| Objective: Atherosclerosis (AS), a heart disease, is associated with multiple factors, including gene, environment and metabolism et al. Recently, more and more studies have showed oxidative stress is one of the most important factors during the development of AS, and oxidative stress is throughout the forming, development, and rupture of AS, until triggering clinical event. In addition, the disorder of lipid metabolism is believed having tight association with AS, and hyperlipidemia is considered one of the most important risk factors. Furthermore, high-fat diet could enhance the generating of free radicals by mitochondrial respiratory chain and acquire more oxidation substrate and free radicals. Zinc is a essential trace element, which is widely distribute in organism. It has antioxidation, and plays significant role in cleaning free radicals. In our experiment, we supplied low dose of zinc sulfate to high-fat diet fed ApoE knockout mice to investigate if zinc supplementation has protection on heart of mice, and to clarify the mechanism. In addition, we will observe the injury of liver, and the regulation of zinc on lipid metabolism in liver. Our study will provide proof for the reasonable dose of zinc to prevent and decrease AS. It has significant role for decreasing the incidence rate of cardiovascular diseases in our country.Methods:Thirty ApoE-knockout mice were randomly divided into three groups, including high-fat model group, low-dose group and high-dose group. And ten C57BL/6J mice were used as control group. During the experiment, all the four groups were fed with "western"diet, except the control group and the high-fat model group drank deionized water freely, the other two groups contiguously administered with different dose of zinc sulfate for14weeks. When mice were sacrificed, we determined the zinc and iron in whole blood and femur, detected the level of SOD, T-AOC and MDA in heart of mice, as well as lipid in serum. To observe the situation of atherosclerotic plague in coronary, we used hematoxylin-feosin staining to deal with coronary. We further determined the level of SOD, T-AOC and MDA in liver, and the AST/ALT in serum. In addition, we observed the lipopexia in liver.Result:1.The zinc level of whole blood in low-dose group and high-dose group mice were (5.15±0.36) mg/Lå'Œ(5.11±0.44) mg/L respectively, and were remarkably higher than the other two groups, moreover the zinc in femur were statistically increased(P<0.05). But zinc supplementation did not markedly change the level of iron in whole blood and femur.2. The T-AOC and SOD level in heart of low-dose group and high-dose group mice were markedly decreased (P<0.05), following the MDA level was significant decreased.3. The triglyceride assay in serum of low-dose group and high-dose group mice were lower than high-fat model group (P<0.05), but the LDL, HDL and total cholesterol levels were not predominance changed.4.The MT mRNA level of mice heart was obviously improved.5.The atherosclerotic plague in coronary of low-dose group was smaller than high-fat model group.6.The level of ALT and AST in serum of low-dose group and high-dose group mice were lower than the other groups, but zinc supplementation did not ameliorate lipid accumulation in liver.Conclusions:1. Zinc supplementation could decease the oxidative damage caused by high-fat, and this protection may through zinc-induced MT.2. Zinc supplementation could regulate triglyceride metabolism and reduce the development of atherosclerotic plague in coronary.3. Zinc supplementation could not change the lipid accumulation of liver. |
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