Effects of anisodine alone and in combination with chlor-promazine on spontaneous acetylcholine release from sensory-motor cortex of cats

The action of anisodine-HBr and chlorpromazine (CPZ) on spontaneous ACh release from the cerebral cortex of curarized cats was studied by collecting the perfusate from the cortex and assaying ACh in it on the dorsal muscle strip of leech in a microbath (0.05 ml). Normal saline showed no effect on the ACh release from the sensory-motor cor-tex of curarized cats. Although the quan-tity of ACh release varied among different cats. the ACh release from each cat was relatively steady. The average rate of ACh release from cerebral cortex of con-trol cats was 0.39± (SD) 0.32 ng/min/cm2 cortex. Anisodine 3 mg/kg iv significantly en-hanced the ACh release from the cortex. The average ratio of ACh release after anisodine over its control was 5.0±1.8. CPZ 4mg/kg iv also enhanced the ACh release from the cortex. The ratio was l.6±0.6. Injection of anisodine (3 mg/kg) and CPZ (4mg/kg) in combination also in-creased the ACh release with a ratio of 3 .3 ± 2.2.