L-精氨酸对糖尿病大鼠坐骨神经损伤的保护作用

目的：探讨L-精氨酸（L-Arg）对糖尿病（DM）大鼠坐骨神经损伤的保护作用及其机制。方法：用链脲佐菌素制备糖尿病模型。SD大鼠随机分为正常对照组（NC组）、DM组、L-Arg治疗组（L-Arg组）。L-Arg治疗12周后，测定三组大鼠血清、坐骨神经组织一氧化氮（N0）含量和一氧化氮合酶（NOS）活性及血浆内皮素-1（ET-1）、降钙素基因相关肽（CGRP）含量，以及坐骨神经组织Ca^2＋-ATPase、Na^＋-K^＋-ATPase活性及神经元型NOS（nNOS）、醛糖还原酶（AR）基因的表达。结果：DM组大鼠血清、坐骨神经NO含量和NOS活性、血浆CGRP含量及坐骨神经Ca^2＋-ATPase、Na^＋-K^＋-ATPase活性和nNOS mRNA的表达均明显低于NC组（P〈0．01或P〈0．05），而血浆ET-1含量、坐骨神经AR mRNA的表达均明显高于NC组（均P〈0．01）；经L—Arg治疗后，上述改变逆转，与DM组比较差异有显著性（P〈0．01或P〈0．05）。结论：L—Arg对DM大鼠坐骨神经损伤具有一定的保护作用，其机制可能与改善神经血供及抑制多元醇代谢途径有关。

Preventl ve effect of L-arginine on sciatic nerve injury of diabetic rats

Objective： To investigate the effects and mechanisms of L-arginine （L-Arg） on preventing and treating sciatic nerve injury of experimental diabetic rats. Methods： The diabetes mellitus（DM） rats medels were made by intraperitoneal injection of streptozotocin （60 mg/kg body weight）, and three groups, including normal control group （NC group）, DM group, L-Arg treatment group （L-Arg group） were allocated at random. After the supplementation of L-Arg （300 mg·kg^-1·d^-1） for 12 weeks, the rats were sacrificed. The nitric oxide （NO） content and nitric oxide synthase （NOS） activity in serum and sciatic nerve, plasma endothelin-1 （ET-1） and calcitonin gene-related peptide （CGRP） content were determined. The activities of Ca^2＋-ATPase, Na^＋-K^＋-ATFase and the mRNA expression level of neuronal NOS （nNOS） and aldose reductase （AR） of sciatic nerve also were measured. Results： The NO content and NOS activity in serum and sciatic nerve, plasma CGRP content, and Ca^2＋-ATPase, Na^＋-K^＋-ATPase activities and nNOS mRNA expression level in sciatic nerve of DM group were significantly lower than those of NC group （P〈0.01 or P〈0.05 respectively）, but plasma ET-1 content and AR mRNA expression level in sciatic nerve were significantly higher than those of NC group （P〈0.01 respectively）. But in L-Arg group, the above changes were reversed, there were significant differences compared with those of the DM group （P〈0.01 or P〈0.05 respectively）. Conclusion： L-Arg plays preventive and remedial roles in diabetic sciatic nerve injury. Improving the level blood supplying and inhibiting polyol metabolic pathway may be its mechanisms.