Ohata H, Trollinger D R, Lemasters J J
Department of Cell Biology & Anatomy, University of North Carolina at Chapel Hill 27599.
Res Commun Mol Pathol Pharmacol. 1994 Dec;86(3):259-71.
The goal of this work was to define the distinction between irreversible structural changes and actual loss of cell viability during hypoxic/ischemic/reperfusion injury to one-day cultured adult rabbit cardiac myocytes. Myocytes were exposed to 5 mM NaCN and 20 mM 2-deoxyglucose (chemical hypoxia) or anoxia at pH 6.2 to simulate ischemia. Shortening and hypercontraction (cell rounding and blebbing) were monitored by bright field microscopy, and loss of viability was determined by nuclear labeling with propidium iodide. After both treatments, myocytes began to shorten after 30 minutes, and most were hypercontracted after 3 hours. 50% loss of viability did not occur until after 6 hours or more. To simulate reperfusion, myocytes were washed with fresh aerobic buffer at pH 7.4. Loss of viability was accelerated when cells were reperfused with Krebs-Ringer solution. This cell killing was prevented when myocytes were reperfused with nutrient culture medium instead of Krebs-Ringer solution. Both contracted and hypercontracted cells partially relaxed after reperfusion. These results indicate that structural changes (contraction, hypercontraction and blebbing) to adult cardiac myocytes are distinct from outright cell death caused by plasma membrane failure. Persistence of cell viability suggests that rescue of cardiac myocytes from necrotic cell death may be possible even very late in injury.
这项工作的目标是明确在对培养一天的成年兔心肌细胞进行缺氧/缺血/再灌注损伤过程中不可逆结构变化与细胞活力实际丧失之间的区别。将心肌细胞暴露于5 mM氰化钠和20 mM 2-脱氧葡萄糖（化学性缺氧）或pH 6.2的无氧环境中以模拟缺血。通过明场显微镜监测细胞缩短和超收缩（细胞变圆和形成泡状），并用碘化丙啶进行细胞核标记来确定细胞活力丧失情况。两种处理后，心肌细胞在30分钟后开始缩短，3小时后大多数出现超收缩。直到6小时或更久后才出现50%的细胞活力丧失。为了模拟再灌注，用pH 7.4的新鲜有氧缓冲液冲洗心肌细胞。当用 Krebs-Ringer 溶液对细胞进行再灌注时，细胞活力丧失加速。当用营养培养基而非 Krebs-Ringer 溶液对心肌细胞进行再灌注时，这种细胞杀伤作用被阻止。再灌注后，收缩和超收缩的细胞都部分松弛。这些结果表明，成年心肌细胞的结构变化（收缩、超收缩和形成泡状）与由质膜破坏导致的直接细胞死亡不同。细胞活力的持续存在表明，即使在损伤后期，将心肌细胞从坏死性细胞死亡中挽救出来也是有可能的。
