IN-VITRO ACTIVATION OF COMPLEMENT AND CONTACT SYSTEM BY LACTIC-ACIDOSIS

THE activation of complement and contact systems occurs in reperfusion injuries with initial tissue hypoxia, and lactic acidosis such as myc ardial infarction and birth asphyxia. The aim of our experiment was th e formal proof of activation by sole lactic acidosis. Lactic acid was added to blood and plasma samples from 10 healthy volunteers. C5a and factor Wa were measured by EIA after incubation at 37 degrees C for 1 h. Both concentrations increased (P < 0.0001 by Friedman analysis) in blood and plasma samples with increasing amount of added lactic acid L actic acidosis can activate C5 from the complement system and factor X II from the contact system directly, even in the absence of cellular c omponents.