title: Metabolism of [17-2H]pregnenolone into 5-[17 beta-2H, 17 alpha-18O]androstene-3 beta, 17 alpha-diol and other products by incubation with the microsomal fraction of boar testis under 18O2 atmosphere.
abstract: [17-2H]Pregnenolone was incubated with the microsomal fraction of boar testis under an 18O2 atmosphere. The metabolites were analyzed by gas chromatography-mass spectrometry, and the following six metabolites labeled with 2H or 18O (or both) were identified: 17 alpha-[17-18O]hydroxypregnenolone, [17-18O]dehydroepiandrosterone, 5-[17-18O]androstene-3 beta, 17 beta-diol, 16 alpha-[16-18O]hydroxy[17-2H]pregnenolone, 5-[17 beta-2H, 17-18O]androstene-3 beta,17 alpha-diol, and 5,16-[17-2H]androstadien-3 beta-ol. The time course of the formation of these metabolites from pregnenolone was also studied using 14C-labeled substrate. The results obtained from these experiments suggest that the first three metabolites were synthesized by a well-documented pathway--pregnenolone yields 17 alpha-hydroxypregnenolone yields dehydroepiandrosterone yields 5-androstene-3 beta,17 beta-diol--, and that 16 alpha-hydroxypregnenolone, 5-androstene-3 beta,17 alpha-diol and 5,16-androstadien-3 beta-ol were synthesized from [17-2H]pregnenolone with retention of 17-2H.
mesh_terms: D006907:17-alpha-Hydroxypregnenolone / Q000032:analysis; D000730:Androstadienes / Q000032:analysis; D015114:Androstenediol / Q000096:biosynthesis*; D000734:Androstenediols / Q000096:biosynthesis*; D000818:Animals; D003687:Dehydroepiandrosterone / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D008297:Male; D008861:Microsomes / Q000378:metabolism*; D010103:Oxygen Isotopes; D011284:Pregnenolone / Q000378:metabolism*; D013552:Swine; D013737:Testis / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000730:Androstadienes; D000734:Androstenediols; D010103:Oxygen Isotopes; D006907:17-alpha-Hydroxypregnenolone; D003687:Dehydroepiandrosterone; D011284:Pregnenolone; D015114:Androstenediol