TESTIS-PITUITARY INTERRELATIONSHIP: THE RELATIVE INABILITY OF TESTOSTERONE TO REDUCE URINARY GONADOTROPIN IN EUNUCHOID MEN

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Abstract
THE following is a report of studies made to compare the effectiveness of testosterone in therapeutic and greater than therapeutic doses with the effectiveness of estrogens, in lowering urinary gonadotropin levels. The subjects were men with severe eunuchoidism. It is well recognized that high levels of follicle-stimulating hormone are present in the urine of men with testicular deficiency. In the patients studied here this feature has been considered an index of anterior pituitary hyperfunction. Experimentally testosterone has proved capable of preventing histologic as well as physiologic alterations in the pituitary gland of castrate male animals (1). Large doses have usually been employed for such studies. Some clinical evidence has been accumulated which indicates that similar results may, under certain circumstances, be demonstrated in man (2, 3). The relative inefficiency of testosterone for inhibition of pituitary activity has been shown before. For example Hertz and Meyer demonstrated that in parabiotic rats doses as small as 0.2 gamma of estrone daily inhibit the male pituitary gland as efficiently as 15 gamma of testosterone propionate (4, 5). They also demonstrated that larger doses of androgenic substances are necessary to suppress the pituitary gland in male-female pairs than in female-female pairs. They concluded that the pituitary of the male rat was more difficult to suppress than that of the female. The ratio of the two hormones producing comparable effects in parabiotic animals is thus approximately 1 to 75. Catchpole, Hamilton, and Hubert (6) have reported a decrease of the urinary gonadotropin excretion to low levels in man following administration of testosterone propionate.