PLASMA FROM PATIENTS EXPOSED TO ISCHEMIA-REPERFUSION CONTAINS CLASTOGENIC FACTORS AND STIMULATES THE CHEMILUMINESCENCE RESPONSE OF NORMAL LEUKOCYTES

Clastogenic factors (CFs) are released by cells exposed to superoxide radicals and are found in various situations of oxidative stress. Cert ain of their components stimulate further superoxide production by com petent cells, as shown with cytochrome c assay in previous work. In th e present study, we report CF formation after ischemia reperfusion in patients undergoing coronary bypass surgery. Plasma ultrafiltrates, co llected 20 min after reperfusion, had clastogenic properties in contra st to those collected before ischemia. We also show that the luminol-e nhanced chemiluminescence response of neutrophils from healthy persons is increased when these cells are exposed to CF-containing postreperf usion samples from patients. Light emission was reduced to control val ues in the presence of superoxide dismutase. The burst of oxyradicals upon reperfusion is probably the initiating event of CF formation, whi ch in turn leads to further oxyradical generation. This amplification process may explain why detectable levels of CF need a delay of at lea st 10 min. The activated state of neutrophils in ischemia reperfusion is at once a consequence and a source of CFs. Individual variation in the persistence of this clastogenic and leukocyte-activating material was observed. Therefore, antioxidants for prevention of ischemia reper fusion injury should be continued during the postoperative course.