[Assessment of the activity of choline acetyltransferase in heart tissues]

A procedure is described for the radioisotope assay of acetylcholine transferase activity (EC 2.3.1.6), which involved specific synthesis of acetylcholine in vivo. Bromine acetylcholine was used as an inhibitor of the enzyme; 14C-AcCoA was used as a substrate and product of the enzymatic reaction. 14C-acetylcholine was separated from the substrate by means of anion exchange chromatography. The procedure described was 5 times more sensitive than the methods developed by F. Fonnum (1975) and S. Tucek (1983) being similarly reproducible. The assay was tested in experiments with rats under various conditions of hyperbaric oxygenation, in simulation of myocardial infarction as well as in moderate immobilization stress. The findings suggest that estimation of the acetylcholine transferase activity may be involved in complex evaluation of the cholinergic system state in tissues, which is essential for the study of pathogenesis of their dysfunctions and development of respective approaches to eliminate these impairments.