红景天苷保护砷中毒大鼠左心功能:二维斑点追踪成像观察

目的 以二维斑点追踪成像（2D-STE）评估红景天苷保护砷中毒大鼠左心功能的价值。方法 将40只大鼠随机分为红景天苷高剂量组（S30组）、红景天苷低剂量组（S15组）、模型组、无毒干预组（Sal组）及对照组，每组8只。于每晨9时对S30组、S15组及模型组以As₂O₃（5 mg/kg体质量）灌胃，Sal组及对照组以无菌水灌胃，持续30天；之后对S30组以红景天苷30 mg/kg体质量、S15组及Sal组以红景天苷15 mg/kg体质量、对照组和模型组以无菌水连续灌胃7天；比较组间超声参数和血清心肌标志物差异，观察心肌组织病理改变，评价分层应变参数与血清心肌标志物的关系。结果 S30组、S15组及模型组血清肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）、心肌丙二醛均高于对照组（P均<0.05），而心肌超氧化物歧化酶、左心室射血分数（LVEF）、左心室短轴缩短率（LVFS）、各层心肌整体圆周应变（GCS）及心内膜下心肌各节段圆周应变均低于对照组（P均<0.05）；上述3组大鼠心肌细胞肿胀、坏死，细胞间隙增宽，核深染，以模型组最为明显，S30组及S15组程度相对较轻。Sal组与对照组各指标差异均无统计学意义（P均>0.05）。各组心内膜下/中层/心外膜下GCS与CK-MB （r＝－0.926、－0.813、－0.738，P均<0.05）及LDH （r＝－0.908、－0.803、－0.737，P均<0.05）均呈负相关。结论 2D-STE可用于评估红景天苷对砷中毒大鼠左心功能的保护作用。

Salidroside for protecting left ventricular function in arsenic-toxic rats: Evaluation with two-dimensional speckle tracking imaging

Objective To observe the protecting value of salidroside for left ventricular function of arsenic-toxic rats with two-dimensional speckle tracking imaging (2D-STE). Methods Forty rats were randomly divided into salidroside high-dose group (S30 group), salidroside low-dose group (S15 group), model group, non-toxic intervention group (Sal group) and control group (each n=8). Rats in S30 group, S15 group and model group were gavage with As₂O₃ (5 mg/kg body mass), while those in Sal group and control group with sterile water at 9:00 a.m.for 30 days. Then rats in S30 group were gavage with salidroside 30 mg/kg body mass, in S15 group and Sal group with salidroside 15 mg/kg body mass, while those in model group and control group with sterile water for 7 days. The ultrasonic parameters and serum myocardial markers were compared among groups, so did the pathological changes of myocardial tissue. The relationships of stratified strain parameters and serum myocardial markers were evaluated. Results The levels of serum creatine kinase isoenzyme-MB (CK-MB), lactate dehydrogenase (LDH), and myocardial malondialdehyde in S30 group S15 group and model group were higher than those in control group (all P<0.05), while the superoxide dismutase, left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), global circumferential strain (GCS) of each layer of myocardium and circumferential strain of each segment of subendocardial myocardium in S30 group,S15 group and model group were all lower than those of control group (all i>P<0.05). Various degrees of swelling and necrosis of myocardial cells were observed, while widened intercellular space and deeply stained nucleus were detected especially in model group, whereas in S30 group and S15 group became improved. There was no significant difference of the above indexes between Sal group and control group (all P>0.05). Subendocardial myocardium/middle myocardium/subepicardial GCS were negatively correlated with CK-MB (r=-0.926, -0.813, -0.738, all P<0.05) and LDH (r=-0.908, -0.803, -0.737, all P<0.05) in all groups. Conclusion 2D-STE could be used to evaluate the protective effect of salidroside on left ventricular function in arsenic poisoned rats.