Circadian phase dependent effects of d-amphetamine sulfate and level of deprivation on water intake in hooded rats

Abstract

Two groups of seven male hooded rats were tested following one and 24 hours of water deprivation under each of four levels of d-Amphetamine sulfate (control, .4, .8, 1.2 mg/kg) at 0900 and 2100 hours EDST. Licks upon a water spout were recorded for two hours after the drug injection. In addition, measures of the latency to begin licking and the amount of food consumed were also taken at each test session. All of the variables examined interacted significantly. Following 24 hours of water deprivation, amphetamine reduced both food and water intake at both times of day. Following one hour of water deprivation, the low dosages of amphetamine produced a significant increase in water intake at both times of day. This increase did not occur for food intake. The results are discussed in terms of an adrenergic mechanism which controls "free-running" water intake in the rat independently of food intake.