title: Lack of reciprocity between opioid and 5-HT3 receptors for antinociception in rat spinal cord.
abstract: We examined the properties of the drug interaction between morphine and 5-HT(3) receptor antagonist at the spinal level. The nociceptive state was induced by subcutaneously injecting formalin solution (5%, 50 microl) into the hindpaw of the rats. Intrathecal morphine and m-CPBG (5-HT(3) receptor agonist) dose-dependently decreased the flinching response during phase 1 and phase 2 in the formalin test. Intrathecal 5-HT(3) receptor antagonists (LY-278,584 and ondansetron) did not reverse the antinociceptive effect of intrathecal morphine. Intrathecal naloxone had little effect on attenuation of the antinociception of intrathecal m-CPBG. Taken together, no reciprocal interaction was noted between 5-HT(3) receptor and opioid receptors at the spinal level. Thus, the 5-HT(3) receptor antagonist may be useful to manage opioid-induced emesis at the spinal level.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, Korea.
authors.forename: Myung Ha
authors.initials: MH
authors.lastname: Yoon
authors.forename: Hong Beom
authors.initials: HB
authors.lastname: Bae
authors.forename: Jeong Il
authors.initials: JI
authors.lastname: Choi
authors.forename: Seok Jai
authors.initials: SJ
authors.lastname: Kim
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Chung
authors.forename: Chang Mo
authors.initials: CM
authors.lastname: Kim
mesh_terms: D000698:Analgesia; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001645:Biguanides / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde / Q000008:administration & dosage / Q000633:toxicity; D006614:Hindlimb; D007191:Indazoles / Q000008:administration & dosage / Q000494:pharmacology; D007278:Injections, Spinal; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D017294:Ondansetron / Q000008:administration & dosage / Q000494:pharmacology; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology* / Q000517:prevention & control; D010147:Pain Measurement / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000502:physiology*; D044406:Receptors, Serotonin, 5-HT3 / Q000502:physiology*; D058831:Serotonin 5-HT3 Receptor Antagonists; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D013116:Spinal Cord / Q000187:drug effects / Q000503:physiopathology*; D014326:Tropanes / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000701:Analgesics, Opioid; D001645:Biguanides; D007191:Indazoles; D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D044406:Receptors, Serotonin, 5-HT3; D058831:Serotonin 5-HT3 Receptor Antagonists; D017366:Serotonin Receptor Agonists; D014326:Tropanes; C061531:LY 278584; D005557:Formaldehyde; D009270:Naloxone; D017294:Ondansetron; D009020:Morphine; C065734:1-(3-chlorophenyl)biguanide