Effects of in vivo corticosterone treatment on the in vitro metabolism of testosterone in the comb and brain of the young male chicken

Male chickens kept in constant light were injected from their second to their 12th day of life daily either with 2.5 mg of corticosterone or with a control solution. In both groups of birds, the in vivo metabolism of labeled testosterone by the comb and by brain tissues (hyperstriatum, hypothalamus, pituitary gland) was then studied. The experimental treatment blocked the growth of the comb observed in control birds. In this tissue, it also reduced the production from testosterone of 5α-dihydrotestosterone and of 5α-androstane-3α,17β-diol, but it increased the production of 5β-androstane-3α,17β-diol. These modifications did not appear in any brain tissue; they were not accompanied by changes either of LH or of testosterone circulating levels or of the testes' weights.