A COMPARISON OF MYOTROPHIC AND ANDROGENIC ACTIVITIES OF TESTOSTERONE PROPIONATE WITH 19-NORTESTOSTERONE AND ITS ESTERS1

Abstract

Investigation of the preferential myotropic activity of oil solutions of 19-nortestosterone and 3 esters of 19-nortestosterone on the basis of levator ani weight and seminal vesicle weight was reported. 19-nortestosterone was found to have more than one-half the myotropic potency of testosterone propionate and less than one-tenth the androgenic potency. The trimethylacetate ester of 19-nortestosterone exhibited very low androgenic activity at all doses tested and relatively high myotropic activity. The propionate ester exerts a myotropic activity more than twice that obtained with TP and has an androgenic potency less than one-half that of TP. The cyclopentylpropionate ester of 19-nortestosterone has a myotropic action approximately twice that of TP, but only about one-fifth the androgenic properties of TP, factors which produce a high myotropic: androgenic ratio and high absolute potency.