The role of brain acetylcholine in the pressor response to centrally infected neostigmine.
In unanaesthetized rats, neostigmine (2.5 mug) injected into the cerebral ventricles produces a rise in arterial blood pressure. The effect on the rise was examined after lowering the acetylcholine (ACh) level of the brain by hemicholinium (HC-3) similarly injected.The pressor response was not significantly altered 2 h after injection of 50 mug HC-3 when the ACh level was reduced by 54%. It was greatly attenuated 2 h after injection of 75 mug when the ACh level was reduced by 76%. However, a similar attenuation was observed as early as 30 min after this injection when the ACh level was reduced by 18% only.It is concluded that the pressor response is not mediated by undestroyed ACh but is a direct central effect of neostigmine.
D000109:Acetylcholine / Q000502:physiology*; D000110:Acetylcholinesterase / Q000032:analysis; D000818:Animals; D001158:Arteries; D001794:Blood Pressure / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D001923:Brain Chemistry; D002552:Cerebral Ventricles; D002849:Chromatography, Gas; D006426:Hemicholinium 3 / Q000008:administration & dosage / Q000494:pharmacology; D007267:Injections; D008297:Male; D009388:Neostigmine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats
D006426:Hemicholinium 3; D009388:Neostigmine; D000110:Acetylcholinesterase; D000109:Acetylcholine