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.
Department of Physiology, University of Toronto, Ontario, Canada.
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Sun
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Yang
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Challis
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