title: Arterial pressure after chronic reductions in suprarenal aortic flow in fetal lambs.
abstract: Experiments were performed on 13 fetal lambs of 126 days gestational age. Seven days after surgery, suprarenal aortic blood flow was reduced to 70% of control with an inflatable occluder for a period of at least 4 days. This produced an almost constant aortic pressure difference of 35 mmHg across the occluder. Plasma renin activity (PRA) rose in the next hour from 6 to 42 ng.ml-1.h-1 (P less than 0.01) but decreased to a level that was statistically insignificantly above normal by the next day. PRA as a function of lower body arterial blood pressure showed rapid adaptation. Upper body arterial blood pressure was statistically significantly elevated by 5 mmHg within 5 min and continued to rise while plasma renin activity was falling. Femoral artery blood pressure dropped immediately but returned to near normal within 1 h and remained there. The long-term upper body hypertension was irreversible with a 30-min infusion of saralasin. Subrenal aortic flow reduction caused none of these changes. We conclude that the fetal kidneys can regulate arterial blood pressure upward but that the long-term effect does not depend solely on a direct vasoconstrictive action of angiotensin.
authors.affiliation: Department of Physiology, Oregon Health Sciences University, Portland 97201.
authors.forename: D F
authors.initials: DF
authors.lastname: Anderson
authors.forename: C M
authors.initials: CM
authors.lastname: Parks
authors.forename: J J
authors.initials: JJ
authors.lastname: Faber
mesh_terms: D000818:Animals; D001011:Aorta / Q000196:embryology* / Q000502:physiology; D001784:Blood Gas Analysis; D001794:Blood Pressure; D003250:Constriction; D005260:Female; D006339:Heart Rate; D011247:Pregnancy; D012039:Regional Blood Flow / Q000187:drug effects; D012077:Renal Artery / Q000502:physiology; D012083:Renin / Q000097:blood; D012504:Saralasin / Q000494:pharmacology; D012756:Sheep
chemical_list: D012083:Renin; D012504:Saralasin