Changes in behaviors of rats with sciatic nerve injury and expression of growth associated protein-43 in dorsal root ganglion

作     者：Chen Wang Yongfa Zhang 

作者机构：Department of Anesthesiology Second Hospital of Xiamen City Xiamen 361021 Fujian Province China Department of Anesthesiology Second Affiliated Hospital of Shantou University Medical College Shantou 515041 Guangdong Province China 

出 版 物：《Neural Regeneration Research》 (中国神经再生研究（英文版）)

年 卷 期：2006年第1卷第4期

页      面：304-308页

核心收录：

学科分类：10[医学] 

基　　金：the Natural Sci-ence Foundation of GuangdongProvince  No. 034628 

主　　题：dorsal root ganglion nerve injury neuropathic pain sciatic nerve immunohistochemical method image analysis system monoclonal antibody animal experiment molecular marker measurement data result analysis survival time Wistar rats 

摘      要：BACKGROUND： Neuropathic pain is closely related to neuroplasticity, and growth associated protein-43 （GAP 43） is a molecular marker for neuronal development and neuroplasticity. The expression of GAP-43 during the development of neuropathic pain should have its own characters. OBJECTIVE： To observe the changes in behaviors of rats with sciatic nerve injury and GAP-43 expression in dorsal root ganglion（DRG） affected ascribing to developing nerve transection and nerve crush, two types of neuropathic pain models. DESIGN： Randomized controlled animal experiment SETTING： Department of Anesthesiology in Second Hospital of Xiamen City and Second Affiliated Hospita of Shantou University Medical College. MATERIALS： Totally 250 adult Wistar rats of either gender, weighing 180 to 250 g, were involved in the study. The rats were randomized into 3 groups： nerve transection group （n =120）, nerve crush group （n =120）, and normal control group （n =10）. The rats in the nerve transection group and nerve crush group were subdivided separately into 6 groups,and were allowed to survive for 3, 7, 14, 21, 30 and 60 days after nerve injury （n =20）. Mouse anti-GAP-43 monoclonal antibody （Sigma Co.,Ltd.）, Supervision TM anti-mouse reagent （HRP, Changdao antibody diagnosis reagent Co.,Ltd., Shanghai）, DAB/H202 （Boster Co. Ltd, Wuhan）, and HMIAS-100 image analysis system （Qianping Image engineering Company, Tongji Medical University） were employed in this study. METHODS： This experiment was carried out in the Surgical Department and Pathological Laboratory, the Second Hospital Affiliated to Shantou Medical College during April 2004 to April 2005. （1） Grouping intervention： Animals were anesthetized and the sciatic nerve of the right side was exposed at thigh around ischial tuberosity. Sciatic nerves of rats in nerve transection group were transected at 1 cm below infrapiriform foramen, and those in nerve crush group were exposed as well as the nerve transection group, and crushed at 0.5 cm below infrapiriform foramen with hemostatic forceps for 10 s× 3 times. Rats in normal control group did not receive any treatments. （2） Behavioral observation： The behavioral changes were observed on the first day after sciatic nerve injury and spontaneous pain severity was measured with autotomy scores. One point was given for the removal of one nail, and the score was added 1 point for each distal digit affected, getting another point still suiting for each proximal digit, the maximum score permitted was 11 for each paw. （3） Detection of GAP-43： The DRG of L5 at right side was taken out respectively 3,7,14,21,30 and 60 days after nerve injury and made into sections. The expression of GAP-43 was detected with immunohistochemical method. T test was used for comparing the difference in the measurement data in clinical analysis. MAIN OUTCOME MEASURES ： （1） The severity of autotomy at the affected feet. （2） The expression of GAP-43 in the right DRG. RESULTS： Totally 250 rats entered the stage of result analysis. （1） Autotomy score： The percentage of autotomy caused by nerve injury pain of rats in the nerve transection group and crush group was increased with the elongation of survival time; The percentage of autotomy in nerve transection group was higher than that in the nerve crush group at each period after nerve injury. Eighty percent rats presented autotomy and forty percent bited digits in the nerve transection group 60 days after nerve injury. Whereas only one third of rats showed autotomy in the nerve crush group. The autotomy scores in the nerve transection group were higher than those in the nerve crush group at each period with nerve injury. The mean scores were 2.1 ±2.1 in the nerve transection group 60 days after nerve injury, while those were only 0.7±1.5 in the nerve crush group. （2）The GAP-43 expression in DRG： The GAP-43 expression in the nerve transection group reached the peak on 7 days after injury （0.614 ±0.004）, still presented 60 days after injury （0.515±0.004）. On the contrast, it reached the peak on 14 days in the nerve crush group （0.583 ±0.006）, sequently, it declined on 21 days （0.563±0.008） and basically recovered to normal level on 60 days after nerve injury （0.231±0.003）. The GAP-43 expression was only （0.225±0.005）in the normal control group. The GAP-43 expressions in both the nerve transection group and nerve crush group were oignificantly stronger than that in the normal control group （t =4.074-14.726, P 〈 0.05）; and the GAP-43 expression was significantly stronger in the nerve transection group in comparison with the nerve crush group （t =3.357-6.236, P 〈 0.05）. CONCLUSION： （1）Nerve transection is more easy to cause spontaneous pain than nerve crush. （2） The GAP-43 expression in DRG is stronger in the nerve transection than that in the nerve crush as the same period, namely, to reach the peak quicker and keep longer peak expression period. （3） The occurrence of neuropathic pain might be related to neuroplasticity.