Prolongation and Potentiation of Anabolic and Androgenic Effects of Steroids: Testosterone and Methylandrostenediol.

Abstract

The authors studied the delaying and potentiating effects of aluminum phosphate on the androgenic and anabolic activity of testos-terone and methylandrostenediol. A long carbon-chain ester of testosterone, testosterone cyclopentylpropionate (TCP), was similarly studied. Androgenic activity was measured by the weight of the seminal vesicles of the castrate immature rat. Anabolic activity was estimated by the weight of the levator ani muscle of the same animals. TCP showed the greatest anabolic and androgenic efficacy of the agents studied. Its increased efficacy cannot be explained on the basis of delayed absorption, suggesting a delayed inactivation of this ester. Aluminum phosphate delayed the onset and decline of the anabolic and androgenic actions of testosterone in aqueous suspensions, but produced no such effect upon the actions of methylandrostenediol.