Effects of puerarin on cat vascular smooth muscle in vitro

Puerarin is an isoflavone compound isolated from Pueraria lobata (Wild). This study characterized the vascular action of puerarin in order to more clearly elucidate its pharmacological activities. Helically cut strips of cat femoral veins and renal arteries were suspended in an organ chamber filled with Krebs bicarbonate solution for measurement of isometric force development. In the cases of femoral veins and renal arteries isoproterenol (0.01 mumol.L-1 -0.1 mmol.L-1) caused relaxation of methoxamine-induced contraction (0.01 mmol.L-1) in a concentration-related manner. Puerarin (0.01-0.1 mmol.L-1) inhibited the relaxation response to isoproterenol in a concentration-response fashion. Propranolol (0.1-1 mumol.L-1) inhibited the isoproterenol-induced relaxation too. Puerarin (0.1mmol.L-1) did not alter the relaxation response to nitroglycerin (1 mumol.L-1). These results indicated that puerarin acted as a beta-adrenoreceptor antagonist in isolated arteries and veins.