title: Action of surugatoxin on nicotinic receptors in the superior cervical ganglion of the rat.
abstract: Surugatoxin (SGTX, 0.1-2 muM) reversibly depressed orthodromic transmission and antagonized the depolarizing action of carbachol on the isolated superior cervical ganglion of the rat. The apparent dissociation equilibrium constant against carbachol-induced depolarization (measured in the presence of hyoscine) was 58 and 76 nM determined at 0.2 and 2 muM respectively. SGTX (2muM) did not reduce the depolarizing effects of (+/-)-muscarine, gamma-aminobutyric acid or angiotensin, but did reduce that to 5-hydroxytryptamine. Release of [3H]-acetylcholine following repetitive (10 Hz) preganglionic sympathetic stimulation was maintained in the presence of 2 muM SGTX. It is concluded that SGTX has a high and selective affinity for ganglionic nicotinic receptors.
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002794:Choline / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000187:drug effects*; D066298:In Vitro Techniques; D008387:Marine Toxins / Q000494:pharmacology*; D008978:Mollusk Venoms; D009116:Muscarine / Q000494:pharmacology; D051381:Rats; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011978:Receptors, Nicotinic / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D008387:Marine Toxins; D008978:Mollusk Venoms; D011950:Receptors, Cholinergic; D011978:Receptors, Nicotinic; D000804:Angiotensin II; D012701:Serotonin; C010340:surugatoxin; D005680:gamma-Aminobutyric Acid; D009116:Muscarine; D002217:Carbachol; D002794:Choline