Renovascular hypertension: effect of halothane and enflurane.
Male Wistar rats were anesthetized at 6 weeks of age and a silver clip placed around the renal artery to produce renovascular hypertension. The rats were allowed to grow on a normal sodium diet for the next 6-9 weeks. Using diethyl ether anesthesia, arterial and venous cannulae were placed and the animals allowed to awaken in restraining cages. The group of rats was divided into three groups: awake (n = 7), halothane 1.3 vol% (n = 9), and enflurane 2.2 vol% (n = 8). The protocol consisted of a 1-h control awake period, 1 h of stable anesthesia (one group received no anesthesia), and 30-min iv infusion of saralasin, a competitive inhibitor of angiotensin II. Plasma renin activity (PRA) and plasma catecholamines were measured after 1 h of stable anesthesia and after the saralasin infusion. In additional rats treated identically, radiolabelled microspheres were used to measure cardiac output and regional blood flows during halothane (n = 7) or enflurane (n = 6) anesthesia. Principal responses were as follows: mean arterial pressure (MAP) was 193 +/- 4 mmHg awake and decreased to 114 +/- 3 mmHg and 135 +/- 3 mmHg with halothane and enflurane, respectively. Saralasin decreased MAP in the awake group to 176 +/- 3 mmHg and to 69 +/- 3 mmHg and 96 +/- 5 mmHg with halothane and enflurane, respectively. PRA in the awake rats was 7.24 +/- 1.3 ng X ml-1 X h-1. PRA increased with halothane but decreased with enflurane. Plasma catecholamines were decreased markedly by saralasin and by both anesthetic agents.(ABSTRACT TRUNCATED AT 250 WORDS)
D000769:Anesthesia, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D004737:Enflurane / Q000494:pharmacology*; D004837:Epinephrine / Q000097:blood; D006221:Halothane / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects*; D006978:Hypertension, Renovascular / Q000097:blood / Q000503:physiopathology*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010100:Oxygen / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D012083:Renin / Q000097:blood
D002245:Carbon Dioxide; D004737:Enflurane; D012083:Renin; D010100:Oxygen; D006221:Halothane; D009638:Norepinephrine; D004837:Epinephrine