Two isolated samples of porcine artery arteries are examined in an experiment to study vasoconstriction of the arterial wall. As norepinephrine is infused in increasing amounts, the control vessel's vascular tone is gauged. Prior to the infusion of norepinephrine, experimental medication A is used to pre-treat the other vessel. The graph below shows the study's findings. Drug A is most similar to which of the following agents?

Question

Two isolated samples of porcine artery arteries are examined in an experiment to study vasoconstriction of the arterial wall. As norepinephrine is infused in increasing amounts, the control vessel's vascular tone is gauged. Prior to the infusion of norepinephrine, experimental medication A is used to pre-treat the other vessel. The graph below shows the study's findings.  Drug A is most similar to which of the following agents?

Quizplus · Accepted Answer

Eductional Objective: A powerful 1 and 2 adrenergic antagonist, phenoxybenzamine significantly lessens the arterial vasoconstriction brought on by norepinephrine. Even very high quantities of norepinephrine, such as those found in pheochromocytoma, cannot counteract the effects of phenoxybenzamine since it is an irreversible antagonist.

Two Isolated Samples of Porcine Artery Arteries Are Examined in an Experiment