Ischemic preconditioning by selective occlusion of the pulmonary artery in rats.
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.
Pilla
Eduardo Sperb
ES
Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Porto Alegre, Brasil.
Vendrame
Giovani Schirmer
GS
Sánchez
Pablo Gerardo
PG
Grun
Gustavo
G
Fontena
Eduardo
E
Forgiarini
Luiz Alberto
LA
Marroni
Norma Anair Possa
NA
Andrade
Cristiano Feijó
CF
Cardoso
Paulo Francisco Guerreiro
PF
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000503:physiopathology*; D035061:Control Groups; D004195:Disease Models, Animal; D019194:Ischemic Preconditioning / Q000379:methods*; D015227:Lipid Peroxidation / Q000502:physiology; D008168:Lung / Q000098:blood supply* / Q000737:chemistry; D008297:Male; D009926:Organ Preservation / Q000379:methods; D011651:Pulmonary Artery / Q000503:physiopathology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000517:prevention & control*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances