The effect of pentoxifylline on ultrastructural picture of type II alveolar epithelial cells and generation of reactive oxygen species during cyclophosphamide-induced lung injury.

The aim of the study was to evaluate the effect of pentoxifylline (PTXF) on the production of reactive oxygen species in the rat lungs after intraperitoneal (i.p.) cyclophosphamide (CP) administration (150 mg/kg b.w.) and to draw a correlation between the morphological changes and biochemical findings. Morphological examinations were based on ultrastructural analysis in the transmission electron microscope. It was found that single i.p. CP administration caused destructive changes, particularly within mitochondria and lamellar bodies of type II alveolar epithelial cells (EP II), and within blood vessels of interalveolar septa. The changes were accompanied by an increase in the MDA (malondialdehyde) homogenates. The animals receiving PTXF + CP showed normalization of MDA level and minor damage to EP II confined to alterations in lamellar bodies of EP II. The vascular changes observed after i.p. CP administration were manifested in endothelial swelling and accumulation of neutrophilic granulocytes, monocytes and in the later period blood platelets within the capillaries of interalveolar septa. The cells were tightly attached to endothelium. The changes in the vascular system were accompanied by a significant decrease in the activity of antioxidant enzymes (Cu,Zn-SOD and GSSG-R) in the blood serum collected from the left ventricle of the heart. In the animals given PTXF + CP, a higher decrease was revealed in the activity of these enzymes. Ultrastructural examinations found morphological signs of a facilitated flow, mainly of cellular elements, through the vessels of the interalveolar septa of the lungs.