Which neurotransmitter is most closely associated with vomiting?
B. Calcitonin gene-related peptide (CGRP)
C. Acetylcholine (Ach)
D. Substance P
E. Vasoactive intestinal peptide
The answer is D.
Substance P (SP)–neurokinin-1 (NK1) receptor pathways are involved in the pathophysiology of emesis and depression. It is a potent vaso-dilator mediated by endothelial release of NO. Substance P is involved in central and peripheral pain transmission; however, although SP antagonists have shown beneficial results in treatment of depression and nausea, their antinociceptive properties have been disappointing. Aprepitant is a SP antagonist used for che-motherapy-induced nausea and vomiting.
Source: Hargreaves, J Clin Psychiatry 2002