17-Hydroxylase: an evaluation of the present view of its catalytic role in steroidogenesis.

This survey analyses the evidence that has led to the belief that the catalytic role of 17-hydroxylase in the biosynthesis of cortisol, estradiol, testosterone and dehydroepiandrosterone is confined to two chemical reactions: pregnenolone-->17-hydroxypregnenolone-->dehydroepiandrosterone. This analysis suggests that the evidence supporting this view is not compelling enough to accept it unquestioningly. Different interpretations of the data can suggest other catalytic roles for 17-hydroxylase that are worthy of consideration. One such alternative is proposed.