THE THYROID AND REPRODUCTIVE PERFORMANCE IN THE ADULT MALE GUINEA PIG¹

Abstract

Experiments on the relationship between the thyroid and reproduction in male mammals have been numerous; nevertheless, much uncertainty exists with respect to reproductive performance in hyper-and hypothyroid individuals. Degeneration of the germinal epithelium or decreased spermatogenesis is reported to follow the administration of thyroid substance to rats (Monterosso, 1912; Smelser, 1939a; Cunningham, King and Kessell, 1941). Elsewhere it is reported that spermatogenesis is unaffected (Cameron and Carmichael, 1920; Courrier, 1921; Doderlein, 1928; Cohen, 1935; Richter, 1944) or that any harmful action is transitory (Belawenetz, 1942). Spermatogenic activity and epithelial proliferation in the seminal vesicles are reported to have been stimulated by feeding mice synthetic thyroprotein (Maqsood and Reineke, 1950). The administration of thyroxine stimulated spermatogenesis and improved the semen quality in young rabbits and rams (Maqsood, 1951). An increased reactivity of the testes of the mouse to pituitary gonadotrophins is reported following treatment with thyroxine (Meites and Chandrashaker, 1948),