Glucocorticoid actions and metabolism in pregnancy: implications for placental function and fetal cardiovascular activity.
The isoforms of the enzyme 11beta hydroxysteroid dehydrogenase (11betaHSD) are expressed in placental tissue and fetal membranes. The two major isoforms, 11betaHSD-1 and 11betaHSD-2, are compartmentalized discretely, and regulated differentially by steroids (oestrogen, progesterone), activators of cAMP pathway, and nitric oxide. 11BetaHSD-2 appears important in human pregnancy in regulating the amount of maternal cortisol that crosses the placenta to reach the fetal compartment. On the other hand, 11betaHSD-1 may allow the local conversion of biologically inactive cortisone to biologically active cortisol, particularly within chorion trophoblasts. The localization, regulation, and importance of these isozymes are examined.
Sun
K
K
Department of Physiology, University of Toronto, Ontario, Canada.
Yang
K
K
Challis
J R
JR
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000328:Adult; D003346:Corticotropin-Releasing Hormone / Q000502:physiology; D005260:Female; D005318:Fetal Heart / Q000502:physiology*; D005938:Glucocorticoids / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000502:physiology; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D007527:Isoenzymes; D009752:Nutritional Status; D010920:Placenta / Q000201:enzymology / Q000502:physiology*; D011247:Pregnancy / Q000378:metabolism*
D005938:Glucocorticoids; D007527:Isoenzymes; D003346:Corticotropin-Releasing Hormone; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D006854:Hydrocortisone