EFFECTS OF ACUTE AND CHRONIC ETHANOL ADMINISTRATION AND WITHDRAWAL ON ADENOSINE 3'-5'-MONOPHOSPHATE AND GUANOSINE 3'-5'-MONOPHOSPHATE LEVELS IN RAT-BRAIN

Abstract

The effect of ethanol on cyclic nucleotide levels was investigated in male Sprague-Dawley rats. The rats were sacrificed by microwave irradiation. The brains were divided into 4 areas, and cyclic nucleotides were measured by radioimmunoassay. Administration of a single oral dose of ethanol produced a dose-dependent decrease of cyclic[c]AMP in the cerebral cortex, cerebellum, pons and medulla oblongata while cGMP was decreased in all brain areas. Dependence on ethanol was induced by 3 daily oral administrations of ethanol for 7 days. The last dose of ethanol did not produce any decrease of cAMP levels while the decrease of cGMP levels was still present. During ethanol withdrawal cAMP levels increased in cerebral cortex, pons and medulla oblongata and did not change in cerebellum. Changes of cAMP in subcortex were more complex. The cGMP levels increased during ethanol withdrawal in cerebellum, pons and medulla oblongata and did not change in cerebral cortex and subcortex. Changes of cyclic nucleotides might participate in the mechanism of ethanol dependence and withdrawal.