1. Comparison of a conscious versus anesthetized canine model in response to milrinone, hydralazine and nitroprusside.
- Author
-
Lee KC, Canniff PC, Hamel DW, and Clas DM
- Subjects
- Animals, Blood Pressure drug effects, Dogs, Dose-Response Relationship, Drug, Female, Heart Rate drug effects, Isoproterenol pharmacology, Male, Milrinone, Pulmonary Circulation drug effects, Anesthesia, Cardiotonic Agents pharmacology, Hemodynamics drug effects, Hydralazine pharmacology, Nitroprusside pharmacology, Pyridones pharmacology
- Abstract
The purpose of this study was to demonstrate, based on previous and new data, that the differences between a conscious and anesthetized canine model in the cardiovascular responses to cardiovasoactive agents were beyond their difference in the sensitivity of the compensatory mechanisms. In both conscious and anesthetized canine models, mean arterial pressure (MAP) was decreased by hydralazine (at 1-3 mg/kg and 0.3-3 mg/kg; by -26.5 +/- 4.5 and -18.8 +/- 11.7% [max. changes expressed as mean +/- SEM], respectively). MAP was also decreased by nitroprusside (both at 0.01-0.1 mg/kg, by 54.6 +/- 2.8 and -60.5 +/- 3.0%, respectively) in the conscious and anesthetized models. However, the differential MAP responses to hydralazine and nitroprusside between the two models are inconsistent with a difference in the sensitivity of the two models. Hydralazine at 1 mg/kg decreased MAP greater in the conscious than anesthetized model, whereas nitroprusside decreased MAP similarly in the two models. In conclusion, not all differential responses to hydralazine and nitroprusside between conscious and anesthetized canine models can be explained by a difference in the sensitivity of their compensatory mechanisms.
- Published
- 1993