Methodological note: intragastric intubation of ethanol to rat pups

A method is described for delivering exact amounts of ethanol to rat pups during the preweaning period. It minimizes the confounding effects of undernutrition as indicated by body weight impairment. Rat pups fed intragastrically with relatively low doses of ethanol (0.8, 1.2, or 2.0 g/kg) in a 20% (w/v) nutriment solution (Sustagen, Mead Johnson) maintained body weights at levels comparable to those of same-sex littermate controls fed equal volumes of isocaloric nutriment or untreated. The findings indicate the feasibility of using the intragastric feeding procedure to administer repeatedly an exact quantity of ethanol which does not alter body weight. Thirty minutes after intubation of a challenge dose of ethanol (2.0 g/kg), the blood alcohol concentration (BAC) of both ethanol and control groups were comparably elevated. After four hours, only the BAC of the control group had fallen significantly. These results suggest that ethanol-induced metabolic effects may occur without alteration of body weight. Higher doses of ethanol (5-7 g/kg) produced body weight impairment and/or death.