Strychnine affects catecholamine secretion from bovine adrenal medulla chromaffin cells.
The effect of strychnine on evoked release of catecholamines from a primary culture of bovine adrenal medullary cells was investigated. Strychnine at > 1 microM inhibited catecholamine release stimulated by 10 microM acetylcholine, or 10 microM nicotine, but not by excess K+ (59 mM), the sodium ionophore veratridine (100 microM) or the calcium ionophore A-23187 (10 microM). The inhibitory response elicited by exposure of the cells to strychnine was rapid (< 3 min) and competitive with acetylcholine. High concentrations of acetylcholine (1 mM) completely overcame this inhibition. Strychnine might be acting on a regulatory site of the nicotinic-cholinergic receptor, which is genetically similar to the strychnine-binding 48 KD subunit of the glycine receptor.
D000109:Acetylcholine / Q000494:pharmacology; D000313:Adrenal Medulla / Q000187:drug effects*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002838:Chromaffin System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D009538:Nicotine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D013331:Strychnine / Q000494:pharmacology*; D013997:Time Factors
D002395:Catecholamines; D009538:Nicotine; D013331:Strychnine; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium