Evaluation of microwave irradiation technique to quantitate acetylcholine in the diaphragm.

This report evaluates rapid enzyme inactivation prior to acetylcholine quantitation in the diaphragm. Methods of sacrifice were decapitation and microwave irradiation. Six-hundred millisecond exposure to microwave irradiation was sufficient to raise diaphragmatic temperature to 91 degrees C and inactivated 90% of the acetylcholinesterase enzyme. The acetylcholine content of the diaphragm was found to be 3.0 nmol/g, independent of the method of sacrifice. The postmortem changes observed in brain acetylcholine content following decapitation did not occur in the diaphragm.