Yan Y, Zhang Y, Yang X, Hua Q
Department of physiology, Beijing Medical Staff College.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 1997 Feb;13(1):18-20.
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 125I-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 12 weeks (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.
本研究旨在确定运动对实验性高胆固醇血症（HC）大鼠肝脏低密度脂蛋白受体（LDL-R）活性调节作用的影响。采用针对125I-LDL受体与匀浆结合的特异性检测方法，测定肝脏LDL-R的活性。结果观察到，与正常对照（NC）大鼠相比，HC大鼠的LDL-R活性降低了37%。HC大鼠的血清总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）和载脂蛋白B（Apo B）水平也更高。喂食高胆固醇饮食并运动12周的大鼠（HE）的TC、LDL-C和Apo B水平低于HC大鼠，且肝脏LDL-R活性更高，比HC大鼠高26%。这些发现表明：（1）在胆固醇负荷大鼠中，LDL-R活性可能下调；（2）运动可能增强细胞内胆固醇的利用和降解，并可能对LDL-R下调的合成产生反馈作用，从而增加LDL-C的摄取并降低血浆脂质水平。
