[Comparison of NMDA and non-NMDA receptor antagonists-induced inhibition in hindpaw withdrawal response to noxious thermal stimulation].
In our previous electrophysiological study, it was shown that NMDA receptors are predominantely involved in the transmission of nociceptive cutaneous afferents, whereas non-NMDA receptors are mainly concerned with the transmission of nociceptive muscular afferents. In the present investigation, the effects of NMDA and non-NMDA receptor antagonists were tested in rat hindpaw withdrawal response to noxious thermal stimulation. Intrathecal application of non-NMDA receptor antagonist 1 nmol/L DNQX (6,7-dinitroquinoxaline-2,3(1H, 4H)-dione) had no effect on paw withdrawal latencies (PWL), but NMDA receptor antagonist 1 nmol/L APV [(+/-) 2-amino-5-phosphonovalerate)] significantly prolonged PWL (P < 0.05). Both APV and DNQX at 10 nmol/L significantly increased PWL with the former agent being more potent. The results further support that both NMDA and non-NMDA receptors are involved in the transmission of spinal nociception, with the former being more preferentially involved in the transmission of nociceptive information from the skin.
Shu
Y S
YS
Shanghai Brain Research Institute, Chinese Academy of Sciences, Shanghai 200031.
Zhao
Z Q
ZQ
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006614:Hindlimb; D006358:Hot Temperature; D008297:Male; D009619:Nociceptors / Q000187:drug effects*; D010146:Pain / Q000503:physiopathology*; D017288:Pain Threshold / Q000187:drug effects*; D010812:Physical Stimulation; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D012867:Skin / Q000503:physiopathology
D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate