摘要
目的探讨钙摄入量对大鼠肝脏胆固醇代谢关键酶3-羟基-3-甲基戊二酰辅酶A还原酶(HMG-CoA还原酶)、7α-羟化酶(CYP7A)的mRNA表达影响。方法雄性Wistar大鼠经14 d诱导高胆固醇血症模型后,分别喂饲不同钙含量的纯合成高脂饲料42 d。结果经14 d诱导高胆固醇模型后,高脂模型组大鼠血浆胆固醇(TC)水平为(2.57±0.57)mmol/L(n=21),是常脂常钙组(1.49±0.14)mmol/L(n=8)的1.72倍。又经42 d喂饲含有处理因素的饲料后,各组大鼠摄食量和体重无变化;高脂高钙组心脏指数和肾脏指数分别显著低于、高于其他各组(P<0.05);随着钙含量增加,实验处理组大鼠骨密度也逐渐增加;高脂常钙组TC浓度为(2.32±0.75)mmol/L,比初始时下降了6.07%;高脂中钙组抑制TC增高能力强于常脂常钙组;除高脂高钙组外,钙摄入可使大鼠肝脏HMG-CoA还原酶mRNA的表达量呈现下降趋势,CYP7A mRNA的表达量呈现增强趋势。结论适量钙摄入可通过影响HMD-CoA还原酶和CYP7A基因的表达来降低或改善血浆胆固醇水平。
Objective To investigate the influence of calcium intake on mRNA expressions of key enzyme of hepatic cholesterol metabolism, HMD-CoA reductase and CYP7A in hypercholesterolemic rats. Methods Four-week-old male Wistar rats, following 2 weeks of inducing hypercholesterolemia model successfully, were fed with purified experimental diets containing 0. 5% （Group B） ,1.0% （Group C） and 2. 0% （Group D） calcium with high fat concentration for 6 weeks. At the end of the experiment, the concentration of total cholesterol（ TC）, the mRNA expressions of HMD-CoA reductase and CYP7A of the rats were examined. Results Compared with the initial of the experiment, TC was （ 2. 32 ± 0. 75 ） mmol/L dropped by 6.07% （ P 〈 0. 05） in group B. Greater inhibition in elevation of serum cholesterol concentration was observed in group C than in group A. Calcium intake tended to decrease the mRNA expression of hepatic HMD-CoA reductase and increase the mRNA expression of CYP7A in the rats. Conclusion Adequate calcium intake decreasses the level of serum total cholesterol in hypercholesterolemic rats. Calcium intake also influences the mRNA expression of HMD-CoA reductase and CYPTA.
出处
《中国公共卫生》
CAS
CSCD
北大核心
2009年第9期1118-1120,共3页
Chinese Journal of Public Health
基金
国家自然科学基金(30471443)
