The effects of neosurugatoxin on evoked catecholamine secretion from bovine adrenal chromaffin cells

The effect of neosurugatoxin (NSTX), a toxin from the Japanese ivory mollusc (Babylonia japonica), on the nicotinic response of bovine adrenal chromaffin cells was examined. NSTX inhibited acetylcholine‐and nicotine‐induced catecholamine secretion from the cultured cells with an IC₅₀ against 5 μm nicotine of 30 nm. This inhibitory effect was reversible and independent of the presence of agonist. NSTX had no effect on the catecholamine release from cultured cells evoked by 50 mm K⁺, or 1 μm histamine. NSTX had no effect on the stimulation of phosphatidylinositol metabolism evoked by 100 μm muscarine. These results suggest NSTX may be useful as a nicotinic receptor probe in tissues such as the adrenal and sympathetic ganglia where α‐bungarotoxin is ineffective. 1988 British Pharmacological Society