USE OF 300-MSEC MICROWAVE IRRADIATION FOR ENZYME INACTIVATION - STUDY OF EFFECTS OF SODIUM PENTOBARBITAL ON ACETYLCHOLINE CONCENTRATION IN MOUSE-BRAIN REGIONS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 197  (2) , 245-252
Abstract
Microwave irradiation of 6 kW at 2450 MHz for 300 ms was sufficient to completely inactivate mouse brain cholinesterase and choline acetyltransferase. After this method of sacrifice, the acetylcholine [ACh] contents of mouse brain regions, given in nmol/g were striatum, 81; medulla-pons, 44; diencephalon-midbrain, 34; hippocampus, 31; cerebral cortex, 26; and cerebellum, 17. Sodium pentobarbital caused a dose-dependent increase in whole brain ACh. A maximal increase of 81% in whole brain was seen at 15 min with 80 mg/kg of sodium pentobarbital. The increase in ACh after sodium pentobarbital treatment was not caused by anoxia from respiratory depression or by hypothermia. All brain regions except the cerebellum exhibited an increase in ACh after pentobarbital treatment. Fifteen minutes after treatment, cerebellar ACh was significantly decreased. However, at the time when half of the animals had regained the righting reflex, the unconscious mice showed an increase in cerebellar ACh which was statistically significant as compared to control. The relative accumulation rate of ACH calculated for cerebral cortex and hippocampus was higher than that for striatum, although the absolute rate of accumulation of ACh was higher in the striatum. After sodium pentobarbital treatment, the cerebral cortex and hippocampus exhibit a greater cholinergic response than the striatum.