Trigger for intercellular adhesion molecule-1 expression in rat lungs transplanted from non-heart-beating donors.
BACKGROUND
Lung transplantation from non-heart-beating donors causes ischemia-reperfusion injury. We sought to determine the trigger for expression of intercellular adhesion molecule-1 (ICAM-1) caused by ischemia-reperfusion injury.


METHODS
Thirty-six Sprague-Dawley rats underwent left lung transplant (six groups of 6). Lungs were transplanted immediately after arrest, or from non-heart-beating donors after 2 hours of oxygen-ventilation or no ventilation. Recipients were reperfused for 4 or 6 hours, then lungs were stained with a mouse anti-rat ICAM-1 monoclonal antibody, developed with avidin-biotin peroxidase to a biotinylated anti-mouse immunoglobin G antibody. Intercellular adhesion molecule-1 expression was graded by two masked observers as 0 = absent, 1 = weak, or 2 = strong in alveoli, arterioles, and venules. Explanted recipient left lungs served as negative controls, and positive controls were generated 6 hours after intraperitoneal injection of endotoxin. Intercellular adhesion molecule-1 expression above baseline among groups was compared by Fisher's exact test.


RESULTS
Constitutive expression of ICAM-1 was present in rat lung alveoli, with 24 of 35 controls staining weakly and 4 of 35 strongly positive in alveolar areas. Intercellular adhesion molecule-1 expression was not increased in transplanted lungs evaluated after 4 hours of reperfusion, even lungs retrieved from non-heart-beating donors. But when non-heart-beating donor lungs were assessed 6 hours after onset of reperfusion, ICAM-1 expression was significantly more apparent in alveolar and arteriolar areas, compared with controls and lungs transplanted immediately after arrest.


CONCLUSIONS
Lungs transplanted immediately after circulatory arrest do not sustain sufficient ischemia-reperfusion injury to upregulate ICAM-1. Onset of reperfusion is the signal for ICAM-1 expression, not the onset of ischemia or the total duration of ischemic and reperfusion time together. Strategies at reperfusion may minimize ICAM-1 expression.
University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. ltxtme@med.unc.edu
Thomas M
TM
Egan
Yalaunda
Y
Thomas
Debra
D
Gibson
William
W
Funkhouser
Paola
P
Ciriaco
Andy
A
Kiser
John
J
Sadoff
Mark
M
Bleiweis
Clarence E
CE
Davis
D000818:Animals; D001160:Arterioles / Q000737:chemistry; D002102:Cadaver; D006323:Heart Arrest / Q000503:physiopathology*; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000737:chemistry*; D016040:Lung Transplantation; D008297:Male; D011650:Pulmonary Alveoli / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism; D013997:Time Factors; D014019:Tissue Donors
D008070:Lipopolysaccharides; D018799:Intercellular Adhesion Molecule-1