a treatment of ischemia and the attendant reperfusion injury entails the administration plasmin and plasmin - forming proteins , including lys - plasminogen and similar substances . lys - plasminogen , which can be obtained from the proteolytic cleavage of glu - plasminogen , has been found to have a protective effect on tissue that has been injured by ischemic conditions . the administration of lys - plasminogen alone , in a dosage of about 10 - 1000 caseinolytic units / kg , can be used to treat subjects during the time of reperfusion and after reperfusion has already occurred . lys - plasminogen also can be administered in conjunction with clot lysis therapies , such as those that employ tissue plasminogen activator and the like . lys - plasminogen can also lessen cerebral edema which results from cerebral ischemia .