The Physiology of the Testis and Application of Male Sex Hormone

Abstract

The beginning of spermato-genesis appears to depend upon the type of pituitary function. Adm. of pituitary tissue, or extracts of it, or other gonadotrophic agents of similar activity induces sperm production earlier than normal in many lower vertebrates and some mammals. In rats and monkeys, however, sperm production has not been hastened. The type of spermatogenesis (whether continuous or of a strictly seasonal variety) appears to depend upon pituitary activity. Adm. of gonadotrophic substances stimulates activity of the testicle of the common ground squirrel of the Chicago area (Citellus tri-decemlineatus) during the long quiescent period. The activity of the pituitary itself depends upon many factors. For instance, exposure of certain animals to light results in excessive pituitary activity with a subsequent increase in testicle activity. Nutritional factors are important modifiers of testicular activity but the indications are that this influence may also involve pituitary activity. For instance, lack of vit-B complex in the diet, as well as inanition, leads to testis injury. Adm. of pituitary substance restores testicle function. Other food requirements have been demonstrated as essential for complete spermatogenesis. Vit. E is the most important substance of this group. Among other influences on spermatogenesis the effects of heat are important. The mammalian generative tissues are particularly sensitive to heat. This has some bearing on clinical problems since therapeutic fever treatments or febrile states may lead to a marked drop in sperm count or to testis degeneration. The active compound from testis is testosterone. Clinically, it has been used in the treatment of eunuchoidal young men without active testis due to faulty development, secondary atrophy or surgical castration. Claims for far-reaching beneficial results in the treatment of prostatic hypertrophy have not been substantiated. Nor have hopes materialized that [male] hormone might prove to be a valuable testicular stimulant in cases of alleged hypogonadism, or that it might find a place in the handling of [male] sterility, or impotence.