RAPID INCREASE IN PLASMA NITRITE CONCENTRATION FOLLOWING INTRAVENOUS ADMINISTRATION OF NIPRADILOL

Nipradilol, a beta-adrenoceptor antagonist with vasodilator activity, has a structure which contains a NO2 group. In anesthetized dogs, the time course of the systemic vasodilatation and plasma nitrite (NO2-) c oncentration was studied following intravenous administration of nipra dilol (1 mg/kg). A fall in systemic vascular resistance was observed a t 1 min, which was rapidly followed by a significant increase in the p lasma NO2- concentration. It is indicated that nipradilol exerts syste mic vasodilatation via nitric oxide (NO) release in vivo.