Possibility of direct transportation of testicular hormone to some target organs located close to the testicle in the postnatal rat and its physiologic significance.

Abstract

THE seminal vesicles and prostates of rats are highly sensitive to androgen. In the hypophysectomized animal the recovery and growth of the regressing organs can be easily obtained by the administration of minute doses of androgen. The maintenance (Cutuly et al., 1938) or reinitiation (Nelson, 1940) of spermatogenesis and the scrotal growth, however, were not accomplished, unless animals were treated with much larger amounts of androgen. In the study of the course of sexual maturation some paradoxical facts came to attract our attention. In our colony of rats, the significant growth of the accessory sexual organs (seminal vesicles and prostates) was never observed until about 60 days of age, while spermiogenesis, descent of testis and epididymal growth began to take place almost simultaneously at the 30–40th day of age (Suzuki, 1950a,b, 1951, 1952a,b, 1954a,b.). Why do the proper accessories fail to start their significant growth at this earlier stage of the maturation process, though these organs,