Dehydrogenase and oxoreductase activities of porcine placental 11β-hydroxysteroid dehydrogenase

摘要

Dehydrogenase (cortisol to cortisone) and oxoreductase (cortisone to cortisol) activities of porcine placental 11β-hydroxysteroid dehydrogenase ( 11β-HSD) were measured in tissue fragment cultures on day 75 of gestation. Dehydrogenase activity was over fivefold greater than oxoreductase activity (p u3c .001). There were positive linear associations (p u3c .01) between net dehydrogenase activity (dehydrogenase minus oxoreductase) and fetal weight, fetal length, and placental weight. These data indicate a predominance of placental 11β-HSD dehydrogenase activity at this gestational stage that would insure a net conversion of cortisol to cortisone as it traverses the placenta. The data further suggest that 11β-HSD activities may provide an optimal glucocorticoid environment that is supportive of enhanced fetal and placental growth.