Neutrophils and the endothelium in post-ischemic alterations in skeletal muscle blood flow

Thromboxane A2, leukotriene B4, and NE are all released from ischemic muscle during reperfusion. Thromboxane A2 levels peaked at 10 min and this potent vasoconstrictor may be responsible for low reflow. Neutrophil elastase levels did not rise until 240 min of reperfusion, following that of leukotriene B4 at 120 min, indicating that neutrophil recruitment and activation is a relatively late event following revascularization. In conclusion, it would appear that endothelial factors have a significant role in the vasomotor changes that account for low reflow. Equally altered neutrophil function almost certainly contributes to the final development of reperfusion injury.