Effects of chronic ethanol exposure on adenylate cyclase activities in the rat

The effects of chronic ethanol administration on striatal and cerebellar adenylate cyclase systems were investigated in the rat. The chronic ethanol treatment resulted in behavioral tolerance, but no difference in the sensitivity of adenylate cyclase to in vitro ethanol was observed. In one set of experiments using 173-195 g rats, GTP-, dopamine- and NaF-stimulated adenylate cyclase activities in the striatum were higher in rats chronically treated with ethanol when compared to animals pair-fed the liquid diet. However, no difference in adenylate cyclase activity was observed in cerebellar or striatal tissues when larger rats (280-385 g) were used. In conclusion, an adaptive change in activation of adenylate cyclase by in vitro ethanol does not occur after chronic ethanol treatment. The observed changes in enzyme activity measured in the absence of in vitro ethanol do not appear to be a simple, direct effect of chronic ethanol treatment.