Distribution of Na, K-ATPase in the epididymis and its control by androgen

附睾液具有独特的离子组成，与细胞外液有很大的不同。为了了解附睾离子组成的形成机制，我们研究了Na， k- atp酶在12周龄sd大鼠附睾和人附睾中的定位。采用大鼠肾Na -亚基特异性多克隆抗体进行免疫组化染色，结果显示Na， k - atp酶在大鼠和人附睾上皮各区域主细胞基底外侧膜上均有高水平表达。为了研究雄激素对附睾Na， k - atp酶的作用，采用免疫组化和Western-blotting方法检测Gn RH类似物（化学去势）处理大鼠附睾Na， k - atp酶的表达。虽然去势组和对照组之间Na， k - atp酶的免疫和活性没有差异，但Western-blotting分析显示，去势组附睾头Na， k - atp酶的数量比对照组减少。去势对附睾体和附睾尾Na、k - atp酶含量无明显影响。我们的研究表明，附睾液的离子组成可能是由附睾上皮内的Na， k - atp酶产生的，而附睾头Na， k - atp酶的表达受雄激素控制。

The epididymal fluid has unique composition of ion, which is much different from the extracellular fluid. Toknow the mechanism of the formation of the ion composition in the epididymis, we studied the localization of Na, K-ATPase in 12-week-old Sprague Dawley rat epididymis and human epididymis. Immunohistochemical staining using a polyclonal antibody specific forthe alpha-subunit of rat kidney Na, K-ATPase demon strated that Na, K-ATPase was expressed at high levels on the basolateral membrane of the chief cells in all regions of the rat and human epididymal epithelium.To study the action of androgen on the epididymal Na, K-ATPase, the expression of Na, K-ATPase was evaluated in rats treated with Gn RH analog (chemical castration) using immuno histochemistry and Western-blotting an alysis. Although there was no difference in the immun or eactivity of Na, K-ATPase between the castrated and control groups, the Western-blotting analysis demonstrated that the quantity of Na, K-ATPase in the caput epididymis decreased in the castrated group compared to the control group. Castration showed no effects on the quantity of Na, K-ATPase in the corpus or cauda epididymis.Our study showed that the ion composition of the epididymal fluid was probably created by Na, K-ATPase in the epididymal epithelium and that the expression of Na, K-ATPase in the caput epididymis was controlled by androgen.