Ethanol and sympathetic denervation effects on rat adrenal catecholamine turnover

Acute and chronic ethanol administration increases catecholamine turnover in both central and peripheral tissues. The importance of adrenal innervation to the modulation of effects produced by acute and chronic ethanol feeding and in alcohol withdrawal was studied in rats. In the acute study, a 4 g/kg dose of ethanol p.o. caused significant increases in adrenal tyrosine hydroxylase, dopamine-β-hydroxylase (DBH) and phenylethanolamine-N-methyl-transferase activities in both intact and denervated ethanol-treated groups. After 30 days of an ethanol liquid diet, tyrosine hydroxylase and DBH activities in the intact group were significantly higher than in their respective denervated treatment groups. Phenylethanolamine-N-methyl-transferase activity was markedly elevated only in the intact ethanol group, but this was not increased further during the stress of withdrawal. Chronic ethanol treatment resulted in an increase in catecholamine (CA) synthesis and release and in CA-containing vesicle synthesis in the intact group as indicated by the marked increase in the epinephrine:norepinephrine ratio and decrease in the CA:DBH ratio; however, the denervated groups showed no change in either enzyme activity or in CA levels relative to controls. Aftr ethanol withdrawal, only the intact animals and not the denervated or control animals showed characteristic withdrawal symptoms and demonstrated marked increases in tyrosine hydroxylase, DBH and phenylethanolamine-N-methyl-transferase activity and CA release. It appears that chronic ethanol intake affects the neuro-adrenal adrenergic system, resulting in physical dependence which is dependent upon transsynaptic regulation. Effects of acute ethanol ingestion on this system are independent of this innervation mechanism.