Systemic administration of baclofen inhibits water intake in rats

1. The present experiments were carried out to investigate the effects of systemic administration of baclofen on water intake in rats. 2. Baclofen (1, 2 and 4 mg/kg, s.c.) inhibited water intake in 16 hr water-deprived rats in a dose-related manner, with maximal effects occurring during the first 30 min after administration. 3. Baclofen (0.25 and 2 mg/kg, s.c.) had no effects on water intake in non-deprived rats. 4. Baclofen (2 mg/kg) inhibited water intake elicited by i.p. injection of hypertonic NaCl in rats. 5. Baclofen (1 mg/kg) did not produce taste aversion in a taste aversion experiment. This indicates that the effects of baclofen on water intake is not due to an aversive effect of the drug.