Effect of withdrawal from chronic ethanol ingestion on phenazine methosulfate uptake by brain mitochondria and nerve endings.

Abstract

The effect of ethanol withdrawal on the uptake of phenazine methosulfate (PMS) by brain synaptosomal and mitochondrial fractions was studied. Prior studies showed that rats made ethanol dependent developed an abnormality in brain mitochondria characterized by an increase in O2 consumption during succinate-supported respiration when PMS was used as an electron acceptor. In the present study it was shown that ethanol withdrawal induced an increase in PMS uptake by brain mitochondrial and synaptosomal fractions during succinate oxidation. PMS uptake was measured directly. Calcium stimulated the succinate-supported PMS uptake in ethanol-withdrawn rats and controls to the same final level indicating that the maximum uptake of PMS was not affected by withdrawal. The results support the hypothesis that the increase in O2 consumption observed in rat brain mitochondria during ethanol withdrawal was due to an increase in transport of PMS.