Haemodynamic and hormonal responses to losartan (DuP753/MK954) infusion during cardiac catheterization in conscious salt-deplete dogs.
1. Haemodynamic and hormonal responses to infused angiotensin II were studied in conscious salt-deplete dogs during infusion of D-glucose or losartan (DuP753/MK954). 2. Mean arterial pressure (118 +/- 13 mmHg) fell rapidly after losartan (60 min 106 +/- 18 mmHg) with a rise in heart rate (107 +/- 16 beats/min) from baseline (98 +/- 17 beats/min). Pressor responses to angiotensin II during D-glucose infusion (6 ng min-1 kg-1, 99 +/- 10 mmHg; 18 ng min-1 kg-1, 140 +/- 15 mmHg; 54 ng min-1 kg-1, 157 +/- 12 mmHg; 162 ng min-1 kg-1, 178 +/- 14 mmHg) showed a parallel shift during losartan infusion with very similar pressures in response to higher rates of angiotensin II infusion (54 ng min-1 kg-1, 108 +/- 17 mmHg; 162 ng min-1 kg-1, 138 +/- 14 mmHg; 486 ng min-1 kg-1, 155 +/- 14 mmHg; 1458 ng min-1 kg-1, 177 +/- 12 mmHg). Losartan caused a fall in baseline systemic vascular resistance. Despite the similar mean arterial pressure, the rise in systemic vascular resistance after angiotensin II during D-glucose infusion (162 ng min-1 kg-1, 8065 +/- 1967 dyn s cm-5) was reduced during losartan infusion (1458 ng min-1 kg-1, 6645 +/- 1720 dyn s cm-5. Losartan caused a small rise in cardiac output related to a rise in heart rate and increased stroke volume. Pressure infusions of angiotensin II caused a fall in cardiac output during D-glucose infusion, which was blocked during losartan infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
MacFadyen
R J
RJ
University Department of Medicine and Therapeutics, Gardiner Institute, Western Infirmary, Glasgow, U.K.
Tree
M
M
Lever
A F
AF
Reid
J L
JL
D000450:Aldosterone / Q000097:blood*; D000804:Angiotensin II / Q000037:antagonists & inhibitors* / Q000097:blood / Q000494:pharmacology; D000818:Animals; D001713:Biphenyl Compounds / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D006328:Cardiac Catheterization; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D019808:Losartan; D008297:Male; D013268:Stimulation, Chemical; D013777:Tetrazoles / Q000494:pharmacology*
D001713:Biphenyl Compounds; D007093:Imidazoles; D013777:Tetrazoles; D000804:Angiotensin II; D000450:Aldosterone; D019808:Losartan