当归挥发油对痛性糖尿病周围神经病变大鼠钙通道蛋白表达的影响

Effect of Angelica volatile oil on expression of calcium channel protein in painful diabetic peripheral neuropathy rats

目的 研究当归挥发油对痛性糖尿病周围神经病变大鼠钙通道蛋白表达的影响。方法 选取SPF级雄性Wistar大鼠10只作为正常组,将50只采用单次腹腔注射烟酰胺和链脲佐菌素造模成功的糖尿病大鼠随机分为模型组和当归挥发油高中低剂量组,每组10只。当归挥发油高、中、低剂量组分别给予10%,5%,2.5%当归油15 mL/(kg·d)灌胃,模型组和正常组灌胃等容量生理盐水,均1次/d,连续灌胃8周。分别于造模成功后灌胃前及灌胃4周、8周后测量各组大鼠体重、空腹血糖水平和双后足机械痛阈,免疫荧光染色检测L_(4~5)背根神经节中Cav3.2表达情况,Western blot技术检测L_(4~5)背根神经节中Cav3.1 Cav3.2 Cav3.3 Cav2.2蛋白表达情况。结果 造模成功灌胃前,模型组及当归挥发油各组大鼠体重均明显低于正常组(P均<0.05),空腹血糖及双后足机械痛阈值均明显高于正常组(P均<0.05);灌胃4周、8周后,当归挥发油各组大鼠体重均明显高于模型组(P均<0.05),空腹血糖及双后足机械痛阈值均明显低于模型组(P均<0.05),且与当归挥发油低中剂量组比较,当归挥发油高剂量组体重、空腹血糖、双后足机械痛阈值变化更明显(P均<0.05)。造模成功灌胃前,模型组及当归挥发油各组大鼠L_(4~5)背根神经节中Cav3.2阳性表达荧光强度明显增强,Cav3.1、Cav3.2、Cav3.3、Cav2.2蛋白表达量均明显高于正常组(P均<0.05);灌胃4周、8周后,当归挥发油各组大鼠Cav3.2阳性表达荧光强度较模型组明显减弱,且当归挥发油低、中、高剂量组呈剂量依赖性减弱;当归挥发油中、高剂量组大鼠灌胃4周后和当归挥发油各组大鼠灌胃8周后Cav3.1、Cav3.2、Cav3.3、Cav2.2蛋白表达量均明显低于模型组(P均<0.05),且当归挥发油高剂量组均明显低于当归挥发油中、低剂量组(P均<0.05)。结论痛性糖尿病周围神经病变的发生与钙离子超载相关,当归挥发油可以显著降低痛性糖尿病周围神经病变大鼠L_(4~5)背根神经节钙通道蛋白表达,减轻神经损伤。

Objective It is to investigate the effect of Angelica volatile oil on the expression of calcium channel protein in painful diabetic peripheral neuropathy rats. Methods Ten SPF male Wistar rats were selected as the normal group, and 50 diabetic rats successfully modeled by single intraperitoneal injection of nicotinamide and streptozotocin were randomly divided into model group and high, medium and low dose angelica volatile oil groups, 10 rats in each group. The high, medium and low dose angelica volatile oil groups were respectively given 10%, 5% and 2.5% angelica oil at 15 mL/(kg·d) by gavage, the model group and normal group were gavaged with the equal volume of normal saline, all once/d, continuously gavaged for 8 weeks. Before gavage and after 4 and 8 weeks of gavage after successful moulding, the body weight, fasting plasma glucose and mechanical pain threshold of both hind feet were measured respectively, and the expression of Cav3.2 in L_(4~5)dorsal root ganglia was detected by immunofluorescence staining, and the expression of Cav3.1, Cav3.2, Cav3.3 and Cav2.2 protein in L_(4~5)dorsal root ganglia were detected by Western blot technique. Results Before gavage after successful modeling, the body weight of rats in both the model group and the Angelica oil groups were significantly lower than that in the normal group(all P<0.05), and the fasting blood glucose and mechanical pain thresholds of both hind feet were significantly higher than those in the normal group(all P<0.05);after 4 weeks and 8 weeks of gavage, the body weight of rats in the Angelica oil groups were significantly higher than that in the model group(P<0.05), and the fasting blood glucose and mechanical pain thresholds of both hind feet were significantly lower than those of the model group(P<0.05), and the changes in body weight, fasting blood glucose and double hindfoot mechanical pain threshold were more significant in the high dose angelica volatile oil group compared with the low and medium dose angelica volatile oil groups(all P<0.05). Before gavage after successful modeling, the positive expression of fluorescence intensity of Cav3.2 in L_(4~5)dorsal root ganglion of rats in the model group and Angelica volatile oil groups was significantly enhanced, and the expression of Cav3.1, Cav3.2, Cav3.3, Cav2.2 protein was significantly higher than that in the normal group(P<0.05);after 4 weeks and 8 weeks of gavage, the positive expression of fluorescence intensity of Cav3.2 of rats in the Angelica volatile oil groups was significantly weaker than that of model group, and the weakening was dose dependent in the low, medium and high dose angelica volatile oil groups. The expression of Cav3.1, Cav3.2, Cav3.3 and Cav2.2 protein was significantly lower in the rats in the middle and high dose groups of Angelica volatile oil after 4 weeks of gavage and in the rats in each group of Angelica volatile oil after 8 weeks of gavage(all P<0.05), and the expression of Cav3.1, Cav3.2, Cav3.3 and Cav2.2 protein was significantly lower in the high dose group of Angelica volatile oil than those in the middle and low dose groups of Angelica volatile oil(all P<0.05). Conclusion The occurrence of painful diabetic peripheral neuropathy is related to calcium overload. Angelica volatile oil can significantly reduce the expression of calcium channel protein in L_(4~5)dorsal root ganglion cells and reduce nerve damage in painful diabetic peripheral neuropathy rats.