... encephalomyelitis in Lewis rats, the animalmodel for multiple sclerosis, reported that administrationof the opioid antagonist naloxone markedly increases theseverity of the condition [27]. In our study, ... [25].Efficiency and toxicity are the two most important aspects in the search for potential pain gene therapies, with toxicityoften being the limiting factor. Because the gene encod-ing POMC has not previously ... except that, 30 minutes beforethe nociceptive test at 7 days after CFA injection, nalox-one (1 mg/kg) was administered intraperitoneally to deter-mine whether any analgesic effect was mediated...