大鼠容量超负荷性心肌肥厚时cAMP、cGMP对机械信号刺激的应答反应

The response of cAMP and cGMP in rat cardiac volume-overload hypertrophy

目的 动态观察大鼠容量超负荷性心肌肥厚模型中环磷酸腺苷 (cAMP)、环磷酸鸟苷(cGMP)对机械信号刺激的应答反应。方法 应用放射免疫方法观察在容量负荷后不同时间点大鼠心肌中cAMP、cGMP的变化以及在慢性容量超负荷基础上给予急性容量负荷时cAMP、cGMP对机械信号刺激的应答反应。结果 容量负荷后即刻及 4～ 6h ,cAMP、cGMP均明显下降 ,其后逐渐上升 ,1周时cAMP超过正常水平 ,cGMP超过手术对照组水平 ,2周后cAMP、cGMP均下降 ,5个月时显著下降 ;在慢性容量超负荷基础上给予急性容量负荷时心功能恶化 ,同时cAMP呈现反常反应。结论 cAMP、cGMP对机械信号刺激的应答反应表明肥厚心肌存在机械信号跨膜传递障碍。研究这种障碍需进一步探索机械信号跨膜传递通路是由那些环节组成及如何相互作用参与机械信号跨膜传递。

Objective To investigate the change of cAMP and cGMP chosen as the indicator of response to volume overload. Methods The time of cAMP and cGMP content on the model of rat cardiac volume overload hypertrophy were examined by RIA study. Results The content of cAMP,cGMP decreased significantly right after the volume overload and at 4～6 hours, then increased gradually and at 1 week cAMP exceeded the content of the normal, while cGMP exceeded that of the sham operated rats, but both decreased again at 2 weeks and decreased more obviously at 5 months. Conclusion In hypertrophic myocardium the signal transduction pathways governing the hypertrophic response of cardiomyocytes suffer disorders.