Abstract: | Ultrastructural localization of nucleozidphosphatases (5'-nucleotidase, adenosin triphosphatase (ATPase) and beta-glicerophosphatase) in antral follicles of the guinea-pig ovary has been studied. Certain heterogeneity has been found in distribution of the enzymes: the cells in the follicular tunic possess the greatest 5'-nucleotidase and ATPase activity. When 5'-adenosin monophosphate (5'-AMP) is used as a substrate, the lead phosphate residue is mainly revealed in the external surface of plasmolemma and as "caps" in the margical zone of nucleoplasm. ATPase activity is chiefly observed in nucleoli of granular cells and in those of the external follicular tunic cells. Histochemical reaction with 5'-AMP proceeds most intensively in the lucid tunic and in processes of the granular cells contacting with the oocyte. A possibility is discussed on participation of the metabolic enzymes, that localize in these structures, in the mechanisms controlling the oocyte maturation. |