糜蛋白酶mRNA水平及其酶活性与糖尿病仓鼠心肌病变的关系  

Relationship of gene expression and activity of chymase with cardiomyopathy in STZ-induced diabetic hamsters

作　　者：赵柯湘[1] 肖谦[1] 黄昶荃[1] 李龙英[1] 

机构地区：[1]重庆医科大学附属第一医院老年病科,400016

出　　处：《中华老年医学杂志》2007年第10期779-782,共4页Chinese Journal of Geriatrics

基　　金：重庆市自然科学基金（2005BB5274）

摘　　要：目的对糖尿病仓鼠模型心肌中糜蛋白酶（chymase）mRNA水平及其酶活性进行检测,观察chymase mRNA水平、酶活性与心肌局部血管紧张素Ⅱ（AngⅡ）水平的关系。方法腹腔注射链脲菌素诱导糖尿病仓鼠模型,电镜观察心肌超微结构,链霉素-亲和素-生物素-过氧化物酶复合物法（SABC）检测心肌Ⅰ、Ⅲ型胶原水平,脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（TUNEL）检测心肌细胞凋亡,反转录-聚合酶链反应（RT-PCR）检测chymase mRNA水平变化,放射免疫分析法测定心肌chymase和血管紧张素转换酶（ACE）活性、AngⅡ含量。结果（1）糖尿病组仓鼠心肌细胞线粒体肿胀明显,局部破裂,肌丝广泛溶解,核肿胀,Ⅰ、Ⅲ型胶原沉积、心肌细胞凋亡明显;（2）糖尿病组与对照组比较,心肌chyamse活性明显升高,分别为（0.88±0.07）U/mg组织和（0.54±0.04）U/mg组织（P〈0.01）.而ACE活性差异无统计学意义;AngⅡ含量明显升高,分别为（95.8±16.0）pg/mg组织和（51.1±20.8）pg/mg组织（P〈0.01）;（3）糖尿病组心肌chyamse mRNA表达水平为0.810±0.026,较对照组0.490±0.087显著升高（P〈0.01）。结论糖尿病仓鼠病变心肌的chymase mRNA表达水平和酶活性明显升高,并伴随心肌局部AngⅡ含量的升高。Objective To investigate the gene expression and the activity of chymase in the cardiomyopathy of streptozotocin （STZ）-induced diabetic hamasters. Moreover, to explore the relationship of the gene expression and activity of chymase with angiotensin Ⅱ. Methods Diabetic state in hamsters was achieved by intraperitoneal injection of STZ. The myocardial uhrastructure was observed by electron microscope and pathologic changes were observed by microscope. Immunohistochemistry was used to measure the levels of type Ⅰ and type Ⅲcollagen. Levels of blood glucose, lipoprotein were determined by using biochemical methods. Apoptosis of cardiomyocyte was measured by using TUNEL methods. Radioimmunuoassay method was used to determine the level of angiotensin Ⅱ and the activity of chymase and angiotensin-convertion enzyme （ACE）. Reverse transcription polymerase chain reaction （RT-PCR） was used to determine chymase gene expression （corrected by β-actin）. Results Levels of collagen Ⅰ and Ⅲ in diabetes mellitus（DM） group were much higher than in the control group. Chymase activity in DM group was much higher than in the control group[ （0.88±0.07）U/rag tissue vs. （0.54±0.04）U/mg tissue,P〈0. 01]. But the activity of ACE unchanged [（0.72±0. 11）U/mg tissue vs. （0.66±0.13）U/mg tissue, P〉0. 05]. The level of angiotensin Ⅱ was much higher in DM group than in the control group [（95.8±16.0）pg/mg tissue vs. （51. 1±20.8） pg/mg tissue,P〈0.01]. RT-PCR results showed that the mRNA expression of chymase in DM group was promoted significantly as compared with the control group （0. 810 ±0. 026 vs. 0. 490±0. 087, P〈0.01）. Conclusions In diabetic hamsters, the gene expression and the activity of chymase are much higher than in the control group, accompanying higher levels of angiotensin Ⅱ, collagen Ⅰand Ⅲ.

关 键 词：糜蛋白酶 糖尿病 实验性 心肌疾病 

分 类 号：R686[医药卫生—骨科学]