R Schreiber1, W D Freund. 1. Bayer-AG, Aprather Weg 18A, 42096 Wuppertal, Germany. rudy.schrelber.rs1@bayer-ag.ge
Abstract
INTRODUCTION: Ethanol (EtOH) affects glutamatergic neurotransmission and this may underlie craving in alcoholics. The present study aimed to further elucidate the EtOH-induced modulation of glutamatergic neurotransmission in a model for alcoholism: the alcohol-preferring cAA rat. MATERIAL AND METHODS: Glutamate transporter binding and function was assessed in membrane and synaptosomal preparations from the cerebral cortex of alcohol-preferring cAA rats and alcohol-naive cAA rats. RESULTS: [3H]L-glutamate transport activity (Vmax) was 699 pmol.min-1.mg-1 in alcohol-naive cAA rats and 487 pmol.min-1.mg-1 in alcohol-preferring cAA rats. The specific binding sites (Bmax) for [3H]D-aspartate were markedly decreased in alcohol-preferring cAA rats (2059 pmol/mg) as compared to alcohol-naive cAA rats (4275 pmol/mg). CONCLUSIONS: We hypothesize that the reduced density and function of glutamate transporter sites in alcohol-preferring cAA rats may represent an adaptive mechanism in order to counteract suppressed glutamatergic neurotransmission during chronic EtOH exposure.
INTRODUCTION:Ethanol (EtOH) affects glutamatergic neurotransmission and this may underlie craving in alcoholics. The present study aimed to further elucidate the EtOH-induced modulation of glutamatergic neurotransmission in a model for alcoholism: the alcohol-preferring cAA rat. MATERIAL AND METHODS:Glutamate transporter binding and function was assessed in membrane and synaptosomal preparations from the cerebral cortex of alcohol-preferring cAA rats and alcohol-naive cAA rats. RESULTS: [3H]L-glutamate transport activity (Vmax) was 699 pmol.min-1.mg-1 in alcohol-naive cAA rats and 487 pmol.min-1.mg-1 in alcohol-preferring cAA rats. The specific binding sites (Bmax) for [3H]D-aspartate were markedly decreased in alcohol-preferring cAA rats (2059 pmol/mg) as compared to alcohol-naive cAA rats (4275 pmol/mg). CONCLUSIONS: We hypothesize that the reduced density and function of glutamate transporter sites in alcohol-preferring cAA rats may represent an adaptive mechanism in order to counteract suppressed glutamatergic neurotransmission during chronic EtOH exposure.
Authors: Hyung W Nam; Sally R McIver; David J Hinton; Mahesh M Thakkar; Youssef Sari; Fiona E Parkinson; Phillip G Haydon; Doo-Sup Choi Journal: Alcohol Clin Exp Res Date: 2012-02-06 Impact factor: 3.455