Pregnenolone metabolism in testicular homogenates of macaques (Macaca fascicularis): some effects of relaxin and freezing.
The metabolism of varying quantities of pregnenolone has been studied in nuclei-free homogenates from Macaca fascicularis testes by using capillary gas chromatography, after derivatization of metabolites as O-methyl oximes/trimethylsilyl ethers. Evidence was obtained indicating that both pathways for testosterone biosynthesis were operating. 5-Androstene-3 beta, 17 beta-diol was formed in especially high quantities. Two 16-androstenes, namely 5,16-androstadien-3 beta-ol and 5 alpha-androst-16-en-3 beta-ol, were also quantitatively important as metabolites. Co-incubation of stored homogenates with relaxin resulted in 80-100% reduction of the formation of all metabolites quantified except for 5 alpha-androst-16-en-3-one, which was stimulated. Freezing the homogenates at -10 degrees C for 3 weeks resulted in marked 4- to 6-fold reduction in the yields of testosterone and of the 5-ene and 4-ene metabolites from pregnenolone.
Kwan
T K
TK
Department of Biochemistry, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Poh
C H
CH
Perumal
R
R
Gower
D B
DB
D015113:Androstane-3,17-diol / Q000378:metabolism; D000737:Androstenols / Q000378:metabolism; D000818:Animals; D002849:Chromatography, Gas; D005615:Freezing; D008252:Macaca fascicularis; D008297:Male; D011284:Pregnenolone / Q000378:metabolism*; D012065:Relaxin / Q000494:pharmacology*; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism
D000737:Androstenols; C000152:androsta-5,16-dien-3 beta-ol; D015113:Androstane-3,17-diol; D013739:Testosterone; C026828:5 alpha-androst-16-en-3 beta-ol; D011284:Pregnenolone; D012065:Relaxin