title: In vivo turnover rate of acetylcholine in rat brain parts at elevated steady-state concentration of plasma choline.
abstract: Cortical and striatal turnover rates of acetylcholine TR(ACh) were estimated by applying steady-state tracer kinetics in rats killed by microwave irradiation following a constant i.v. infusion of 3H-Ch. In control rats TR(ACh) was 3.6 nmol . g-1 . min-1 in the cortex and 23.8 nmol . g-1 . min-1 in the striatum. When steady-state plasma concentrations of Ch were increased from 17 to 140 mumol . 1-1 by a 15-min infusion of unlabelled Ch the corresponding TR(ACh) were 3.6 nmol . g-1 . min-1 and 21.4 nmol . g-1 . min-1, respectively. These results indicate that increased plasma levels of Ch are not accompanied by increased synthesis of brain ACh.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002540:Cerebral Cortex / Q000378:metabolism; D002794:Choline / Q000032:analysis / Q000097:blood*; D003342:Corpus Striatum / Q000378:metabolism; D008297:Male; D051381:Rats
chemical_list: D002794:Choline; D000109:Acetylcholine