Patol Fiziol Eksp Ter. 1992 Sep-Dec; (5-6): 7-9.
[Nociceptive sensitivity of rabbits in varying localization of pain stimuli and naloxone administration]
Study of the dynamics of changes of evoked potential (EP) amplitude in electrodental and electrocutaneous stimulation (EDS and ECS, respectively) as an index of the perceptual component of the nociceptive reaction showed that 0.2 mg/kg and 0.5 mg/kg doses of naloxone produce both a hyper- and an analgesic effect in rabbits. The effect of naloxone depended on the individual properties of the rabbits, while its degree was determined by the localization of the nociceptive stimulus. The animals' individual properties were manifested by the presence or absence of an analgesic effect of auricular electrostimulation--acupuncture-sensitive (AS) or acupuncture-resistant (AR) rabbits. Naloxone injection caused a dose-dependent hyperalgesic effect in AS animals and an analgesic effect in AR rabbits in EDS. Similar effects were recorded in ECS, but their degree differed: hyperalgesia in AS rabbits was demonstrated more clearly than analgesia in AR animals.