机械牵张对离体跳动兔心房磷酸二酯酶3表达及其活性的影响

Effects of mechanical stretch on expression and activity of PDE3 in perfused rabbit atriumin vitro

[目的]探讨机械牵张对离体跳动兔心房磷酸二酯酶3(PDE3)表达及其活性的影响.[方法]利用增加离体灌流心房内压的方法建立兔心房颤动模型,观察灌流2h后心房组织形态学改变,利用免疫印迹和HPLC法检测PDE3的表达水平及其活性变化.[结果]HE染色结果显示,机械牵张2h后心肌纤维呈长带状,有分支,可见明暗相间的横纹,与正常组比较未见明显改变;透射电子显微镜下观察可见增加心房内压后心房肌肌浆网扩张,线粒体肿胀、变形,脊排列紊乱、消失;机械牵张2h后心房组织中PDE3表达较对照组无明显变化,但活性显著降低(P<0.05).[结论]心房颤动心房组织中PDE3活性降低与机械牵张引起的心房内压增高有关系.

OBJECTIVE To study the effects of mechanical stretch on the expression and activity of phosphodiesterase-3（PDE3）in perfused rabbit atriumin vitro.METHODS An rabbit atrial fibrillation model was established by increasing the isolated atrial perfusion pressure.Atrial morphological changes after perfusion for 2hours were observed,and the expression and activity of PDE3 were detected by Western blot and HPLC.RESULTS Elongated and ramate myocardial fibers,visible alternately light and dark stripes after perfusion for 2hours were observed by light microscope,and there was no significant difference between the normal group and AF group,and the expanded atrial sarcoplasmic reticulum,swelled and deformed mitochondria,and disorderly arranged and disappeared mitochondria cristae were observed by transmission electron microscope.The expression of PDE3 in atrial tissue was not significantly changed,but its activity was significantly increased in experimental group.CONCLUSION The increased activity of PDE3 in atrial fibrillation is connected with the high-pressure atrial perfusion.