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空间飞行对心血管系统具有深远的影响.但是,目前关于心肌细胞如何对空间飞行条件发生响应尚未见报道.本研究报道了空间飞行对体外培养的心肌细胞结构与功能的影响.神舟六号飞船将原代培养的新生大鼠心肌细胞载入太空,并于发射后4h进行在轨激活.其中8个样品分别于发射后4,48以及96h进行在轨固定,并于飞船返回后进行细胞骨架的荧光染色观察;另外2个样品未进行固定,于飞船返回后进行心肌细胞收缩及分泌功能的分析;地面样品在实验室中进行平行处理.飞行115h结束后,与地面样品比较,飞行样品中心肌细胞的自发搏动位点显著减少,同时搏动位点中的细胞收缩频率明显加快,并失去同步性;对飞行样品培养液进行的放射免疫检测显示,飞行细胞的心钠素分泌水平下降59.6%.对固定样品进行的激光共聚焦显微图像分析显示,飞行细胞呈现时间依赖性的微管解聚,而微丝骨架的结构与分布没有明显变化.总之,上述结果提示,空间飞行诱发体外培养的心肌细胞发生功能减退和微管解聚,对于进一步研究空间心血管功能紊乱的机制提供了细胞学基础.
Space flight has a profound impact on the cardiovascular system.However, there is no report on how cardiomyocytes respond to space flight conditions at present.This study reports the effect of space flight on the structure and function of cultured cardiomyocytes in vitro. Primary cultured neonatal rat cardiomyocytes were loaded into space and in-orbit-activated at 4h after launch, 8 of which were fixed on-orbit at 4, 48, and 96h after launch, respectively, and the cytoskeleton Of the other two samples were not fixed, after the return of the spacecraft myocardial contractility and secretion function analysis; ground samples were processed in parallel in the laboratory after the flight 115h, compared with the ground samples, the flight sample center The spontaneous pulsation of muscle cells decreased significantly, meanwhile the frequency of cell contraction in pulsatile sites accelerated significantly and synchronism was lost. The radioimmunoassay of flight samples showed that the atrial natriuretic peptide level of flight cells decreased by 59.6% Laser confocal microscopy analysis of fixed samples showed that the flying cells exhibited time-dependent microtubule disaggregation, While the structure and distribution of actin filaments did not change significantly.In summary, the above results suggest that the spatial flight induced cardiomyocyte hypofunction and microtubule disaggregation in vitro provide a cytological basis for further investigation of the mechanism of spatial cardiovascular dysfunction .