| Abstract: | Changes in responses of frog sympathetic ganglion neurons to perfusion with cholinomimetics were studied during modification of acetylcholine receptors by dithiothreitol and ferricyanide. Perfusion with dithiothreitol suppressed responses to carbachol, suberyldicholine, and 5-methylfurmethide, whereas subsequent perfusion with ferricyanide partly restored responses to suberyldicholine but suppressed responses to 5-methylfurmethide. Acetylcholine and tetramethylammonium, used as protectors, protected nicotinic and muscarinic receptors against the action of dithiothreitol, but acetylcholine was more effective than tetramethylammonium for nicotinic acetylcholine receptors. It is suggested that disulfide bonds, some of them located in the anionic centers of the receptors, are present in the recognition sites of acetylcholine receptors of the frog sympathetic ganglion.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 11, No. 6, pp. 593–600, November–December, 1979. |
