Effect Of On Contract Function And Calcium Transient Of Single Cardiomyocyte In Rat

ObjectiveTo investigate the effect of thyroid hormone on contractile function and calcium transient of single cardiomyocyte chronic heart failure cells in rat.Methods1 A total of SD rats were randomly divided into two groups: control group and thyroid hormone group. Hemodynamic parameters were collected, and ventricular myocytes were then enzymatically isolated. Contractile function and calcium transient of the myocytes were detected simultaneously and compared with the control group by video-based motion edge-detection system.2 Chronic heart failure(CHF) was induced by surgical abdominal aortic stenosis in forty SD rats. The rats with CHF were randomized into CHF group and thyroid hormone treated group. Sham-operated (PS) group rats served as negative controls. The cardiac functions of all these rats were measured 16 weeks later. And ventricular myocytes were then enzymatically isolated. Contractile function and calcium transient of the myocytes were detected simultaneously and compared with the control group by video-based motion edge-detection system.Result 1 Left ventricular systolic pressure(LVSP)and±dp/dtmax dramatically increased and left ventricular end-diastolic pressure(LVEDP) significantly decreased in thyroid hormone group compared with the control group (P<0.05). The PTA,±dL/dtmax andΔFFI were significantly increased and the TTPCa and T50DCa were markedly shortened in the thyroid hormone group as compared with the control group.2 Left ventricular systolic pressure(LVSP)and±dp/dtmax dramatically increased and left ventricular end-diastolic pressure(LVEDP) significantly descended in thyroid hormone treated group compared with the heart failure group(P<0.05). The PTA,±dL/dtmax andΔFFI were significantly increased and the TTPCa and T50DCa were markedly shortened in the thyroid hormone group as compared with the control group.Conclusion1 Thyroid hormone may improve the function of rat hearts and enhance the contractile function and calcium transient level of ventricle myocytes.2 Thyroid hormone may improve the contractile function and calcium transient level of ventricle myocytes isolated from rats with CHF,which may provide a experimental support for the further research of mechanisms about CHF treated with thyroid hormone.