Characteristics of catecholamine release from adrenal chromaffin cells cultured in medium containing ethanol-I. Spontaneous and K⁺-induced release

Bovine adrenal chromaffin cells were dissociated and grown in primary culture for 9 days. Three days after plating, half the cultures were grown in a medium containing 200 mM ethanol and the other half in a control medium, for a further 6 days. The catecholamine content of the ethanol-treated cells was increased after 6 days of ethanol treatment, compared to control cells and there was a slight reduction in protein and DNA content. An enhanced spontaneous release of catecholamines was seen, which was Ca²⁺-dependent and was inhibited by cadmium but not by the organic dihydropyridine Ca²⁺ antagonist nitrendipine. The fraction of catecholamines released by K⁺ was also enhanced in ethanol-treated preparations, particularly at high K⁺ or Ca²⁺ concentrations. Release induced by K⁺ was sensitive to inhibition by both cadmium and organic dihydropyridine Ca²⁺ antagonists. The results show many similarities with changes observed in catecholaminergic transmission in rat brain during the development of ethanol physical dependence.