Inhibition of neutrophil proteinases by recombinant serpin Lex032 reduces capillary no-reflow in ischemia/reperfusion-induced acute pancreatitis.

Because neutrophil proteinases such as elastase and cathepsin G are considered to play a major role in inflammatory tissue damage, the microcirculatory effect of the serine proteinase inhibitor (serpin) Lex032 after ischemia/reperfusion (I/R)-induced pancreatitis was investigated. Lex032 inhibits these proteinases by recombinant combination of alpha(1)-antitrypsin and alpha(1)-antichymotrypsin. Twenty-eight anesthetized rats received either Lex032 or NaCl 0.9% as a control solution during baseline conditions or after 1 h of complete reversible ischemia induced by microclip occlusion of the pancreatic arteries. The number of erythrocyte-perfused capillaries (functional capillary density) and the leukocyte adherence in postcapillary venules were assessed by intravital microscopy 45, 90, and 120 min after administration. In the baseline group, Lex032 increased leukocyte adherence compared with the NaCl 0.9% baseline group, without changing any other parameter. I/R without Lex-032 treatment resulted in a 50% reduction in functional capillary density, a 2-fold increase in leukocyte adherence, an increase in interleukin-6 serum concentration, and a significant fall in blood pressure during reperfusion time compared with baseline animals. Treatment with Lex032 in I/R resulted in significant preservation of capillary perfusion, an absence of interleukin-6 increase, and preservation of mean arterial pressure during reperfusion time, without changing the leukocyte adherence, compared with the NaCl 0.9% I/R group. Because of its considerable amelioration of microcirculatory perfusion, Lex032 might be useful in the treatment of pancreatic I/R tissue damage (e.g., cardiac bypass surgery, pancreas transplantation, and hemorrhagic shock) by prevention of capillary perfusion failure.