Fluid consumption in water-deprived rats after administration of naloxone or quaternary naloxone.
Water-deprived male rats were given access to water, or to a 0.005M sodium saccharin solution, or to a 0.9% sodium chloride solution, during a 30 min test period. Naloxone (0.01-10.0 mg/kg) produced dose-dependent reductions in the consumption of each fluid. Saccharin-drinking was significantly reduced by 0.01 mg/kg naloxone, and water- and saline-drinking by 0.1 mg/kg naloxone. Quaternary naloxone (0.01-10.0 mg/kg) had no effect on drinking under any condition. Access to the saline solution resulted in hyperdipsia, due to a prolongation of the initial bout of avid drinking in the thirsty rats. Naloxone, in small doses, completely abolished this hyperdipsia. Since the quaternary compound had no effect, it was concluded that opiate antagonist suppression of saline-induced hyperdipsia was probably mediated at central opiate receptors.
D000818:Animals; D004326:Drinking / Q000187:drug effects*; D004091:Hydromorphone / Q000031:analogs & derivatives*; D008297:Male; D009115:Muridae; D009270:Naloxone / Q000494:pharmacology*; D010111:Oxymorphone / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects; D013649:Taste / Q000187:drug effects; D013894:Thirst / Q000187:drug effects*; D014868:Water Deprivation
D011957:Receptors, Opioid; D009270:Naloxone; D010111:Oxymorphone; D004091:Hydromorphone