Pancreatite aguda experimental grave cursa com disfunção pulmonar, envolvimento de macrófagos e dano diafragmático

Abstract

Acute pancreatitis (AP) is considered an emergency abdominal situation. In the severe form of the disease, patients develop marked systemic inflammatory response and Multiple Organ Dysfunction Syndrome. Lungs are the main affected organs, being responsible for deaths in individuals with AP for the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Alveolar macrophages can orchestrate both initiation and resolution of this inflammation. The diaphragm, as the main muscle of breathing, should be evaluated in cases of pulmonary mechanical dysfunction. Objectives: To evaluate the functional and inflammatory pulmonary repercussions in the course of acute alcoholic and experimental biliary pancreatitis, exploring the main cells involved. Methods: Swiss and C57BL / 6 male mice (25-30 g) were used. For induction of biliary AP, the animals were anesthetized, submitted to a median laparotomy for cannulation of the pancreatic duct and received infusion of 50 μL of saline solution (0.9%) or TLC-S (3%). For the induction of alcoholic AP, the animals received intraperitoneal administrations of saline (250 μl), ethanol (1.35 g / kg) or ethanol associated with palmitolic acid (POA), 150 mg / kg (twice, with an hour interval) . After 24 h of AP induction, the animals were anesthetized to collect bronchoalveolar lavage (BAL) and blood samples, then euthanized and pancreas and lung samples were collected. We performed the following analysis: amylase and lipase plasma dosage; inflammatory changes of the pancreas and lung (histopathological evaluation; Mieloperoxidase - MPO activity; TNF-α and IL-1β dosage); investigation of pulmonary functional responses (spirometry, pulmonary mechanics and diaphragmatic contractility). In addition, we studied the role of alveolar macrophage by flow cytometry (using labeling for CD206 antibody) and macrophage culture. Nitrite, total protein and cytokine (TNF-α, IL-1β and IL-10) concentrations in BAL were also performed. Results: Serum levels of amylase, lipase, cytokines (TNF-α, IL-1β), pancreatic and pulmonary MPO activity were increased in animals with AP; there was damage to the pancreatic and pulmonary tissue, revealed in the histopathological evaluation of the animals with AP when compared to the control group. Comparing the animals with AP to control animals, there was deterioration in pulmonary mechanics and spirometry, which was measured by the following parameters: Flow, Tidal Volume, Minute Volume, Functional Residual Capacity, Total Pulmonary Capacity, Residual Volume, Dynamic Complacency, Quasi-Static Complacency and Inspiratory Capacity. There was dysfunction in diaphragmatic contractility characterized by decreased contraction rate and increased fatigability. In the BAL of the animals with PA, it was found a greater amount of cells (predominantly macrophages) and an increase in total proteins and nitric oxide. Culture of macrophages from BAL showed increased pro-inflammatory cytokines TNF-α, IL-1β. In the flow cytometric assay, a decrease in the labeling of the CD206 antibody was observed in the animals with PA when compared to the control animals, suggesting a phenotypic profile change from M2 to M1 in the alveolar macrophages of the animals with AP. Conclusion: Experimental severe AP presents with ALI, with involvement of alveolar macrophages, pulmonary mechanical dysfunction and diaphragmatic damage.