Dopamine D2 receptor binding in striatal membranes of rat lines selected for differences in alcohol-related behaviours.

The specific binding of 3H-spiperone to striatal membranes was compared within two pairs of rat lines produced by selective breeding for either differences in voluntary alcohol consumption or for differences in acute ethanol-induced motor impairment. Although a significant difference was found between the alcohol-preferring rats and alcohol-avoiding rat lines, the estimate for the Bmax value was only slightly lower in naive alcohol-preferring rats. The small magnitude of the difference suggests it is unimportant for the genetically-determined differences in alcohol preference. No significant differences were found in the estimates for their Kd values. There were no significant differences for either the Bmax and Kd values between the alcohol-sensitive and alcohol-insensitive rat lines, which suggests that striatal dopaminergic D2 receptors are not involved in the genetically-determined factors influencing sensitivity to alcohol (and also barbital and lorazepam).