CONSTANT ABSOLUTE ETHANOL INTAKE BY SARDINIAN ALCOHOL-PREFERRING RATSINDEPENDENT OF ETHANOL CONCENTRATIONS

The present study was designed to evaluate ethanol drinking behaviour in Sardinian alcohol-preferring (sP) and Sardinian alcohol-non-preferr ing (sNP) rats in the presence of different ethanol concentrations. Et hanol intake was tested under the two-bottle, free-choice regimen and continuous access schedule. Ethanol-naive sP and sNP rats were initial ly given ethanol solution at the standard, constant concentration of 1 0% (v/v) for 8 consecutive days (Phase 1). As expected, daily ethanol intake in sP rats rose from 4 to similar to 6 g/kg; in contrast sNP ra ts consumed <10 g/kg/day ethanol. Subsequently, an ascending series of ethanol concentrations, ranging from 3 to 60% (v/v), was presented to sP and sNP rats over a 28-day period (Phase 2). At concentrations var ying from 7 to 30%, sP rats consumed constant amounts of absolute etha nol per kg of body weight (similar to 6.0 g/kg/day). Daily ethanol int ake in sNP rats remained constantly lower than 1.0 g/kg, irrespective of the ethanol concentration. Data from Phase 2 demonstrate the abilit y of sP rats to precisely adjust daily ethanol intake and support the hypothesis that voluntary ethanol drinking in sP rats is sustained by specific pharmacological effects of ethanol.