Central action of drugs acting on the cholinergic muscarinic receptor. IV. Influence of cholinomimetics and cholinolytics injected into the lateral cerebral ventricle in the rat on concentrations of 5-HT and 5-HIAA.

The influence of cholinomimetics (carbachol--CCh, physostigmine--Pht, pilocarpine--Pil) and cholinolytics (atropine--At, scopolamine--Sc) injected into the lateral ventricle of the brain (ivtr) in rats on metabolism of 5-HT was studied by assaying levels of 5-HT and 5-HIAA. In several comparative experiments cholinomimetics were injected i.p. CCh had no influence on levels of 5-HT and 5-HIAA when injected i.p., but raised levels of 5-HIAA injected ivtr. Pht had no influence on concentrations of both substances by either route of administration. Pil raised levels of 5-HIAA when injected i.p. (and by this route of administration also raised levels of 5-HT) as well as ivtr, Both cholinolytics injected ivtr had no influence on concentrations of 5-HT or 5-HIAA.