Study objectives: Ischemia-reperfusion injury of the
lung frequently occurs after cardiopulmonary bypass, after pulmonary
thromboembolectomy, and especially during lung transplantation. The
protective effects of preconditioning on the heart, liver, bones, and
various other organs have been previously evaluated. In this
comparative study, we used isolated guinea pig lungs to show the
effects of preconditioning on lung ischemia.
The lungs (n = 10 in each group) were mounted on a modified
Langendorff perfusion apparatus and perfused by Krebs-Henseleit
solution for 30 min. We applied an ischemic preconditioning (5 min
ischemia + 5 min perfusion, two times) in the experimental group.
After 3 h of normothermic ischemia, the lungs were reperfused for
30 min. Pulmonary artery pressures and malondialdehyde (MDA) and
glutathione (GSH) levels of the tissue and the perfusate were measured
before and after the ischemic period and also at the end of
reperfusion. Electron microscopic evaluation was done on randomly
selected lungs of three animals in each group at the end of the
Results: Both MDA and GSH levels of tissue
and perfusate decreased in the experimental group after reperfusion,
although the reduction in GSH levels did not reach statistical
significance. The increase in pulmonary artery pressure was lower in
the preconditioning group after reperfusion.
Conclusions: Our data showed that ischemic
preconditioning of the lung may have a protective effect in