Which of the following statements correctly describes propertiesof a gas neurotransmitter?A. Nitric oxide is synthesized by enzymatic degradation ofarginine, actively transported across cell membranes, storedin vesicles, released by neuronal depolarization, and binds tonitric oxide receptors.B. Nitric oxide is synthesized from arginine by nitric oxidesynthase, diffuses across cell membranes, is released byneuronal depolarization, and acts on presynaptic nitric oxidereceptors to enhance the release of glutamate.C. Nitric oxide is synthesized from arginine by nitric oxidesynthase, diffuses across cell membranes, activates guanylylcyclase, and may enhance release of glutamate.D. Carbon monoxide is endogenously formed in neurons bythe action of carbon monoxide synthase, stimulates solubleguanylyl cyclase to enhance endotoxin-induced argininevasopressin release.E. Carbon monoxide is synthesized in the periphery byenzymatic degradation of heme by heme oxygenase-2,transported to the brain where it activates guanylyl cyclase,and has a role in long-term potentiation.

To determine which statement correctly describes the properties of a gas neurotransmitter, let's analyze each option step by step:

Option A:

"Nitric oxide is synthesized by enzymatic degradation of arginine, actively transported across cell membranes, stored in vesicles, released by neuronal depolarization, and binds to nitric oxide receptors."

• Synthesis: Nitric oxide (NO) is indeed synthesized from arginine, but not by "enzymatic degradation." It is synthesized by the enzyme nitric oxide synthase (NOS).
• Transport: NO is not actively transported across cell membranes; it diffuses freely due to its gaseous nature.
• Storage: NO is not stored in vesicles; it is synthesized on demand.
• Release: NO is released by neuronal depolarization, but this is not the primary mechanism.
• Receptors: NO does not bind to specific nitric oxide receptors; it typically activates guanylyl cyclase.

This option contains several inaccuracies.

Option B:

"Nitric oxide is synthesized from arginine by nitric oxide synthase, diffuses across cell membranes, is released by neuronal depolarization, and acts on presynaptic nitric oxide receptors to enhance the release of glutamate."

• Synthesis: Correct, NO is synthesized from arginine by nitric oxide synthase.
• Diffusion: Correct, NO diffuses across cell membranes.
• Release: NO is not released by neuronal depolarization; it is synthesized on demand.
• Receptors: NO does not act on presynaptic nitric oxide receptors; it typically activates guanylyl cyclase.

This option is partially correct but contains some inaccuracies.

Option C:

"Nitric oxide is synthesized from arginine by nitric oxide synthase, diffuses across cell membranes, activates guanylyl cyclase, and may enhance release of glutamate."

• Synthesis: Correct, NO is synthesized from arginine by nitric oxide synthase.
• Diffusion: Correct, NO diffuses across cell membranes.
• Activation: Correct, NO activates guanylyl cyclase.
• Enhancement: Correct, NO may enhance the release of glutamate.

This option is entirely correct.

Option D:

"Carbon monoxide is endogenously formed in neurons by the action of carbon monoxide synthase, stimulates soluble guanylyl cyclase to enhance endotoxin-induced arginine vasopressin release."

• Formation: Carbon monoxide (CO) is formed by the action of heme oxygenase, not carbon monoxide synthase.
• Stimulation: CO does stimulate soluble guanylyl cyclase.
• Enhancement: The statement about enhancing endotoxin-induced arginine vasopressin release is not a well-known property of CO.

This option contains inaccuracies.

Option E:

"Carbon monoxide is synthesized in the periphery by enzymatic degradation of heme by heme oxygenase-2, transported to the brain where it activates guanylyl cyclase, and has a role in long-term potentiation."

• Synthesis: CO is synthesized by the degradation of heme by heme oxygenase, but this occurs in various tissues, not specifically in the periphery.
• Transport: CO is not specifically transported to the brain; it diffuses freely.
• Activation: CO does activate guanylyl cyclase.
• Role: CO does have a role in long-term potentiation.

This option is partially correct but contains some inaccuracies.

Conclusion:

The correct statement is:

C. Nitric oxide is synthesized from arginine by nitric oxide synthase, diffuses across cell membranes, activates guanylyl cyclase, and may enhance release of glutamate.