THE ACTIONS OF McN-A-343, PILOCARPINE AND ACETYL--METHYLCHOLINE ON SYMPATHETIC GANGLION CELLS OF THE FROG

¹ Department of Pharmacology, University of Edinburgh, Edinburgh, Scotland

The actions of McN-A-343, pilocarpine and acetyl--methylcholine have been tested on synaptic transmission in isolated frog sympathetic ganglia. Individual ganglion cells were impaled with microelectrodes and stimulated both ortho- and antidromically. McN-A-343 (in concentrations >10^-5 M) and piocarpine (in concentrations >2 x 10^-4 M) depressed synaptic transmission. They did not depolarize or stimulate. Acetyl--methylcholine (in concentrations >10^-4 M) also depressed synaptic transmission but in addition (in concentrations >10^-3 M) depolarized and stimulated cells. The depolarization was transient but the depression of transmission persisted indefinitely in the presence of the drug. The stimulating action of acetyl--methylcholine was blocked by both hexamethonium and atropine.