title: Amino acid transport system A is involved in inflammatory nociception in rats.
abstract: Previous studies have indicated that central sensitization is a state of increased excitability of nociceptive neurons in the spinal dorsal horn following peripheral tissue injury and/or inflammation and astrocytes play an important role in the central sensitization. The current study investigated the role of amino acid transport system A in central sensitization and hyperalgesia induced by intraplantar injection of formalin in rats. Formalin (5%, 50μl) injected subcutaneously into the unilateral hindpaw pad induced typical biphase nociceptive behaviors, including licking/biting and flinching of the injected paw and an increase of glial fibrillary acid protein (GFAP, an activated astrocyte marker) expression in spinal dorsal horn, and these effects could be attenuated by intrathecal injection of the competitive inhibitor of amino acid system A transporter, methylaminoisobutyric acid (MeAIB, 0.1, 0.3, 0.5, and 0.7mmol), in a dose-dependent manner. Intrathecal injection of vehicle (PBS) had no effect on the formalin-induced nociceptive behaviors and increase of the GFAP. These findings suggest that amino acid transport system A is involved in inflammation-induced nociception, and inhibition of this transporter system results in inhibition of the central sensitization and hyperalgesia.
authors.affiliation: Institute of Orthopaedics, Second Hospital of Lanzhou University, Lanzhou University, No. 82 Cui Ying Men Street, Lanzhou, Gansu 730030, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Geng
authors.forename: Hai-Li
authors.initials: HL
authors.lastname: Shen
authors.forename: Xu
authors.initials: X
authors.lastname: Xu
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Cui-Fang
authors.initials: CF
authors.lastname: Wang
authors.forename: Jing-Ling
authors.initials: JL
authors.lastname: Ma
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Wang
mesh_terms: D026924:Amino Acid Transport System A / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D059333:Central Nervous System Sensitization / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism; D008297:Male; D059226:Nociceptive Pain / Q000378:metabolism*; D009619:Nociceptors / Q000187:drug effects / Q000378:metabolism; D010147:Pain Measurement / Q000187:drug effects; D020671:Posterior Horn Cells / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism; D015091:beta-Alanine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D026924:Amino Acid Transport System A; D005904:Glial Fibrillary Acidic Protein; D015091:beta-Alanine; C012924:2,2-dimethyl-beta-alanine