Age related differences in dopamine-stimulated adenylate cyclase sensitivity to "in vivo" chronic ethanol treatment

The effect of chronic ethanol consumption on adenylate cyclase activity was measured in striatal membranes derived from aged male rats. The results indicate that the cyclic AMP generating system of old rats has a different sensitivity to ethanol effect compared to the adult animals. In young animals the basal adenylate cyclase activity was enhanced by alcohol consumption while the DA stimulated cyclic AMP production was reduced. In contrast, in 24 months old rats ethanol reduced the basal adenylyl cyclase and enhanced the response to DA indicating a supersensitivity of adenylate cyclase linked DA receptors. This observation was further supported by 3H-Spiperone binding studies. In fact, a higher Bmax was measured in striatal membranes of aged ethanol-dependent rats in comparison to control.