ANALYSIS OF CENTRAL VASOMOTOR EFFECTS OF CHOLINE

Choline injected into the lateral cerebral ventricle (ICV) of the anesthetized dog produced biphasic vasomotor effects. There was an initial short-lasting pressor response which was blocked by atropine and reduced by bilateral adrenalectomy. This was followed by a delayed secondary depressor response which was absent in dogs pretreated with reserpine (1 eV) or tetrabenazine (i.p.). The depressor response was blocked by ICV administration of β-adrenergic receptor blocking drugs. A central cholinergic action leading to a peripheral sympathoadrenal discharge appears to be responsible for the initial pressor phase. The delayed depressor phase was attributed to a central action of catecholamines released from central neural structures. © 1969.