Ontogeny of steroid metabolizing enzymes in rat oligodendrocytes

Rat oligodendroglial cells were isolated from newborn and developing brains and used immediately after, for quantification of steroid metabolizing act ivities. Oligodendrocytes (O1) and their progenitor cells were incubated wi th [C-14] testosterone, [C-14] progesterone, [C-14] pregnenolone or [C-14] dehydroepiandrosterone (DHEA). Oligodendrocytes and their progenitor cells expressed different steroid metabolizing enzymes. The main activities were 5 alpha reduction of testosterone and progesterone and 3 beta hydroxy stero id dehydrogenase-isomerase which transformed pregnenolone into progesterone and DHEA into Delta4 androstenedione. 5 alpha reductase activity increased in male and female rats in parallel with testosterone or progesterone. Con trary to this, 3 beta hydroxysteroid dehydrogenase-isomerase activity was f ound to be high in the young rat and to decrease when testosterone and prog esterone plasma concentration increased. (C) 2001 Elsevier Science Ltd. All rights reserved.