STUDIES ON ARTIFICIAL CRYPTORCHIDISM: DEGENERATIVE AND REGENERATIVE CHANGES IN THE GERMINAL EPITHELIUM OF THE RAT TESTIS

Abstract

SUMMARY 1. In the rat bilateral artificial cryptorchidism results in degenerative changes in the seminiferous tubules which are maximal about the 15th day after operation. Up to this stage all germ cells are reduced in number, spermatogonia being least affected and spermatids most. Spermatogonial mitoses and spermatocytial meioses are also inhibited to some extent. 2. Following this initial phase of degeneration there is a partial regeneration, most marked in the case of spermatocytes and total germ cells, which at the 35th day results in the formation of early spermatids. 3. The degree of germ-cell degeneration after 15 days of cryptorchidism is greater than the maximal degeneration after hypophysectomy. It is considered that the increased environmental temperature of the testes may 'block' the action of gonadotrophins on the seminiferous tubules as well as damage the germ cells directly. The occurrence of a certain degree of regeneration may indicate that this 'block' can be overcome to some extent by increased production of pituitary gonadotrophins.