Adenosine protects ultrastrueture of isolated rat lungs against fat emulsion injury

In isolated rat lungs subjected to fat emulsion damage, a model simulating adult respiratory distress syndrome, we have previously reported that adenosine (ADO) reduces pulmonary vascular resistance (PVR) and the fluid filtration rate (FFR). In the present study the aim was to examine morphologically this effect of ADO. Two groups of isolated rat lungs were subjected to the injury. Marked and significant differences were found between the groups; in lungs not given ADO, FFR and airway pressure were higher and, as evaluated by electron microscopy, the endothelial lining was thin and partly disrupted. The epithelial cells of the alveolar walls were also partly disrupted and the alveolar septa were split enclosing interstitial edema. In lungs receiving ADO from the onset of exposure to fat emulsion, FFR was lower and ultrastructure did not differ from non–injured non–treated controls perfused for the same length of time.