<prompt> Tolazoline is used as -As thrombin inhibitor in peripheral angiographyAs vasodilator in treating coronary aery stenosis during angio proceduresAs vasoconstrictor in tt of varicesAntispasmodic during biliary spasm  <response>: Ans. is b i.e., As vasodilator in treating coronary aery stenosis during angio procedures o Tolazoline is a competitive a receptor antagonist and has similar affinities for al and a2 receptors. It is a vasodilator and is quite similar to phentolamine but less potent. Vasodilatory action is due to increase in histamine secretion. 