The effect of reserpine and stress on feeding behaviour in the light and dark phases of the diurnal cycle in rats.

Abstract

The effect of reserpine (2.5 mg kg-1 subcutaneously) and stress (3 h restraint) on food and water consumption and body weight change in the light and dark phases of the diurnal cycle in rats was investigated. Reserpine increased water intake and body weight loss in the light phase (250 and 180% of the control, respectively). In the dark phase the reserpinized rats consumed less food and water (20 and 30% of the control, respectively) and body weight gain was reversed (-250% of the control). After stress, rats consumed more food and water (200 and 500% of the control, respectively) and their body weight loss was diminished (60% of the control) in the light phase. In the dark phase the consumption of food and water in the stressed rats was diminished (80 and 85% of the control, respectively) without any change in body weight gain. The dark/light phase ratio for food consumption, water intake and body weight change (gain/loss) was highly statistically significant in the stressed and reserpine-treated rats. The results indicate that evaluation of behaviour in animal models should be carried out during both phases of the diurnal cycle.