Innervatiuon of steroid-producing cells in the gonads of fish.

本文对尼罗罗非鱼性腺的神经支配进行了组织化学和超微结构研究。在睾丸中，输出管周围的管壁上分布着许多粗大的神经束。神经元似乎终止于输出管壁的平滑肌细胞表面。细神经束穿过包含生精细胞包囊的小叶之间的间隙。这些神经纤维的末端还与包围小叶的平滑肌细胞和类固醇产生细胞的表面接触。这些观察结果表明，睾丸的神经支配可能不仅控制平滑肌细胞的收缩和舒张，而且还控制类固醇的分泌。在卵巢，粗神经束局限于卵巢动脉和静脉附近的区域，卵巢壁面向肠系膜的一侧。几组轴突从粗神经分支，并终止在附近的类固醇产生细胞的集群分布在卵黄卵母细胞之间的间质区。轴突终末与类固醇产生细胞关系密切。终末含有许多透明小泡、少数致密核小泡和线粒体。此外，在卵黄卵母细胞周围的分泌类固醇的卵泡膜细胞的表面上观察到少数终末。我们的观察类固醇产生细胞的直接神经支配带来光一个可能的新途径，调节类固醇激素的产生在罗非鱼卵巢。

The innervation of the gonads of Oreochromis niloticus examined immunohistochemically and ultrastructurally. In testis, many thick nerve bundles are distributed in the wall surrounding the efferent duct. The neurons appear to terminate at the surface of smooth muscle cells in the efferent duct wall. Thin nerve bundles penetrate the interstices among lobules containing cysts of spermatogenic germ cells. terminal ends of these nerve fibers also make contact with smooth muscle cells enclosing lobules and with the surface of steroid-producing cells. These observations suggest that innervation of the testis may not only control the contracting and relaxing of smooth muscle cells but also control steroid secretion. In ovary, thick nerve bundles were localized in the area near the ovarian artery and vein in the ovarian wall on the side facing the mesentery. Groups of a few axons ramified from the thick nerves and were terminated in the proximity of clusters of steroid-producing cells which are distributed in the interstitial area among yolky oocytes. The axon terminals were in intimate relation with the steroid-producing cells. The terminals contained many clear vesicles, a few dense-cored vesicles and some mitochondria. Moreover, a few terminals were observed on the surface of steroid-producing theca cells surrounding yolky oocytes. Our observations of direct innervation of steroid-producing cells bring to light a possible new avenue for regulation of steroid production in the tilapia ovary.