Is reperfusion injury of postischemic skeletal muscle attenuated by the 21-aminosteroids U-74389F and U-74500A independent of iron binding?
High-grade partial ischemia of skeletal muscle is associated with iron delocalization, which persists on reperfusion. Each lazaroid achieved a similar "membranoprotective" effect during reperfusion only despite lack of iron binding by U-74389F, suggesting a direct interaction with the cell membrane. These data support the concept that ischemic injury and reperfusion injury occur through fundamentally different mechanisms.
Our results are consistent with the hypothesis that the transfusion of PRBCs during CPB may increase postoperative morbidity. However, due to the limitations of this retrospective analysis, further studies are needed to confirm a causal relationship between the timing of the transfusion and the clinical outcome and to elucidate putative mechanisms of such an association.