title: Effects of chronic ethanol consumption and aging on dopamine, serotonin, and metabolites.
abstract: This study examined the hypothesis that chronic ethanol consumption results in significant abnormalities in both the dopaminergic and the serotonergic system of aged rats. Levels of dopamine (DA), serotonin [5-hydroxytryptamine (5-HT)], 3,4-dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindole-3-acetic acid (5-HIAA) were determined in brain areas of both the nigrostriatal and mesocorticolimbic DA systems in 5-, 14-, and 24-month-old male Fischer 344 rats. Aging was associated with a reduced concentration of DA in the striatum (ST), ventral tegmental area (VTA), and ventral pallidum (VP) and an increased concentration of 5-HIAA in the ST, globus pallidus, nucleus accumbens, frontal cortex, and VP. In addition, there was an increase in the 5-HIAA/5-HT ratio in all brain areas analyzed. Six weeks of ethanol consumption was accompanied by significant changes in mesocorticolimbic brain areas. In the VTA of 5-month-old ethanol-fed rats DA content was decreased to the levels found in aged rats, e.g., 24 months of age. Ethanol also significantly lowered 5-HT and 5-HIAA contents in the VTA and reduced DOPAC and 5-HIAA levels in the VP. In addition, ethanol blunted the normal age-related increase in 5-HIAA/5-HT ratio in the VTA, VP, and substantia nigra. It is interesting that although the age-related changes were found in both nigrostriatal and mesocorticolimbic brain areas, the ethanol-associated effects were found only in brain areas of the mesocorticolimbic system. The changes in DA and 5-HT function that accompany aging and ethanol consumption may contribute to the problems in motor function and ethanol abuse found in the aged.
authors.affiliation: Department of Molecular and Cellular Biochemistry, Loyola University of Chicago, Stritch School of Medicine, Maywood, Illinois 60153, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Woods
authors.forename: M J
authors.initials: MJ
authors.lastname: Druse
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000428:Alcohol Drinking; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009994:Osmolar Concentration; D051381:Rats; D011916:Rats, Inbred F344; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine