葛根素对臂丛神经根性撕脱伤脊髓前角iNOS、CGRP蛋白表达及PI3K/Akt信号通路的影响

目的　探讨葛根素对臂丛神经根性撕脱伤（brachial plexus root avulsion injury，BPRAI）脊髓前角iNOS、CGRP蛋白表达及PI3K/Akt信号通路的影响。 方法　将50只雄性SD大鼠随机分为正常组、模型组、葛根素低、中、高剂量治疗组，每组10只。模型组，葛根素低、中、高剂量治疗组进行BPRAI造模，撕脱大鼠右侧C5~7脊神经前根，后根剪断，术后3个治疗组予腹腔注射葛根素，剂量分别为50、100、200 mg·kg-1·d-1，正常组、模型组腹腔注射等体积生理盐水，持续4周。采用尼氏染色、免疫荧光化学、Western blot方法，观察损伤侧脊髓前角α运动神经元（alpha motorneurons，α-MNs）的存活率，iNOS、CGRP、PI3K/Akt通路相关蛋白的表达。 结果　第4周时，低、中、高剂量的葛根素治疗可抑制α-MNs丢失（P<0.05或P<0.01）；中、高剂量的葛根素治疗可抑制iNOS表达（P<0.05）；高剂量的葛根素治疗可促进CGRP蛋白表达（P<0.05或P<0.01）；低、中、高剂量葛根素均可显著抑制p-Akt1/2/3表达（P<0.01）。 结论　葛根素可改善BPRAI造模引起的α-MNs死亡，其机制可能与葛根素能抑制iNOS蛋白的表达、促进CGRP蛋白的表达有关，并且PI3K/Akt信号通路参与其调控。

Effects of Puerarin on the expression of iNOS,CGRP, and PI3K/Akt signaling pathway in spinal cord anterior horn after brachial plexus root avulsion injury

Objective　To investigate the effect of Puerarin on the expression of iNOS, CGRP and PI3K/Akt signaling pathway in spinal anterior horn following brachial plexus root avulsion injury (BPRAI). Methods　Fifty SD rats were randomly divided into a normal group, a model group, a low-dose group, a middle-dose group and a high-dose group with 10 rats in each group. BPRAI modeling was made in the model group, low-dose group, middle-dose group and high-dose group by avulsing the anterior roots and transecting posterior roots of right C5~7 segment of spinal nerve. Puerarin was injected intraperitoneally in the low-dose group, middle-dose group and high-dose group after the operation at doses of 50, 100 and 200 mg·kg-1·d-1 respectively. The normal group and model group were given intraperitoneal injection of saline of equal volume for 4 weeks. Nissl staining, immunofluorescence and Western blot were used to observe the survival rate, the expression of iNOS and CGRP of alpha motorneurons (α-MNs), and PI3K/Akt pathway related proteins in the spinal cord on the injured side. Results At the 4th week, low, middle and high doses of Puerarin could inhibit the loss of α-MNs (P<0.05 or P<0.01); middle and high doses of Puerarin could inhibit the expression of iNOS (P<0.05); high doses of Puerarin could significantly promote the expression of CGRP protein (P<0.05 or P<0.01); low, middle and high doses of Puerarin could significantly inhibit the expression of p-Akt1/2/3 (P<0.01). Conclusions Puerarin can ameliorate the death of alpha-MNs induced by BPRAI. The protective effect of Puerarin may be related to its inhibition of iNOS expression and promotion of CGRP expression, and PI3K/Akt signaling pathway is involved in its regulation.