Ethanol dependence as a determinant of fluid preference.

Rats made dependent on ethanol by a schedule-induced polydipsia procedure preferred 5% ethanol to an increasing concentration of dextrose solution to a greater extent than animals on a non-dependent, non-polydipsic procedure which allowed an equivalent opportunity to drink ethanol, confirming a previous study. Two corresponding groups of animals drinking isotonic (0.9%) NaCl rather than 5% ethanol behaved similarly to the latter group, changing to a dextrose preference at a lower dextrose concentration than the ethanol polydipsic group. Therefore, neither the intermittent food regimen (polydipsia-generating procedure) in itself, nor a history of isotonic saline polydipsia biased fluid preference against dextrose solution choices. The enhanced preference for ethanol over dextrose solutions shown by the ethanol polydipsic group can be attributed to physical dependence rather than regiment produced artifacts.