单纯肥胖症脂质代谢紊乱的运动防治──Ⅱ.有氧运动对饮食诱导肥胖大鼠肝脏低密度脂蛋白受体活性调节的影响

研究了实验性高胆固醇血症肥胖大鼠肝脏低密度脂蛋白受体（ＬＤＬ－Ｒ）活性变化及有氧运动对ＬＤＬ－Ｒ活性调节的影响。结果显示，１２和２０周饮食诱导高胆固醇血症肥胖大鼠血汗总胆固醇（ＴＣ）、低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）显著增高，伴随肝组织ＬＤＬ－Ｒ活性显著降低。１２周实验模型后，８周有氧运动结合饮食干预，肝脏ＬＤＬ－Ｒ结合话性较同期高脂膳食组提高５８．３％（Ｐ＜０．０５），单纯运动干预ＬＤＬ－Ｒ结合活性也有增加趋势（增加２１．９％），单纯饮食干预则无明显变化。研究提示：（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摄取而改善血脂水平。

A Study on Prevention and Treatment of Lipid Metabolism Disorders in SimpleObesity through Exercise.Part Ⅱ.Effect of Aerobic Exercise on Regulating Activity ofhepatic LDL-R in Rats with Diet-induces Simple Obesity and Hypercholesterolemia

The aim of the pressent study was to determine the effects of exercies on activities of hepatic low density lipoprotein receptor (UDL-R)in experimental obese and hypercholesterolemic rats.Using a specific assay for the binding of 125 I-LDL receptor to ho- mogenate,the activities of hepatic LDL-R were measured.It was observed that the acitivity of LDL-R significantly decreased in diet- induced obese and hypercholesterolemic rats after high-cholesterol diet for 12 weeks.The aerobic exercies combined with diet and simple exercise therapy induced the increases in 58.3%and 21.9% of LDL-R activity,respectively,and LDL-R activity was un- changed in the rats with diet alone.These finding suggested:(1) LDL-R acitvity was regulated downward in cholesterol-loaded rats; (2)Exercise might have a feedback effect on the down-regulated synthesis of LDL-R through an enhanced degradation of intracellu- lar cholesterol,which contributed to a lowering of plasma levels of LDL-C.