Characterization of a delta 5-3 beta-hydroxy pathway of testosterone synthesis in the human spermatozoa.
Sonicated specimens of freshly ejaculated sperm from two groups of husbands (n = 6, age 32-38 years; n = 7, age 27-38 years) of infertile couples in the range of sperm concentration between 237.5 and 568.5; 131.1 and 256.7 millions per ejaculate were separately incubated with [7n-3H]pregnenolone and [1,2,6,7(-3)H]dehydroepiandrosterone. Using the reverse-isotope dilution technique [3H]dehydroepiandrosterone and [3H]testosterone formed from the respective substrates were isolated and characterized, yielding 1.2 x 10(-2) to 4.6 x 10(-20/0) and 7.1 x 10(-2) to 2.5 x 10(-10/0)/ Such metabolites were not evident in the controls. These results provide evidence for metabolic transformation of pregnenolone to testosterone via the delta 5-3 beta-hydroxy route.
Gunasegaram
R
R
Department of Obstetrics & Gynaecology, National University Hospital, Singapore.
Loganath
A
A
Peh
K L
KL
Chew
P C
PC
Ratnam
S S
SS
Arulkumaran
S
S
D000328:Adult; D003687:Dehydroepiandrosterone / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D011284:Pregnenolone / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis*
D013739:Testosterone; D003687:Dehydroepiandrosterone; D011284:Pregnenolone