Hormonal Regulation of Uridine Diphosphatase during Spermatogenesis in the Rat1

Abstract

Uridine diphosphatase, a protein marker of internal cytoplasmic membranes, and 5'–nucleotidase, a protein marker of plasma membranes, have been studied in terms of their SA and cytochemical localization during spermatogenesis in the rat. The plasma membranes of all the germinal epithelial cells stained for 5'–nucleotidase activity. The SA of this enzyme increased markedly during the formation of spermatogonia, and was unaltered by hypophysectomy or injections of testosterone or pituitary gonadotropins. The SA of UDPase increased markedly with the formation of spermatogonia and spermatocytes (up to 26 days of age), and then decreased sharply with the formation of spermatids, in which cells the enzyme was not detectable by cytochemical staining techniques. Hypophysectomy of the adult rat (58–60 days) induced a loss of spermatids and a rapid increase of the specific activity of UDPase to levels characteristic of the 26–day—old rat. Treatment of hypophysectomized rats with LH and FSH or with testosterone induced the normal pattern of decrease in UDPase concentration with spermatid maturation. UDPase serves as a marker protein for internal cytoplasmic membrane formation in spermatogonia and spermatocytes, and its absence from developing spermatids represents a specific hormone—dependent biochemical transition during spermatogenesis. (Endocrinology91:415, 1972)