Effect of hypoxia on mechanical function in the neonatal mammalian heart.
Effect of hypoxia on mechanical function in the neonatal mammalian heart.
复制标题
缺氧对新生哺乳动物心脏机械功能的影响。
DOI：
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发表时间：
1978
影响因子：
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通讯作者：
G. Langer
中科院分区：
文献类型：
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作者：
J. Jarmakani;M. Nakazawa;T. Nagatomo;G. Langer
在离体、动脉灌注、新生兔和狗心脏中研究了 30 分钟缺氧后复氧对机械功能的影响。所有研究均以 2.5 ml/g-min 的灌注速率、60 次/min 的起搏速率和 27°C 进行。用 95% O2 和 5% CO2（对照）或 95% N2 和 5% CO2（缺氧）平衡的 Krebs-Henseleit 溶液灌注肌肉。在新生兔和狗中，在缺氧的前 3 分钟内，张力产生 (DT) 和最大张力产生速率 (dT/dtmax+) 均下降，然后恢复到与对照组无差异的值。缺氧对兔子和狗的 DT 和 dT/dtmax+ 的影响与年龄呈负相关。描述缺氧期间 DT 和 dT/dTmax+ 下降以及复氧期间恢复的方程最好用两个或三个指数表示。在缺氧期间，达到峰值紧张的时间和达到放松的半衰期会减少，并且这种减少也与年龄成反比。新生儿在缺氧期间能够维持正常的机械功能这一事实表明，由于通过糖酵解途径的流量增加，新生儿能够维持正常的心肌 ATP 水平。
The effect of 30 min of hypoxia followed by reoxygenation on mechanical function was studied in isolated, arterially perfused, neonatal rabbit and dog hearts. All studies were performed at a perfusion rate of 2.5 ml/g-min, at a pacing rate of 60 beats/min and at 27 degrees C. The muscles were perfused with Krebs-Henseleit solutions equilibrated with 95% O2 and 5% CO2 (control) or 95% N2 and 5% CO2 (hypoxia). In the newborn rabbit and dog, both the developed tension (DT) and the maximal rate of tension development (dT/dtmax+) decreased during the first 3 min of hypoxia and then recovered to values not different from control. The effect of hypoxia on DT and dT/dtmax+ was inversely related to age in both the rabbit and dog. The equations describing the decline in DT and dT/dTmax+ during hypoxia and the recovery during reoxygenation were best expressed by two or three exponentials. Time to peak tension and half time to relaxation decreased during hypoxia and the decrease was also inversely related to age. The fact that the newborn was able to maintain normal mechanical function during hypoxia suggests that the newborn is capable of maintaining normal myocardial ATP levels due to enhanced flux through the glycolytic pathway.