Wang H, Nie H, Zhang R X, Qiao J T
Department of Neurobiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China.
J Neurosci Res. 1999 Sep 15;57(6):824-9.
Nociceptive c-fos expressions in the dorsal horn following intraplantar injection of two kinds of algogenic agents combined with different doses of nitric oxide (NO) synthase inhibitor (N(omega)-nitro-L-arginine methyl ester (L-NAME)) or of NO donor (L-arginine) were used to explore if NO was involved in the activation of peripheral nociceptors. The results showed that: 1) combined injections of L-NAME with formalin into the plantar aspect of one hindpaw of normal rats elicited a dose-dependent suppression of c-fos expression as compared to that induced by formalin alone; 2) combined injections of L-arginine with formalin elicited considerable enhancement of c-fos expression when the dosages of L-arginine were less than 20 micromol, while it elicited marked suppression of c-fos expression when the dosages were in the range from 50 to 100 micromol; and 3) combined injection of L-NAME with NMDA, a selective agonist for NMDA receptors, into the hindpaw could also inhibit the NMDA-induced c-fos expression in the spinal dorsal horn. These results suggest that endogenously generated concentrations of nitric oxide may enhance the initiation of nociceptive inputs of peripheral nociceptors following local injection of formalin or NMDA.
通过向足底注射两种致痛剂并联合不同剂量的一氧化氮（NO）合酶抑制剂（N（ω）-硝基-L-精氨酸甲酯（L-NAME））或NO供体（L-精氨酸），观察背角中伤害性c-fos表达，以探究NO是否参与外周伤害感受器的激活。结果显示：1）正常大鼠一侧后足足底联合注射L-NAME和福尔马林，与单独注射福尔马林相比，c-fos表达呈剂量依赖性抑制；2）联合注射L-精氨酸和福尔马林，当L-精氨酸剂量小于20 μmol时，c-fos表达显著增强，而当剂量在50至100 μmol范围内时，c-fos表达显著抑制；3）后足联合注射L-NAME和NMDA（一种NMDA受体选择性激动剂），也可抑制脊髓背角中NMDA诱导的c-fos表达。这些结果表明，内源性产生的一氧化氮浓度可能会增强局部注射福尔马林或NMDA后外周伤害感受器伤害性传入的起始。
