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AIM To study the kinetic character of zinc transport and its influencing factors in osteoblasts, and scientific evidence is expected to provide to clarify the role of zinc on bone development. METHODS 65Zn tracing method was used to evaluate kinetic character of zinc transport. RESULTS Increase of extracellular zinc level could enhance the influx of zinc, but when the osteoblast became zinc deficiency the influx of zinc decreased. The histidine, Na+、K+-ATPase enzyme inhibitor had no effect on zinc transport into the cell, but Ca2+ channel blocker could enhance the influx of zinc. CONCLUSION The excellular level of zinc could influence zinc transport into osteoblasts, and Ca2+ channel could interact with Zn2+ transport.
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Objective: To study the effect of Mg 2+ onc fos, c jun, p53 and ref 1, that are transcription factors related to redox regulation, in cultured human umbilical vein endothelial cell. Methods: Imunohistochemistry techniques and image analysis system were used. Results:In the group of H 2O 2, the expresson of c fos, c jun, p53 and ref 1 was increased compared to the normal control group (P
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Objective: To investigate the effect of Mg 2+ on oxidative DNA damage of cultured human umbilical vein endothelial cells. Methods: The single-cell gel electrophoresis was used to determine the frequencies of cells with tail moment (TM) and the tail lengths. Results: The supplementation of Mg 2+ in the incubation medium influenced the H 2O 2-induced oxidative DNA damage. When compared with the group of H 2O 2, the frequencies of cells with TM and the tail lengths were markedly decreased in the group of H 2O 2+Mg 2+ at all doses (P
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The effects of high erucic acid rapeseed oil (HER) on fatty acid oxidation in rat livers compared with low erucic acid rapeseed oil (LER) were studied. Weanling male SD rats were fed on 20% (% by weight, similarly hereinbelow) HER or LER diet for a week or 4 weeks, or 5% HER diet for 4 weeks. The hepatic capacity for oxidation of butyric acid and palmitic acid was determined by titrating the acetone produced by the fatty acid oxidation. The results showed that feeding HER to rats led to an increse in weight of liver and the extent of this increase was positively correlated to the intake of erucic acid (C22:1, n-9 cis). Feeding HER reduced the hepatic oxidation capacity for palmitic acid, notably in 20% HER (1 wk) group. Feeding LER had not shown this effect,indicating that erucic acid plays an important role in the toxicity of rapeseed oil. In the present study it was not found that the hepatic oxidation capacity for butyric acid was influenced by the intake of HER. Therefore, we considered that the inhibitory effect of HER on oxidation of long-chain fatty acids probably resulted from that the incorporation of erucic acid into mitocho-ndrial membranes interfered with the fatty acyl-CoA transfering system on the membranes, leading the fatty acyl-CoA to be unable to enter the mitochondria and to be oxidized there, but not from that the B-oxidation system in mitochondria was directly inhibited.
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Objective: The effects of magnesium on the oxidation of low density lipoprotein (LDL) were systematically investigated by two different oxidation systems. Methods: LDLs were isolated from pooled healthy human fresh sera by ultracentrifugation. Oxidation of LDL was induced by adding Cu 2+ or co-cultured with cultured human umbilical vein endothelial cells. Conjugate diene was measured to assess the susceptibility of LDL to oxidation. The extent of LDL modification was determined by measuring the formation of thiobarbituric acid reaction substances (TBARS). Results: (1)The presence of Mg 2+ resulted in a protracted lag phase at doses of 0.3 mmol/L, 0.6 mmol/L, 1.2 mmol/L, and 2.4 mmol/L, as well as decreased production of TBARS when LDL was oxidized by the addition of Cu 2+ , at doses of 0.3 mmol/L and 0.6 mmol/L Mg 2+ .(2)Treatment of LDL with Mg 2+ (0.3 mmol/L, 0.6 mmol/L, 1.2 mmol/L, and 2.4 mmol/L) reduced the production of TBARS during endothelial cell-mediated LDL oxidation, P
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This paper reports a study regarding the verity of the hypocholestero-lemic effect of konjac-polysaccharide. The konnyaku powder (KP) used in this study was prepared and refined from the tubers of Amorphophallus ko-njac K. Koch and contained 84.8% of glucomannan. Male and female Spra-ue-Dawley rats aged 5 weeks were divided into 5 groups and fed on normal basal diet, hypercholesterolemic diet (control diet) and 3 test diets (i.e. KP was added to the control diet at a dosage of 2.5%, 5% or 10%) respe- ctively, for 12 weeks.The results obtained from this study showed that KP could markedly lower the level of the cholesterol in sera and livers of rats feeding hyper-cholesterolemic diets. At the end of the 4th week of the feeding experiment, the serum cholesterol level of the 5% and the 10% KP groups, and the liver cholesterol level of the 10% KP group were shown to be significantly lower than those of the control group. At the end of the 12th week, serum cholesterol levels of all the 3 KP groups were found to be lowered to the level of the normal group and so did the liver cholesterol level of the 10% KP group. The lipotropic (anticholesteatosis) effect of KP was also confirmed by the hepatic histopathological examination. Besides the hypocholest-eroletmic eftect, KP diets can also increase the bulk of stool. Finally, there were not any harmful effects on the absorption and utilization of Ca, Fe, Zn and Cu being found.
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Objective:The effect of magnesium on lipid peroxidation of endothelial cells induced by H 2O 2 and t bultyl hydroperoxide and subsequent alterations of extracellular superoxide dismutase(EC SOD) and cellular selenium dependent and selenium independent GSH Px were studied. Methods:The extent of cellular lipid peroxides was determined by measuring the formation of TBARS, EC SOD by the method of pyrogallol auto oxidation, and GSH Px by the method of DTNB. Results:The results showed that the formation of TBARS was significantly reduced in the group of H 2O 2+Mg 2+ at doses of 0.3, 0.6, 1.2,and 2.4 mmol/L compared to the group of H 2O 2(P