Abstract
SUMMARY: A pool of 500 ml. normal equine follicular fluid was examined for the presence of Δ5 3β-hydroxy steroids. Neither pregnenolone nor 17α-hydroxypregnenolone could be detected (< 1 μg./l.), but there appeared to be a small amount of dehydroepiandrosterone (DHA) present (8 μg./l.). These findings suggest that in the Graafian follicle of the mare the conversion of pregnenolone to progesterone normally proceeds fairly rapidly, and the pregnenolone → 17α-hydroxypregnenolone → DHA → androstenedione pathway is probably of minor importance.