Effect of parasympathetic and beta-adrenergic blockade on the umbilical circulation in the unanesthetized fetal sheep.
Parasympathetic and beta-adrenergic blocking agents were administered to near term chronically instrumented sheep. Parasympathetic blockade resulted in a significant increase in fetal heart rate and fetal arterial blood pressure, with a minimal nonsignificant increase in umbilical blood flow. beta-Adrenergic blockade resulted in a decrease in fetal heart rate and umbilical blood flow, though neither was statistically significant. There was no change in arterial blood pressure. The net result of parasympathetic and beta-adrenergic blockade on fetal heart rate suggests that the intrinsic rate is the same as when these influences are present.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D005318:Fetal Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D010276:Parasympatholytics / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D012756:Sheep; D014470:Umbilical Cord / Q000098:blood supply*
D000319:Adrenergic beta-Antagonists; D010276:Parasympatholytics; D001285:Atropine; D011433:Propranolol