黄精多糖对糖尿病鼠心、肾组织糖基化终产物受体mRNA表达的调节(英文)

Regulation of polygonati polysaccharide on expression of glycosylated end-product receptor mRNA in cardiac and renal tissues of diabetic mice

背景黄精是一种传统的抗衰老中药,其有效成分黄精多糖具有降低血糖和糖化血红蛋白的作用。目的采用反转录聚合酶链反应测定黄精多糖对蛋白非酶糖基化的关键物质—糖基化终产物受体m RNA表达的调节作用,为开发有效的蛋白非酶糖基化抑制剂和防治糖尿病及其并发症提供实验依据。设计随机对照动物实验。单位中南大学湘雅二医院老年病科,中南大学湘雅医学院附属海口医院心内科。材料实验于2004-03/2004-06在中南大学湘雅二医院实验动物室完成。选用清洁级BALB/C小鼠30只,随机分为正常对照组、模型对照组、黄精多糖治疗组,10只/组。方法模型对照组、黄精多糖治疗组腹腔注射链脲佐菌素建立糖尿病模型,血糖≥8.0m m oL/L为造模成功。黄精多糖治疗组予以2m L/(kg·d)的黄精多糖,正常对照组、模型对照组予以注射用水0.5m L,1次/d灌胃给药,连续12周。给药完毕后断头处死小鼠,采用反转录-聚合酶链反应法测定各组实验动物心脏、肾组织糖基化终产物m RNA的表达。主要观察指标①造模12周后各组小鼠大体情况观察。②造模前后各组小鼠血糖的变化。③各组小鼠心脏、肾组织糖基化终产物受体m RNA凝胶电泳图谱。④各组小鼠心脏、肾组织糖基化终产物受体的半定量测定。结果实验选用30只小鼠,全部进入结果分析。①造模12周后各组小鼠大体情况观察正常对照组体质量增加,活动自如;模型对照组出现消瘦、多尿、精神萎靡不振、反应迟钝等情况;黄精多糖治疗组多尿症状较轻,反应动作较模型对照组灵敏。②造模前后各组小鼠血糖的变化正常对照组和模型对照组造模前后血糖基本相似(P>0.05),黄精多糖治疗组造模12周后血糖显著降低[(10.05±1.16),(7.18±0.84)m m oL/L,P<0.05]。③各组小鼠心脏、肾组织糖基化终产物受体m RNA凝胶电泳图谱模型对照组小鼠心、肾组织糖基化终产物受体m RNA的表达较正常对照组增高,而黄精多糖治疗组的表达较模型对照组明显降低。④各组小鼠心脏、肾组织糖基化终产物受体的半定量测定模型对照组心、肾组织糖基化终产物受体/β-actin相对值显著高于正常对照组(P<0.01);而黄精多糖治疗组其相对值较模型对照组显著降低(0.760±0.121,0.998±0.202;0.609±0.146,0.765±0.113;P均<0.05)。结论黄精多糖除可降低血糖外,还可显著下调糖尿病鼠心、肾组织糖基化终产物受体m RNA的高表达,进而抑制糖基化终产物的结合位点及与其受体结合后的一系列细胞生物反应,保护高血糖时受损的靶器官和组织。

BACKGROUND： Siberian solomonseal rhizome is a sort of Chinese traditional medicine for anti-senilism. The effective component, polygonati polysaccharide, has the effects of reducing blood glucose and glycosylhemoglobin. OBJECTIVE： To assay regulative effect of polygonati polysaccharide on expression of the key substance of non-enzymic glycosylation of proteinsglycosylated end-product receptor mRNA by reverse transcriptase polymerase chain reaction, so as to develop effective inhibitor for non-enzymic glycosylation of proteins and provide experimental evidences for preventing diabetes and its complications. DESIGN： Randomized control animal trial SETTING： Department of Geriatrics, the Second Xjangya Hospital, Central South University; Department of Cardiology, Haikou Hospital Affiliated to Xiangya Medical College, Central South University. MATERIALS： The experiment was coml-leted in Animal Room of Second Xiangya Hospital of Central South University form March to June 2004. A total of 30 BALB/C mice of clean grade were selected and randomly divided into normal control group, model control group and polygonati polysaccharide group, with 10 in each group. METHODS： Diabetic models were established by intraperitoneal injection with streptozotocin to mice in model control group and polygonati polysaccharide group. Model establishment would be regard as successful if blood glucose of mouse was 8.0 mmoL/L or above. Mice in polygonati polysaccharide group were treated with polygonati polysaccharide （2 mL/kg per day）, while mice in normal control group and model control group were treated with injection of 0.5 mL water once a day for 12 consecutive weeks. After medicine had been given to the mice, they were put to death by decapitation. Reverse transcriptase polymerase chain reaction was used to assay expression of glycosylated end-product receptor mRNA in cardiac and renal tissues of experimental animals. MAIN OUTCOME MEASURES： （1） Observation of general situation of mice in each group 12 weeks later after model establishment. （2） Change of blood glucose of mice in each group before and after model establishment. （3） Gel electrophoretic maps of glycosylated end-product receptor mRNA in cardiac and renal tissue of mice in each group. （4） Semi-quantitative assay of glycosylated end-product receptor in cardiac and renal tissue of mice in each group RESULTS： All the 30 mice entered the results analysis. （1） Observation of general situation of mice in each group 12 weeks later after model establishment： mice in normal control group gained weight and moved freely; mice in model control group manifested the symptoms of losing weight, polyuria, listlessness, lags in response etc.; mice in polygonati polysaccharide group manifested milder symptom of polyuria and more sensitive in responses as compared with model control group. （2） Changes of blood glucose of mice in each group before and after model establishment： blood glucose levels were similar between normal control group and model control group before and after model establishment （P 〉 0.05）, while blood glucose in polygonati polysaccharide group significantly decreased 12 weeks later after model establishment [（10.05＋1.16）, （7.18＋0.84） retooL/L, P 〈 0.05]. （3） Gel electrophoretic maps of glycosylated end-product receptor mRNA in cardiac and renal tissue of mice in each group： Compared with normal control group, the expression of glycosylated end-product receptor mRNA increased in cardiac and renal tissue of mice in model control group, while the expression in polygonati polysaccharide group significantly decreased as com- pared with model control group. （4） Semi-quantitative assay .of glycosylated end-product receptor in cardiac and renal tissue of mice in each group： the relative value of glycosylated end-product receptor to β-aetin in cardiac and renal tissue of mice in model control group was significantly higher than normal control group （P 〈 0.01）; however, the relative value of polygonati polysaecharide group significantly decreased as compared with model control group （0.760＋0.121,0.998＋0.202;0.609＋0.146; 0.765＋0.113; P 〈 0.05）. CONCLUSION： Besides reducing blood glucose, polygonati polysacehafide can significantly down regulate high expression of glyeosylated endproduct receptor mRNA in cardiac and renal tissue of mice with diabetes, so as to inhibit the combining sites for glyeosylated end-products and a series of cytobiological reactions after combined with their receptors, and protect the target organs and tissues from injuring by hyperglycemia.