Bing O H, LaRaia P J, Franklin A, Stoughton J, Weintraub R M
Circulation. 1984 Sep;70(3 Pt 2):I84-90.
The mechanism of myocardial protection provided by red blood cells was studied with a preparation of isolated, blood-perfused dog heart. Myocardial function, metabolism, and high-energy phosphate stores were determined before and at the end of cardioplegic arrest and after reperfusion. Cardioplegic solutions containing NaCl, KCl, and dextran (crystalloid; C) were compared, at 27 degrees C, with an identical solution containing 20% washed red cells (R) and a third solution in which the red cells were treated with 0.02M NaNO2, resulting in methemoglobin (M) formation or red cells able to buffer pH but unable to transport oxygen. Solutions were delivered at 15 min intervals during 2 hr of arrest and coronary effluent pH, PCO2, and lactate were measured. Both R and M solutions prevented the increases in effluent PCO2 and decreases observed in pH with C. On the other hand, mechanical, metabolic, and high-energy phosphate determinations revealed that marked protection was provided by R but not by M or C. Thus, myocardial protection provided by R at 27 degrees C is not the result of buffering but appears to be primarily the result of oxygen delivery by the red cells to the myocardium.
利用离体血液灌注犬心标本研究了红细胞提供心肌保护的机制。在心脏停搏前、停搏结束时及再灌注后测定心肌功能、代谢及高能磷酸储存。将含氯化钠、氯化钾和右旋糖酐的心脏停搏液（晶体液；C）在27℃下与含20%洗涤红细胞的相同溶液（R）以及第三种溶液进行比较，在第三种溶液中红细胞用0.02M亚硝酸钠处理，导致高铁血红蛋白（M）形成或红细胞能够缓冲pH值但不能运输氧气。在停搏2小时期间每隔15分钟给予溶液，并测量冠状动脉流出液的pH值、PCO₂和乳酸。R溶液和M溶液均可防止流出液PCO₂升高以及C溶液中观察到的pH值降低。另一方面，机械、代谢和高能磷酸测定表明，R溶液提供了显著的保护作用，而M溶液和C溶液则没有。因此，27℃下R溶液提供的心肌保护不是缓冲作用的结果，而似乎主要是红细胞向心肌输送氧气的结果。
