16-unsaturated C 19  3-oxo steroids as metabolic intermediates in boar testis.
1. The formation of the two 16-unsaturated alcohols 5alpha-androst-16-en-3alpha-ol and 5alpha-androst-16-en-3beta-ol from [5alpha-(3)H]5alpha-androst-16-en-3-one has been demonstrated in boar testis homogenates. 2. The optimum yield (23%) of the 3alpha-alcohol was obtained in the presence of NADPH, whereas that for the 3beta-alcohol (74%) was obtained when NADH was the added cofactor. 3. The two alcohols were not interconvertible. 4. Prolonged storage of boar testis tissue at -20 degrees C abolished the ability to form all androst-16-enes except androsta-4,16-dien-3-one from [4-(14)C]progesterone. 5. The production of 5alpha-androst-16-en-3-one and the two alcohols from [7alpha-(3)H]androsta-4,16-dien-3-one only occurred when fresh tissue was used, whereas reduction of [5alpha-(3)H]5alpha-androst-16-en-3-one was unaffected by storage of testis at -20 degrees C. 6. NADPH was the preferred cofactor for the reduction of androsta-4,16-dien-3-one. 7. The previously established conversion of androsta-5,16-dien-3beta-ol into androsta-4,16-dien-3-one was shown to be reversible, NADH and NADPH being equally effective cofactors. 8. Pathways of biosynthesis of 5alpha-androst-16-en-3alpha- and 3beta-ols, with the C(19) 3-oxo steroids as intermediates, are presented.
D000736:Androstenes / Q000378:metabolism; D000737:Androstenols / Q000096:biosynthesis / Q000378:metabolism; D000818:Animals; D002247:Carbon Isotopes; D002845:Chromatography; D066298:In Vitro Techniques; D008297:Male; D009243:NAD; D009249:NADP; D011374:Progesterone / Q000378:metabolism; D013552:Swine; D013737:Testis / Q000378:metabolism*; D013997:Time Factors
D000736:Androstenes; D000737:Androstenols; D002247:Carbon Isotopes; D009243:NAD; D011374:Progesterone; D009249:NADP