果糖-1,6-二磷酸对糖尿病大鼠心肌有保护作用,但不能被超声背向散射积分正确评价

Fructose-1,6-bisphosphate can protect diabetic myocardium of rates,but this effection can't be accurate evaluated by ultrasonic integrated backscatter

目的:通过分析超声背向散射积分(IBS)参数的变化评价果糖-1,6-二磷酸(FBP)对糖尿病(DM)大鼠心肌纤维化及超微结构的影响。方法:通过一次性腹腔注射链脲佐菌素(STZ,65mg/kg)建立SD大鼠糖尿病模型,分成模型对照组(DM组)和FBP干预组(FBP500mg.kg-1.d-1腹腔注射),DM组及正常对照组(NC组)给予等量生理盐水腹腔注射。1月后,超声测量IBS参数(包括标化的背向散射积分IBS%、背向散射积分周期变异幅度CVIB);取心肌组织进行透射电镜(TEM)观察、羟脯氨酸浓度(HPC)测定、Masson染色、嗜银染色及结缔组织生长因子(CTGF)免疫组织化学染色。结果:①3组间比较IBS%值FBP组>DM组>NC组(P<0.05),CVIB值无明显变化(P>0.05);②HPC、胶原容积分数(CVF)3组间比较,均DM组>FBP组>NC组(P<0.05);而嗜银纤维容积分数(APFVF)DM、FBP组间无明显差异(P>0.05),两组均>NC组(P<0.05);CTGF的表达FBP、NC组无明显差异,两组均<DM组;③超微结构变化:与NC组比较,DM组肌原纤维减少,线粒体增多且伴空泡变性,FBP组线粒体空泡变性明显减轻。结论:FBP可以减轻糖尿病大鼠心肌纤维化及保护心肌线粒体功能,IBS不能准确评价此种保护作用的原因是:线粒体作为主要散射体之一,其空泡化减轻使IBS%值增大。

Objective：To investigate the effect of fructose-1, 6-bisphosphate （FBP） on the myocardial fibrosis and uhrastructure of diabetic rats by ultrasonic integrated backscatter （IBS）. Methods：The diabetes mellitus （DM） in healthy male Sprague-Dawley rats was induced by a single injection of streptozotocin （STZ, Sigma） into intrapefitoneal cavaty at a dose of 65 mg/kg body weight. Intervening sub： jects （FBP group） were given 500 mg·kg^-1· d^- 1 body weight of FBP intrapefitoneal administration, while diabetes meUitus subjects （DM group） and normal control subjects （NC group） received 500 mg·kg^-1·d^-1 of saline. After one month, the time averaged value of IBS （IBS）, the normalized IBS（IBS%）, the magnitude of the cyclic variation of IBS（CVIB） were determined in rats. The myocardial hydroxyproline concentration （HPC） was performed. Masson＇s trichrome and argyrophilic staining were used in the study of total collagen area and argyrophilic fibers in heart interstitial tissue. The expression of connective tissue growth factor （CTGF） protein was evaluated by qualitative and semiquantitative immnnohistochemieal staining. Myocardial ultrastructure was study by transmission electron microscopy （TEM）.Results：IBS% was higher in FBP group 〉 DM group〉 NC group （ P 〈0.05）, while CVIB had no great alteration in three groups （ P 〉 0.05）. HPC and collagen volume fraction （CVF） were increased in DM group 〉 FBP group〉 NC group （ P 〈 0.05）. Argyrophilic fiber volume fraction （APFVF） in DM and FBP group were more than in NC group. CTCF in NC and FBP group were higher than in DM group. Compared with NC group, it was manifestated as fewer myofibrils, more but vacuolar degenerated mitochondria in DM group under TEM, while the obviously changes in FBP group were light of mitochondria＇ s vacuolar degeneration. Conclusion： FBP can decrease myocardial interstitial fibrosis, improve mitochondria function in diabetic rats. The reason of tiffs protection can＇t be appreciated by integrated backscatter may be involved in that mitochondria were regarded as one of scattereres, decreased damage of them can increase the value of integrated backseatter.