Effect of oxotremorine, physostigmine, and scopolamine on brain acetylcholine synthesis: a study using HPLC.
The synthesis rate of brain acetylcholine (ACh) was estimated in mice following i.v. administration of [3H]choline (Ch). The measurements were performed 1 min after the tracer injection, using the [3H]ACh/[3H]Ch specific radioactivity ratio as an index of ACh synthesis rate. Endogenous and labeled Ch and ACh were quantified using HPLC methodology. Oxotremorine and physostigmine (0.5 mg/kg, i.p.) increased the steady state concentration of brain ACh by + 130% and 84%, respectively and of Ch by + 60% (oxotremorine); they decreased ACh synthesis by 62 and 55%, respectively. By contrast, scopolamine (0.7 mg/kg, i.p.) decreased the cerebral content of Ch by - 26% and of ACh by - 23% without enhancing the synthesis of ACh. The results show the utility of HPLC methodology in the investigation of ACh turnover.
Bertrand
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N
Laboratoire de Pharmacodynamie et de Physiologie Pharmaceutique, Faculté de Pharmacie, Dijon, France.
Beley
A
A
D000109:Acetylcholine / Q000096:biosynthesis*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D008297:Male; D051379:Mice; D010095:Oxotremorine / Q000494:pharmacology*; D010830:Physostigmine / Q000494:pharmacology*; D012601:Scopolamine / Q000494:pharmacology*; D014316:Tritium
D014316:Tritium; D010095:Oxotremorine; D010830:Physostigmine; D012601:Scopolamine; D002794:Choline; D000109:Acetylcholine