• Journal of Nutrition and Health
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• v.41 no.4
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• pp.291-298
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• 2008

To study antioxidant role of zinc, the effects of dietary zinc deficiency and vitamin E supplementation on lipid peroxidation were studied. Levels of zinc and vitamin E in blood and liver were also measured. Forty Sprague-Dawley male rats aging 8 weeks old were used as experimental animals. Zinc deficient diet (Zn, 0 ppm), zinc normal diet (Zn,36.5 ppm), and vitamin E supplemented diet (1,000 IU ${\alpha}$-tocopherol/kg of diet) were used as experimental diet. During the first three weeks, rats were divided into zinc normal (ZnN, 8 animals) and zinc deficient (ZnD, 32 animals) group. Eight rats from each group were sacrificed to get blood and liver after 3 weeks of experiment. The remaining 24 zinc deficient rat were then divided into zinc normal (ZnDN), zinc deficient (ZnDD), vitamin E supplemented (ZnDE) diet groups. After another 3 weeks of experiment, all animals were sacrificed as well. Thiobarbituric acid reactive substanc (TBARS) levels in plasma and liver, conjugated diene levels in liver were measured as lipid peroxidation index. There were no significant differences in food intake, body weight gain, and food efficiency ratio among groups. Weights of liver per 100 g body weight were not significantly different. There were no significant differences in Zn levels in serum. Plasma and liver TBARS level, and liver conjugated diene level were significantly lower in ZnDE than in ZnDN or ZnDD, and significantly higher in ZnDD than in ZnDN. Therefore, it seems that lipid peroxidation is accelerated by dietary zinc deficiency and recovered partly by vitamin E supplementation.

• Toxicological Research
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• v.28 no.1
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• pp.39-49
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• 2012

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Sixweek old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of ${\beta}$-catenin was also performed on the mucous membrane of colon. The number of large ACF (${\geq}4$ AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.1048-1052
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• 2008

The objective of this study was to determine the effect of sodium selenite and zinc-L-selenomethionine on performance and egg Se concentration in laying hens. Two hundred and twenty-four CP Browns aged 71 weeks were divided according to a $2{\times}3$ factorial in a completely randomized design. One more group without additional Se supplementation was used as a negative control. Each treatment consisted of four replicates and each replicate contained eight laying hens. The dietary treatments were T1: basal diet; T2, T3 and T4: basal diets plus 0.3, 1.0 and 3.0 mg Se from sodium selenite/kg, respectively; T5, T6 and T7: basal diets plus 0.3, 1.0 and 3.0 mg Se from zinc-L-selenomethionine/kg, respectively. The findings revealed that feed conversion rate/kg eggs, egg production, egg weight, Haugh units and eggshell thickness were not affected by source and level of Se (p>0.05). Increasing level of dietary Se significantly increased (p<0.05 the Se content of eggs. Zinc-L-selenomethionine markedly increased p<0.05 egg Se concentration as compared with sodium selenite. The results indicated that Se source did not influence performance of laying hens. However, zinc-L-selenomethionine increased p<0.05 egg Se concentration more than sodium selenite.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.1-6
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• 1994

The present study was conducted to evaluate the effect of dietary levels of vitamin A on the lipid composition in rats fed Zn-deficient diets. Fifty male Sprague-Dawley rats were fed 5 experimental diets for 7 weeks. Rats were fed Zn-and vitamin A-deficient diet or the same diets supplemented with various levels of vitamin. A liver total lipid, cholesterol and triglycerides contents tended to decrease in Zn-deficient rats, but the supplementation of excess vitamin A enhanced those contents. Plasma cholesterol content was significantly higher in feeding Zn-deficient and excess vitamin A diet. Plasma triglyceride and phospolipid contents were higher in Zn-deficient groups, but not influenced by dietary levels of vitamin. A . Plasma HDL-cholesterol content was not changed by Zn-deficient diets. Plasma alkaline phosphatase activity was significantly reduced in Zn-deficient groups. Zinc contents of plasma and liver were influenced by the dietary level of zinc, but not changed by supplementation of vitamin A.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.718-724
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• 1994

The study was conducted to investigated the effect of dietary levels of zinc (Zn) on lipid metabolism in cadmium (Cd) treated rats. Sixty male Sprague-Dawley rats weighing about 110$\pm$10g were divided into 6 groups. The Zn levels were low (0ppm), control (30 ppm) and Cd-treated groups were administrated with Cd chloride (5.0mg/kg of body weight) by oral intubation at the same time once a week. Serum total lipid, triglyceride , total cholesterol and DHL-cholesterol contents decreased significantly in low Zn group. In serum dietary high Zn group, it decreased significantly in the content of triglyceride but total cholesterol and HDL- cholesterol revealed increase slightly . Total lipid and triglyceride contents increased by Cd oral intubation, but triblyceride content of control group decreased significantly in Cd-treated groups. HDL-cholesterol content also decreased by Cd oral intubationl. Cd-treatment increased total cholesterol content in low Zn group. Liver triglyceride content increased as dietary Zn level became more increasing and total lipid was not influenced by dietary Zn levels. Liver cholesterol content was higher in low and high Zn groups than that of control group. Liver phospholipid content decreased in low Zn group . Oral intubation of Cd increased in the contents of triglyceride and total lipid. The content of liver Zn was not influenced by the dietary low Zn but that of serum showed a remarkable increased . Oral Cd intubation increased the Cd contents of liver and serum.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1110-1117
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• 1993

The purpose of this was to analyse zinc intakes and effect of Zn(30mgZnSO4/day) supplementation on plasma zinc level, serum HDL-cholesterol and serum Alkaline Phosphatase (AP) activity of Korean adults. The men consumed 8.52($\pm$2.08)mg of zinc, and the women consumed 6.4($\pm$2.62)mg of zinc. Although protein intakes of subjects were lower than normal values. The first source of zinc was cereal and grain group, the second was meat, fish, egg and soybean group. Two food groups supplied about 80% of zinc. After two weeks of zinc supplementation, the zinc concentration in plasma was significantly increased. The highest plasma zinc level was 78.80ug/dl(men), 76.04ug/dl(women) at 2 weeks after zinc supplementation(p<0.05). Serum DHL-cholesterol was significantly decreased by zinc supplementation. The lowest serum HDL-cholesterol level was 39.29mg/dl(men), 44.84mg/dl(women) at 4 weeks after zinc supplementation(p<0.01). Serum AP activity was significantly increased by zinc supplementation. The highest AP activity was 86.40units/L(man), 67.93units/L(women) at 2 weeks after zinc supplementation(p<0.05). It seems that the supplementation of 30mg ZnSO4/day can be beneficial for improving zinc nutriture. However it can be negative factor on coronary heart disease because serum HDL-cholesterol was significantly decreased(p<0.01)

• Journal of the East Asian Society of Dietary Life
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• v.14 no.1
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• pp.27-33
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• 2004

The objectives of the present study were to measure the content of iron, copper and zinc in human milk and to estimate the intake of iron, copper and zinc of breast-fed infants during the early period of lactation. Twenty-five lactating women who delivered in a hospital in Seoul volunteered for the study. Milk samples were collected at day 2, 3, 4, 5, 6, 7, 15 and 30 postpartum. The contents of iron, copper and zinc were determined using the atomic absorption spectrophotometer after wet digestion. The intakes of iron, copper and zinc of infants were estimated by multiplization with the infant milk intake reported in our laboratory. The content of iron was 0.58 $\mu\textrm{g}$/g in colostrum, 0.48 $\mu\textrm{g}$/g in transitional milk and 0.39 $\mu\textrm{g}$/g in mature milk while the estimated iron intake of infants was 271, 255 and 259 $\mu\textrm{g}$/day, respectively. The content of copper in the milk was 0.45 $\mu\textrm{g}$/g in colostrum, 0.43 $\mu\textrm{g}$/g in transitional milk and 0.33 $\mu\textrm{g}$/g in mature milk while the estimated copper intake of infants was 210, 229 and 220 $\mu\textrm{g}$/day, respectively. The content of zinc in the milk was 5.24 $\mu\textrm{g}$/g in colostrum, 3.70 $\mu\textrm{g}$/g in transitional milk, 2.93 $\mu\textrm{g}$/g in mature milk while the estimated zinc intake of infants was 2452, 1968, and 1949 $\mu\textrm{g}$/day, respectively. These results suggest that copper and zinc intake of infants are met to RDA but iron is not.

• Culinary science and hospitality research
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• v.3
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• pp.291-313
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• 1997

This experiment was conducted to study the effects of dietary zinc and ethanol on the mineral contents of serum and changes of the liver tissue. Eighty male rats of Sprague-Dawley strain with average weight of 80$\pm$5g were divided into five groups according to zinc levels(5ppm and 100ppm), ethanol and isocaloric sucrose feedings. The rats were sacrificed after 4 and 7 weeks of feeding periods. The results are summarized as follows. 1. There was a decrease of weight gain in the ZD group compared with the C group and also decreased in the CE and ZDE groups fed the ethanol solution. The feed intake was decreased in the ZD and ZDE groups, and the feed efficiency was also greatly reduced in the ZDE group. 2. The liver weight of the ZD and ZDE groups was increased, however, the weight of testis was decreased in the same groups. And the weight of spleen was decreased in the ZD group. 3. The AST and ALT activities of serum were significantly increased in the ZDE group. 4. The content of serum zinc was influenced by the dietary zinc level, and the amount was significantly decreased in the ZD group. But the content of serum copper was remarkably increased in the ZD grou. The calcium and magnesium contents of serum were decreased in the ZD and ZDE groups. 5. The morphological changes of the liver tissue were not different among the C, CE and PF groups, but the abllooning denaturation of the liver cell together with the infiltration of the local inflammation cell was found in ZD and ZDE groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1037-1041
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• 2009

The effect of dietary zinc levels on macro mineral contents was investigated in rats. Rats were divided into three groups by zinc levels, such as low (50% of requirement, Zn/L), adequate (100%, Zn/A) and high (200%, Zn/H) levels of dietary zinc. The calcium, magnesium, sodium and potassium contents in serum and organs were measured. The food intake was significantly higher in Zn/L group compared to that of Zn/H group. The body weight gain in Zn/H group was significantly lower than that of other two groups. There were no significant differences in liver, kidney and spleen weights. Also, serum calcium, magnesium, sodium and potassium concentrations were not significantly changed by the zinc diet at any level. In the low zinc diet group, liver calcium content was significantly lower, but the magnesium and potassium contents in spleen were significantly higher than that in other groups. The calcium, magnesium, sodium and potassium contents of kidney were not significantly different for any level of zinc. In conclusion, the macro mineral contents of liver and spleen in the normal rats were changed by zinc levels. Based on this study, the interaction between micro and macro minerals remains to be further studied.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.139-144
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• 1998

Eighteen lambs were used to determine the effects of zinc (Zn) level and source on Zn status and immune function during both normal conditions and conditions of physiologic stress. Treatments consisted of a basal diet (27.6 mg of Zn/kg), and the basal diet supplemented with 25 mg of Zn/kg, added as either zinc oxide or zinc methionine. The basal diet was a corn-cottonseed hull-isolated soy protein- based diet (14% CP). Lambs were weighed and blood samples taken at 28-d intervals for determination of serum Zn and alkaline phosphatase activity. Weights and serum Zn were similar (p > 0.10) among treatments at all sampling days. To evaluate immune responses and Zn status during conditions of physiologic stress lambs were administered 100 I.U. of adrenocorticotrophin (ACTH) on d 112 and feed was withheld for 48 h. Cortisol levels were elevated (p < .01) 5 h post ACTH injection, but had returned to initial levels after 48 h. Lymphocyte blastogenesis ([$^3H$]-thymidine incorporation) on d 112 (prior to ACTH injection) and 114 was unaffected (p > .10) by dietary treatment. However, blastogenesis in response to pokeweed mitogen was greater (p < .0001), whereas the response to phytohemagglutinin was reduced (p < .01) following ACTH administration and fasting. Antibody response to administration of porcine red blood cells was unaffected (p > .05) by dietary treatment. These results indicate that, given the Zn concentration of the basal diet, there was no enhancement of immune function by supplemental Zn, either before or after lambs were subjected to stress.