不同左心室构型甲亢性心肌病兔血清肌钙蛋白Ⅰ水平变化

Levels of serum cardic troponin in the different geometric patterns of left ventricle in rabbits with hyperthyroid cardiomyopathy

目的探讨不同左心室构型甲状腺功能亢进症(简称甲亢)性心肌病兔血清肌钙蛋白I(cTn-I)水平变化。方法实验组兔(20只)腹腔注射左甲状腺素(45μg·kg-1·d-1×28d)建立甲亢动物模型,并依据Ganau的超声参数分为两型:向心性肥厚组(CH组)和离心性肥厚组(EH组);对照组兔(10只)每日腹腔注射生理盐水至实验结束;对各组兔均行超声心动图检查,并测定血清中cTn-I水平。结果 CH组左心室质量指数(LVMI)及相对室壁厚度(RWT)明显增加(P<0.01);左心室射血分数(LVEF)、短轴缩短率(FS)与对照组比较差异无统计学意义(P>0.05)。EH组LVMI明显增加(P<0.01),而RWT与对照组比较差异无统计学意义(P>0.05);LVEF、FS与对照组比较明显减低(P<0.01)。CH组和EH组血清cTn-I水平明显高于对照组(P<0.01),EH组较CH组血清cTn-I水平高(P<0.01)。血清cTn-I水平与LVMI呈正相关。病理学结果EH组损伤较CH组重。结论不同左心室构型甲亢性心肌病兔血清cTn-I水平具有不同程度的升高,并与病理损害程度基本一致。

Objective To observe and study the level of serum cardiac troponin (cTn-I) in the different geometric patterns of left ventricle in rabbits with hyperthyroid cardiomyopathy. Methods Thirty New Zealand purebred rabbits were randomly divided into two groups: control group (n=10) and experimental group (n=20). Hyperthyroidism animal model was established by peritoneal injection of Levothyroxine (L-Thy) in experimental group. According to the ultrasound parameter changes, the ventricular geometries of experimental group were divided into two groups: concentric hypertrophy (CH) and eccentric hypertrophy(EH). Each groups underwent conventional echocardiogram, and evaluate cTn-I values. Results In CH group, the LVMI and RWT increased obviously(P<0.01). In EH group,the LVMI increased obviously(P<0.01), but RWT did not change significantly(P>0.05). EF and FS were significantly lower in EH group than those of the control group (P<0.01). The cTn-I in blood of CH group was conspicuously higher than that of the control group (P<0.01). The cTn-I in blood of EH group was conspicuously higher than that of the control group and CH group (P<0.01). The serum cTn-I was positive correlatd with LVMI. The pathological examination demonstrated that the damages increased in EH group than that in CH group. Conclusions Serum cTn-I in the different geometric patterns of left ventricle in rabbits with hyperthyroid cardiomyopathy increased in varying degree and the elevation of cTn-I is in accordance with the degree of pathological injury.