Kinetic studies of food intake and sucrose solution preference by rats treated with low doses of Δ 9-tetrahydrocannabinol

Abstract

The experiments to be described were undertaken to determine time-related effects of single low-dose levels of Δ9-tetrahydrocannabinol on food and sucrose solution consumption of rats. One hour after receiving oral doses of 0.00, 0.25, and 0.40 mg/kg, rats were offered free access to wet and dry chow and one of five concentrations of sucrose solution and water. Intakes were recorded after various time intervals during the 24 hr following treatment. Rats treated with Δ9-tetrahydrocannabinol consumed dry chow at significantly higher rates, during the first hour of feeding, and the strongest sucrose solution, at significantly higher rates during the first half-hour of drinking, than controls. Treatment group differences in food and sucrose solution intakes existed throughout the 24-hr period. In both studies, rats treated with the drug initially consumed kilocalories from food and sucrose at higher rates than controls. Rats compensated for early large kilocalorie intakes by decreasing consumption rates later to yield a total 24-hr intake which nearly matched control values. The findings suggest that low doses of Δ9-tetrahydrocannabinol produce dose- and time-dependent effects on food and sucrose solution intake and preference and on kilocalorie consumption rates in rats during the 24-hr period following administration of the drug.