There are a number of observations which suggest that acetylcholine exerts an ex citatory influence over the medullary vasomotor center. Dhawan et al. (1) reported that both acetylcholine and carbachol produce a pressor response on intracerebroventri cular (i.c.v.) administration in dogs and this pressor response is blocked by atropine. Sinha et al. (2) observed that hemicholinium, which blocks...
