Powerful vasoconstrictor is?

Ans. is 'b' i.e., Epinephrine Among the given options, only epinephrine has significant action on a-receptor, thus causes vasoconstriction. Svmpathomimetic drugs Non selective Adrenaline - a, + a, + 13, + [3, Noradrenaline- a, + a, + [3, + Slight 13, no. 132 Isoprenaline- R + [32+ 133 but no a action Mephentramine- a and 13 Selective al agonists - Phenylephrine, methoxamine, naphazoline, oxymetazoline, xylometazoline. a, agonists- Clonidine, methyldopa, brimonidine, apraclonidine, guanfacine, guanabenz 13, agonists- Prenalternol, dobutamine [3, agonsits - Salbutamol, terbutaline, salmeterol, orciprenaline, ritodrine, isotharine, bitolterol, pirbuterol, tenoterol, formoterol.