Intrathecal injection of glutamate receptor antagonists/agonist selectively attenuated rat pain-related behaviors induced by the venom of scorpion Buthus martensi Karsch.
The present study investigated the involvement of spinal glutamate receptors in the induction and maintenance of the pain-related behaviors induced by the venom of scorpion Buthus martensi Karsch (BmK). (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5-10-imine hydrogen maleate (MK-801; 40nmol; a non-competitive NMDA receptor antagonist), 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 40nmol; a non-NMDA receptor antagonist), dl-amino-3-phosphonopropionic acid (dl-AP3; 100nmol; a group I metabotropic glutamate receptor antagonist) and 4-aminopyrrolidine-2,4-dicarboxylate (APDC; 100nmol; a group II metabotropic glutamate receptor agonist) were employed. On intrathecal injection of glutamate receptor antagonists/agonist before BmK venom administration by 10min, BmK venom-induced spontaneous nociceptive responses could be suppressed by all tested agents. Primary thermal hyperalgesia could be inhibited by MK-801 and dl-AP3, while bilateral mechanical hyperalgesia could be inhibited by CNQX and dl-AP3 and contralateral mechanical hyperalgesia could be inhibited by APDC. On intrathecal injection of glutamate receptor antagonists/agonist after BmK venom injection by 4.5h, primary thermal hyperalgesia could be partially reversed by all tested agents, while bilateral mechanical hyperalgesia could only be inhibited by APDC. The results suggest that the role of spinal glutamate receptors may be different on the various manifestations of BmK venom-induced pain-related behaviors.
Liu
Tong
T
Graduate School of the Chinese Academy of Sciences, Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, PR China.
Pang
Xue-Yan
XY
Bai
Zhan-Tao
ZT
Chai
Zhi-Fang
ZF
Jiang
Feng
F
Ji
Yong-Hua
YH
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000008:administration & dosage; D000409:Alanine / Q000008:administration & dosage / Q000031:analogs & derivatives; D000818:Animals; D016291:Dizocilpine Maleate / Q000008:administration & dosage; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage*; D007278:Injections, Spinal; D008297:Male; D010146:Pain / Q000188:drug therapy*; D011392:Proline / Q000008:administration & dosage / Q000031:analogs & derivatives; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D012604:Scorpion Venoms / Q000633:toxicity*
C097299:4-aminopyrrolidine-2,4-dicarboxylic acid; D018691:Excitatory Amino Acid Antagonists; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D012604:Scorpion Venoms; C000211:2-amino-3-phosphonopropionic acid; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D011392:Proline; D000409:Alanine