Concerning ischemic cellular injury, the following is/are true:

b. Microvascular endothelium is a significant source of xanthine oxidase

d. Endothelial cells lack the defense system for oxidative damage 

Prolonged hypoxic metabolism is not only inefficient but the accumulation of lactic acid produces direct injury to organelles, alters enzyme activity, and enhances cytokine production. The microvascular endothelium reacts to ischemia by production of xanthine oxidase, but lacks the defense system for oxidative damage. The “no-reflow” phenomenon is associated with an increased number of WBCs adherent to the luminal surface of the microcirculation and cellular swelling