福尔马林致痛兔脊髓背角浅层内P物质含量的变化

目的 :观察福尔马林致痛兔脊髓背角浅层内P物质 (SP)含量的变化和行为反应的改变。方法 :健康成年日本大耳白兔 6只随机分为两组 :实验组 (A组 ,n=3)和对照组 (B组 ,n =3)。A组在一侧前肢趾部皮下注射 3 %福尔马林溶液 0 .2ml,B组用等量生理盐水 ,观察并记录动物的行为反应。 2h后灌注固定取脊髓颈段 6～ 8(C6～ 8)和胸段 6～ 8(T6～ 8) ,用免疫组织化学方法 (SABC法 )显示脊髓背角浅层内SP含量的变化。结果 :SP阳性反应物集中分布在脊髓背角Ⅰ、Ⅱ层。A组刺激侧脊髓颈段SP的光密度 (OD)值较对侧明显下降 (P <0 .0 1 ) ,与B组相比也明显下降 (P <0 .0 1 ) ;B组脊髓颈段两侧SP的OD值无明显差别 (P >0 .0 5) ,两组脊髓胸段两侧SP的OD值也无明显差别 (P >0 .0 5)。福尔马林致痛后兔的行为反应与大鼠相似。结论 :家兔皮下注射福尔马林出现类似大鼠的行为反应 ,同时引起脊髓内SP含量下降

Changes of Substance P in the Superficial Layers of the Spinal Dorsal Horn in the Rabbit Following Formalin Stimulation

Objective To observe the change of substance P (SP) in the superficial layers of spinal dorsal horn and behavior following formalin stimulation in rabbits.Methods Six rabbits were randomly divided into two groups: experiment group (group A, n =3) and control group (group B, n =3).0.2 ml of 3% formalin was injected subcutaneously into one front paw in group A with equal normal solution in group B.The behavior changes of the rabbits were observed and recorded.Two hours later, a single block of each of cervical 6～8(C 6～8 ) and thoracic 6～8(T 6～8 ) spinal cord were removed from each rabbit after anesthesia and fixing.Immunohistochemical strept avidin-biotin enzyme complex (SABC) technique was used to display SP in slices of spinal dorsal horn.Results The behavior changes of the rabbit are similar to the rat's in formalin stimulation.Immunoreaction of SP was distributed mainly in lamina Ⅰand Ⅱof dorsal horn.In group A,the optical density(OD) of SP in ipsilateral cervical slices was decreased significantly compared with contralateral and with group B( P <0.01, P <0.01);the OD of SP in cervical slices in group B and between the two groups showed no difference( P >0.05).Conclusion The behavior changes of the rabbit are similar to the rat's in formalin test with the content of SP decrease in the superficial layers of the spinal dorsal horn in the rabbitsimultaneously.