PIG I-ALPHA-I APPEARS UNMODIFIED IN PLASMA IN CASE OF ENDOTOXIN-INDUCED DISSEMINATED INTRAVASCULAR COAGULATION

The unrestricted activity of leukocyte proteinases is thought to contr ibute to the degradation of plasma proteins and thus amplify the coagu lation disorders occurring in septic shock. Inter-alpha-inhibitor (I a lpha I) is a plasma protein particularly susceptible to their action. Therefore we investigated its behavior in a porcine model of endotoxin shock which reproduces the coagulation changes observed in human seps is. We did not detect any qualitative or quantitative modification of porcine I alpha I in plasmas collected from pigs after endotoxin infus ion. To explain these data, I alpha I was incubated with polymorphonuc lear neutrophils (PMN) stimulated by FMLP in the presence of cytochala sin B. We found that, unlike human PMN, porcine cells were unable to p roteolyze I alpha I. Moreover, in the incubation medium of pig PMN, tr iggered either by FMLP or PMA, no measurable elastase activity was evi denced. Therefore, we urge to better take into account species differe nces in functional responses of PMN, to explain the experimental resul ts obtained in animal models of septic shock.