Hypersensitivity to the tremorogenic action of nicotine in rats withdrawn from ethanol.

The tremorogenic effect of nicotine was studied in control rats and in rats withdrawn for 16-48 h from chronic ethanol administration. The intensity of tremor was measured electronically. Rats withdrawn from ethanol showed a marked hypersensitivity to the tremorogenic action of nicotine. Propranolol abolished the nicotine-induced tremor in the control rats. Propranolol did not, however, reduce the intensity of nicotine-induced tremor in rats withdrawn from ethanol. Thus, the observed hypersensitivity does not seem to be mediated by a sympathetic beta-adrenergic mechanism.