超声联合一氧化氮微泡对大鼠心肌组织的生物学效应

目的:本研究旨在探讨超声联合一氧化氮(NO)微泡的作用对大鼠心肌组织局部基质衍生因子-1(SDF-1)的影响,及其对心肌组织作用的安全性?方法:将32只SPF级SD雄性大鼠随机分为4组,每组8只?第1?2?3组分别经尾静脉输入1 ml的NO微泡?普通脂质微泡以及PBS,并采用频率为1 MHz?强度为1 W/cm2的超声辐照大鼠心前区,辐照时间为10 min;第4组为空白对照组?4 h后每组处死4只大鼠,留取心肌组织进行HE染色,观察局部的炎症反应情况;同时留取血清标本用于检测肌酸激酶(CK),乳酸脱氢酶(LDH)和肌钙蛋白I(TnI)的含量?1周后处死剩余大鼠,取心肌组织进行RT-PCR和Western blot分别检测SDF-1的基因及蛋白相对表达量?结果:辐照4 h后留取心肌组织行HE染色显示各组均可见少量炎性细胞浸润,组间没有明显差异;血清学指标检测显示,第1组与第2组血清CK和LDH高于第3组和第4组,且差异有统计学意义(P < 0.05);第1组血清TnI低于第2组,但高于第3组和第4组,且差异有统计学意义(P < 0.05);辐照1周后留取的心肌组织行RT-PCR和Western blot分析结果均显示第1组SDF-1相对表达量最多,各组间进行两两比较,差异均有统计学意义(P < 0.05)?结论:超声联合NO微泡辐照大鼠心肌组织,与内含全氟显气体的普通脂质微泡一样,对心肌组织无明显破坏;但能使大鼠心肌组织SDF-1表达增加,其程度高于应用超声联合普通脂质微泡,因此,NO微泡应用于干细胞归巢将优于目前普通脂质微泡?

Biologic effects of ultrasound-stimulated nitric oxide microbubbles on rat myocardium

Objective:This study evaluated myocardium damage under the irradiation of ultrasound combined with homemade nitric oxide (NO) microbubbles. Furthermore,we intended to investigate the stromal cell-derived factor-1(SDF-1) expression in rat myocardium after the intervention of ultrasound combined with NO microbubbles. Methods:Thirty-two rats were divided into four groups randomly. Ultrasound (1MHz,1W/cm2) was applied to the anterior chest for ten minutes in group one (US+NOMB),group two (US+MB) and group three (US+PBS),group four was set for contrast. Four rats were sacrificed in each group four hours later and myocardium was harvested for HE staining. Serum was also collected for myocardial enzyme testing. One week later,all rats were sacrificed,and RT-PCR and western blotting were performed for testing SDF-1 expression. Results:HE staining showed that there were no significant differences in pairwise comparison. Creatine kinase and lactic dehydrogenase were higher in the group one and the group two than those in the group three and group four (P < 0.05),but there was no significant difference between the group one and the group two (P > 0.05). Troponin I was lower in the group one than that in group two,but higher than those in the group three and group four (P < 0.05). RT-PCR and Western blotting demonstrated that the expression of SDF-1 was higher in the group one than that in the group two,group three and group four,and all the P values were less than 0.05. Conclusion:NO microbubble,as a novel microbubble,is safe for rat myocardium. Moreover,it can induce a higher SDF-1 expression than common lipidic microbubbles,which shows great potential for stem cells homing.