title: Blockade of 5-HT7 receptors reduces tactile allodynia in the rat.
abstract: This study assessed the role of systemic and spinal 5-HT(7) receptors on rats submitted to spinal nerve injury. In addition, the 5-HT(7) receptors level in dorsal root ganglion and spinal cord was also determined. Tactile allodynia was induced by L5/L6 spinal nerve ligation. Systemic (0.01-10mg/kg) or spinal (0.3-30 μg) administration of the selective 5-HT(7) receptor antagonist SB-269970 but not vehicle reduced in a dose-dependent manner established tactile allodynia. This effect was maintained for about 6h. SB-269970 was more potent and effective by the spinal administration route than through systemic injection. Spinal nerve ligation reduced expression of 5-HT(7) receptors in the ipsilateral but not contralateral dorsal root ganglia. Moreover, 5-HT(7) receptor levels were lower in the ipsilateral dorsal spinal cord of neuropathic rats compared to naïve and sham rats. No changes in the receptor levels were observed in the contralateral dorsal spinal cord and in both regions of the ventral spinal cord. Data suggest that spinal 5-HT(7) receptors play a pronociceptive role in neuropathic rats. Results also indicate that spinal nerve injury leads to a reduced 5-HT(7) receptors level in pain processing-related areas which may result from its nociceptive role in this model. Data suggest that selective 5-HT(7) receptor antagonists may function as analgesics in nerve injury pain states.
authors.affiliation: Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados (Cinvestav), Sede Sur, México, D.F., Mexico.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Amaya-Castellanos
authors.forename: Jorge B
authors.initials: JB
authors.lastname: Pineda-Farias
authors.forename: Gabriela
authors.initials: G
authors.lastname: Castañeda-Corral
authors.forename: Guadalupe C
authors.initials: GC
authors.lastname: Vidal-Cantú
authors.forename: Janet
authors.initials: J
authors.lastname: Murbartián
authors.forename: Héctor I
authors.initials: HI
authors.lastname: Rocha-González
authors.forename: Vinicio
authors.initials: V
authors.lastname: Granados-Soto
mesh_terms: D000700:Analgesics; D000818:Animals; D019540:Area Under Curve; D015153:Blotting, Western; D003627:Data Interpretation, Statistical; D005260:Female; D007839:Functional Laterality / Q000187:drug effects / Q000502:physiology; D006930:Hyperalgesia / Q000188:drug therapy* / Q000523:psychology; D007274:Injections, Intraperitoneal; D007278:Injections, Spinal; D008026:Ligation; D009437:Neuralgia / Q000188:drug therapy; D010147:Pain Measurement / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology; D010812:Physical Stimulation; D020671:Posterior Horn Cells / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013127:Spinal Nerves; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D000700:Analgesics; D010636:Phenols; D011985:Receptors, Serotonin; C404922:SB 269970; D012702:Serotonin Antagonists; D013449:Sulfonamides; C104425:serotonin 7 receptor