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

Abstract
Background: Although myeloperoxidase (MPO) and adenosine‐deaminase (ADA) levels are markers of activated leukocytes, both enzymes have not been currently addressed in inflammation models.Aims: This study evaluates whether the concentrations of these enzymes are significantly correlated with the content of leukocytes in a pleurisy model.Methods: The pleurisy was induced by carrageenan (1%) in mice, and the parameters analyzed 4 and 48 h after.Results: After the induction of inflammation (4 h), 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).Conclusions: 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.