甲状腺素对鼠肝细胞PPARγ和GluT_2表达影响及意义

EFFECTS AND MEANINGS OF THYROXINE UPON THE EXPRESSIONS OF PPARγ AND GluT_2 IN HEPATIC CELLS OF RATS

目的通过喂饲的方法,观察过量甲状腺素对正常SD大鼠肝细胞PPARγ和GluT2表达的影响,以了解过量甲状腺素对肝细胞胰岛素应答敏感性及葡萄糖转运的影响,以探讨甲状腺功能亢进时合并糖耐量异常或糖尿病的可能发病机制。方法左旋甲状腺素(优甲乐)1μg/kg体重灌胃,1次/d,连续2周,免疫组织化学法观察SD大鼠肝细胞PPARγ和GluT2表达影响。结果甲状腺素喂饲后大鼠肝细胞PPARγ明显低于对照组、而GluT2表达明显高于对照组(P分别<0.01)。结论甲状腺素对大鼠肝细胞PPARγ和GluT2表达影响显著,降低了肝细胞对胰岛素应答敏感性和对葡萄糖的转运功能,可能与甲亢时糖耐量异常或合并糖尿病的发病机制有关。

ABSTRACT： Objective To investigate the mechanisms of impaired glucose tolerance or dia- betes mellitus in patients with hyperthyroidism, we observed the effects of thyroxin upon the ex- pressions of peroxisome proliferator-activated receptor gamma（PPART）and Glucose transporter2 （GluT2） in hepatic cells of rats. Methods Observing the expressions of PPA7 and GluT2 with im- munohistochemistry in hepatic ceils of rats fed with low dosage of thyroxine per os. Results The expression of PPAR7 in experimental groups is higher than that of the normal group, and the re- verse results of GluT2 are also observed（P 〈 0.01 respectively）. Conclusions Thyroxin alters the expressions of PPAR7 and GluT2 in hepatic cells of rats, and these may be one of the mechanisms of impaired glucose tolerance or diabetes mellitus in patients with hyperthyroidism.