Cardiovascular action of propranolol in rats under various anesthetic procedures.

We previously reported that the pressor action of propranolol was observed in the rat anesthetized with urethane. In the present study, rats, anesthetized with pentobarbitone or ether, treated with curare or unanesthetized, were used to investigate the influence of anesthetics on the blood pressure response to propranolol. Propranolol always produced a pressor response under these experimental conditions as well as urethane anesthesia. But under pentobarbitone anesthesia, the magnitude of the pressor action was significantly lower than that obtained under the other experimental conditions. It is concluded that the choice of urethane as the anesthetic does not create a situation irrelevant to that found with other anesthetics and that the cardiovascular responses of rat to propranolol are unique when compared to other species.