摘要
目的评价兔甲状腺功能亢进(简称甲亢)性心肌病模型左心室收缩功能的变化与心肌细胞凋亡的相关性。方法将30只纯种新西兰大白兔分为两组,实验组20只,对照组10只。对实验组兔每日腹腔注射左旋甲状腺素45μg/kg体质量,共4周,建立甲亢动物模型;对照组兔腹腔注射同等剂量生理盐水。于第4周末行常规超声心动图,依据所测参数将实验组分为向心性肥厚亚组(CH亚组)和离心性肥厚亚组(EH亚组);以组织追踪法(TT)测量兔心脏二尖瓣瓣环的收缩期位移峰值(Ds),检测各组兔凋亡心肌细胞及bcl-2、bax的表达。结果对照组未见凋亡心肌细胞;CH亚组、EH亚组细胞凋亡指数明显升高(P均<0.01),其中EH亚组凋亡指数明显高于CH亚组(P<0.01)。CH亚组、EH亚组bcl-2表达明显低于对照组(P均<0.01),EH亚组bcl-2表达明显低于CH亚组(P<0.01)。CH亚组、EH亚组bax表达明显高于对照组(P均<0.01),EH亚组bax表达明显高于CH亚组(P<0.01)。CH亚组、EH亚组bcl-2/bax明显低于对照组(P均<0.01)。CH亚组的Ds低于对照组,EH亚组的Ds明显低于对照组及CH亚组(P均<0.01)。CH亚组、EH亚组Ds与心肌细胞凋亡指数呈负相关(r=-0.53,P<0.05),与bax呈显著负相关(r=-0.74,P<0.01),与bcl-2呈显著正相关(r=0.82,P<0.01)。结论心肌细胞凋亡可能为兔甲亢性心肌病左心室收缩功能减低的重要机制之一。
Objective To assess the relationship between left ventricular systolic function and cardiomyocyte apoptosis of different geometric patterns with hyperthyroid cardiomyopathy in rabbit models evaluated with tissue tracking （TT）. Methods Thirty New Zealand purebred rabbits were stochastically divided into experiment group （n= 20） and control group （n=10）. Hyperthyroidism models were established by peritoneal injection of levothyroxine in experimental group, while the same dose of saline was given to rabbits in control group for 4 weeks. Conventional echocardiographic parameters were obtained at the ending of the 4th week in both groups. According to the changes of ultrasound parameters, the rabbits of experimental group were divided into concentric hypertrophy （CH） subgroup and eccentric hypertrophy （EH） subgroup. The systolic mitralannular displacement （Ds） was measured using TT. Apoptotic cardiomyocytes and the expression of bcl- 2 and bax were also detected. Results There was no apoptotic cardiomyocyte in control group. However, the index of apoptic cardiomyocytes increased significantly in CH subgroup and EH subgroup （both P〈0. 01）. The index of apoptotic cardiomyocytes in EH subgroup was higher than that in CH subgroup （P〈 0.01）. Compared with the control group, the expression of bcl-2 protein was significantly lower in CH subgroup and EH subgroup （both P〈0. 01）, and the expression of bcl-2 protein in EH subgroup was lower than that in CH subgroup （P〈0. 01）. The expression of bax protein was con- siderably higher in CH subgroup and EH subgroup （both P〈0.01）, and the expression of bax protein in EH subgroup was higher than that in CH subgroup （P〈0.01）. bcl-2/bax was significantly lower in CH subgroup and EH subgroup than that in the control group （both P〈0. 01）. Compared with the control group, the average Ds determined with TT was slightly lower in CH subgroup and EH subgroup （both P〈0. 01）, which was lower in EH subgroup than that in CH sub- group （P〈0.01）. Ds of both subgroups negatively correlated with the index of apoptic cardiomyocytes and bax （r= -0.53, -0. 74, both P〈0.05）, while positively correlated with bcl-2 （r=0.82, P〈0.01）. Conclusion Cardiomyocyte apoptosis may be an important mechanism of the decreasing left ventricular systolic function of hyperthyroid cardiomyopa- thy in rabbit models.
出处
《中国医学影像技术》
CSCD
北大核心
2013年第5期678-682,共5页
Chinese Journal of Medical Imaging Technology
基金
辽宁省科技厅科技计划项目(2009225009-7)
