The biosynthesis of androst-16-enes in boar testis tissue

• Published in: Biochemical journal 1970-04, Vol.117 (3), p.533-538
• Main Authors: Katkov, T, Gower, D B
• Format: Article
• Language: English
• Subjects: 17-alpha-Hydroxypregnenolone - metabolism; Adenosine Triphosphate - metabolism; Androstanes - biosynthesis; Animals; Carbon Isotopes; Chromatography, Thin Layer; In Vitro Techniques; Male; NADP - metabolism; Pregnenolone - metabolism; Swine; Testis - metabolism; Testosterone - metabolism; Tritium
• ISSN: 0264-6021; 0306-3283; 1470-8728
• DOI: 10.1042/bj1170533

1. The metabolism of [4-(14)C]pregnenolone to androst-16-enes has been studied in short-term incubations of boar testis tissue. With fresh tissue androsta-5,16-dien-3beta-ol (8%) and 5alpha-androst-16-en-3beta-ol (2%) were formed. Tissue that had been stored at -20 degrees C was still capable of metabolizing pregnenolone to androsta-5,16-dien-3beta-ol. 2. NADPH was essential for the formation of androsta-5,16-dien-3beta-ol from pregnenolone; NADH had less activity and ATP was not necessary for the reaction. 3. [4-(14)C]Androsta-5,16-dien-3beta-ol, prepared biosynthetically from [4-(14)C]pregnenolone, was shown to be converted by boar testis preparations into androsta-4,16-dien-3-one (31%) if NAD(+) was present or into 5alpha-androst-16-en-3beta-ol (4%) if NADPH was present. 4. 17alpha-Hydroxyandrost-4-en-3-one and 3beta,17alpha-dihydroxypregn-5-en-20-one were considered as possible precursors for androst-16-ene formation, but both were shown to be ineffective. 5. No radioactivity was incorporated into androst-5-en-3beta-ol used to trap any corresponding (14)C-labelled compound formed from [4-(14)C]pregnenolone.