Time course of decline of radiolabeled acetylcholine formed following intracerebroventricular administration of tritiated choline: effects of oxotremorine and scopolamine.
Rats were injected intracerebroventricularly with 5 microCi of [methyl-3H]choline. The time course of decline of the radiolabeled acetylcholine (ACh) formed was estimated in the ipsilateral cerebral cortex and striatum. The [3H]ACh levels declined biphasically from the cerebral tissue. The initial decline proceeded rapidly, after which labeled ACh declined more slowly. Scopolamine (1 mg/kg, i.v.) caused a significant increase in the rate of [3H]ACh disappearance, which can be interpreted as an enhancement of ACh release. By contrast, oxotremorine (0.8 mg/kg, i.v.) markedly reduced the [3H]ACh disappearance. The results show that drug-induced changes in cholinergic neuronal activities can be estimated from the disappearance of radioactive ACh after labeling the endogenous transmitter through intracerebroventricular administration of labeled choline.
Bertrand
N
N
Laboratoire de Pharmacodynamie, Faculté de Pharmacie, Dijon, France.
Bralet
J
J
Beley
A
A
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002552:Cerebral Ventricles / Q000187:drug effects / Q000378:metabolism*; D002794:Choline / Q000008:administration & dosage / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D009928:Organ Specificity; D010095:Oxotremorine / Q000494:pharmacology*; D011865:Radioisotope Dilution Technique; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012601:Scopolamine / Q000494:pharmacology*; D013997:Time Factors; D014316:Tritium
D014316:Tritium; D010095:Oxotremorine; D012601:Scopolamine; D002794:Choline; D000109:Acetylcholine