[MK-801 attenuates NOS expression and NO content in the spinal cord of rats with inflammatory pain].
Using NADPH-d histochemistry, the effect of NMDA receptor antagonist MK-801 on the expression of nitric oxide synthase (NOS) in the dorsal horn of the spinal cord was investigated during inflammatory pain and hyperalgesia induced by injection of formalin into the right hind paw. The course of the change in the nitric oxide (NO) content of the lumbar intumescence was observed by measuring the ratio of nitrate/nitrite (NO3T/NO2T) and also the end product of NO. The results showed that the NOS expression and NO contents significantly increased 24 h after formalin injection, which were substantially inhibited when MK-801 was intrathecally injected 15 min prior to formalin injection or 12 h after formalin injection. The results suggest that the increases in the expression of NOS and NO contents in the dorsal horn of the spinal cord are mediated by activation of NMDA receptors during pain and hyperalgesia after formalin injection.
Zeng
J B
JB
Department of Pathophysiology, Basic Medical Institute, Hebei Medical University, Shijiazhuang 050017.
Li
W B
WB
Li
Q J
QJ
Chen
X L
XL
Zhou
A M
AM
Ling
Y L
YL
D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D005260:Female; D006930:Hyperalgesia / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D010146:Pain / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000502:physiology; D013116:Spinal Cord / Q000378:metabolism*
D016194:Receptors, N-Methyl-D-Aspartate; D009569:Nitric Oxide; D016291:Dizocilpine Maleate; D019001:Nitric Oxide Synthase