How androgens exert their anabolic effects. Interaction of testosterone and growth hormone at the hepatic level.

Observations from previous studies suggest that the full action of GH requires the presence of male hormones like Testosterone (T). We will test the hypothesis that T enhances GH effect acting on the liver. We will compare the body protein production after delivering T exclusively to the liver (capsules) and to peripheral tissues (patch). The first phase (11 weeks, 6 visits) aims to find the T dose which exposes the liver to normal/physiological T levels. The second phase (16 weeks, 5 visits) will compare the effect of delivering T to the liver and to peripheral tissues.