title: Androstenedione metabolism by human lymphocytes.
abstract: Intact human lymphocytes were incubated with tritium-labeled androstenedione; after extraction and appropriate chromatographic separation, followed by crystallization to constant tritium to carbon-14 ratio to establish radiochemical homogeneity, the following metabolites were identified: testosterone, 5 alpha-androstane-3,17-dione, 5 alpha-dihydrotestosterone, androsterone and isoandrosterone. Neither estrogen nor 5 beta-reduced metabolites were found as products. The major androstenedione metabolizing activities in human lymphocytes were 5 alpha-reductase and 17 beta-hydroxysteroid oxidoreductase; in addition, 3 alpha-and 3 beta-hydroxysteroid oxidoreductase activities also were present in these cells. The rates of metabolite formation were linear with incubation time up to 4 h, and with cell number up to 2 x 10(7) lymphocytes per ml for the 5 alpha-reduced products and up to 1.6 x 10(7) lymphocytes per ml for testosterone. These findings are suggestive that, in the human, lymphocytes are a potential site of peripheral metabolism of androstenedione to potent adnrogens.
mesh_terms: D000735:Androstenedione / Q000097:blood*; D000738:Androsterone / Q000097:blood; D013196:Dihydrotestosterone / Q000097:blood; D005043:Etiocholanolone / Q000031:analogs & derivatives / Q000097:blood; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008214:Lymphocytes / Q000378:metabolism*; D013739:Testosterone / Q000097:blood; D013997:Time Factors
chemical_list: D013196:Dihydrotestosterone; D013739:Testosterone; D000735:Androstenedione; C006576:androstane-3,17-dione; D005043:Etiocholanolone; D000738:Androsterone