• Nutrition Research and Practice
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• v.4 no.5
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• pp.356-361
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• 2010

Zinc is an essential trace element required for bone formation, however not much has been clarified yet for its role in osteoblast. We hypothesized that zinc would increase osteogenetic function in osteoblasts. To test this, we investigated whether zinc treatment enhances bone formation by stimulating osteoblast proliferation, bone marker protein alkaline phosphatase activity and collagen synthesis in osteoblastic MC3T3-E1 cells. MC3T3-E1 cells were cultured and treated with various concentrations of zinc (0, 1, 3, 15, 25 uM) along with a normal osteogenic medium (OSM) as control for 1, 5, 10 days. As measured by MTT assay for mitochondrial metabolic activity, cell proliferation was stimulated even at low zinc treatment (1-3 ${\mu}M$) compared to OSM, and it was stimulated in a zinc concentration-dependent manner during 5 and 10 days, with the most pronounced effect at 15 and 25 uM Zn. Cellular (synthesized) alkaline phosphatase (ALP) activity was increased in a zinc concentration-dependent manner, so did medium (secreted) ALP activity. Cellular collagen concentration was increased by zinc as time went by, therefore with the maximum zinc stimulatory effect in 10 days, and medium collagen concentration showed the same pattern even on 1 and 5 day. This zinc stimulatory effect of collagen synthesis was observed in cell matrix collagen staining. The study results imply that zinc can increase osteogenic effect by stimulating cell proliferation, ALP activity and collagen synthesis in osteoblastic cells.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.347-356
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• 1993

Plasma concentrations of zinc and copper were measured in 59 non-pregnant women and 105 pregnant women(12 ; early pregant, 93 ; late pregnant) to estimate and compare both groups and to detect the effects of iron supplementation on the plasma zinc and copper concentrations in the pregant women. The mean plasma zinc concentration of the early pregnant group was not significantly different with those of the non-pregnant group. But in contrast, the mean plasma zinc concentration of the late pregnant group was significantly lower than those of the non-pregnant and early pregnant group. Mean plasma copper concentration were significantly elevated in ealry pregnant group and doubled in late pregnant compared to non-pregnant. In Fe supplemented group, mean plasma zinc concentrations were lower and mean plasma copper higher than those of Fe non-supplemented group. It appeared that Fe supplementation had effects on the decrease of plasma zinc concentrations in pregnancy.

• Journal of Surface Science and Engineering
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• v.33 no.5
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• pp.356-364
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• 2000

Factors that affect the hardness of the zinc electrodeposits in the sulfate electrolyte were investigated. The hardness of zinc deposit was enhanced by increasing the concentration of impurities such as iron and nickel in the bath that changed the crystallographic orientation of the zinc deposit from the strong basal plane to the random orientation. The increase of the concentration of sodium sulfate and current density in iron contained bath improved the hardness of zinc deposit because those were easily codeposited in zinc layer. However the increase of the concentration of sodium sulfate up to 80g/$\ell$ in the bath darkened the surface of zinc electrodeposits due to change of morphology by the codeposition of iron.

• Journal of Life Science
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• v.18 no.7
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• pp.947-951
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• 2008

Zinc is an essential trace element participating in many physiological functions and notably an important function for sperm physiology. Zinc-enriched yeast strain, Saccharomyces cerevisiae, isolated from tropical fruit rambutan. This strain contained 306 ppm zinc concentration and other components contained by K 28,640 ppm, Mg 2,342 ppm, Na 1,048 ppm, Ca 366 ppm, Fe 236 ppm and Mn 4 ppm. The serum concentration of testosterone was decreased in ethanol treatment rats. As compared with ethanol treated control rats, the zinc-enriched yeast strain supplementation showed significantly increased the testosterone concentration in serum. In addition, zinc concentration in serum was decreased in alcohol treatment, but this reduction was significantly increased by zinc-enriched yeast strain supplementation in ethanol feeding rats. These results indicate that zinc-enriched yeast Saccharomyces cerevisiae strain could play an important role in the sperm physiology by the marked elevation of serum testosterone concentration.

• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.25-38
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• 2005

In order to investigate the effect of dietary zinc and phytic acid levels on enzyme activity and lipid metabolism in rats, male Sprague-Dawley rats, weighing approximately 60-74g, were fed different diets which contained 0, 0.35 or $1.05\%$ phytic acid each at 3 levels of zinc (0, 30 and 1500ppm zinc) for 28 days. Body weight gain, food consumption, and food efficiency ratio were lower in the rats fed a zinc deficient diet (0ppm zinc) than those consuming 30 or 1500ppm dietary zinc. The activities of GOT, GPT and alkaline phosphatase were lower in the rats consuming 30ppm zinc than those fed 0 or 1500ppm zinc diet. The activity of GOT was increased in rats consuming $0.35\%$ phytic acid, whereas that of alkaline phosphatase was decreased in the rats fed phytic acid-containing diet. The concentration of phospholipid in serum was higher in rats fed $0.35\%$ dietary phytic acid, whereas that of liver phospholipid was higher in zinc deficient groups, and increased by addition of dietary phytic acid. The concentration of triglyceride in serum from rats fed 30ppm zinc was lower than those fed 0 or 1500ppm zinc On the other hand, liver triglyceride was higher in both the rats fed 30ppm zinc and $0.35\%$ phytic acid. The concentration of serum total cholesterol was lower in the rats fed 30ppm zinc diet, and it was increased by addition of dietary phytic acid. But liver total cholesterol was higher in 30ppm zinc group. HDL-cholesterol in serum was the highest in both rats consuming 30ppm zinc and $0.35\%$ dietary phytic acid, and the ratio of HDL-cholesterol to total cholesterol was higher in rats consuming 30ppm zinc diet. In conclusion, we suggest that coronary heart disease or liver disease can be prevented with phytic acid in rats which are fed the high zinc diet.

• Journal of Nutrition and Health
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• v.33 no.5
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• pp.517-523
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• 2000

The effect of dietary zinc deficiency and age on lipid peroxide level was investigaed in rats. Zinc level in serum and liver were also measured. Fifty Sprague-Dawly male rats aging 8 months(older rats) and 2 months(younger rats) were used as experimental animal. Zinc deficient diet(1.1ppm) and normal zinc diet(36.5ppm) were used as experimental diets. Rats in each age group were divided into zinc deficient(ZnDF), zinc pair-fed(ZnPF) and zinc ad-libitum(ZnAL) to remove the variances of food intake. After 4 weeks of experimetal period, rats were sacrificed. Thiobarbituric acid reactive substance(TBARS) levels in plasma and liver, lipofuscin and conjugated diene levels in liver were measured as lipid peroxide index. Food intakes of all groups were not different because zinc deficiency did not reduce food intake in ZnDF group. Younger rats gained weight continuously, while older rats lost weight in the begining of experiment and regained afterwards. In older rats, serum zinc level was decreaed while plasma TBARS. level was increased in ZnDF group. In younger rats, plasma TBARS concentration was increased in dietary zinc deficient rats although serum zinc concentration was not reduced. Liver zinc concentration was significantly higher in older rats comparing to younger rats. However, there was no difference among the three dietary groups. Liver TBARS level was not different by age or dietary zinc level. However it was tended to be higher in older rats. However there was no difference by the dietary zinc level. In both age groups, ZnDF group significantly increased plasma TBARS levels, which suggested dietary zinc deficiency could increase lipid peroxidation in part. Significantly higher levels of lipofuscin and conjugated diene in older rats suggested lipid peroxidation was accelerated by aging.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.62-67
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• 1993

This study aims at investigating the relationships between the urinary mercury concentration and blood zinc-protoportphyrin, serum cholinestrase activity, making 149 workers exposed to mercury vapor and 68 workers who were not exposed to mercury among the workers in a flurorescent lamp manufactureing factory an object of this investigation. The results are as follows ; 1. In an exposed group the number of those whose urinary mercury concentration showed over $100{\mu}g/l$ was 21 persons (14.3%) among 147 workers. The average urinary mercury concentration was $52.1{\pm}46.1{\mu}g/l$($1.8-361.2{\mu}g/l$), which proved to be higher than the average concentration in a control group. 2. In an exposed group, the average concentration of blood zinc-protoporphyrin was $27.8{\pm}12.5{\mu}g/dl$($12.2-101.5{\mu}g/dl$), which proved to be somewhat higher than the average concentration in a control group. But it did not show a significant difference. 3. In an exposed group, the average concentration of serum cholinesterase activity showed $1936.7{\pm}341.0IU/l$(1,120,0-2,8750IU/l), which proved to be lower than the average concentration in a control group. 4. The relational coefficient between urinary mercury concentration and blool zinc-protoporphyrin, serum cholinesterase activity of the whole workers exposed to mercury showed little difference. While the relational coefficient between the urinary mercury concentration and blood zinc-protoporphyrin of the workers whose urinary mercury concentration showed over $100{\mu}g/l$ was relatively high, which was 0.62.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.966-969
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• 2001

Some researchers reported that beef marbling was improved by the supplementation of organic zinc to a diet satisfying zinc requirement. We studied the relationship between serum zinc concentration and marbling score or serum adipogenic activity in 40 fattened steers. To determine serum adipogenic activities of the steers, preadipocytes were cultured in medium containing the serum samples during differentiation. Although serum zinc concentration was not related to beef marbling score, it was positively correlated to adipogenic activity. Then, we studied the effect of zinc on adipocyte differentiation. Zinc was added into the medium with the similar methods except the addition of fattened calf serum. The activity of glycerophosphate dehydrogenase, a marker of adipocyte differentiation, was significantly increased by the addition of zinc in culture with or without insulin. These results suggest that zinc possibly improved beef marbling through increasing adipogenic activity during fattening.

• Journal of Surface Science and Engineering
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• v.34 no.6
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• pp.537-544
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• 2001

In the present study, tin-zinc alloys were coated on a cold-rolled steel sheet with variations of electrolyte concentration, additives quantity and current density employing the Hull cell and circulation cell simulator. With an addition of additives of 2m1/L, tin-zinc deposits containing 10 to 40 percent Zn revealed a good surface appearance with weak acidic electrolytes. The organic additives suppressed the Sn deposition rate and thus increased the zinc contents in tin-zinc coating layers. The zinc contents in the tin-zinc coating layers depended almost linearly on the concentrations of metal ions of tin and zinc. Temperature of the electrolyte affected the composition tin-zinc coating layer. However, the concentration of complexants revealed little effectiveness. The surface morphology of tin-zinc coating showed dense tin and zinc phases with fine equiaxed grains with the high current density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.163-165
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• 1999

The study was conducted to find the critical concentrations of zinc toxicity and to determine the changes of the contents of free proline and organic acids with treatment of different zinc chloride concentrations during rice germination and seedlings grown for seven days. The concentration of zinc chloride, 140 ppm, inhibited root elongation as much as 46 times compared with the control, and the germination rate was also decreased in all treatments of zinc chloride, showing that the germination rate decreased more with increasing concentrations of zinc chloride. Its rate was only 13% with treatment of 140 ppm zinc chloride. The content of free proline with treatment of zinc chloride, 140 ppm, was highest about 4,873 $\mu$M at 3 days compared with the control. Malic acid concentration with treatment of zinc chloride, 140 ppm, increased to approximately 4 times compared to the control. Citric and succinic acid content were also slightly increased in all treatments of zinc chloride.