PCP, THC, ethanol, and morphine and consumption of palatable solutions

Water-deprived rats were given daily opportunities (2.0-hr sessions) to take water or a sweet solution (20% or 24% sugar-water). After stable intakes of each fluid were achieved, the effects of phencyclidine hydrochloride (PCP), delta-9-tetrahydrocannabinol (THC), ethanol (E), and morphine (M) on intakes were tested. PCP, THC, and M all enhanced intake of the sweet solution, while E produced varying effects across doses tested. With other rats, nearly the same procedure was used except that the test solution presented with water was 0.9% sodium chloride. Doses of PCP enhanced intake of the salty solution. These data, combined with the data from similar studies of the effects of opioids and benzodiazepines, indicate that a wide variety of agents that are self-administered also modify intake of ingesta.