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采用改进的Ｍｏｒｅｙ－Ｈｏｌｔｏｎ尾部悬吊大鼠模型模拟失重状态和用离体乳头肌灌流技术，观察模拟失重大鼠左心室乳头肌收缩性能与钙反应性的变化过程。结果表明，模拟失重１周，收缩性能呈增高趋势；２周时，收缩性能有降低趋势；４周时，收缩性能明显降低，主要表现为等长张力降低２９．２％，达到张力峰值的时间延长１０．４％，舒张时间则呈降低趋势。另外，模拟失重４周大鼠乳头肌对Ｃａ２＋的反应性均较相应的对照组明显降低。这些变化提示，４周模拟失重可能引起心肌肌原纤维含量减少和肌浆网Ｃａ２＋运转功能降低。
The modified Morey-Holton tail-suspended rat model was used to simulate the condition of weightlessness and the effect of isolated papillary muscle remodeling on the contractility and calcium reactivity of left ventricular papillary muscle in simulated weightless rats. The results showed that the shrinkage performance increased with the first weight loss for one week, and the shrinkage decreased after two weeks. The shrinkage decreased significantly after 4 weeks, which was mainly due to the reduction of isometric tension by 29.2% and the peak time Prolonged 10.4%, diastolic time showed a downward trend. In addition, the reactivity of papillary muscle to Ca2 + in simulated 4-week weight rats was significantly lower than that of corresponding control group. These changes suggest that 4-week simulated weightlessness may cause decreased myocardial myofibrillar content and reduced sarcoplasmic reticulum Ca2 + functioning.