QUANTITATIVE STUDY OF SPERMATOGENESIS IN THE HYPOPHYSECTOMIZED RAT

Abstract

THE rapid regression of the seminiferous tubules of the rat following hypophysectomy has been repeatedly observed since the original investigation of Smith (1930). This author as well as Crooke and Gilmour (1938), Tonutti (1943), and others reported that spermatids disappeared from the regressed tubules of hypophysectomized rats but that spermatogonia and spermatocytes as well as Sertoli cells persisted. Smith (1930) even noted the presence of spermatogonial mitoses months after hypophysectomy. Except in the recent work of Mess (1952) no attempt had been made to assess quantitatively the precise changes taking place during spermatogenesis and resulting in a partial rather than total regression of seminiferous tubulues. In fact, until quite recently even the normal processes of spermatogenesis had not been investigated by means of quantitative techniques and the mode of proliferation and renewal of spermatogonia had remained obscure. The recent use of such techniques allowed a precise study of the evolution of the cellular population in the seminiferous epithelium (Roosen-Runge and Giesel, 1950;