The roles of pregn-5-ene-3 beta, 20 alpha-diol and 20 alpha-hydroxy steroid dehydrogenase in the control of progesterone synthesis preceding parturition and lactogenesis in the rat.

1. The activity of 20alpha-hydroxy steroid dehydrogenase in rat ovarian corpora lutea increased at least 50-fold between 2 days before and 2 days after parturition, and then fell gradually during lactation. The activity of 3beta-hydroxy Delta(5)-steroid dehydrogenase decreased by 50% at parturition but remained constant at other times. 2. The 20alpha… (More)