Which two drugs are listed as inhibitors of norepinephrine release?

Which two drugs are listed as inhibitors of norepinephrine release?

• A. Guanethidine and Reserpine
• B. Propranolol and Metoprolol
• C. Celecoxib and Meloxicam
• D. Diuretics and ACE inhibitors

Answer: (A)

Inhibitors of norepinephrine release work by reducing how much NE is available for signaling at sympathetic nerve endings. Guanethidine acts as a false transmitter that is taken up into sympathetic neurons and into vesicles, where it displaces NE and ultimately prevents its release. Reserpine blocks the vesicular monoamine transporter, so NE cannot be packaged into vesicles and is depleted from nerve terminals, leading to a diminished NE release. The other options don’t target NE release. Propranolol and metoprolol block beta-adrenergic receptors, not the release of NE. Celecoxib and meloxicam are NSAIDs, and diuretics with ACE inhibitors affect blood pressure through other mechanisms rather than NE release.

Inhibitors of norepinephrine release work by reducing how much NE is available for signaling at sympathetic nerve endings. Guanethidine acts as a false transmitter that is taken up into sympathetic neurons and into vesicles, where it displaces NE and ultimately prevents its release. Reserpine blocks the vesicular monoamine transporter, so NE cannot be packaged into vesicles and is depleted from nerve terminals, leading to a diminished NE release.

The other options don’t target NE release. Propranolol and metoprolol block beta-adrenergic receptors, not the release of NE. Celecoxib and meloxicam are NSAIDs, and diuretics with ACE inhibitors affect blood pressure through other mechanisms rather than NE release.