Tags

Type your tag names separated by a space and hit enter

Antiallodynic effects of intrathecally administered 5-HT(2C) receptor agonists in rats with nerve injury.
Pain. 2004 Mar; 108(1-2):163-9.PAIN

Abstract

Intrathecal administration of serotonin type 2 (5-HT(2)) receptor agonists, alpha-methyl-5-hydroxytryptamine maleate (alpha-m-5-HT) or (+/-)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI), produces antiallodynic effects in a rat model of neuropathic pain. In the present study, we examined the antiallodynic effects of intrathecally administered agents which are selective for 5-HT(2C) receptors. Allodynia was produced by tight ligation of the left L5 and L6 spinal nerves, and was measured by applying von Frey filaments to the left hindpaw. Administration of the 5-HT(2C) receptor agonist, 6-chloro-2-(1-piperazinyl)-pyrazine (MK212; 3-100 microg), 1-(m-chlorophenyl)-piperazine (mCPP; 30-300 microg), or 1-(m-trifluoromethylphenyl)-piperazine (TFMPP; 30-300 microg), produced antiallodynic effects in a dose-dependent manner with no associated motor weakness. The ED(50) values of MK212, mCPP, and TFMPP were 39.2, 119.9, and 191.9 microg, respectively. Intrathecal pretreatment with the selective 5-HT(2C) receptor antagonist RS-102221 (30 microg) diminished the effects of the highest doses of 5-HT(2C) receptor agonists. The preferential 5-HT(2A) receptor antagonist ketanserin (30 microg) did not reverse the effects. In contrast to 5-HT(2C) receptor agonists, the antiallodynic effects of intrathecally administered alpha-m-5-HT (30 microg) and DOI (100 microg) were reversed by ketanserin, but not by RS-102221. These results indicate that 5-HT(2C) receptors have a role in spinal inhibition of neuropathic pain, and the effects produced by intrathecal administration of 5-HT(2C) receptor agonists are mediated by a mechanism different from that of alpha-m-5-HT or DOI, which seem to produce their effects through 5-HT(2A) receptors.

Authors+Show Affiliations

Department of Anesthesiology, Gunma University Graduate School of Medicine, 3-39-22, Maebashi, Gunma 371-5811, Japan. hobata@showa.gunma-u.ac.jpNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15109520

Citation

Obata, Hideaki, et al. "Antiallodynic Effects of Intrathecally Administered 5-HT(2C) Receptor Agonists in Rats With Nerve Injury." Pain, vol. 108, no. 1-2, 2004, pp. 163-9.
Obata H, Saito S, Sakurazawa S, et al. Antiallodynic effects of intrathecally administered 5-HT(2C) receptor agonists in rats with nerve injury. Pain. 2004;108(1-2):163-9.
Obata, H., Saito, S., Sakurazawa, S., Sasaki, M., Usui, T., & Goto, F. (2004). Antiallodynic effects of intrathecally administered 5-HT(2C) receptor agonists in rats with nerve injury. Pain, 108(1-2), 163-9.
Obata H, et al. Antiallodynic Effects of Intrathecally Administered 5-HT(2C) Receptor Agonists in Rats With Nerve Injury. Pain. 2004;108(1-2):163-9. PubMed PMID: 15109520.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Antiallodynic effects of intrathecally administered 5-HT(2C) receptor agonists in rats with nerve injury. AU - Obata,Hideaki, AU - Saito,Shigeru, AU - Sakurazawa,Shinobu, AU - Sasaki,Masayuki, AU - Usui,Tadashi, AU - Goto,Fumio, PY - 2003/03/18/received PY - 2003/10/13/revised PY - 2003/12/17/accepted PY - 2004/4/28/pubmed PY - 2004/6/4/medline PY - 2004/4/28/entrez SP - 163 EP - 9 JF - Pain JO - Pain VL - 108 IS - 1-2 N2 - Intrathecal administration of serotonin type 2 (5-HT(2)) receptor agonists, alpha-methyl-5-hydroxytryptamine maleate (alpha-m-5-HT) or (+/-)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI), produces antiallodynic effects in a rat model of neuropathic pain. In the present study, we examined the antiallodynic effects of intrathecally administered agents which are selective for 5-HT(2C) receptors. Allodynia was produced by tight ligation of the left L5 and L6 spinal nerves, and was measured by applying von Frey filaments to the left hindpaw. Administration of the 5-HT(2C) receptor agonist, 6-chloro-2-(1-piperazinyl)-pyrazine (MK212; 3-100 microg), 1-(m-chlorophenyl)-piperazine (mCPP; 30-300 microg), or 1-(m-trifluoromethylphenyl)-piperazine (TFMPP; 30-300 microg), produced antiallodynic effects in a dose-dependent manner with no associated motor weakness. The ED(50) values of MK212, mCPP, and TFMPP were 39.2, 119.9, and 191.9 microg, respectively. Intrathecal pretreatment with the selective 5-HT(2C) receptor antagonist RS-102221 (30 microg) diminished the effects of the highest doses of 5-HT(2C) receptor agonists. The preferential 5-HT(2A) receptor antagonist ketanserin (30 microg) did not reverse the effects. In contrast to 5-HT(2C) receptor agonists, the antiallodynic effects of intrathecally administered alpha-m-5-HT (30 microg) and DOI (100 microg) were reversed by ketanserin, but not by RS-102221. These results indicate that 5-HT(2C) receptors have a role in spinal inhibition of neuropathic pain, and the effects produced by intrathecal administration of 5-HT(2C) receptor agonists are mediated by a mechanism different from that of alpha-m-5-HT or DOI, which seem to produce their effects through 5-HT(2A) receptors. SN - 0304-3959 UR - https://www.unboundmedicine.com/medline/citation/15109520/Antiallodynic_effects_of_intrathecally_administered_5_HT_2C__receptor_agonists_in_rats_with_nerve_injury_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0304395903005013 DB - PRIME DP - Unbound Medicine ER -