有氧运动对高胆固醇血症大鼠肝脏低密度脂蛋白受体活性调节的影响

本文研究了实验性高胆固醇血症大鼠肝脏低密度脂蛋白受体（ＬＤＬＲ）活性变化及有氧运动时ＬＤＬＲ活性调节的影响。发现，高脂（ＨＣ）组肝组织匀浆ＬＤＬＲ活性较正常对照（ＮＣ）组降低３７％（Ｐ＜０．０５），同时血清总胆固醇（ＴＣ）、低密度脂蛋白胆固醇（ＬＤＬＣ）及血清载脂蛋白Ｂ（ＡｐｏＢ）均显著高于ＮＣ组（Ｐ＜０．０１）；高脂＋运动（ＨＥ）组ＴＣ、ＬＤＬＣ及ＡｐｏＢ均明显低于ＨＣ组，而ＬＤＬＲ活性则较ＨＣ组增高２６％（Ｐ＜０．０５）。结果提示：（１）高胆固醇负荷时细胞可通过下行调节影响ＬＤＬＲ活性；（２）运动可能通过增加对细胞内胆固醇利用和降解，反馈作用于下行调节过程影响ＬＤＬＲ的合成，增加对ＬＤＬＣ摄取而显著改善血脂水平。

EFFECTS OF AEROBIC EXERCISE ON REGULATION OF ACTIVITIES OF HEPATIC LOW DENSITY LIPOPROTEIN RECEPTOR IN HYPERCHOLESTEROLEMIC RATS

The present study is to determine the effects of exercise on the regulatory role in activities of hepatic low density lipoprotein receptor (LDL R) in experimental hypercholesterolemic (HC) rats.Using a specific assay for the binding of 125 I LDL receptor to homogenate, the activity of hepatic LDL R were measured.It was observed that the activity of LDL R in HC decreased by 37% as compared with the normal control (NC) rats.HC rats also had a higher levels of serum total cholesterol(TC),LDL Cholesterol (LDL C) and apolipoprotein B(Apo B).The rats fed on high cholesterol diet combined with exercise for 12weeks (HE) had lower TC,LDL C and Apo B levels than those of HC rats,and had a higher hepatic LDL R activity which was 26% higher than that of HC rats.These finding suggested:(1) LDL R activity may be regulated downward in cholesterol loaded rats;(2) Exercise may enhance the utilization and degradation of intracellular cholesterol,and may have a feedback effect on the down regulated synthesis of LDL R,thus increase the uptake of LDL C and lower plasma level of lipid.