EFFECT OF RECOMBINANT HUMAN ADULT T-CELL LEUKEMIA-DERIVED FACTOR ON RAT LUNG REPERFUSION INJURY

The formation of reactive oxygen species (ROS) is a major factor respo nsible for reperfusion injury in lungs. Adult T cell leukemia derived factor (ADF), a polypeptide made of 104 amino acids, is induced by a v ariety of stresses including X-ray, ultraviolet, H2O2, and mitogen. AD F has a reducing activity, which catalyzes the proton transfer between thiol-radical of cystein-containing proteins. Furthermore, ADF has a protective activity of ROS which are formed by xanthine oxidase and ot her alternative pathways in vitro. Using a rat in vivo model of lung i schemia, we examined the protective effect of recombinant human ADF (r hADF) against ischemia reperfusion injury of the lung. Ischemia, lasti ng for 75 min, was induced in the left lung of rats at 23 degrees C. T he lung was then reperfused. These animals were divided into two group s: group 1 (n = 6, treatment with normal saline) and group 2 (n = 6, t reatment with 28 mu g/g of rhADF). One minute after the beginning of r eperfusion, arterial oxygen tension (PaO2) decreased significantly in both groups (p<0.01), without any significant intergroup difference (5 5.5+/-9.8, 49.8 +/- 8.6 mm Hg, respectively). Twenty minutes after rep erfusion, PaO2 was significantly higher (p < 0.05) in group 2 (113.0 /- 8.1 mm Hg) than in group 1 (72.3 +/- 13.6 mm Hg). The wet/dry weigh t ratio was significantly higher in group 1 (7.31 +/- 0.54) than in gr oup 2 (5.82 +/- 0.36). Histologically, lung injury tended to be milder in group 2 than in group 1. These results suggest that rhADF has a pr otective effect against ischemia reperfusion injury of the rat lung.