title: Effects of unilateral orchidectomy on rat epididymal delta 4-5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase.
abstract: The effects of unilateral orchidectomy on the adult rat epidiymal testosterone metabolizing enzymes, delta 4-5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase, are investigated. Five weeks following unilateral orchidectomy, it is found that the activity of 3 alpha-hydroxysteroid dehydrogenase per organ is not altered, whereas delta 4-5 alpha-reductase activity decreased by more than 80% on the side of the orchidectomy. Neither accessory sex tissue weights, ventral prostate and seminal vesicles, nor the concentration of circulating testosterone, luteinizing hormone, follicle-stimulating hormone, or prolactin is altered by unilateral orchidectomy. These data indicate that (1) epididymal 3 alpha-hydroxysteroid dehydrogenase activity can be maintained by circulating androgens and that (2) the major factor regulating delta 4-5 alpha-reductase activity is not a substance secreted by the testes into the peripheral circulation. It is suggested that a substance directly secreted into the epididymis by the testis regulates epididymal delta 4-5 alpha-reductase activity.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism*; D000818:Animals; D002369:Castration; D004822:Epididymis / Q000201:enzymology*; D012739:Gonadal Steroid Hormones / Q000097:blood; D008297:Male; D009929:Organ Size; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D012669:Seminal Vesicles / Q000201:enzymology*; D013087:Spermatids / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D012739:Gonadal Steroid Hormones; D010088:Oxidoreductases; D015096:3-Hydroxysteroid Dehydrogenases; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase