Effect of chronic ethanol treatment on specific [3H]ouabain binding to (Na+ + K+)-ATPase in different areas of cat brain.

Chronic ethanol administration to cats increased specific [3H]ouabain binding by 63% in cerebral cortex, 47% in cerebellum, 84% in amygdala, and 100% in hippocampus when the binding assays were performed in the presence of 160 nM [3H]ouabain. There was no significant change in specific [3H]ouabain binding in hypothalamus, thalamus, corpus striatum, and brain stem following chronic ethanol ingestion. Scatchard analysis revealed that enhancement of specific [3H]ouabain binding following chronic ethanol treatment in some areas of cat brain is primarily due to changes in densities of ouabain binding sites. Since ouabain is a specific inhibitor of (Na+ + K+)-ATPase the present observations suggest that the molecular mechanism for the enhancement of (Na+ + K+)-ATPase activity after chronic ethanol ingestion may be due to increased net rate of synthesis of (Na+ + K+)-ATPase molecules or exposure of non-functional enzyme system following conformational change of plasma membrane.