Journal article
Hemodynamic effects of pirbuterol in conscious dogs
The American heart journal, Vol.102(3), pp.591-596
09/1981
DOI: 10.1016/0002-8703(81)90749-3
PMID: 6115576
Abstract
We studied a new synthetic “selective” beta
2 catecholamine, pirbuterol (PBL), in eight conscious, chronically instrumented dogs. PBL was administered as 10-minute intravenous infusions of 0.125, 0.5, 2, 4, and 8 μg/kg/min. At 2 μg/kg/min, changes from control (all significant at p < 0.01) were heart rate (HR) + 118 ± 13 (SEM) bpm, left ventricular (LV) maximum rate of pressure rise (
dP
dt
max
) + 110 ± 16%, and mean arterial pressure (AP) − 16 ± 4 mm Hg. Cardiac output (CO) increased 114 ± 36% (p < 0.05), and systemic vascular resistance decreased 59 ± 4% (p < 0.01). LV end-diastolic diameter decreased 15 ± 3%, and LV end-systolic diameter decreased 24 ± 5% in four dogs. The magnitude of all changes increased only slightly at the higher infusion rates. When HR was maintained constant by electrical pacing, responses to PBL infusion were similar to results without pacing. All PBL effects were blocked by propranolol (1 mg/kg intravenously) except at the infusion rates of 4 and 8 μg/kg/min. Practolol (5 mg/kg intravenously) blocked the inotropic effects of PBL, but the chronotropic and vasodilator effects were still apparent. When PBL and isoproterenol were compared in four dogs at doses that increased LV
dP
dt
max
by 50%, the double product of HR and systolic AP increased in three dogs approximately 50% with PBL vs 81% with isoproterenol. In the fourth dog, however, isoproterenol increased the double product less (13%) than PBL (50%). Thus PBL has both beta
2 and beta
1 effects, and compared with isoproterenol at doses that give equivalent increases in myocardial contractility, PBL produced less increase in an index of myocardial oxygen consumption in three of the four dogs studied. On the basis of these data PBL may be useful for treating low CO syndromes without provoking myocardial ischemia.
Details
- Title: Subtitle
- Hemodynamic effects of pirbuterol in conscious dogs
- Creators
- Frank L. Gold - United States Department of Veterans AffairsLawrence D. Horwitz - United States Department of Veterans Affairs
- Resource Type
- Journal article
- Publication Details
- The American heart journal, Vol.102(3), pp.591-596
- Publisher
- Mosby, Inc
- DOI
- 10.1016/0002-8703(81)90749-3
- PMID
- 6115576
- ISSN
- 0002-8703
- eISSN
- 1097-6744
- Language
- English
- Date published
- 09/1981
- Academic Unit
- Cardiovascular Medicine; Internal Medicine
- Record Identifier
- 9984656531502771
Metrics
3 Record Views