[Action of propranolol on the perfusion pressure into the peripheral vasculature of rat hindquarters].

Several investigators have confirmed that beta-adrenergic blocking agents produced a sustained pressor action in anesthetized rats. In this experiment, rat hindquarters were perfused with the rat's own blood under a constant perfusion rate. The effect of propranolol administered intraarterially to the hindquarters was studied. Propranolol (0.001--0.1 mg/ml, 5 microliter intraarterial injection) produced a sustained rise in the perfusion pressure dose-dependently. In contrast, propranolol did not produce any sustained rise in the perfusion pressure of guinea pigs and rabbits. These results support that the beta-adrenoceptive vasodilation in skeletal muscle is stronger in rats than in guinea pigs and rabbits.