Ethanol does not affect serotonin receptor binding in rodent brain

Abstract

The effects of ethanol on serotonin (5-hydroxytryptamine, 5-HT) receptor binding in rat and mouse brain were determined under in vitro conditions and in mouse brain following seven days of ethanol ingestion. 5-HT 1A receptor characteristics were measured utilizing the agonist [ 3H]8-hydroxy-2-(di-n-propylamino)tetralin ([ 3H]DPAT), and 5HT 2 receptor-binding studies utilized the antagonist [ 3H]ketanserin. At the highest concentration of ethanol tested in vitro (680 mM), there was only 25% inhibition of [ 3H]DPAT binding in rat and mouse brain and 14% inhibition of [ 3H]ketanserin binding in rat brain. Effects of an anesthetic concentration of ethanol (100 mM) on agonist binding in the presence and absence of the guanine nucleotide GTP were also evaluated in vitro in mouse brain. In no case did ethanol (100 mM) significantly affect 5-HT 1A or 5-HT 2 receptor-binding characteristics. When 5-HT receptor characteristics were measured after mice consumed ethanol for seven days, there was no change in either 5-HT 1A or 5-HT 2 receptor-binding properties in any of the brain areas examined.