title: Corticosteroids, ornithine decarboxylase activity and the incorporation of leucine, uridine, and thymidine into mouse placenta.
abstract: The in vitro incorporation into mouse placenta of [14C]leucine, [3H]uridine, and [3H]thymidine fell between gestational days 14 and 19 by 61, 30 and 72%, respectively; ornithine decarboxylase activity fell by 75%. Injection of dexamethasone resulted on day 14 in values normally found between days 15 and 18. These changes coincided with rising activity in fetal liver of the enzyme 11 beta-hydroxysteroid:NADP oxidoreductase, which reduced the abundant 11-dehydrocorticosterone to the active hormone, corticosterone. These events appear to be part of a spectrum of effects produced by corticosteroids on fetal growth at this time, probably mediated primarily by fetal liver.
mesh_terms: D000367:Age Factors; D000818:Animals; D002262:Carboxy-Lyases / Q000378:metabolism*; D003345:Corticosterone / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005333:Fetus / Q000032:analysis; D007930:Leucine / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D008297:Male; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000032:analysis; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism*; D014529:Uridine / Q000378:metabolism*
chemical_list: D003907:Dexamethasone; D009247:NADH, NADPH Oxidoreductases; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D007930:Leucine; D013936:Thymidine; D003345:Corticosterone; D014529:Uridine