Expression of apoptosis signal-regulating kinase 1 in dibated cardiomyoprthy and its correlation with left ventricular ejection fraction

Abstract

Objective To observe the changes of apoptosis signal-regulating kinase 1(ASK1) expression in left ventricular myocardium of the dilated cardiomyopathy(DCM) rats induced by adriamycin and its correlation with left ventricular ejection fraction(LVEF). Methods One hundred and twenty SPF Wistar rats were divided into 2 groups as follows: control group(n=15), model group(n=105). Adriamycin was administered in the model group by intraperitoneal injection for 3 times in a week and repeated with a two-week interval for 6 times, while 9 g/L saline were administered in the control group in the same pattern, thus DCM rats model were constructed by the end of the 8th week.Both the model group and control group rats were drawn out and their LVEF were tested by the end of the 8th week and 12th week.Apoptosis index (AI) and the ASK1 in myocardium were tested respectively by apoptotic cells situ labeling, semi-quantitative analysis and Western blot. Results The AI of the control group, the 8th weekend model group and the 12th weekend model group were 0.53±0.27, 16.13±1.72, 19.54±2.24.The AI of the 8th and the 12th weekend mo-del groups were obviously higher than that in the control group.Comparing the differences among the 3 groups were statistically significant (F=18.98, P<0.05). The relative ASK1 expressions in ventricular myocardium of the control group, the 8th weekend model group and the 12th weekend model group were 0.169±0.010, 0.649±0.071, 0.781±0.077.Comparing the differences among the 3 groups were statistically significant (F=27.72, P<0.01). The LVEF(%)results of the control group, the 8th weekend model group and the 12th weekend model group were 75.41±2.02, 53.25±3.74, 39.21±6.13.Comparing the differences among the 3 groups were statistically significant(F=154.87, P<0.01). There was a negative correlation between the ASK1 expression and LVFE in model group at the end of 12 weeks(r=-0.86, P<0.01). Conclusions The ASK1 expression in myocardium of the DCM group increases obviously, thus apoptosis signal-regulating probably participates in the pathological process of DCM induced by ASK1. Key words: Cardiomyopathy; Apoptosis signal-regulating kinase 1; Apoptosis index; Adriamycin; Apoptosis