Wittenberg B A, Robinson T F
Cell Tissue Res. 1981;216(2):231-51. doi: 10.1007/BF00233618.
The morphological, functional, and biochemical properties of freshly isolated heart muscle cells were examined. A reproducible method for the separation and purification of such cells isolated from adult rat heart was developed. It yields an average of 5 X 10(6) striated rectangular cells which retain normal morphology (range 2.5 to 11 X 10(6) and 4 X 10(6) calcium-tolerant cells (range 2.5 to 5.5 X 10(6) per heart. After purification, 85 to 95% of the cells retain normal morphology in solutions of calcium ion activity equal to 10 microM, and 65 to 79% of the cells are rectangular in solutions of calcium ion activity equal to 1 mM. Under the light microscope we were able to identify functionally intact individual cells that are calcium-tolerant and contract only in response to electrical stimulations, as well as dying myocytes that beat spontaneously. The examination of such cells under the electron microscope permitted us to address the question: What is the sequence of structural changes in a dying cell? The sarcomere lengths measured both in the living state and after preparation for electron microscopy are in the physiological range. In steady states of oxygen tension, respiration of the intact cells is undiminished from 50 torr to 2 torr. The oxygen tension for half maximal respiration is 0.15 torr. Therefore, the limitation of oxygen diffusion to the mitochondria of isolated heart muscle cells must be remarkably small.
对新鲜分离的心肌细胞的形态、功能和生化特性进行了检测。开发了一种可重复的从成年大鼠心脏分离和纯化此类细胞的方法。该方法平均可获得5×10⁶个保留正常形态的横纹长方形细胞（范围为2.5至11×10⁶），以及4×10⁶个耐钙细胞（每个心脏范围为2.5至5.5×10⁶）。纯化后，在钙离子活性等于10微摩尔的溶液中，85%至95%的细胞保留正常形态；在钙离子活性等于1毫摩尔的溶液中，65%至79%的细胞呈长方形。在光学显微镜下，我们能够识别出功能完整的耐钙单个细胞，这些细胞仅在电刺激下收缩，以及自发搏动的濒死心肌细胞。在电子显微镜下对这些细胞进行检查，使我们能够回答这个问题：濒死细胞的结构变化顺序是什么？在活态以及制备用于电子显微镜观察后测量的肌节长度均在生理范围内。在稳定的氧张力状态下，完整细胞的呼吸从50托到2托均未减弱。半最大呼吸时的氧张力为0.15托。因此，氧扩散到分离的心肌细胞线粒体的限制必定非常小。
