Effects of partial lower aortic obstruction in the pregnant ewe on fetal arterial pressure, heart rate, plasma renin activity and prostaglandin E concentration.
Fetal haemodynamic changes, together with changes in the fetal renin-angiotensin system and in circulating concentration of prostaglandin E, were studied in chronically prepared fetal sheep before, during and after asphyxia induced acutely by maternal aortic occlusion in last third of gestation. A total of thirty experiments were performed in seventeen animals. Severe fetal asphyxia (fall in PO2 greater than 30%) was associated with transient fall in heart rate and rise in blood pressure but not with changes in plasma concentrations of either prostaglandin E or renin substrate. Fetal plasma renin activity increased to 140% of control values during moderate asphyxia and to 400% during severe asphyxia. We conclude that the fetal renal angiotensin-renin system is activated by asphyxia.
D000818:Animals; D001011:Aorta / Q000473:pathology*; D001018:Aortic Diseases / Q000503:physiopathology*; D001157:Arterial Occlusive Diseases / Q000503:physiopathology*; D001794:Blood Pressure; D005260:Female; D005311:Fetal Hypoxia / Q000473:pathology*; D006339:Heart Rate; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011458:Prostaglandins E / Q000097:blood; D012083:Renin / Q000097:blood; D012756:Sheep / Q000502:physiology*
D011458:Prostaglandins E; D012083:Renin