The Influence of Catecholamine Systems and Thyroid Function on the Actions of Ethanol in Long‐Sleep (LS) and Short‐Sleep (SS) Mice a

During the past two decades, a considerable number of investigations have been conducted on the effects of ethanol on catecholamine levels and turnover in both the central and peripheral nervous systems. Whereas the bulk of the investigations have failed to demonstrate an effect of acute ethanol administration on levels of brain norepinephrine or dopamine,14 many investigators have reported that ethanol may affect biogenic amine turnover in the central nervous system. However, conflicting results have been reported on the nature of the effects elicited. Corrodi and co-workers' examined norepinephrine turnover by monitoring the decline in brain norepinephrine content after administration to rats of alpha-methyl-p-tyrosine, an inhibitor of tyrosine hydroxylase. Brain norepinephrine levels fell more rapidly shortly after rats were treated with 2 g/kg of ethanol, suggesting that an enhancement of brain norepinephrine turnover occurs following ethanol administration. These workers reported no effect of ethanol on dopamine turnover shortly after ethanol. At later times following ethanol administration, the turnover rates of both norepinephine and dopamine were reduced. Utilizing the incorporation of radiolabeled tyrosine into brain catecholamines as an index of catecholamine synthesis and turnover, Carlsson et al.' observed that the oral administration of 7 g/kg of ethanol was associated with an increased rate of incorporation of 'H-tyrosine into dopamine and, to a lesser extent, norepinephrine. These authors claimed that there was a direct correlation between the intensity of the behavioral effects produced by ethanol and the extent of the enhancement of the incorporation of tyrosine into brain dopamine and norepinephrine in these rats. Carlsson and Lindqvid demonstrated that the intraperitoneal administration of ethanol is associated with a significant increase in the accumulation of L-3,4dihydroxyphenylalanine (dopa) in the brain following inhibition of L-aromatic amino acid decarboxylase. These effects were observed in regions of the brain that contain both norepinephrine and dopamine neurons. The authors concluded that ethanol stimulates the synthesis of both catecholamines. Ahtee and Sarstrom-Fraser' reported that chronic ethanol administration fails to alter turnover rates of either dopamine or