Investigation of putative androgen-like activity of alpha 2u-globulin in castrated and estrogen-treated male rats.

Abstract

alpha 2u-Globulin, a male sex-dependent protein of the rat, was tested for its ability to produce androgenic or anabolic responses. Castrated rats were injected with alpha 2u-globulin isolated from urine or kidney and the effects on urinary nitrogen excretion, body weight, and weight of ventral prostate, seminal vesicles, and levator ani muscle were studied. alpha 2u-Globulin had no effect but testosterone propionate gave the expected stimulation of nitrogen retention, body growth, and growth of androgen-responsive tissues. alpha 2u-Globulin injected into estrogen-treated male rats (animals with suppressed serum levels of alpha 2u-globulin, gonadotropins, and testosterone) was also found to be without effect on body weight and on the weight of ventral prostate, seminal vesicles, levator ani muscle, and testes. We conclude that the alpha 2u-globulin molecule, by itself, is incapable of producing, directly or indirectly, androgenlike responses.