Potentiation of evoked adrenal catecholamine release by cyanide: possible role of calcium.

The effect of cyanide on release of catecholamines was evaluated in isolated bovine adrenal glands stimulated with 4 different agonists. Cyanide (0.1-1 mM) increased catecholamine release induced by barium or cadmium 2-3-fold. Acetylcholine or potassium induced secretion of adrenal catecholamines was also enhanced by cyanide, but only to the extent of 30-50%. These data suggest that cyanide acts by multiple mechanisms to enhance evoked catecholamine release. The above results may be partly explained by the fact that cyanide inhibited 45Ca efflux from stimulated bovine adrenals. Changes in plasma membrane permeability may be crucial in the alterations of ion flux and evoked catecholamine release caused by cyanide.