Androgens and particularly, a Metabolite of Testosterone, 5α-Dihydrotestosterone
1974; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-408-70539-4.50009-8
AutoresR.J.B. King, W. Ian P. Mainwaring,
Tópico(s)Adipose Tissue and Metabolism
ResumoThis chapter discusses androgens and particularly, a metabolite of testosterone, 5α-dihydrotestosterone. There have been no indications that testosterone is bound to specific, high-affinity binding sites in lymphocytes. Testosterone has no influence on the metabolic processes in lymphocytes isolated from rat thymus gland, and does not compete for the glucocorticoid receptor sites present in these cells. Testosterone and particularly its 5β-reduced metabolites of the 5β-androstane series of steroids stimulate erythropoiesis in fetal avian liver and blastoderm, human bone marrow, and unspecified sites of red cell formation, bone marrow, in normal and polycythemic mice. Formerly, the effects of testosterone on heme synthesis had been attributed to an enhanced production and release of erythropoietin. As the 5β-reduced metabolites have a pronounced effect on heme synthesis, the demonstration of the formation of these metabolites in chick blastoderm, prior to the induction of heme synthesis, is a particularly important finding. The principal androgen, testosterone, is secreted by the testis of sexually mature male animals in considerable quantities, and additional but relatively minor amounts of androgens enter the systemic circulation from the adrenals.
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