Cellular infiltrates and injury evaluation in a rat model of warm pulmonary ischemia-reperfusion.
BACKGROUND
Beside lung transplantation, cardiopulmonary bypass, isolated lung perfusion and sleeve resection result in serious pulmonary ischemia-reperfusion injury, clinically known as acute respiratory distress syndrome. Very little is known about cells infiltrating the lung during ischemia-reperfusion. Therefore, a model of warm ischemia-reperfusion injury was applied to differentiate cellular infiltrates and to quantify tissue damage.


METHODS
Fifty rats were randomized into eight groups. Five groups underwent warm ischemia for 60 min followed by 30 min and 1-4 hours of warm reperfusion. An additional group was flushed with the use of isolated lung perfusion after 4 hours of reperfusion. One of two sham groups was also flushed. Neutrophils and oedema were investigated by using samples processed with hematoxylin/eosin stain at a magnification of x500. Immunohistochemistry with antibody ED-1 (magnification x250) and antibody 1F4 (magnification x400) was applied to visualize macrophages and T cells. TdT-mediated dUTP nick end labelling was used for detecting apoptosis. Statistical significance was accepted at P < 0.05.


RESULTS
Neutrophils were increased after 30 min until 4 hours of reperfusion as well as after flushing. A doubling in number of macrophages and a fourfold increase in T cells were observed after 30 min until 1 and 2 hours of reperfusion, respectively. Apoptosis with significant oedema in the absence of necrosis was seen after 30 min to 4 hours of reperfusion.


CONCLUSIONS
After warm ischemia-reperfusion a significant increase in infiltration of neutrophils, T cells and macrophages was observed. This study showed apoptosis with serious oedema in the absence of necrosis after all periods of reperfusion.
Van Putte
Bart P
BP
Department of Thoracic and Vascular Surgery, University Hospital Antwerp, Antwerp, Belgium. bvanputte@yahoo.com
Kesecioglu
Jozef
J
Hendriks
Jeroen M H
JM
Persy
Veerle P
VP
van Marck
Erik
E
Van Schil
Paul E Y
PE
De Broe
Marc E
ME
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D004487:Edema / Q000503:physiopathology; D016676:Macrophages, Alveolar / Q000502:physiology*; D008297:Male; D009504:Neutrophils / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000276:immunology / Q000473:pathology*; D012128:Respiratory Distress Syndrome / Q000276:immunology / Q000503:physiopathology*