R. Afar et al., NICOTINE-INDUCED INTRACELLULAR CALCIUM CHANGES ARE NOT ANTAGONIZED BYALPHA-BUNGAROTOXIN IN ADRENAL-MEDULLARY CELLS, Brain research, 641(1), 1994, pp. 127-131
The snake toxin alpha-bungarotoxin distinguishes between neuronal nico
tinic 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 no
t affect the nicotine-evoked calcium response in suspended chromaffin
cells. On the other hand, the classical nicotinic receptor blocker d-t
ubocurarine potently blocked nicotinic receptor mediated effects. The
degree of inhibition of the nicotinic response observed with d-tubocur
arine was not modified by prior treatment with alpha-bungarotoxin. The
se results suggest that nicotinic alpha-bungarotoxin receptors are not
primarily involved in nicotine-mediated increases in intracellular ca
lcium in bovine adrenal medullary cells.