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 ca pillary gas chromatography, after derivatization of metabolites as O-m ethyl oximes/trimethylsilyl ethers. Evidence was obtained indicating t hat both pathways for testosterone biosynthesis were operating. 5-Andr ostene-3 beta,17 beta-diol was formed in especially high quantities. T wo 16-androstenes, namely 5,16-androstadien-3 beta-ol and 5 alpha-andr ost-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 homogen ates at -10 degrees C for 3 weeks resulted in marked 4- to 6-fold redu ction in the yields of testosterone and of the 5-ene and 4-ene metabol ites from pregnenolone.