What effect does pure norepinephrine have in patients with extra-adrenal pheochromocytoma?

Pure norepinephrine primarily acts as a potent vasoconstrictor by stimulating alpha-1 adrenergic receptors, leading to an increase in systemic vascular resistance and, subsequently, blood pressure. In the context of extra-adrenal pheochromocytoma, which secretes catecholamines, patients may experience episodes of hypertension due to the released norepinephrine and epinephrine.

In this scenario, when norepinephrine is administered, the vasoconstriction causes a rise in blood pressure (hypertension), making the correct answer clear. This is particularly relevant in patients with pheochromocytomas, as these tumors may lead to excessive release of catecholamines, thus amplifying the hypertensive effects when pure norepinephrine is introduced.

Understanding the physiological impacts is crucial; in pheochromocytoma, the exaggerated response to norepinephrine not only reinforces its hypertensive effect but may also lead to secondary complications if not managed appropriately.

Consequently, the other choices, such as hypotension, bradycardia, and reflex tachycardia, do not align with the pharmacological profile of norepinephrine when considering the specific pathophysiological context of extra-adrenal pheochromocytoma. These options typically involve