Lack of reciprocity between opioid and 5-HT3 receptors for antinociception in rat spinal cord.
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.
Yoon
Myung Ha
MH
Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, Korea.
Bae
Hong Beom
HB
Choi
Jeong Il
JI
Kim
Seok Jai
SJ
Chung
Sung Tae
ST
Kim
Chang Mo
CM
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
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