促性腺激素释放激素在不同品种母牛垂体中的免疫组化定位

为了掌握促性腺激素释放激素（GnRH）及其受体在不同品种母牛垂体中的变化规律,采用免疫组化SP染色法分别对广西沼泽型水牛、摩拉杂交水牛、荷斯坦奶牛、广西本地黄牛垂体中GnRH的分布表达进行对比研究。结果表明,不同品种母牛垂体中均发现有呈棕黄色或黄褐色的GnRH阳性物质存在,经Image-Pro Plus 6.0软件统计发现,摩拉杂交母水牛的GnRH免疫阳性细胞较其他3个品种的大（P〈0.05）,而平均光密度值介于荷斯坦母奶牛和广西本地母黄牛之间（P〉0.05）。在神经垂体中仅发现GnRH免疫阳性纤维,而未发现GnRH免疫阳性细胞;在腺垂体远侧部的细胞均呈GnRH免疫反应阳性,阳性物质主要分布在腺垂体远侧部嫌色细胞和嗜色细胞胞质内。说明GnRH对腺垂体激素分泌的调节可能是直接通过神经调节,而神经垂体可能只是GnRH调节过程的通路。

Immuno-histochemical localization of gonadotropin-releasing hormone in pituitary gland of different cow varieties

The present experiment was conducted to investigate the changes in gonadotropin-releasing hormone（GnRH） in pituitary gland of different cow varieties.The distribution of GnRH in pituitary gland was compared in Guangxi native swamp female buffalo,Murrah hybrid buffalo,Holstein cow and Guangxi native female yellow cattle using immunohistochemical staining.The results showed that claybank or fulvous GnRH-positive productions were found in bovine pituitary gland of different cow varieties.Statistical analysis showed that the GnRH-positive cells in Murrah hybrid buffalo varieties were significantly larger there than those in other three cow varieties（P〈0.05）,while the average optical density values were found similar between Holstein cow and Guangxi native female yellow cattle（P〉 0.05）.There were only existing immune GnRH-positive fibers in neurohypophysis,but without GnRH-positive cells.The cells in pars distalis hypophyseos showed GnRH-positive reaction,and positive productions were mainly found in cytoplasm of chromophobe and chromophilic cell.These results indicated that the secretion of pituitary hormone directly depends on neuroregulation of GnRH and neurohypophysis may help in the process of GnRH regulation.