996
Abstract
Antioxidant enzymes' Cu/Zn- and Mn-superoxide dismutase' catalase'
and glutathione peroxidase' constitute an important defense mechanism
against cytotoxicity of reactive oxygen species. copper is essential
for the activity of Cu/Zn-superoxide dismutase. Oxidative stress'
therefore' is expected in organs of rats fed copper-deficient
diet due to reduced Cu/Zn-superoxide dismutase activity. Our
previous studies have shown that the expression of antioxidant
enzymes was altered in copper-deficient rat liver. The present
report was undertaken to study further the transcription of these
enzymes in liver nuclei of rats made copper-deficient for 4 weeks.
While copper deficiency decreased the copper in liver by about
80%' it did not alter the copper content in liver nuclei. In
spite of a 100% elevation in nuclear iron concentration' liver
nuclei from copper-deficient rats showed normal appearance. The
transcriptional rates for Cu/Zn-superoxide dismutase' glutathione
peroxidase' and glyceraldehyde-3-phosphate dehydrogenase were
not altered by dietary copper deprivation. In contrast' transcriptional
rates for Mn-superoxide dismutase and beta-actin were increased
but that for catalase was reduced in the nuclei isolated from
the copper-deficient rat liver. These results suggest that oxidative
stress' resulting from copper deficiency' differentially modulates
the gene transcription for the antioxidant enzymes in rat liver.
Title
Concentrations of thyroid hormones in serum and activity of hepatic
5` monodeiodinase in copper-deficient rats.
Author
Kralik A; Kirchgessner M; Eder K
Address
Institut f ur Ern ahrungsphysiologie' Technische Universit at
M unchen' Freising-Weihenstephan.
Source
Z Ernahrungswiss, 35(3):288-91 1996 Sep
Abstract
The aim of the present study was to investigate the effect of
copper deficiency on thyroid hormone metabolism in rats. Therefore'
an experiment with growing male Sprague-Dawley rats was carried
out' consisting of two groups of rats fed either a copper-deficient
(0.06 mg Cu/kg) or a copper-adequate diet (16 mg Cu/kg). Both
groups of rats were fed identical quantities of diet by pair-feeding.
copper deficiency decreased the final body weight of the rats
by 5% compared to copper-adequate control rats. A severe copper-deficient
state in the rats fed the copper-deficient diet was proved by
a large decrease of ceruloplasmin activity in serum (by 97%)
and hematological changes. For estimation of thyroid hormone
metabolism' the concentrations of total and free thyroxine (T4)
and triiodothyronine (T3) in serum and the activity of hepatic
5`monodeiodinase (5`D) were determined. copper-deficient rats
had an increased concentration of T3 in serum' whereas the concentrations
of total and free T4 as well as the activity of hepatic 5`D were
not different compared with copper-adequate control rats. Therefore'
the study shows that copper deficiency has only slight effects
on thyroid hormone metabolism in growing rats.
Title
copper as an essential nutrient.
Author
Olivares M; Uauy R
Address
Institute of Nutrition and Food Technology' University of Chile'
Santiago.
Source
Am J Clin Nutr, 63(5):791S-6S 1996 May
Abstract
Animal and human studies have shown that copper is involved in
the function of several enzymes. Studies have also shown that
copper is required for infant growth' host defense mechanisms'
bone strength' red and white cell maturation' iron transport'
cholesterol and glucose metabolism' myocardial contractility'
and brain development. copper deficiency can result in the expression
of an inherited defect such as Menkes syndrome or in an acquired
condition. Acquired deficiency is mainly a pathology of infants;
however' it has been diagnosed also in children and adults. Most
cases of copper deficiency have been described in malnourished
children. The most constant clinical manifestations of acquired
copper deficiency are anemia' neutropenia' and bone abnormalities.
Other' less frequent manifestations are hypopigmentation of the
hair' hypotonia' impaired growth' increased incidence of infections'
alterations of phagocytic capacity of the neutrophils' abnormalities
of cholesterol and glucose metabolism' and cardiovascular alterations.
Measurements of serum copper and ceruloplasmin concentrations
are currently used to evaluate copper status. These indexes are
diminished in severe to moderate copper deficiency; however'
they are less sensitive to marginal copper deficiency. Erythrocyte
superoxide dismutase and platelet cytochrome c activities may
be more promising indexes for evaluating marginal copper deficiency.
Title
Auditory startle response is diminished in rats after recovery
from perinatal copper deficiency.
Author
Prohaska JR; Hoffman RG
Address
Department of Biochemistry' University of Minnesota' Duluth'
USA.
Source
J Nutr, 126(3):618-27 1996 Mar
Abstract
Recovery from perinatal copper deficiency was studied in female
and male Sprague Dawley rats for 6 mo. Month-old offspring reared
by dams on copper-deficient treatment starting d 7 of pregnancy
had up to 80% reductions in regional brain copper concentrations
compared with offspring from copper-supplemented dams. Liver
copper concentrations and plasma ceruloplasmin diamine oxidase
activities of copper-deficient rats were restored to control
levels within 1 mo of nutritional repletion with dietary copper.
However' brain copper concentrations' with the exception of the
hypothalamus and medulla' remain lower than in controls even
after 5 mo of treatment. Rats were screened for startle responses
and foot splay after 1' 3 and 5 mo of repletion. Diminished auditory
startle was evident in rats of both sexes at all repletion times
tested' whereas tactile startle and preimpulse inhibition of
tactile startle were not influenced by prior copper deficiency'
suggesting auditory sensory perception abnormalities. In a separate
study' postweaning male rats deprived of dietary copper for 5
wk exhibited clear signs of copper deficiency but normal acoustic
startle responses and foot splay. Long-term neurochemical and
behavioral abnormalities persist in rats after perinatal copper
deficiency.
Title
Altered expressions of cardiac Na/K-ATPase isoforms in copper
deficient
rats.
Author
Huang W; Lai CC; Wang Y; Askari A; Klevay LM; Askari A; Chiu
TH
Address
Medical College of Ohio' Toledo 43699-0008' USA.
Source
Cardiovasc Res, 29(4):563-8 1995 Apr
Abstract
OBJECTIVE: The aim was to determine if copper deficiency affects
the expression of Na/K-ATPase alpha isoforms in the rat heart.
METHODS: copper deficiency was induced by placing weanling rats
on a copper deficient diet for 4-5 weeks. Adult ventricular tissue'
isolated ventricular myocytes' and brain stems of the control
and deficient rats were compared for Cu' Zn-superoxide dismutase
(CuZn-SOD) activity and for protein and mRNA contents of Na/K-ATPase
alpha isoforms. RESULTS: In brain stem' where copper deficiency
did not alter CuZn-SOD activity' mRNA and protein levels of alpha
isoforms also remained unchanged. In ventricular tissue and ventricular
myocytes' copper deficiency reduced CuZn-SOD activity' mRNAs
of alpha 1 and alpha 2 isoforms' and the alpha 2 isoform protein.
The alpha 1 isoform protein of ventricular tissue and its myocytes
was marginally reduced by copper deficiency. CONCLUSIONS: In
the rat ventricular tissue' oxidative stress resulting from copper
deficiency (1) enhances the turnover of the more oxidant sensitive
alpha 2 isoform to a greater extent than the turnover of the
alpha 1 isoform; (2) regulates mRNA levels of alpha 1 and alpha
2 isoforms; and (3) contributes to the cardiomyopathy of copper
deficiency.
Title
Expression of gamma-glutamylcysteine synthetase in the liver
of copper-deficient rats.
Author
Chen Y; Saari JT; Kang YJ
Address
Department of Pharmacology and Toxicology' University of North
Dakota School of Medicine' Grand Forks 58202' USA.
Source
Proc Soc Exp Biol Med, 210(2):102-6 1995 Nov
Abstract
copper deficiency in rats increases hepatic glutathione concentration.
The present study was undertaken to determine the biochemical
and molecular basis for the glutathione elevation. Weanling Sprague-Dawley
rats were fed a purified diet deficient in copper (0.4 micrograms/g
diet) or one containing adequate copper (5.7 micrograms/g diet)
for 4 weeks. Hepatic glutathione concentration' the activity
of the rate-limiting enzyme in glutathione biosynthesis' gamma-glutamylcysteine
synthetase (gamma-GCS) and the relative amount of mRNA for the
enzyme were determined. Hepatic glutathione concentration in
copper-deficient rats was significantly elevated (6.6 vs 5.6
mumol/g). The activity of hepatic gamma-GCS was 1.6 times higher
in the copper-deficient than in the copper-adequate rats (58.0
vs 35.9 nmol NADH/min.mg protein). The steady-state amount of
mRNA for gamma-GCS was increased 5-fold in the copper-deficient
rat liver. The findings demonstrate that the elevated hepatic
glutathione concentration in copper-deficient rats results from
upregulation of gamma-GCS activity. This study provides further
understanding of changes in hepatic glutathione metabolism induced
by copper deficiency.
Title
Feeding of excessive cystine and cysteine enhances defects of
dietary copper deficiency in rats by differential mechanisms
involving altered
iron status.
Author
Wan Q; Yang BS; Kato N
Address
Department of Applied Biochemistry' Faculty of Applied Biological
Science' Hiroshima University' Japan.
Source
J Nutr Sci Vitaminol (Tokyo), 42(3):185-93 1996 Jun
Abstract
We have reported that excess cystine feeding exaggerates the
defects of dietary copper deficiency in rats by a mechanism not
involving oxidative stress and altered copper status. This study
was conducted to examine whether this exacerbation is caused
by a mechanism involving altered iron status and to compare the
influences of cystine and cysteine feeding on the defects of
copper deficiency. Male Wistar rats were fed copper-adequate
or copper-deficient diet with supplementation of L-cystine or
L-cysteine (2%) for 10 days or 21 days. copper-deficient diet
increased heart weight' caused anemia' reduced plasma iron and
elevated liver iron. These defects were exacerbated by supplemental
cystine. Cysteine feeding also exacerbated the defects of dietary
copper deficiency including anemia' increased heart weight' and
reduced plasma iron' although cysteine feeding had no influence
on liver iron concentration. Supplemental cysteine reduced apparent
absorption of iron' while supplemental cystine did not. These
results suggest that cystine feeding enhances the defects of
copper deficiency by a mechanism involving impaired mobilization
of iron from liver into blood' and that cysteine feeding enhances
the defects of copper deficiency by a mechanism involving reduced
intestinal absorption of iron.
Title
Regulated copper uptake in Chlamydomonas reinhardtii in response
to copper availability.
Author
Hill KL; Hassett R; Kosman D; Merchant S
Address
Department of Chemistry and Biochemistry' University of California'
Los
Angeles 90095-1569' USA.
Source
Plant Physiol, 112(2):697-704 1996 Oct
Abstract
A saturable and temperature-dependent copper uptake pathway has
been identified in Chlamydomonas reinhardtii. The uptake system
has a high affinity for copper ions (Km approximately 0.2 microM)
and is more active in cells that are adapted to copper deficiency
than to cells grown in a medium containing physiological (submicromolar
to micromolar) copper ion concentrations. The maximum velocity
of copper uptake by copper-deficient cells (169 pmol h-1 10(6)
cells-1 or 62 ng min-1 mg-1 chlorophyll) is up to 20-fold greater
than that of fully copper-supplemented cells' and the Km (approximately
2 x 10(2) nM) is unaffected. Thus' the same uptake system appears
to operate in both copper-replete and copper-deficient cells'
but its expression or activity must be induced under copper-deficient
conditions. A cupric reductase activity is also increased in
copper-deficient compared with copper-sufficient cells. The physiological
characteristics of the regulation of this cupric reductase are
compatible with its involvement in the uptake pathway. Despite
the operation of the uptake pathway under both copper-replete
and copper-deficient conditions' C. reinhardtii cells maintained
in fully copper-supplemented cells do not accumulate copper in
excess of their metabolic need. These results provide evidence
for a homeostatic mechanism for copper metabolism in C. reinhardtii.
Title
Plasma diamine oxidase activities in renal dialysis patients,
a human with spontaneous copper deficiency and marginally copper
deficient rats.
Author
DiSilvestro RA; Jones AA; Smith D; Wildman R
Address
Ohio State University, Columbus 43210-1295, USA. disilvestro.1@osu.edu
Source
Clin Biochem, 30(7):559-63 1997 Oct
Abstract
OBJECTIVES: Intestine and kidney are generally the most concentrated
sources of the copper metalloenzyme diamine oxidase (DAO). Clinically,
plasma DAO activities are used to diagnose disruptions in intestinal
integrity. This study determined whether DAO activities were
also affected by kidney injury or copper nutritional status.
DESIGN AND METHODS: Plasma DAO activities were measured in renal
dialysis patients without diagnosed intestinal disease (n = 75),
controls (n = 23), an adult with spontaneous copper deficiency
before and after copper repletions, and in rats fed either adequate
or marginal copper diets (8 or 2 mg copper/kg diet) for 7 months.
RESULTS: This study found high DAO activities in renal dialysis
patients and low activities during spontaneous copper deficiency.
Low activities were also seen for marginally copper deficient
rats. CONCLUSIONS: Tissue injury-induced elevation of DAO activities
is not limited to intestinal injury, and low DAO values may be
useful for assessing copper nutritional status.
Title
Effects of copper deficiency and Cu complexes on superoxide dismutase
in rats.
Author
Dashti SI; Thomson M; Mameesh MS
Address
Nutrition Unit' University of Kuwait' Kuwait.
Source
Nutrition, 11(5 Suppl):564-7 1995 Sep-Oct
Abstract
The effect of dietary copper (Cu) deficiency on the antioxidant
enzyme superoxide dismutase (SOD) was investigated in both erythrocyte
and liver samples of 40 weanling Wistar rats. Groups were fed
control (10 mg Cu/kg) or Cu-deficient (0.5 mg Cu/kg) diets for
7 wk. In this study' dietary copper deficiency did not affect
growth' food intake' liver size' or hemoglobin levels. Protein
concentrations were considerably decreased in the livers of the
copper-deficient group compared to control groups after 7 wk.
Erythrocyte SOD activity was not significantly different in copper-deficient
groups. In contrast' SOD activity was significantly reduced in
livers of rats consuming the Cu-deficient diet compared to controls.
The in vitro SOD activities in the presence of five different
macro-cyclic copper-II containing complexes with different stability
constants were studied. The moderately stable copper complex
increased the SOD activity in Cu-deficient liver and erythrocyte
samples only at wk 7. At wk 6' a significant increase in SOD
activity in liver samples only was observed. In contrast' at
wk 4' no significant differences in SOD activity were observed
upon addition of Cu complexes. These results suggest that the
increase in SOD activity may be due to superoxide-like action
or other properties of this copper complex.
Title
copper deficiency increases hepatic apolipoprotein A-I synthesis
and secretion but does not alter hepatic total cellular apolipoprotein
A-I mRNA abundance in rats.
Author
Hoogeveen RC; Reaves SK; Lei KY
Address
Department of Nutritional Sciences' University of Arizona' Tucson
85721' USA.
Source
J Nutr, 125(12):2935-44 1995 Dec
Abstract
This study was designed to determine whether an increase in hepatic
apolipoprotein A-I (apo A-I) synthesis and mRNA abundance is
responsible for the enlarged plasma apo A-I pool observed in
copper-deficient rats. Weanling male Sprague-Dawley rats were
divided into two dietary treatments: copper-adequate (102.2 mumol
Cu/kg diet) and copper-deficient (9.0 mumol Cu/kg diet). copper
deficiency resulted in a significant increase (124%) in intravascular
apo A-I pool size after 6 wk of treatment. Following intraportal
inJection of a flooding dose of [3H phenylalanine' in vivo hepatic
apo A-I synthesis and secretion were significantly greater in
the copper-deficient animals as detected by [3H phenylalanine
incorporation into immunoprecipitable apo A-I isolated from liver
homogenates and plasma using anti-rat apo A-I antibodies. Pulse-chase
experiments using freshly isolated hepatocytes demonstrated that
a significant increase (148%) in apo A-I secretion by hepatocytes
derived from copper-deficient rats may have resulted from increased
hepatic synthesis rather than altered intracellular degradation
of apo A-I. Hepatic total cellular apo A-I mRNA abundance was
not altered by copper deficiency when expressed per microgram
of RNA. Thus' the enhanced hepatic apo A-I synthesis' observed
in copper-deficient cells' may have resulted from alterations
in post-transcriptional and translational processes. |
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