Eduardo Sperb Pilla, Giovani Schirmer Vendrame, Pablo Gerardo Sánchez, Gustavo Grun, Eduardo Fontena, Luiz Alberto Forgiarini Júnior,
Norma Anair Possa Marroni, Cristiano Feijó Andrade, Paulo Francisco Guerreiro Cardoso
Objective: To evaluate the effect of lung ischemic preconditioning (IPC) on normothermic ischemia/reperfusion (I/R) injury in a rat model,
quantifying the production of reactive oxygen species. Methods: Forty-seven male Wistar rats were randomized into four groups: control,
sham, I/R and IPC. Control group animals were anesthetized and killed by decapitation, after which pneumonectomy was performed and
the left lungs were stored in liquid nitrogen. Sham, IPC and I/R group rats were anesthetized, tracheostomized, ventilated, anticoagulated
and submitted to left thoracotomy with dissection of the left pulmonary artery for clamping. Sham group rats underwent dissection of the
left pulmonary artery, I/R group rats underwent 30 min of total hilar clamping, and IPC group rats underwent 5-min clamping of the left
pulmonary artery followed by 30 min of total hilar clamping. Lungs were reperfused for 90 min and ventilated with the same parameters,
with additional positive end-expiratory pressure of 1 cmH2O. Hemodynamic and blood gas values were obtained prior to thoracotomy,
prior to total hilar clamping, after 30 min of reperfusion and after 90 min of reperfusion. Lipid peroxidation was determined by measuring
levels of thiobarbituric acid reactive substances. Results: There were no significant differences among the groups in terms of the levels of
thiobarbituric acid reactive substances. Nor were there any significant differences among the sham, I/R and IPC groups in terms of arterial
oxygen tension, arterial carbon dioxide tension or hemodynamic values. Conclusions: In an in situ I/R rat model, 5-min IPC of the left
pulmonary artery does not attenuate I/R injury.
Keywords: Ischemia; Reperfusion; Organ preservation; Reactive oxygen species.