福尔马林致痛对大鼠行为学及脊髓NO、Fos的影响

目的：探讨大鼠福尔马林致痛的可能机制。方法：雄性SD大鼠64只，随机分为对照组(NS组、福尔马林对照组)和实验组(LaF组、LnF组)。NS组为正常对照组，LaF组、LnF组在同福尔马林对照组处理前分别给予L-精氨酸(L-Arg)，L-NG-硝基精氨酸甲酯(L-NAME)鞘内注射，在福尔马林处理后1／2h、O～1h分别检测大鼠脊髓NOS及Fos的表达及观察大鼠的行为学表现。结果：福尔马林对照组的缩腿舔爪时间长于NS组、脊髓的NOS及Fos表达显著强于NS组，预先给予L-Arg或L-NAME分别能加强或抑制以上作用。结论：福尔马林致痛能引起大鼠脊髓背角NO的释放，诱导Fos的表达可能是其产生伤害作用的机制之一。

Effect of Fos Expression Induced by Spinal Nitric Oxide on the Nociception of Formalin in Rats

OBJECTIVE: To assess the effect of s.c. injected formalin and clarify the possible mechanism of nociception in SD rats. METHODS: Sixty-four healthy male rats were randomly distributed into the control groups (group NS, group formalin) and test groups (group LaF, group LnF) with correponding numbers. Group NS served as normal control. Group formalin was treated with 5% formalin 100 microliters, s.c. Groups LaF and LnF were treated respectively with L-Arg 4.7 mumol ith and L-NAME 370 nmol ith before receiving 5% formalin 100 microliters, s.c. like group formalin. 1/2 h and 0-1 h after formalin treatment, spinal cord segments were removed for expression of NOS, and behavior responses were observed. RESULTS: The flinching and licking time of group formalin was longer than that of group NS, and NOS expression of group formalin was stronger than that of group NS. Pretreatment with L-Arg potentiated formalin-induced response, but pretreatment with L-NAME reduced the response. CONCLUSIONS: Spinal nitric oxide release might be one of the nociception mechanisms in the formalin test.