摘要
为探讨尾部悬吊大鼠心肌收缩性能是否呈进行性降低及心肌肌浆网的功能，将２４只雄性大鼠分为三组，进行为期８周的尾部悬吊。结果大鼠心肌等长收缩的静息张力保持不变，发展张力较同步对照组明显降低，与４周悬吊组无明显差别。悬吊８周大鼠乳头肌等长收缩达到发展张力峰值的时间，较同步对照组明显延长。与悬吊４周大鼠乳头肌舒张一半所需时间呈缩短趋势不同，悬吊８周的明显延长。经两周恢复后，心肌等长收缩各参数均接近其同步对照水平。悬吊８周组收缩力－刺激间隔曲线的早恢复期段曲线位于同步对照组的上方，而静息增强期与静息衰退期段曲线均位于其同步对照组的下方。以上结果提示中、长期尾部悬吊引起的心肌收缩性能的降低可能为适应性变化，８周尾部悬吊可能引起大鼠心肌肌浆网Ｃａ２＋释放功能降低。
To observe the changes in myocardial function and calcium ion release of sarcoplasmic reticulum in rats under simulated weightlessness,24 Sprague- Dawley male rats were divided into control (CON), 8 week tail-suspension (SUS) and recovery for 2 weeks (RE) groups.The results showed that there was no change in resting tension of myocardial twitch in SUS.While the developed tension (DT) of myocardial twitch significantly decreased in SUS as compared with CON.The time to peak tension (TPT) and time to half relaxation (T1/2R) of myocardial twitch were prolonged in SUS.DT, TPT and T1/2R recoverd to their corresponding control values after 2 w of recovery from tail-suspension.The early recovery curve of force-interval relation in SUS was in a higher position over that of CON, but the rest potentiation and rest depression curve was positioned under that of CON. These results suggested that there might be an adaptative change in myocardial function in medium-or long-term tail-suspended rats while 8 w tail-suspension reduces calcium ion release from cardiac sarcoplasmic reticulum in rats.
出处
《航天医学与医学工程》
CAS
CSCD
1997年第3期206-209,共4页
Space Medicine & Medical Engineering
基金
国家863-2中
长期航天课题
关键词
失重模拟
心肌
肌浆网
收缩功能
weightlessness simulation myocardium myocardial contraction sarcoplasmic reticulum adaptation
