A histological study on the effect of pentoxifylline on acute lung injury induced by renal ischemia–reperfusion

Abstract

Pentoxifylline (PTX) is a methylxanthine derivative that improves blood flow by decreasing its viscosity. Recently, PTX was proven to be an antioxidant [7], an inhibitor of inflammatory cytokines [8], and a phosphodiesterase inhibitor [9]. BackgroundKidney ischemia-reperfusion injury (IRI) occurs under many clinical conditions. It leads to acute kidney injury, which may affect various remote but important organs such as the lung. Aim of the workThe aim of the present study was to investigate the effect of renal IRI on the lung structure and evaluate the possible protective effect of pentoxifylline (PTX). Materials and MethodsFifteen adult male Wistar rats aged 8-10 weeks and weighing 150-200 g were used in this study. They were divided into the following groups: group I (the control group) was subjected to sham operation; group II (the IRI group) was subjected to renal ischemia by bilateral clamping of the renal pedicles for 45 min and then allowed 24 h of reperfusion. Group III (the PTX-treated group) was given two doses of PTX (40 mg/kg) intraperitoneally and subjected to an ischemia-reperfusion procedure as performed in group II. Lung specimens were processed for light and electron microscopic examination. The mean thickness of the interalveolar septa and the mean number of type-II pneumocytes were measured. ResultsGroup II showed diffuse lung injury affecting mainly the alveoli, which appeared flooded with exudate and red blood cells, which also extravasated in the interstitium. There was vacuolation of the cytoplasm of both type-I and type-II pneumocytes with significant increase in the number of type-II cells and depletion of lamellar bodies. Significant increase in the mean thickness of the interalveolar septa was detected and it showed infiltration by macrophages and neutrophils. PTX caused marked improvement in the lung structure after ischemia-reperfusion. Most of the alveoli appeared empty and a few of them showed minimal red blood cells and macrophages. Thin interalveolar septa were detected with thickness comparable to that of the control group. ConclusionRenal IRI caused alteration in the lung structure, which was ameliorated by PTX administration.