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1.
The effect of dietary selenium and vitamin E on plasma total (TC) and high density lipoprotein cholesterol (HDLC) was evaluated in 54 Sprague Dawley rats fed cholesterol/cholic acid enriched diets. Diets 1, 2, and 3 had no added selenium (low Se) and 0 (low), 60 (adequate), and 600 (high) mg/kg dL alpha tocopheryl acetate added respectively. Sodium selenite at 0.2 mg/kg (adequate Se) was added to diets 4, 5, and 6 and at 4.0 mg/kg (toxic Se) to diet 7, 8, and 9 with the same pattern of vitamin E added to the diet as described above. TC and HDLC were measured using the Kodak Ectachem system. Rats in the low and adequate Se groups fed high vitamin E had lower TC values than rats fed lower vitamin E levels but differences were not significant. In the toxic Se groups, rats fed high vitamin E had significantly (p<0.05) higher plasma TC values than did lower Vitamin E groups. Rats on the high vitamin E diets with low or adequate Se had significantly (p<0.05) higher mean plasma HDLC values when compared to rats fed low or adequate vitamin E diets. HDLC values for animals on Se toxic diets were significantly (p<0.05) lower in rats fed a low vitamin E diet. In rats fed Se deficient and adequate diets, a high vitamin E intake resulted in a decrease in TC and an increase in HDLC. In Se toxic rats, TC was elevated by a high dietary intake of vitamin E as was HDLC with both values being significantly higher than values found in the vitamin E deficient rats. Vitamin E deficiency resulted in a plasma lipid pattern that has been associated with greater cardiovascular disease risk. 相似文献
2.
Huawei Zeng Eric O. Uthus Sharon A. Ross Cindy D. Davis 《Biological trace element research》2009,131(1):71-80
Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon
cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se.
The present study was designed to determine whether dietary selenite affects somatic mutation frequency in vivo. We used the
Big Blue transgenic model to evaluate the in vivo mutation frequency of the cII gene in rats fed either a Se-deficient (0 μg Se/g diet) or Se-supplemented diet (0.2 or 2 μg Se/g diet; n = 3 rats/diet in experiment 1 and n = 5 rats/group in experiment 2) and injected with DMH (25 mg/kg body weight, i.p.). There were no significant differences
in body weight between the Se-deficient and Se-supplemented (0.2 or 2 μg Se/g diet) rats, but the activities of liver glutathione
peroxidase and thioredoxin reductase and concentration of liver Se were significantly lower (p < 0.0001) in Se-deficient rats compared to rats supplemented with Se. We found no effect of dietary Se on liver 8-hydroxy-2′-deoxyguanosine.
Gene mutation frequency was significantly lower in liver (p < 0.001) than that of colon regardless of dietary Se. However, there were no differences in gene mutation frequency in DNA
from colon mucosa or liver from rats fed the Se-deficient diet compared to those fed the Se-supplemented (0.2 or 2 μg Se/g
diet) diet. Although gene mutations have been implicated in the etiology of cancer, our data suggest that decreasing gene
mutation is not likely a key mechanism through which dietary selenite exerts its anticancer action against DMH-induced preneoplastic
colon cancer lesions in a Big Blue transgenic rat model.
The US Department of Agriculture, Agricultural Research Service, Northern Plains Area, is an equal opportunity/affirmative
action employer and all agency services are available without discrimination.
Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department
of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.
This work was supported by the US Department of Agriculture and National Cancer Institute. 相似文献
3.
The effects of selenium depletion and repletion on the metabolism of thyroid hormones in the rat 总被引:2,自引:0,他引:2
Rats were fed selenium-deficient (less than 0.005 mg selenium/kg) or selenium-supplemented diets (0.1 mg selenium/kg, as Na2SeO2) for up to five wks from weaning to assess the effects of developing selenium deficiency on the metabolism of thyroid hormones. Within two wks 3:5,3'-triiodothyronine (T3) production from thyroxine (T4) in liver homogenates from selenium-deficient rats was significantly lower compared with the activity in liver homogenates from selenium-supplemented rats. This decreased activity was probably responsible, in part, for the higher T4 and lower T3 concentrations in plasma from the selenium-deficient rats after 3, 4, and 5 weeks of experiment. Repletion of selenium-deficient rats with single intra-peritoneal injections of 200 micrograms selenium/kg body wt. (as Na2SeO3) 5 days before sampling reversed the effects of the deficiency on thyroid hormone metabolism and significantly increased liver and plasma glutathione peroxidase activities. However a dose of 10 micrograms selenium/kg body wt given to rats of similar low selenium status had no effect on thyroid hormone metabolism or glutathione peroxidase activity but did reverse the increase in hepatic glutathione S-transferase activity characteristic of severe selenium deficiency. Imbalances in thyroid hormone metabolism are an early consequence of selenium deficiency and are probably not related to changes in hepatic xenobiotic metabolizing enzymes associated with severe deficiency. 相似文献
4.
The study was conducted to investigate the effects of dietary maternal selenomethionine or sodium selenite supplementation
on performance and selenium status of broiler breeders and their next generation. Two hundred and forty 39-week-old Lingnan
yellow broiler breeders were allocated randomly into two treatments, each of which included three replicates of 40 birds.
Pretreatment period was 2 weeks, and the experiment lasted 8 weeks. The groups were fed the same basal diet supplemented with
0.30 mg selenium/kg of sodium selenite or selenomethionine. After incubation, 180 chicks from the same parental treatment
group were randomly divided into three replicates, with 60 birds per replicate. All the offspring were fed the same diet containing
0.04 mg selenium/kg, and the experiment also lasted 8 weeks. Birth rate was greater (p < 0.05) in hens fed with selenomethionine than that in hens fed with sodium selenite. The selenium concentration in serum,
liver, kidney, and breast muscle of broiler breeders, selenium deposition in the yolk, and albumen and tissues' (liver, kidney,
breast muscle) selenium concentrations of 1-day-old chicks were significantly (p < 0.01) increased by maternal selenomethionine supplementation compared with maternal sodium selenite supplementation. The
antioxidant status of 1-day-old chicks was greatly improved by maternal selenomethionine intake in comparison with maternal
sodium selenite intake and was evidenced by the increased glutathione peroxidase activity in breast muscle (p < 0.05), superoxide dismutase activity in breast muscle and kidney (p < 0.05), glutathione concentration in kidney (p < 0.01), total antioxidant capability in breast muscle and liver (p < 0.05), and decreased malondialdehyde concentration in liver and pancreas (p < 0.05) of 1-day-old chicks. Feed utilization was better (p < 0.05), and mortality was lower (p < 0.05) in the progeny from hens fed with selenomethionine throughout the 8-week growing period compared with those from
hens fed with sodium selenite. In summary, we concluded that maternal selenomethionine supplementation increased birth rate
and Se deposition in serum and tissues of broiler breeders as well as in egg yolk and egg albumen more than maternal sodium
selenite supplementation. Furthermore, maternal selenomethionine intake was also superior to maternal sodium selenite intake
in improving the tissues Se deposition and antioxidant status of 1-day-old chicks and increasing the performance of the progeny
during 8 weeks of post-hatch life. 相似文献
5.
Selenium and hepatic microsomal hemoproteins 总被引:3,自引:0,他引:3
R F Burk A M Mackinnon F R Simon 《Biochemical and biophysical research communications》1974,56(2):431-436
The microsomal share of liver homogenate 75Se after injection of a tracer dose of 75SeO32? was three times greater in rats fed a selenium-deficient diet than in rats fed a selenium-adequate diet. Basal levels of microsomal cytochromes P-450 and b5 were unaffected by selenium deficiency. However, induction of these cytochromes by phenobarbital was markedly inpaired in selenium-deficient rats, whereas liver weight increase and NADPH cytochrome reductase induction were not impaired. These data indicate that selenium is essential for phenobarbital induction of microsomal hemoproteins. 相似文献
6.
Protective role of intraperitoneally administered vitamin E and selenium in rats anesthetized with enflurane 总被引:2,自引:0,他引:2
Mustafa Naziroglu 《Biological trace element research》1999,69(3):199-209
The aim of this investigation was to determine levels of liver vitamins A and E and blood biochemical and hematological parameters
in the enflurane anesthesia of rats. Fifty adult male Wistar rats were used in this study. All rats were randomly divided
into five groups. The first and second groups were used as the control and anesthesia control groups, respectively, and only
the placebo was intraperitoneally injected. The third group was intraperitoneally administered with vitamin E (dl/-α-tocopheryl
acetate, 100 mg/kg body weight), the fourth group with Se (Na2SeO3 1.5 mg/kg body weight), and the fifth group with vitamin E and Se (dl-α-tocopheryl acetate, 100 mg/kg body weight + Na2SeO3 1.5 mg/kg body weight). This administration was done for three times with overday intervals and the second, third, forth,
and fifth group rats were taken to enflurane anesthetise for 2 h.
The liver vitamin E level was slightly lower in the anesthesia control group than in control group. However, the liver vitamin
E content was significantly (p < 0.05 andp < 0.01) increased in vitamin E, Se, and combination groups, whereas the vitamin A level in liver was not statistically different.
In general, plasma levels of alanine aminotransferase, creatin kinase, total bilirubin, urea, red blood cell counts, packet
cell volume, and hemoglobulin values were significantly (p < 0.05 andp < 0.001) increased during the anesthesia and returned to near control values after the vitamin E plus selenium injection.
However, administration of vitamin E had less effect on the hematological and biochemical parameters compared to that of selenium
and their combination with vitamin E. However, the white blood cell count and levels of alkaline phosphatase, aspartate aminotransferase,
total cholesterol, triglycerides, total protein, and creatinine were not statistically influenced by the anesthesia.
In conclusion, we observed that plasma levels of some enzymes and metabolites were significantly increased in the enflurane
anesthesia of rats, whereas the liver vitamin E levels were slightly decreased. Therefore, we observed that vitamin E and
selenium have a protective effect against anesthesia complication, but the effect of selenium appears to be much greater than
the vitamin E. 相似文献
7.
Sodium selenosulfate has been extensively used as a precursor of selenide ions in the preparation of nano Se-containing compounds.
Its biological properties remain completely unknown. Sodium selenosulfate and sodium selenite were added to the medium of
HepG2 cells and administered intraperitoneally at a dose of 0.1 mg Se/kg body weight to selenium-deficient mice, respectively.
Both of the selenium compounds could increase the activities of glutathione peroxidase (GPx) and thioredoxin reductase (TrxR)
in a dose-dependent manner in cells and efficiently restore selenium retention and activities of GPx and TrxR in mice. All
of the variables were in correlation with the Se supply. There was no distinction in elevating activities of GPx and TrxR
between selenosulfate and selenite in vitro. After a 2-d supply of selenosulfate, the activity of GPx in the liver was 65%
(p < 0.001) and Se accumulations in the liver, kidney and blood were 64%, 86%, and 65%, respectively, of those treated with
selenite (allp < 0.01). With the 7-d selenosulfate supplementation, the activity of GPx in the kidney and activities of TrxR in the liver
and kidney were 88%, 75%, and 78%, respectively, of those treated with selenite (allp < 0.01); Se retentions in the liver and kidney were 85% and 93%, respectively of those supplemented with selenite (bothp < 0.01). These facts indicated that selenosulfate could be absorbed and utilized in the biological system. No difference
in vitro demonstrated that selenosulfate could be absorbed and generate reduced selenide as efficiently as selenite. The differences
between the two compounds in vivo were the result of other factors that affected selenosulfate utilization in tissues. 相似文献
8.
Muharrem Bitiren Ali Ziya Karakilcik Mustafa Zerin Ilyas Ozardalı Sehabettin Selek Yaşar Nazlıgül Abdullah Ozgonul Davut Musa Ali Uzunkoy 《Biological trace element research》2010,136(1):87-95
Ulcerative colitis increases oxidative damage accompanied by production of free oxygen radicals. Selenium (Se) and vitamin
E are two natural antioxidants. The present study was undertaken to investigate the possible protective role of Se and vitamin
E combination in experimental colitis induced by acetic acid (AA) in rats. This study was carried out on three groups, namely
the first (control), the second (experimental colitis group, 2 ml 5% acetic acid), and the third groups (2 ml 5% acetic acid,
vitamin E (100 mg/kg body weight (bw)) plus Se (0.2 mg/kg bw)). The activities of catalase (CAT), prolidase (PRS), myeloperoxidase
(MPO), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), total thiol (T-SH) were
determined in plasma and colon samples. Macroscopic and microscopic damages in colon were increased by AA treatment (p < 0.01 and p < 0.01, respectively), whereas they were decreased by selenium and vitamin E treatment (p < 0.05 and p < 0.01, respectively). The activities of CAT and PRS in the plasma and colon were significantly affected (p < 0.05 and p < 0.01) by treatment of AA, Se, and vitamin E. MPO activity in colon was increased (p < 0.01) by AA treatment and decreased (p < 0.05) by Se and vitamin E administration. The values of TOS and OSI in plasma were increased (p < 0.5) by AA. The TAC and T-SH in colon were decreased (p < 0.05) by AA and increased (p < 0.05) by Se and vitamin E. Based upon these results, Se and vitamin E may play an important role in preventive indication
of the oxidative damage associated by acetic acid caused inflammation. 相似文献
9.
Xin Gen Lei Deborah A. Ross John E. Parks Gerald F. Combs 《Biological trace element research》1997,59(1-3):195-206
Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is the second intracellular selenium (Se)-dependent glutathione
peroxidase (GSH-Px) identified in mammals. Our objectives were to determine the effect of dietary vitamin E and Se levels
on PHGPX activity expression in testis, epididymis, and seminal vesicles of pubertal maturing rats, and the relationship of
PHGPX expression with testicular development and sperm quality. Forty Sprague-Dawley male weanling rats (21-d old), were initially
fed for 3 wk a torula yeast basal diet (containing 0.05 mg Se/kg) supplemented with marginal levels of Se (0.1 mg/kg as Na2SeO3) and vitamin E (25 IU/kg as all-rac-α-tocopheryl acetate). Then, rats were fed the basal diets supplemented with 0 or 0.2
mg Se/kg and 0 or 100 IU vitamin E/kg diet during the 3-wk period of pubertal maturing. Compared with the Se-supplemented
rats, those fed the Se-deficient diets retained 31, 88, 67, and 50% of Se-dependent GSH-Px activities in liver, testis, epididymis,
and seminal vesicles, respectively. Testes and seminal vesicles had substantially higher (5-to 20-fold) PHGPX activity than
liver. Dietary Se deficiency did not affect PHGPX activities in the reproductive tissues, but reduced PHGPX activity in liver
by 28% (P < 0.0001). Dietary vitamin E supplementation did not affect PHGPX activity in liver, whereas it raised PHGPX activity
in seminal vesicles by 43% (P < 0.005). Neither dietary vitamin E nor Se levels affected body weight gains, reproductive organ
weights, or sperm counts and morphology. In conclusion, expression of PHGPX activity in testis and seminal vesicles was high
and regulated by dietary Se and vitamin E differently from that in liver. 相似文献
10.
Ayhan Dogukan Nurhan Sahin Mehmet Tuzcu Vijaya Juturu Cemal Orhan Muhittin Onderci James Komorowski Kazim Sahin 《Biological trace element research》2009,131(2):124-132
The present study was conducted to investigate the effects of chromium histidinate (CrHis) against experimentally induced
type II diabetes and on chromium (Cr), zinc (Zn), selenium (Se), manganese (Mn), iron (Fe), and copper (Cu) in serum, liver,
and kidney of diabetic rats. The male Wistar rats (n = 60, 8 weeks old) were divided into four groups. Group I received a standard diet (12% of calories as fat); group II were
fed standard diet and received CrHis (110 mcg CrHis/kg body weight per day); group III received a high-fat diet (HFD; 40% of calories as fat) for 2 weeks and then
were injected with streptozotocin (STZ) on day 14 (STZ, 40 mg/kg i.p.; HFD/STZ); group IV were treated as group III (HFD/STZ)
but supplemented with 110 mcg CrHis/kg body weight per day. The mineral concentrations in the serum and tissue were determined
by atomic absorption spectrometry. Compared to the HFD/STZ group, CrHis significantly increased body weight and reduced blood
glucose in diabetic rats (p < 0.001). Concentrations of Cr, Zn, Se, and Mn in serum, liver, and kidney of the diabetic rats were significantly lower
than in the control rats (p < 0.0001). In contrast, higher Fe and Cu levels were found in serum and tissues from diabetic versus the non-diabetic rats
(p < 0.001). Chromium histidinate supplementation increased serum, liver, and kidney concentrations of Cr and Zn both in diabetic
and non-diabetic rats (p < 0.001). Chromium supplementation increased Mn and Se levels in diabetic rats (p < 0.001); however, it decreased Cu levels in STZ-treated group (p < 0.001). Chromium histidinate supplementation did not affect Fe levels in both groups (p > 0.05). The results of the present study conclude that supplementing Cr to the diet of diabetic rats influences serum and
tissue Cr, Zn, Se, Mn, and Cu concentrations. 相似文献
11.
Cell culture studies have suggested that arsenic exposure results in decreased S-adenosylmethionine (SAM), causing DNA hypomethylation. Previously, we have shown that hepatic SAM is decreased and/or S-adenosylhomocysteine increased in arsenic-deprived rats; these rats tended to have hypomethylated DNA. To determine, the
effect of dietary arsenic on dimethylhydrazine (DMH)-induced aberrant crypt formation in the colon, Fisher 344 weanling male
rats were fed diets containing 0,05, or 50 μg As (as NaAsO2)/g. After 12 wk, dietary arsenic affected the number of aberrant crypts (p<0.02) and aberrant crypt foci (p<0.007) in the colon and the amount of global DNA methylation (p<0.04) and activity of DNA methyltransferase (DNMT) (p<0.003) in the liver. In each case, there were more aberrant crypts and aberrant crypt foci, a relative DNA hypomethylation,
and increased activity of DNMT in the rats fed 50 μg As/g compared to those fed 0.5 μg As/g. The same phenomenon, an increased
number of aberrant crypts and aberrant crypt foci, DNA hypomethylation, and increased DNMT tended to hold when comparing rats
fed the diet containing no supplemental arsenic compared to rats fed 0.5 μg As/g. The data suggest that there is a threshold
for As toxicity and that possibly too little dietary As could also be detrimental.
The U.S. Department of Agriculture, Agricultural Research Service. Northern Plains Area is an equal opportunity/affirmative
action employer and all agency services are available without discrimination. 相似文献
12.
We examined the effect of methionine deficiency on iodothyronine 5’-deiodinase activity in selenium-deficient rats or selenium-sufficient
rats fed sodium selenate or selenomethionine. Forty-two weanling male Wistar rats were divided into six groups and pair fed
the respective purifiedl-amino acid-based diets for 4 wk.l-methionine concentrations in the diet were 8.0 g/kg for sufficient rats, and 2.0 g/kg for deficient rats. Selenium concentrations
in the diet were 0.5 mg/kg (as sodium selenate or selenomethionine) for selenium-sufficient rats and less than 0.005 mg/kg
for selenium-deficient rats. Type I 5’-deiodinase activities were significantly lower in liver and higher in kidney of methionine-deficient
rats than in those of methionine-sufficient rats fed either the selenium-sufficient or the selenium-deficient diets. The type
I 5’-deiodinase activity in brain was significantly lower in the methionine-deficient rats than in the methionine-sufficient
rats fed the selenium-deficient diet. Type II 5’-deiodinase activity in brain was significantly higher in the methionine-deficient
rats than in the methionine-sufficient rats fed selenium-sufficient diet as sodium selenate. Both thyroxine and 3,3’,5-triiodothyronine
concentrations in plasma were significantly higher in the methionine-deficient rats than in the methionine-sufficient rats.
It is suggested that the methionine deficiency affects the 5’-deiodinase activity and thyroid hormones level in the rats. 相似文献
13.
The aim of this work was to determine the protective effects of intraperitoneally administered vitamin E and selenium (as
Na2SeO3, Se) on the lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and vitamin E levels, glutathione peroxidase
(GSH-Px), reduced glutathione (GSH) activities in the plasma, red blood cell (RBC), liver, and muscle of rats with streptozotocin-induced
diabetes. Fifty adult male Wistar rats were used and all rats were randomly divided into five groups. The first group was
used as a control and the second group as a diabetic control. A placebo was given to first and second groups by injection.
The third group was intraperitoneally administered with vitamin E (20 mg over 24 h), the fourth group with Se (0.3 mg over
24 h), and the fifth group with vitamin E and Se combination (COM) (20 mg vitamin E + 0.3 mg Se over 24 h). This administration
was done for 25 days and the TBARS, vitamin E, GSH-Px, GSH levels in the plasma, RBC, liver, and muscle samples were determined.
The vitamin E level in the plasma and liver was significantly (p < 0.05) higher in the control than in the diabetic control group. Also, the TBARS levels in the RBC, liver, and muscle were
significantly (p < 0.05) lower in the control than in the diabetic control group. However, GSH-Px and GSH activities in RBC, liver, and muscle
were not statistically different between the control and the diabetic control groups. The vitamin E levels in plasma and liver
(p < 0.01 and p < 0.001) and GSH-Px activities (p < 0.01, p < 0.001) in RBC were significantly higher in vitamin E, Se, and COM groups than in both control and diabetic control groups.
However, the TBARS levels of RBC, muscle, and liver in vitamin E and Se administered groups were significantly (p < 0.05-p < 0.001, respectively) decreased. These results indicate that intraperitoneally administered vitamin E and Se have significant
protective effects on the blood, liver, and muscle against oxidative damage of diabetes.
The abstract of this study was presented in Physiological Research
48(Suppl. 1), S99 (1999). 相似文献
14.
Selenium is an essential micronutrient that function through selenoproteins. Selenium deficiency results in lower concentrations of selenium and selenoproteins. The brain maintains it's selenium better than other tissues under low-selenium conditions. Recently, the selenium-containing protein selenoprotein P (Sepp) has been identified as a possible transporter of selenium. The targeted disruption of the selenoprotein P gene (Sepp1) results in decreased brain selenium concentration and neurological dysfunction, unless selenium intake is excessive However, the effect of selenoprotein P deficiency on the processes of memory formation and synaptic plasticity is unknown. In the present studies Sepp1(-/-) mice and wild type littermate controls (Sepp1(+/+)) fed a high-selenium diet (1 mg Se/kg) were used to characterize activity, motor coordination, and anxiety as well as hippocampus-dependent learning and memory. Normal associative learning, but disrupted spatial learning was observed in Sepp1(-/-) mice. In addition, severe alterations were observed in synaptic transmission, short-term plasticity and long-term potentiation in hippocampus area CA1 synapses of Sepp1(-/-) mice on a 1 mg Se/kg diet and Sepp1(+/+) mice fed a selenium-deficient (0 mg Se/kg) diet. Taken together, these data suggest that selenoprotein P is required for normal synaptic function, either through presence of the protein or delivery of required selenium to the CNS. 相似文献
15.
Twenty-four weanling male Wistar rats were divided into four groups fed diets containing adequate or deficient levels of selenium
(0.5 ppm [+ Se] or <0.02 ppm [−Se] and protein (15% [+Pro] or 5% [−Pro]), but adequate levels of all other nutrients for 4
wk to determine the effects of Se deficiency and protein deficiency on tissue Se and glutathione peroxidase (GSHPx) activity
in rats. Plasma, heart, liver, and kidney Se and GSHPx were significantly lower in Se-deficient groups in relation to Se-sufficient
groups. In Se-deficient groups, Se and GSHPx were significantly higher in −Se−Pro rats in heart, liver, and kidney. Data analysis
showed that there were significant interaction effects between dietary Se and protein on Se and GSHPx of rats. It is assumed
that under the condition of Se deficiency. a low level of protein may decrease Se and GSHPx utilization, increase GSHPx synthesis,
and result in Se redistribution. This could account for high levels of Se and GSHPx in the −Se−Pro rats compared to −Se+Pro
rats. 相似文献
16.
Belma Turan Nezahat Zaloglu Emine Koc Yüksel Saran Nuri Akkas 《Biological trace element research》1997,58(3):237-253
The present study was designed to investigate and compare the effects of dietary selenium (Se) and vitamin E on some physiological parameters and histological changes in liver, heart, and skin tissues, as well as the blood parameters and the related enzymes. Both sex young rabbits were fed with deficient (9.8 μg/kg diet), adequate (225 μg/kg diet), and rich (4.2 mg/kg diet) Se and vitamin E diets for 12–15 wk for this purpose. As the plasma Se levels and the erythrocyte glutathione (GSH) peroxidase activity decreased (79.8±9.4 ng/ml and 2.0±0.3 U/g Hb, respectively) in the deficient group, these values increased (100.4±2.7 ng/mL and 14.5±4.3 U/g Hb) in the rich group significantly with respect to the control group. The other antioxidant enzyme activities and the related element levels did not change significantly in either one of the experimental groups. Although the platelet counts of the two experimental groups were not different from the control values, the collagen and the adenosine diphosphate (ADP) stimulated platelet aggregation rate and intensity increased in the deficient group (p<0.05) and decreased very significantly (p<0.001) in the rich group. In both of the experimental groups, as the percentage values of the neutrophils decreased, the lymphocytes and the eosinophils increased significantly. According to the light microscopic investigations, the observed lesions of considerable intensity within the tissues that elicit cell degenerations were more pronounced in the animals fed with the rich diet than in those fed with the deficient diet. The deficiency as well as toxicity of Se and the deficiency of vitamin E caused several alterations in the physiological functions of the tissues, and these alterations were supported by the histological lesions within these tissues. 相似文献
17.
Importance of Molar Ratios in Selenium-Dependent Protection Against Methylmercury Toxicity 总被引:2,自引:0,他引:2
The influence of dietary selenium (Se) on mercury (Hg) toxicity was studied in weanling male Long Evans rats. Rats were fed
AIN-93G-based low-Se torula yeast diets or diets augmented with sodium selenite to attain adequate- or rich-Se levels (0.1,
1.0 or 15 μmol/kg, respectively) These diets were prepared with no added methylmercury (MeHg) or with moderate- or high-MeHg
(0.2, 10 or 60 μmol/kg, respectively). Health and weights were monitored weekly. By the end of the 9-week study, MeHg toxicity
had impaired growth of rats fed high-MeHg, low-Se diets by approximately 24% (p < 0.05) compared to the controls. Growth of rats fed high-MeHg, adequate-Se diets was impaired by approximately 8% (p < 0.05) relative to their control group, but rats fed high-MeHg, rich-Se diets did not show any growth impairment. Low-MeHg
exposure did not affect rat growth at any dietary Se level. Concentrations of Hg in hair and blood reflected dietary MeHg
exposure, but Hg toxicity was more directly related to the Hg to Se ratios. Results support the hypothesis that Hg-dependent
sequestration of Se is a primary mechanism of Hg toxicity. Therefore, Hg to Se molar ratios provide a more reliable and comprehensive
criteria for evaluating risks associated with MeHg exposure. 相似文献
18.
A previous experiment using rats indicated that dietary nickel (Ni), folic acid, and their interaction affected variables associated with one-carbon metabolism. That study used diets that produced only mild folate deficiency. Thus, an experiment was performed to determine the effect of a severe folate deficiency on nickel deprivation in rats. A 2×2 factorially arranged experiment used groups of six weanling Sprague-Dawley rats. Dietary variables were nickel, as NiCl2·6H2O, 0 or 1 μg/g and folic acid, 0 or 4 mg/kg. All diets contained 10 g succinylsulfathiazole/kg to suppress microbial folate synthesis. The basal diet contained <20 ng Ni/g. After 50 d, an interaction between nickel and folate affected the urinary excretion of formiminoglutamic acid (FIGLU) and the liver concentration of S-adenosylmethionine (SAM). Because of this, it is proposed that the physiological function of nickel is related to the common metabolism shared by SAM and FIGLU. Possibly the physiological function of nickel could be related to the tissue concentration of 5-methyltetrahydrofolate (MTHF) or tetrahydrofolate (THF). 相似文献
19.
Thirty-two wether lambs of Tan sheep were randomly assigned into four dietary treatment groups (eight per group) for an 8-wk
study and then fed a basal diet deficient in Se (0.06 mg/kg) or diets supplemented to provide 0.10 mg/kg Se from sodium selenite,
selenized yeast, and selenium-enriched probiotics, respectively. Blood samples were collected at d 0, 28, and 56 of the experiment
and tissue samples were collected at experiment termination. Tissue and blood Se concentrations, blood glutathione peroxidase
(GSH-Px) activities, and plasma interleukin levels were analyzed. The results showed that the concentrations of Se in the
kidney, liver, and muscle increased in all of the supplemented groups (p<0.01) compared with the control group. However, the Se concentrations in the kidney, liver, and muscle in the groups supplemented
with Se yeast and Se-enriched probiotics were higher than those in the group supplemented with sodium selenite (p<0.01). The activities of GSH-Px and the concentrations of Se in blood also increased in all of the supplemented groups during
the period of supplementation (p<0.01) compared with the control group. The activities of GSH-Px and the concentrations of Se in the whole blood of the lambs
fed with selenized yeast and Se-enriched probiotics were higher than those of lambs fed with sodium selenite (p<0.01 or p<0.05). The concentrations of interleukin-1 and interleukin-2 in plasma significantly increased in all of the supplemented
groups during the entire period of experiment (p<0.01) compared with the control group, but had no significant differences among all of the supplemented groups. In conclusion,
a diet supplemented with Se for finishing lambs was able to increase the concentrations of Se in tissue and blood, activities
of GSH-Px in blood, and levels of interleukins in plasma. Organic Se sources (selenized yeast and Se-enriched probiotics)
were more effective than the inorganic Se source (sodium selenite) in increasing tissue and blood Se concentrations and blood
GSH-Px activities of lambs. However, there were no significant differences in plasma interleukin levels of lambs between organic
and inorganic Se sources. 相似文献
20.
《Animal : an international journal of animal bioscience》2020,14(1):215-222
The enrichment of meat with selenium is important to improve the intake of selenium by humans. The effects of supranutritional doses of sodium selenite or selenium-enriched yeast on performance, carcass characteristics and meat quality were evaluated using 63 Nellore cattle in a completely randomized design with two sources (sodium selenite and selenium-enriched yeast), three levels (0.3, 0.9 and 2.7 mg Se/kg DM) and control treatment (without addition of selenium). Final body weight (BW), average daily gain, dry matter intake and gain to feed ratio (G : F) at the end of 84 days of supplementation were not influenced by treatments (P>0.05). Values of pH, ribeye area, back fat thickness and marbling score were also not influenced by treatments (P>0.05). Dressing percentage was greater (P=0.02) in Nellore cattle supplemented with organic Se (58.70%) compared to animals supplemented with inorganic Se (57.94%). Hot carcass weight increased (P=0.05) with the increasing of Se levels in the diet. Colour, shear force (SF), cooking and drip loss remained unchanged (P>0.05); however thiobarbituric acid reactive substances was 15.51% higher with inorganic Se compared with organic Se. The selenium concentration in the meat of animals receiving organic selenium was higher (P<0.001) than that of animals receiving sodium selenite, at all levels (0.3; 0.9 and 2.7 mg/kg DM). The meat of animals receiving 2.7 mg of organic Se/kg of DM presented concentration of 372.7 μg Se/kg in the L.dorsi muscle, and the intake of 150 g of this meat by humans provides approximately 100% of the recommended Se intake (55 μg Se/day for adults). Therefore, the use of supranutritional doses of 2.7 mg Se/kg of DM, regardless of source, is a way of naturally producing selenium-enriched meat without compromising performance, carcass characteristics and quality of Nellore bovine meat. 相似文献