ALTERED DOPAMINE TRANSPORTER DENSITIES IN ALCOHOL-PREFERRING VERVET MONKEYS

ALTERED dopamine (DA) transporter densities have been implicated in me chanisms of vulnerability and relapse in human alcoholics. The regiona l distribution and density of the DA transporter was studied in alcoho l-preferring vervet monkeys to investigate baseline status and regulat ion of the DA transporter at different stages of chronic alcohol drink ing. Combined ligand binding and in vitro autoradiography of the cocai ne congener [I-125]RTI-55 (beta-CIT) demonstrated a significant increa se in DA transporter densities in abstinent alcohol-preferring monkeys over those in alcohol-avoiding monkeys. Chronic alcohol consumption d own-regulated DA transporter densities, and this effect was reversed b y acute withdrawal. These results demonstrate that the DA transporter is regulated by alcohol exposure and suggest that increased DA transpo rter densities may be a phenotypic marker of alcohol preference in vul nerable monkeys.