大鼠垂体瘤模型下丘脑中神经肽Y及其受体的表达变化

Expression of neuropeptide Y (NPY) and Its receptors in hypothalamus of estrogen-induced rat pituitary adenoma model

目的观察神经肽Y(NPY)及其受体在垂体腺瘤模型大鼠下丘脑中的表达,探讨下丘脑中NPY表达变化与垂体腺瘤形成的关系。方法雌性Wistar大鼠40只,摘除双侧卵巢后,通过腹腔注射雌激素的方法建立大鼠垂体腺瘤模型,在此基础上采用免疫组织化学和逆转录-聚合酶链反应(RT-PCR)的方法,研究大鼠下丘脑中NPY及其受体的表达。结果实验组大鼠符合垂体腺瘤的诊断标准;免疫组织化学和RT-PCR研究结果表明,在实验组大鼠下丘脑中NPY及其Y1受体(Y1R)的表达水平明显低于对照组。Y2受体(Y2R)在两组之间的表达水平差异无统计学意义(P>0.05)。结论通过雌激素诱导Wistar大鼠,可以成功建立垂体腺瘤动物模型;实验组大鼠下丘脑中NPY及其Y1R表达下调可能与肿瘤发生有关。

Objective To explore the expression of neuropeptide Y （NPY） and its receptors in hypothalamus of estrogen-induced rat pituitary adenoma model and investigate their roles in pituitary tumorigenesis. Methods Forty female Wistar rats were induced with estradiol benzoate by peritoneal injection. The expression of NPY and its receptors in hypothalamus was detected by immunohistochemical assay and semi-quantitative reverse transcription polymerase chain reaction （RT-PCR）. Results Chronic treatment with estradiol could result in pituitary adenoma in female Wistar rats. The expression level of NPY and Y1 receptor in the hypothalamus of experimental groups was significantly lower than that in control groups （ P 〈 0.01 ） ,but no significant differences were observed with regard to Y2 receptor gene expression in the hypothalamus between experiment and control groups. Conclusion Chronic treatment with estrogen can result in pituitary adenoma in female Wistar rats. Down-regulation of NPY and its Y1 receptor expression in hypothalamus may be responsible for estrogen-induced pituitary tumorigenesis in rats.