EFFECT OF RAT’S LIVER ON ACTIVITY OF TESTOSTERONE AND METHYL TESTOSTERONE1

Abstract

The ability of the rat''s liver to inactivate testosterone and methyl testosterone was tested by implanting into various locations pellets of both hormones in such sizes that equivalent amts. were absorbed daily. The wts. of the accessories compared to the castrate level were used as the criteria for effectiveness of the androgens. Both testosterone and methyl testosterone were markedly effective when absorbed directly into the peripheral blood stream from subcut. located pellets. When the pellets were located in the spleen so that the androgens were carried by the portal blood stream directly to the liver, methyl testosterone had some effect, but testosterone was completely ineffective. Testosterone is evidently more efficiently inactivated by the liver than methyl testosterone. The moderate effectiveness of both hormones when absorbed from the intramesenterically located pellets is tentatively explained on the basis of at least partial absorption into the lymph stream, by which route both hormones get into the general circulation without first passing through the liver. The results are discussed in relation to the relative oral efficiency of the 2 hormones.