超声生物显微镜评估大鼠急慢性心肌肥厚模型左心室心肌形态及功能的可行性

Feasibility of assessing left ventricular myocardial morphology and function in acute and chronic myocardial hypertrophy rat models with ultrasound biomicroscopy

目的探讨超声生物显微镜(UBM)评估异丙肾上腺素(ISO)所致大鼠急性、慢性心肌肥厚模型左心室形态和功能的可行性。方法将40只SD大鼠随机均分为4组。急性模型组大鼠皮下注射ISO 85 mg/kg体质量,1次/天,连续2天;急性对照组以相同剂量、频次皮下注射生理盐水;慢性模型组皮下注射ISO 5 mg/kg体质量,1次/天,连续7天;慢性对照组以相同剂量、频次皮下注射生理盐水。采用UBM测量左心室前壁厚度(LVAWD)、左心室后壁厚度(LVPWD)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)及左心室质量。处死大鼠后对左心室质量进行精密称重。结果急性模型组LVAWD、LVPWD较急性对照组增加(P均<0.05);慢性模型组LVAWD、LVPWD、LVESD及LVESV较慢性对照组增大,而LVEF、LVFS降低(P均<0.05);慢性模型组LVEDD、LVESD、LVEDV、LVESV较急性模型组增大,而LVEF、LVFS降低(P均<0.05)。4组UBM所测左心室质量均高于精确称重(P均<0.05),2种方法所测急性模型组左心室质量均低于慢性模型组(P均<0.05)。4组UBM所测左心室质量与精确称重所测左心室质量均呈正相关(P均<0.05)。结论UBM能够无创评估ISO所致大鼠急、慢性心肌肥厚模型左心室形态及功能。

Objective To investigate the feasibility of assessing left ventricular myocardial morphology and function in acute and chronic myocardial hypertrophy rat models induced by isoproterenol(ISO)with ultrasound biomicroscopy(UBM).Methods Totally 40 SD rats were randomly divided into 4 groups(each n=10).Rats in acute myocardial hypertrophy model group(acute model group)were given subcutaneous injection with ISO 85 mg/kg once a day for 2 days,and those in acute control group were given equal amount saline with subcutaneous injection for equal course.Rats in chronic myocardial hypertrophy model group(chronic model group)were given subcutaneous injection with ISO 5 mg/kg once a day for 7 days,and those in chronic control group were given equal amount saline with subcutaneous injection for equal course.The following parameters,including left ventricular anterior wall diameter(LVAWD),left ventricular posterior wall diameter(LVPWD),left ventricular end diastolic diameter(LVEDD),left ventricular end systolic diameter(LVESD),left ventricular end diastolic volume(LVEDV),left ventricular end systolic volume(LVESV),left ventricular ejection fraction(LVEF),left ventricular fractional shortening(LVFS)and left ventricular myocardial mass were measured with UBM.Then the rats were sacrificed,the left ventricular myocardial masses were accurately weighed.Results Compared with acute control group,LVAWD and LVPWD increased in acute model group(both P<0.05).Compared with chronic control group,LVAWD,LVPWD,LVESD and LVESV increased in chronic model group,while LVEF and LVFS decreased(all P<0.05).Compared with acute model group,LVEDD,LVESD,LVEDV and LVESV of chronic model group increased,but LVEF and LVFS decreased(all P<0.05).Left ventricular myocardial masses measured with UBM were higher than anatomical accurate weighing in all 4 groups(all P<0.05).Left ventricular myocardial masses of acute model group measured with both methods were all lower than those of chronic model group(both P<0.05).The left ventricular myocardial masses measured with UBM were positively correlated with the value measured by anatomical accurate weighing in all 4 groups(all P<0.05).Conclusion UBM can non-invasively evaluate left ventricular morphology and function in rats with acute and chronic myocardial hypertrophy induced by ISO.