糖尿病大鼠下丘脑神经肽Y mRNA及蛋白表达研究

目的 研究糖尿病大鼠下丘脑神经肽Y（NPY）mRNA及蛋白表达情况，以探讨NPY在糖尿病中的病理生理作用。方法 建立链脲佐菌素（STZ）诱导的糖尿病大鼠模型，设立3周、24周糖尿病组〔其中分为非胰岛素（Ins)治疗组和Ins治疗组以及正常对照组〕。用原位杂交和免疫组化检测下丘脑NPY的mRNA及蛋白表达情况。结果 糖尿病大鼠下丘脑弓状核NPY的mRNA和蛋白表达均增加，室旁核及室周NPY的蛋白含量增加，且3周组较24周组增加更明显。给予Ins治疗后上述区域NPY的mRNA和蛋白表达均下降。结论 在糖尿病大鼠下丘脑的NPY mRNA和蛋白表达均增高，NPY的增加在糖尿病的多饮多食中起着重要作用。Ins缺乏可有是造成下丘脑NPY增多的重要因素。

Study on neuropeptide Y mRNA and its protein expression in the hypothalamus of streptozotocin-induced diabetic rats

Objective To study the changes of neuropeptide Y (NPY) mRNA and its protein expression in the hypothalamus of streptozotocin (STZ) induced diabetic rats and the effect of neuropeptide Y on the pathophysiological roles of diabetes mellitus. Methods The rats were divided into five groups, i.e. normal control, 3 and 24 week diabetes, 3 and 24 week diabetes treated with insulin. The NPY content and its mRNA in the hypothalamus were detected by immunocytochemistry and in situ hybridization respectively. Results The NPY contents in arcuate nucleus, paraventricular nucleus and paraventricular area were significantly increased in 3 and 24 week diabetic rat groups as compared with the normal control. The NPY mRNA was only increased in the arcuate nucleus. However, the content of NPY and its mRNA in 3 week STZ diabetic rats were higher than those in 24 week STZ diabetic rats. The NPY content and its mRNA were visibly reduced after insulin treatment. Conclusion The increase of NPY in hypothalamus may be responsible for the development of hyperphagia and polydipsia in diabetic rats. Insulin deficiency may contribute to the increase of hypothalamic NPY gene expression in diabetic rats.