丙烯酰胺对大鼠钙调蛋白和蛋白激酶C含量的影响

Effects of Acrylamide on Calmodulin and Protein Kinase C in Spinal Cord of Rats

目的研究丙烯酰胺(ACR)对钙调蛋白(CaM)和蛋白激酶C(PKC)含量的影响。方法将27只健康SPF级成年雄性Wistar大鼠随机分为3组,分别为对照组(双蒸水)和20、40mg/kgACR染毒组,每组9只。采用腹腔注射方式染毒,隔天染毒,连续染毒8周。每周测量大鼠体重和步态得分。染毒结束后,迅速分离脊髓组织,采用ELISA试剂盒测定CaM的含量,采用聚丙烯酰胺凝胶电泳(SDS-PAGE)和免疫印迹法(WesternBlotting)测定蛋白激酶C(PKC)的含量。结果对照组大鼠的步态得分均为1分;20、40mg/kgACR染毒组分别自第7、3周开始出现步态得分增高,差异均有统计学意义(P<0.05或P<0.01)。与对照组相比,20、40mg/kgACR染毒组大鼠脊髓组织CaM含量均下降(P<0.01),40mg/kgACR染毒组大鼠脊髓组织PKC含量下降(P<0.05),差异有统计学意义。结论 ACR可降低大鼠脊髓组织CaM和PKC的含量,造成对神经丝(NF)的损害,这可能是ACR所致神经性疾病的发病机制之一。

Objective To know the role of the protein kinase C （PKC） and calmodulin （CAM） in acrylamide （ACR） induced toxic neuropathies. Methods ACR was administrated to male Wistar rats by intraperitoneal injection at doses of 20 or 40 mg/kg for 8 consecutive weeks （3 times per week）. The gait score was measured every week. The relative contents of CaM in spinal cord were determined by using ELISA kit. The relative contents of PKC in spinal cord were determined by using SDS-PAGE and Western Blotting. Results After 8 weeks of treatment with ACR at 20 or 40 mg/kg , the rats showed neurological deficits of completely different levels; slight neurotoxicity （slight ataxia, hopping gait and foot splay） or severe neurotoxicity （dragged their feet as they walked, foot splay or paralysis）. All the rats in 40 mg/kg group exhibited severe neurotoxicity and those of 20 mg/kg group, slight neurotoxicity. The contents of CaM in 20 mg/kg and 40 mg/kg group was significantly decreased （P〈0.01）. The contents of PKC in 40 mg/kg group decreased significantly. Conclusion ACR can decrease the contents of CaM and PKC which may be one of the toxic mechanisms of ACR-induced neuropathies.