Myeloperoxidase and adenosine-deaminase levels in the pleural fluid leakage induced by carrageenan in the mouse model of pleurisy.

Although myeloperoxidase (MPO) and adenosine-deaminase (ADA) levels are markers of activated leukocytes, both enzymes have not been currently addressed in inflammation models. This study evaluates whether the concentrations of these enzymes are significantly correlated with the content of leukocytes in a pleurisy model. The pleurisy was induced by carrageenan (1%) in mice, and the parameters analyzed 4 and 48 h after. After the induction of inflammation (4h), MPO and ADA levels peaked in parallel to neutrophils (p<0.01). Regarding the second phase of pleurisy (48 h), the highest concentrations of ADA were detected in parallel to the highest levels of mononuclears (p<0.01). At this time, MPO levels and neutrophils remained elevated, although at lower levels than those found at 4 h. A significant positive correlation was found among neutrophiLs and MPO, and mononuclears and ADA (p<0.01). These findings support the evidence that both enzymes are markers of the inflammatory process, and provide new tools for a better understanding of the immunoregulatory pathways that occur in inflammation.