Nicotine-induced intracellular calcium changes are not antagonized by alpha-bungarotoxin in adrenal medullary cells.
The snake toxin alpha-bungarotoxin distinguishes between neuronal nicotinic receptor subtypes. In chick ciliary ganglion neurons, activation of alpha-bungarotoxin-sensitive nicotinic receptors has been proposed to produce elevations in intracellular calcium levels. In the present study we show that prolonged treatment with alpha-bungarotoxin did not affect the nicotine-evoked calcium response in suspended chromaffin cells. On the other hand, the classical nicotinic receptor blocker d-tubocurarine potently blocked nicotinic receptor mediated effects. The degree of inhibition of the nicotinic response observed with d-tubocurarine was not modified by prior treatment with alpha-bungarotoxin. These results suggest that nicotinic alpha-bungarotoxin receptors are not primarily involved in nicotine-mediated increases in intracellular calcium in bovine adrenal medullary cells.
Afar
R
R
Department of Pharmacology, McGill University, Montréal, Québec, Canada.
Trifaró
J M
JM
Quik
M
M
D000313:Adrenal Medulla / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D002038:Bungarotoxins / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D009538:Nicotine / Q000037:antagonists & inhibitors*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D002038:Bungarotoxins; D009538:Nicotine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium