Abstract
The fibrinolysis induced by intraperitoneal injection of adrenaline in the rat was inhibited by prior intraperitoneal injection of very low doses of α-adrenergic blocking agents. For example, 5 μg/kg of phenoxybenzamine or 10 μg/kg of phentolamine was sufficient to prevent almost completely the fibrinolysis induced by 1 mg/kg of adrenaline. These α-blockers also inhibited the fibrinolysis induced by serotonin and bisobrin, but a much higher dosage was required. Phenoxybenzamine did not inhibit the adrenaline-induced fibrinolysis when the drug was injected after the injection of adrenaline. No inhibitory effect was observed with β-blockers, dichloroisoproterenol, pronethalol and practolol, even at a dose of 10 mg/kg, although propranolol at a dose of 3 mg/kg did exert an inhibitory effect. The involvement of peritoneal blood vessels in adrenaline-induced fibrinolysis is suggested.
