有氧运动改善高脂血症分子机理的研究IV.有氧运动上调饮食性高脂血症大鼠肝脏LDL-R基因表达

Study on Molecular Mechanism for Favorable Effects of Aerobic Training on Hyperlipidemia IV:Aerobic Exercise Up-regulate the Expression of LDL-R of Liver in Diet-induced Hyperlipidemic Rats

目的 :采用RT -PCR技术测定和分析高脂高胆固醇膳食和有氧运动干预对大鼠肝脏低密度脂蛋白受体基因表达的影响 ,以探讨有氧运动对低密度脂蛋白代谢影响的分子机理。方法 :雄性SD大鼠 4 0只 ,随机分为 :(1) 8周普通膳食对照组 (NS ,n =10 ) ,(2 ) 8周高脂膳食对照组 (HS ,n=10 ) ,(3) 8周普通膳食 +运动组 (NE ,n =10 )和 (4) 8周高脂膳食 +运动组 (HE ,n =10 )。建立高脂高胆固醇膳食诱导SD大鼠高脂血症的实验动物模型和有氧运动训练模型 ,用RT -PCR方法测定肝脏LDL -RmRNA表达量。结果 :高脂膳食对照组大鼠肝脏LDL -RmRNA水平显著低于普通膳食对照组 (P <0 0 1) ;高脂膳食 +运动组显著高于高脂膳食对照组 (P <0 0 1)。结论 :有氧运动可在转录水平对抗高脂负荷并上调大鼠肝脏LDL -R表达的作用 ,有助于预防和改善高脂饮食引起的LDL代谢异常。

Objective In order to deeply investigate the molecular mechanism of the effect of exercise on the metabolism of LDL, the effects of aerobic exercise on expression of LDL-R mRNA of Liver by RT-PCR were observed. Methods SD rats were divided into four groups: (1) normal diet for 8 weeks (NS); (2) high-fat-high-cholesterol (HFC) diet for 8 weeks (HS); (3) normal diet and aerobic exercise for 8 weeks(NE); (4) HFC diet and aerobic exercise for 8weeks(HE). Our study used RT-PCR determining the effect of aerobic swimming exercise on hepatic level of LDL-R mRNA in hyperlipidemic rats. Results The levels of LDL-R mRNA of liver in HS group are lower than that in NS group (P < 0.01); the LDL-R mRNA in HE group are higher than that in HS group (P < 0 01). Conclusion HFC diet can down-regulate the hepatic transcription of LDL-R gene in rats. Swimming training might protect against the atherogenic effects of HFC diet by up-regulating the hepatic transcription of LDL gene. Thus, these molecular regulation might be responsible for the availability of reverse cholesterol transport in hyperlipidemia.