Figure 4

Representative photomicrographs of lung parenchyma. Samples were stained with (top) haematoxylin & eosin, (middle) TUNEL, and (bottom) double immunofluorescence for TTF1 (Thyroid Transcription Factor 1, alveolar epithelium) and CD34 (endothelium). Control lung (C) shows thin alveolar septa (Alv) with sparse apoptotic cells and normal histoarchitecture after tridimensional reconstruction of confocal microscopy. Positive staining is indicated by black-brown and the contrast background staining is green. CLP-SAL lung presented thickened alveolar septa with inflammatory cells, numerous brownish alveolar apoptotic cells and distortion of the architecture after tridimensional reconstruction at confocal microscopy. Note the regeneration and decreased apoptosis of alveolar epithelial cells after glutamine treatment and restoration of the acinar architecture by tridimensional reconstruction at confocal microscopy (CLP-Gln). Photomicrographs are representative of data obtained from lung sections derived from five animals. CLP = cecal ligation and puncture; Gln = glutamine; SAL = saline.