牛蒡子苷元对自发性糖尿病GK大鼠合并高血压大血管病变的保护作用

Protective effect of arctigenin in GK rats combined with hypertension macroangiopathy

探讨牛蒡子苷元对自发性糖尿病(goto-kakizaki,GK)大鼠合并高血压大血管病变的保护作用。将6周龄GK大鼠按血糖水平随机分为模型组,牛蒡子苷元低、中、高剂量组(12.5,25,50 mg·kg-1),以Wistar大鼠作为正常组。所有GK大鼠饲喂高糖高脂饲料,16周后灌胃10 mg·kg-1·d-1L-N-硝基精氨酸甲酯(L-NAME)连续8周。造模同时各组动物每天上下午灌胃给药2次,模型组和正常组灌溶剂。实验开始、中期及结束期检测血糖,实验结束前检测血压,麻醉后腹主动脉采血检测血常规,放血后取胸主动脉固定制作石蜡切片,观察形态,免疫组化方法检测血管内皮生长因子(VEGF)表达。结果显示,所有GK大鼠血糖持续升高,给药组与模型组相比没有明显差别,实验结束时GK大鼠血压显著升高,牛蒡子苷元可以明显降低GK大鼠血压,且具有剂量依赖性。血常规检测结果显示GK大鼠白细胞总数及分类计数均升高,血小板参数异常,PLT减少,MPV,PDW增高,牛蒡子苷元可以显著降低白细胞总数和分类计数,降低MPV,PDW。胸主动脉形态学观察发现GK大鼠血管内膜病变明显,牛蒡子苷元可以减轻病变程度,VEGF免疫组化染色结果表明模型组GK大鼠VEGF表达较多,牛蒡子苷元各剂量组表达较少。结果表明牛蒡子苷元对GK大鼠大血管具有保护作用,机制可能与降低血压、抗炎、改善血小板功能、减少VEGF表达有关。

To study the protective effect of Arctigenin in goto-kakizaki （GK） rats combined with hypertension macroangiopathy. Six-week-old GK rats were divided randomly according to blood glucose level into four groups： the model group and low, middle and high dose arctigenin groups （12. 5, 25, 50 mg · kg-1）, with Wistar rats as the normal group. All of GK rats were given high-glucose and high-fat diet. After 16 weeks, GK rats were orally administrated with 10 mg· kg-1 ~ d-1N-co-nitro-L-arginine methyl ester for eight weeks. During the modeling, all of arctigenin groups were orally administrated with different dose of arctigenin twice a day; The model group and the normal group were given solvents. At the beginning, mid-term and end of the experiment, blood glucose was measured. At the end of the experiment, efforts were made to detect blood pressure, collect abdominal aortic blood after anesthesia, fix thoracic aorta after bloodletting to make paraffin sections, observe morphological characteristics and detect the expression of VEGF by immunohistochemistry. According to the results, the blood glucose rose in all GK rats, with no significant difference between the drug group and the model group. At the end of the experiment, the blood pressure significantly increased in GK rats, indicating that Arctige- nin could notably reduce the blood pressure in GK rats in a dose-dependent manner. The blood routine test showed increases in both thetotal white blood cell count and differential blood count, MPV and PDW, abnormal blood platelet parameters and decrease in PLT in GK rats, suggesting that Arctigenin could remarkably reduce the total white blood cell count and differential blood count, MPV and PDW. The thoracic aortic morphological observation revealed obvious endangium lesions in GK rats, demonstrating that Arctigenin could ameliorate the lesion extent. VEGF immumohistochemical staining showed a higher VEGF expression in the model group but low- er expression in Arctigenin groups. In conclusion, Arctigenin had a protective effect on aorta in GK rats. Its mechanism may be related to blood pressure lowering, anti-inflammation, improvement in blood platelet function and reduction of VEGF expression.