17α, 20α‐dihydroxy‐4‐pregnen‐3‐one, not its 20β isomer, is produced from 17α‐hydroxyprogesterone by spermatozoa of secondary male groupers (Epinephelus tauvina) derived from females implanted with 17α‐methyltestosterone

Abstract

Sperm of secondary male groupers (Epinephelus tauuina), derived from females implanted with 17a-methyltestosterone (MTj, were incubated with [3H117-hydroxyprogesterone for 2 hr. The medium was extracted and analyzed by high performance liquid chromatography (HPLC). A single major metabolite with relative retention time corresponding to 17a,20a-dihydroxy-4-pregnen-3-one (17,201~-P) was produced by the sperm. The metabolite was isopolar with 17,201~-P on thin layer chromatography (TLCj. The presumptive identity of the metabolite was confirmed to be 17,20a-P when the metabolite was oxidised by periodic acid and the derivative recrystallized with authentic androstenedione to specific constant activity. This experiment indicates that grouper sperm possess the enzyme, 20a-hydroxysteroid dehydrogenase (20a-HSD1, and suggests that 17,20a-P may play a role in grouper reproduction. 0 1995 wiley-~iss, Inc.

The role of the maturation‐inducing steroid, 17,20β‐dihydroxypregn‐4‐en‐3‐one, in male fishes: a review

“…It seems, so far, to be only salmonid spermatozoa that predominantly convert 17‐P to 17,20β‐P (Sakai et al , 1989 b ; Ebrahimi et al , 1996). In other species, spermatozoa incubated with 17‐P produce either mainly 17,20α‐P including: P. platessa (Canario & Scott, 1990), greasy grouper Epinephelus tauvina (Forsskål) (Tan et al , 1995), C. carpio (Asahina et al , 1990; Barry et al , 1990 b ) and C. auratus (Asahina et al , 1993; Ebrahimi et al , 1996). There are other species in which the spermatozoa convert 17‐P to a range of steroids including: roughly equal amounts of 17,20α‐P and 17,20β‐P in flounder Platichthys flesus (L.) (Asahina et al , 1994), a range of 5β‐pregnanes, 17,20α‐P and a trace of 17,20β‐P in male E. coioides (Lee et al , 1998), and a mixture of 17,20β‐P, 17,20α‐P, 11‐KT and androstenedione in R. rutilus , with, however, exclusive production of 17,20α‐P in the presence of excess 17‐P (Ebrahimi et al , 1995).…”