THE USE OF MICROWAVE HEATING TO INACTIVATE CHOLINESTERASE IN THE RAT BRAIN PRIOR TO ANALYSIS FOR ACETYLCHOLINE

Abstract— Heating with 2450 MHz microwave radiation has been investigated as a means for animal sacrifice concurrent with enzyme inactivation. Uniform inactivation of cholinesterase (EC 3.1.1.8) in the entire brain can be effected in the rat within 4 s and in the mouse within 2 s without destruction of acetylcholine. The acetylcholine content in the whole brain of a rat was found to be 25.4 ± 1.5 nmol/g after irradiation, in comparison to 13.8 ± 1.7 nmol/g after standard methods of sacrifice. In the mouse whole brain, the comparable acetylcholine contents were 25.5 ± 2.6 and 13.7 ± 1.7 nmol/g, respectively. The value of this procedure for rapid inactivation of enzymes in the study of acetylcholine turnover is discussed.