Pathway of testosterone biosynthesis in the testis of the marmoset Saguinus oedipus.
These studies were undertaken to determine the principal pathway of androgen biosynthesis by the testis of the marmoset Saguinus oedipus. Testicular fragments (25 mg) were incubated at 37 degrees C in Krebs-Ringer bicarbonate buffer, pH 7.4, containing pregnenolone-7-3H (3beta-hydroxy-5-pregnen-20-one) or progesterone-7-3H. Duplicate fragments were incubated with each substrate for 30 min, one hr, three hr, or five hr, for a total of 16 separate incubations. Metabolites were separated by paper and thin-layer chromatography, with identity established by recrystallization to constant specific activities and 3H/14C ratios. Pregnenolone was readily metabolized to progesterone, 17alpha-hydroxyprogesterone, androstenedione (4-androstene-3, 17-dione) and testosterone. Progesterone was converted to 17alpha-hydroxyprogesterone, androstenedione and testosterone. 17alpha-hydroxyprogesterone was the predominant metabolite obtained from both substrates at one, three and five hrs of incubation. Neither 17alpha-hydroxypregnenolone (3beta-17-dihydroxy-5-pregnen-20-one) nor dehydroepiandrosterone (3beta-hydroxy-5-androsten-17-one) was detected in the incubates. These data suggest a predominant delta4 pathway with accumulation of 17alpha-hydroxyprogesterone in the testis of this primate specie.
D000818:Animals; D002143:Callitrichinae / Q000378:metabolism*; D000882:Haplorhini; D066298:In Vitro Techniques; D008297:Male; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis*
D013739:Testosterone; D011374:Progesterone; D011284:Pregnenolone