Plasma Testosterone Levels in Vasectomized Rats

Department of Biological Sciences, State University of New York at Binghamton, Binghamton, New York 13901, U.S.A. (Received 25th January 1975) Conflicting reports based upon the indirect effects of vasectomy on plasma testosterone levels of the rat have recently been published. Sackler et al. (1973) reported decreased urinary ketosteroids and testicular weight after vasectomy of immature rats. Thakur et al. (1972) studied the fructose levels in the coagulating gland and maltase activity in the dorsolateral prostate gland in the mature rat after vasectomy and concluded that testosterone secretion increased. McGlynn & Erpino (1974) found no change in sexual behaviour after vasectomy and concluded that there was no change in androgen production, as did Smith (1962) who reported a normal spermatogenic cycle in the vasectomized rat and Flickinger (1972) who found that vasectomy did not alter the ultrastructure of the rat testis. Direct measurements of plasma testosterone levels in men 3 months