Effects of acute and chronic administration of pentobarbital on catecholamine uptake in mouse brain synaptosomes.

The studies showed that pentobarbital at concentrations up to 10(-4) M failed to exhibit any effect on catecholamine uptakes in vitro. In mice treated both acutely and chronically with pentobarbital, there was a significant attenuation in both dopamine and norepinephrine uptakes into synaptosomal preparations. The decrease in both catecholamine uptakes during the course of the development of tolerance to pentobarbital was demonstrated to be time dependent. The ability of catecholamine uptake processes was restored by abrupt withdrawal of pentobarbital by the removal of pentobarbital pellet. It appears that both acute and chronic effects of pentobarbital on catecholamine uptakes may be associated with the development of tolerance to pentobarbital.