Identification of a unique Sertoli cell steroid as 3-alpha-hydroxy-4-pregnen-20-one (3 alpha-dihydroprogesterone: 3...

An allylic steroid produced from progesterone by rat Sertoli cells and which does not appear to have been described previously as a product of gonadal or adrenal tissues has been isolated and identified as 3 alpha-hydroxy-4-pregnen-20-one (3 alpha-dihydroprogesterone; 3 alpha-DHP). 3 alpha-DHP appears to be a reactive molecule which is easily oxidized or dehydrated and its identification was possible by a combination of microchemical procedures, derivative formation, specific enzyme reaction, TLC, GC, HPLC, spectrophotometry and mass spectrometry. The biological functions of this Sertoli cell steroid are not known, but it is suggested that 3 alpha-DHP is more than a metabolic waste product because (a) its production rate varies with age and is highest at the onset of meiosis, and (b) there appear to be specific receptors for it in the testis.