Modulation of 5-HT1C receptors and phosphoinositide system by ethanol consumption in rat brain and choroid plexus (original) (raw)

The effect of chronic ethanol consumption (60 days) on 5-HTlc receptors as measured by [3H]mesulergine binding in the hippocampus, cortex, and choroid plexus of rats was investigated. The 5-HT~c receptor-mediated phosphoinositide hydrolysis in rat choroid plexus was also investigated. It was observed that chronic ethanol treatment significantly increased the 5-HT-stimulated [3H]inositol 1-phosphate ([3H]IP1) formation, as well as the density (Bma x) of 5-HTIc receptors without causing a significant change in affinity (K D) of [3H]mesulergine binding in rat choroid plexus. It was also observed that chronic ethanol consumption had no significant effect on the Bma x or K o of 5-HT~c receptor binding sites in the hippocampus and cortex brain regions of rats. These results thus suggest that chronic ethanol consumption causes an up-regulation of both 5-HT~c receptors and 5-HT w receptor-mediated phosphoinositide hydrolysis in rat choroid plexus but has no significant effects on the 5-HTlc receptors in brain. These results also suggest that 5-HT~c receptors and their functional response may be involved in the pathogenesis of alcohol dependence.