I型三磷酸鸟苷环化水解酶在2型糖尿病大鼠

探讨血管内皮功能异常状态下，I型三磷酸鸟苷环化水解酶（GTPCH I）mRNA在2型糖尿病及硫辛酸干预大鼠主动脉中的表达。方法：选择雄性Wistar大鼠35只，随机选择10只作为正常对照组(NC 组)，25只采用高脂饲料喂养8周后，小剂量链脲佐菌素注射诱导建立2型糖尿病大鼠模型(成模21只)，其中10只给予硫辛酸50?mg/kg腹腔注射，作为硫辛酸干预组（LA组），其余11只作为2型糖尿病组（T2DM组）。所有大鼠饲养16周后均处死测定其主动脉舒张功能，并用半定量RT PCR检测主动脉GTPCH I mRNA表达。结果：T2DM组和LA组主动脉的内皮依赖性血管舒张（EDVR）明显减弱，而LA组较T2DM组有明显改善（P＜0.05）。主动脉GTPCH I mRNA的表达在T2DM组下降70.28%，LA组下降26.88％，两组差异具有统计学意义（P＜0.05）。结论：T2DM大鼠离体主动脉EDVR减弱时，主动脉GTPCH I mRNA表达显著下降。硫辛酸可改善EDVR，此作用可能与改善GTPCH I mRNA表达有关。

Alteration of GTPCH I gene expressions in type 2 diabetic rats' aorta

To explore the expression of GTPCHⅠmRNA in aorta of diabetic and lipoic acid cured rats when the endothelial function was abnormal. Methods： Thirty five male Wistar rats were enrolled in this study; 10 of them were regarded as healthy control and 25 were given high fat diet, 8 weeks later they were administered STZ to the abdomen, finally only 21 became diabetic rats. The diabetic rats were divided into type 2 diabetes mellitus group(T2DM group, n=11) and alpha lipoic acid cured group (LA group, n=10) who were given 50?mg/kg lipoic acid per day. After 16 weeks some indexes of three groups were measured, and EDVR in the isolated aortic rings were measured, and GTPCHⅠmRNA was measured by RT PCR in all rats′ aortas. Results： EDVR decreased obviously in both T2DM and LA group, that was better in LA group than in T2DM (P＜0.05). Compared with NC group, GTPCHⅠmRNA content in T2DM group decreased by 70.28%, and in LA group by 26.88%, the difference was significant(P＜0.05). Conclusions： The expression of GTPCHⅠmRNA in rats′ aorta decreases in type 2 diabetes mellitus with the attenuate of EDVR. Alpha lipoic acid makes EDVR better in type 2 diabetes mellitus, which may correlate with the change of GTPCHⅠmRNA′s expression.