Immunohistochemical localization of taurine in the male reproductive organs of the rat

The amino acid taurine has been implicated in several aspects of reproducti ve system physiology. However, its localization in these organs has not bee n previously analyzed. The aim of this study was to characterize its distri bution in male rat reproductive organs by immunohistochemical methods. Taur ine was localized in the smooth muscle cells of the tissues studied and in the skeletal fibers of the cremaster muscle. In the testis, taurine was fou nd in Leydig cells, vascular endothelial cells, and other interstitial cell s. No immunoreactivity was observed in the cells of the seminiferous tubule s, either in germ cells at all spermatogenic stages or in Sertoli cells. Ho wever, peritubular myoid cells were immunostained. Most epithelial cells of the efferent ducts were immunolabeled, whereas the epithelial cells of the rete testis (extratesticular segments), epididymis (caput, corpus, and cau da regions), and ductus deferens were unstained. However, most epithelial c ells from the intratesticular segments of the rete were immunopositive. Som e cells identified as intraepithelial macrophages and lymphocytes, apical c ells, and narrow cells were intensely immunolabeled. Regional differences i n the distribution of these cell types along the ducts studied were also no ted. The possible functional roles for taurine in these cells are discussed .