Abstract
The localization of lipids and the activities of nonspecific esterase, aryl sulfatase and acid phosphatase were studied in different stages of spermatogenesis in rats. In addition, the distribution of acid phosphatase activity was demonstrated electron histochemically. The spermatogenetic cycle was divided into two phases—corresponding to the first and the last four stages of Roosen-Runge-Giesel (RG) classification. Spermatids in the first phase contained abundant endoplasmic reticulum with rosette formation and well developed Golgi apparatus with numerous vesicles. They displayed high activity of hydrolytic enzymes but contained no appreciable amount of lipids. The Sertoli cells contained large lipid granules but showed minimal enzyme activity. During the second phase reduction of the cytoplasm of spermatids with fragmentation of the endoplasmic reticulum and Golgi lamellae, accumulation of lipids, aggregation of ribonucleo-protein particles, formation of residual bodies and marked decrease of enzyme activity were seen. The Sertoli cells contained large mitochondria, well developed endoplasmic reticulum and numerous dense bodies and revealed high activities of hydrolytic enzymes and rapid depletion of lipids. These ultrastructural and histochemical findings suggested an interaction between the Sertoli cells and the developing spermatids which probably contributed to the regulation of spermatogenesis.