Effects of pharmacologic agents on umbilical blood flow in fetal lambs in utero.
We studied the effects of pharmacologic agents on umbilical blood flow and umbilical-placental vascular resistance in 18 fetal lambs in utero. Three groups of drugs were identified: the first had no effect on umbilical blood flow or umbilical-placental vascular resistance; the second altered umbilical blood flow secondary to changes in heart rate and placental perfusion pressure, but did not change umbilical-placental vascular resistance; the third decreased umbilical blood flow and increased umbilical-placental vascular resistance. The studies suggest mechanisms by which umbilical blood flow is regulated in the fetal lamb.
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001920:Bradykinin / Q000494:pharmacology; D002395:Catecholamines / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D005260:Female; D005318:Fetal Heart / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology; D008954:Models, Biological; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D011453:Prostaglandins / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D012756:Sheep; D014043:Tolazoline / Q000494:pharmacology; D014470:Umbilical Cord / Q000098:blood supply*; D014655:Vascular Resistance / Q000187:drug effects
D002395:Catecholamines; D011453:Prostaglandins; D000804:Angiotensin II; D012701:Serotonin; D006632:Histamine; D014043:Tolazoline; D000109:Acetylcholine; D001920:Bradykinin