Alteration of dipeptidyl peptidase IV activity in rodents with exudative in flammation

Abstract

The role of dipeptidyl peptidase IV (ÅÑ 3.4.14.5., CD26, DPPIV) in inflammation is based on its effects on chemotaxis, proliferation, and accumulation of immune cells in tissues, and proteolysis of some inflammation mediators. The goal of this study was to evaluate the activity of soluble DPPIV in rodents with exudative in flammation and effects of DPPIV inhibitors on exudation. Methods. DPPIV activity was measured using the fluorometric assay in peritoneal exudate from rats with acetic acid-induced peritonitis and mice with glycogen-induced peritonitis as well as
in serum of rats with acetic-induced peritonitis and carrageenan-induced paw edema. Results. The DPPIV activity was significantly increased in the exudate from mice and rats with experimental peritonitis. Furthermore, the DPPIV activity was significantly higher in blood serum of rats with acetic acid-induced peritonitis. Absence of a significant increase in the serum DPPIV activity in rats with paw edema could be due to less severe inflammation. DPPIV inhibitors with different ICs₅₀, sitagliptin (IC₅₀ = 25.0 ± 9.0 nmol/l) and AlaPrdN (2-S-alanine cyanopyrrolidine, IC₅₀ = 2.0 ± 0.3 nmol/l), did not significantly change the exudation intensity in mice with acetic acid-induced peritonitis. Conclusion. The increased DPPIV activity in acute exudative inflammation results from inflammatory process onset.