二甲双胍对大鼠垂体—性腺轴内分泌功能的影响

目的研究二甲双胍(Metformin,MF)对大鼠垂体-性腺轴内分泌功能的影响。方法采用放射免疫分析法和电子显微镜技术,系统研究MF对大鼠血清性激素含量及靶腺组织形态的影响。结果MF135mg·kg-1·d-1,ig,连续用药14d,可使♂大鼠睾酮(T)的含量及♀大鼠血清黄体生成素(LH)水平明显降低,而对♀大鼠卵泡刺激素(FSH)、雌二醇(E2)、孕酮(P)的含量和♂大鼠血清LH、FSH的含量均无影响。270mg·kg-1·d-1MF除明显降低♂大鼠血清T和♀大鼠血清LH的含量外,可使♀大鼠血清P、E2的含量升高(P<0.01)。电镜观察显示,大鼠睾丸内分泌细胞超微结构发生退行性改变,而卵巢细胞超微结构则呈现分泌旺盛的表现。结论MF对♀大鼠垂体-卵巢轴内分泌功能有促进作用,而对♂大鼠垂体-睾丸轴内分泌功能有抑制作用,且使靶腺内分泌细胞的超微结构出现相应的变化。

Effects of metformin on endocrine function of the pitutary-gonad axis in rats

Aim To study the effects of Metformin (MF) on endocrine function of pituitary-gonad axis in rats. Methods The serum hormone concentration was measured with radioimmunoassay (RIA) and the morphology of gonad endocrine cells was observed with electron microscope. Results MF(135 mg·kg-1·d-1,ig,14 d)decreased serum T concentration in male rats and serum LH concentrations in female rats significantly(P<0.05, P<0.01, respectively),but had no effects on serum LH, FSH concentrations in male rats and serum P and E_2 concentrations in female rats.Besides markedly decreasing male rats serum T and female rats LH concentrations, MF(270 mg·kg-1·d-1,ig,14 d) increased serum E_2 and P concentrations significantly in female rats.Electron microscope observation showed that there was obvious stimulative change in ovary cells and retrograde changes in testis, especially in MF high dosage group. Conclusion MF has promotive effects in female rats and inhibitory effects in male rats on the secretory function of the pituitary-gonad axis. It makes the ultramicrostructure of the secretion cells of target organs change.