Cardiovascular effects of vasopressors in @entity1508 -anesthetized @entity235 before and after XXXX .

@entity7202 @entity64 @entity452 @entity1508 @entity548 @entity235 @entity1425 @entity26 @entity1372
Exogenously administered vasopressors (sympathomimetics) were evaluated in @entity1508 -anesthetized @entity235 to determine the effects of these drugs on cardiovascular function before and after @entity548 . Six @entity235 were anesthetized with thiamylal @entity1372 (20 mg/kg of body weight) and @entity1508 (1.25 minimal alveolar concentration) in 100% @entity26 . After instrumentation, cardiac output, systemic arterial blood pressure (SAP), heart rate (HR), left ventricular pressure, pulmonary arterial pressure, and an index of cardiac contractility (dP/dT) were measured. @entity64 volume, cardiac index (CI), @entity64 index (SI), rate-pressure product, and systemic vascular resistance (SVR) were calculated. @entity1425 (0.1, 0.3, and 0.5 micrograms/kg/min [low, medium, and high doses, respectively]) and @entity452 (1, 5, and 10 micrograms/kg/min [low, medium, and high doses, respectively]) were infused. @entity7202 was given in a bolus of 0.22 mg/kg, IV. All measurements were taken at 2.5 minutes after infusion, and were repeated after removal of 40% of the estimated blood volume. @entity452 administered at the low dose before @entity548 increased SAP and dP/dT. At the high and medium dose, @entity452 significantly increased CI, dP/dT, and SAP, with no significant change in HR or SVR. The medium dose of @entity1425 was the most effective dose of @entity1425 at increasing key variables (CI, SI, dP/dT). The response of CI and SI to this dose was not significantly different from the changes seen with high-dose administration of @entity452 . The dP/dT was significantly lower with @entity1425 than with @entity452 , and SVR and HR were unchanged with @entity1425 , except at the low dose, which decreased SVR.
