Macrophage activation enhances the human chorionic gonadotrophin-induced disruption of spermatogenesis in the rat

Abstract

The objective of this study was to examine the role of intertubular macrophages in modifying the response of the rat testis to stimulation by human chorionic gonadotrophin (hCG). The phagocytic activity of macrophages was stimulated by a unilateral intratesticular injection of polystyrene latex beads. Latex beads were engulfed by the resident macrophages and retained within their cytoplasm. Contralateral testes received injection of vehicle alone. A group of control rats was killed 3 days later; other groups received 100 IU hCG s.c. and the morphological and functional responses of the testes were examined 12, 24 and 48 h later. Spermatogenesis was unaffected in control rats, whereas in the testes of all hCG-treated rats leukocytes infiltrated into the intertubular tissue and the seminiferous tubules exhibited focal disruptions of spermatogenesis which were more severe in testes containing activated macrophages. Spermatogenic disruption was dependent upon the stage of the spermatogenic cycle, with the maximum tubule degeneration occurring at or near stages III and IX–XI. However these changes were not a consequence of androgen deprivation, since no consistent correlation was demonstrated between alterations in testosterone levels in testicular interstitial fluid and the accompanying damage to germ cells. It is concluded that hCG alone or in combination with activated macrophages induces an inflammatory-type response of the intertubular tissue and localized degeneration of the seminiferous epithelium. The antispermatogenic effects of hCG may have important implications for in-vivo investigations of Leydig cell function in laboratory animals and for the efficacy of hCG administration used in the clinical treatment of male hypogonadism. Journal of Endocrinology (1989) 121, 285–292