Abstract
Background: The goal of this study was to determine the effect of ischemic preconditioning on
the extent of normothermic lung ischemia reperfusion injury in rabbits in vivo. Methods: Thirty male Japanese white rabbits were randomized into two groups. Fifteen rabbits
were treated with ischemic preconditioning (their left lung hilus clamped for 10 minutes
and released for 15 minutes (group IP)). Fifteen rabbits were not treated with ischemic
preconditioning (group C). Then the left lung hilus of both groups were occluded for
60 minutes and reperfused for 60 minutes. Mean arterial pressure, mean pulmonary artery
pressure, and core temperature were recorded. Femoral artery blood samples and lung
tissue samples were collected after ischemic preconditioning and after 60 minutes
of reperfusion. Results: The lung tissue showed little injury after ischemic preconditioning. After 60 minutes
of reperfusion, the angiotensin II (A II) and arterial oxygen tension (PaO2) levels in group IP were significantly higher than those in group C, mean pulmonary
artery pressure in group IP was significantly lower than that in group C, the wet/dry
ratio and malondialdehyde content of lung tissue in group IP was significantly lower
than that in group C, the Superoxide dismutase contents of lung tissue in group IP
was significantly higher than that in group C, and histological findings showed less
damage in group IP than in group C. Conclusion: Lung ischemic preconditioning could reduce normothermic rabbit lung ischemia-reperfusion
injury. The possible mechanisms are increased production of endogenous A II and reduced
formation of oxygen free radicals during lung ischemia for 60 minutes followed by
reperfusion for 60 minutes.
Key words
Ischemic preconditioning - Rabbit - Ischemia reperfusion injury - Angiotensin II
