title: Effects and interactions of oxygen and prostaglandins on the tone of the isolated human umbilical artery.
abstract: Prostaglandin E2 (PGE2) and prostaglandin F2alpha (PGF2alpha) were found to be equipotent contractors of the isolated human umbilical artery (HUA) in the concentration range 0.2-40 mug/ml. Prostaglandin E1 (PGE1) relaxed HUA at 0.1-3.0 mug/ml, whereas at 10-50 mug/ml contraction occurred. PGE2 was significantly more potent at a PO2 of 102 mmHg than at 27, 48 and above 400 mmHg. An increase in PO2 per se (27- greater than 400 mmHg) resulted occasionally in minor increases in the tone of the HUA. Such effects of oxygen had a lag period of 10-15 min. It is suggested that an increased formation of prostaglandins in the umbilical artery at birth is a more likely cause of the closure of the vessel than an increase in PO2.
mesh_terms: D004347:Drug Interactions; D006801:Humans; D009119:Muscle Contraction / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010100:Oxygen / Q000494:pharmacology*; D010313:Partial Pressure; D011458:Prostaglandins E / Q000494:pharmacology*; D011460:Prostaglandins F / Q000494:pharmacology*; D014469:Umbilical Arteries / Q000187:drug effects*
chemical_list: D011458:Prostaglandins E; D011460:Prostaglandins F; D010100:Oxygen