Multiregional cerebral blood flow changes induced by a cholinomimetic drug

The effect of parasympathomimetic drug, carbachol, on regional cerebral blood flow was tested in the rabbit with the 14C-ethanol tissue sampling technique. Intracarotid injection of carbachol significantly increased flow with respect to untreated control animals in 6 out of 10 structures sampled. However, compared with animals to which atropine was also administered, the flow increases were greater with carbachol alone. These effects are discussed in terms of muscarinic and nicotinic activation.