芦丁对丙烯酰胺致大鼠坐骨神经髓鞘损伤的保护作用

Protective effect of rutin on myelin sheath injury in the sciatic nerve of rats induced by acrylamide

目的 通过观察芦丁(Rut)对丙烯酰胺(ACR)染毒大鼠坐骨神经髓鞘结构、髓鞘碱性蛋白(MBP)及髓鞘相关糖蛋白(MAG)表达的变化,探讨Rut对ACR致大鼠坐骨神经髓鞘损伤的保护作用。方法 成年SD雄性大鼠36只,随机分为4组:对照组(control,给予ddH;O)、20 mg/kg ACR染毒组(ACR)、100 mg/kgRut预保护ACR染毒组(R1+ACR)、200 mg/kg Rut预保护ACR染毒组(R2+ACR),每组9只,灌胃21 d后取材。后肢间距测量评估各组大鼠后支撑力的变化;HE染色和透射电子显微镜观察大鼠坐骨神经髓鞘结构的变化;免疫组织化学和Western blotting检测MBP和MAG表达量的变化。结果 后肢间距测量显示,与control组相比,ACR组大鼠后肢间距随染毒时间延长而增加(P<0.05),而给予Rut预处理后,R1+ACR和R2+ACR组的后肢间距明显低于ACR组;HE染色显示,ACR染毒后,神经纤维排列紊乱,髓鞘出现肿胀的现象,而R2+ACR组神经纤维排列有序,髓鞘肿胀减轻。透射电子显微镜结果显示,ACR组髓鞘出现肿胀和松解,板层间出现空泡,部分轴突空泡样变性;与ACR组相比,R2+ACR组髓鞘松解情况改善,空泡样变性不明显,髓鞘板层及轴突中仅有少量的空泡。免疫组织化学和Western blotting检测结果显示,与control组相比,ACR组坐骨神经MBP和MAG的表达量均明显减少(P<0.01),与ACR组相比,R1+ACR组及R2+ACR组MBP和MAG的表达量增加(P<0.05)。结论 芦丁对ACR致大鼠坐骨神经髓鞘损伤具有保护作用,其保护作用可能与Rut改善ACR引起的坐骨神经髓鞘蛋白MBP和MAG表达减少有关。

Objective To investigate the effect of rutin(Rut) on sciatic nerve myelin injury induced by acrylamide(ACR), and to observe the changes of myelin structure, myelin basic protein(MBP) and myelin associated glycoprotein(MAG) in rats exposed to ACR. Methods Thirty-six adult male SD rats were randomly divided into 4 groups: control group(ddH;O), 20 mg/kg ACR exposure group(ACR), 100 mg/kg Rut pre-protection ACR exposure group(R1+ACR), 200 mg/kg Rut pre-protection ACR exposure group(R2+ACR), 9 rats in each group, and were given gastric gavage for 21 days. HE staining and transmission electron microscopy were used to observe the changes of the sciatic nerve myelin sheath structure, immunohistochemistry and Western blotting were used to detect the changes in the expression of MBP and MAG in each group of rats. Results Hind limb distance measurement showed that compared with the control group, the hind limb distance of rats in the ACR group increased with the prolonged exposure time(P<0.05). After pre-protection with Rut, the hind limb distance of the R1+ACR and R2+ACR groups was significantly lower than that in the ACR group. HE staining showed that after ACR was infected, nerve fibers were disordered and myelin swelling appeared, while in R2+ACR group, nerve fibers were orderly and myelin swelling was reduced. Transmission electron microscopy showed that the myelin in ACR group was swollen and loosened, vacuoles were found in the interlamellar area, and some axons had vacuolar degeneration. Compared with the ACR group, the laxity of myelin in the R2+ACR group was improved and vacuolar degeneration was not obvious, and only a few vacuoles were found in the myelin lamina and axons. Immunohistochemistry and Western blotting results showed that the expression levels of MBP and MAG in the ACR group decreased significantly compared with the control group(P<0.01), compared with ACR group, the expression levels of MBP and MAG in R1+ACR group and R2+ACR group increased(P<0.05). Conclusion Rut has a protective effect on myelin sheath in the sciatic nerve of rats induced by acrylamide, which may be related to the inhibition of Rut on the decreased expression of MBP and MAG in the sciatic nerve induced by ACR.