饮食诱导雄性肥胖大鼠生长激素轴变化

目的　探讨饮食诱导雄性肥胖大鼠生长激素 (GH)轴〔GH/胰岛素样生长因子 -I(IGF -I)〕的轴性变化。方法　建立高脂饮食诱导肥胖的大鼠模型 ,实验 12周末处死大鼠 ,采用放射免疫分析方法检测大鼠血清GH、IGF -I、胰岛素水平 ,用免疫组化方法检测肝脏IGF -I的含量。结果　饮食诱导肥胖后高脂组大鼠血清GH水平下降 (P <0 0 5 ) ;游离IGF -I水平升高 (P <0 0 1) ;血清胰岛素水平升高 (P <0 0 5 ) ;肝脏IGF -I的积分光密度值和阳性面积百分比均显著低于对照组 (P <0 0 1) ,肝脏的IGF -I合成分泌下降。结论　在饮食诱导肥胖的雄性大鼠体内 ,可能并不存在真正意义上的GH/IGF -I轴性变化损伤。

Study on change of GH/IGF-I axis in diet-induced male obese rats

Objective To study the change of GH/IGF-I axis in diet-induced male obese rats.Methods The rats were made obese model by high-fat diet.All rats were put to death at the twelfth weekend.The lelvels of serum GH,free IGF-I and insulin in rats were determined by radioimmunoassay.The concentrations of IGF-I in the livers were detected by immunohistochemistry.Results The level of serum GH was lower in high-fat diet group than that of controls( P <0 05);the level of serum free IGF-I was higher in high fat diet group than that of controls( P <0 01),and the level of serum insulin was higher in high fat diet group than that of controls( P <0 05);High-fat diet rats showed a significantly decrease in the integrate OD total and threshold area% of hepatic IGF-I compared with control rats( P <0 01),IGF-I secretion in obese rats livers decreased.Conclusion There might be no GH/IGF-I axis impaired in real sense in diet-induced obese male rats