Pré-condicionamento isquêmico por oclusão seletiva da artéria pulmonar em ratos

Abstract

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 cmH 2 O. 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. ResumoObjetivo: Avaliar o efeito do pré-condicionamento isquêmico (PCI) em modelo de isquemia e reperfusão (I/R) pulmonar normotérmica em ratos, quantificando a produção de espécies reativas do oxigênio. Métodos: Quarenta e sete ratos Wistar foram randomizados em quatro grupos: controle, sham, I/R e PCI. Após anestesia, animais do grupo controle foram sacrificados por decapitação, pneumonectomizados, e os pulmões esquerdos armazenados em nitrogênio líquido. Animais dos grupos sham, I/R e PCI foram anestesiados, traqueostomizados, ventilados, anticoagulados e submetidos a uma toracotomia esquerda com dissecção da artéria pulmonar esquerda para clampeamento. No grupo sham procedeu-se a dissecção da artéria pulmonar esquerda; no grupo I/R, clampeamento hilar total de 30 min e no grupo PCI, clampeamento da artéria pulmonar esquerda por 5 min seguido por reperfusão de 10 min e um clampeamento hilar total de 30 min. Pulmões foram reperfundidos por 90 min e ventilados com os mesmos parâmetros, acrescidos de pressão expiratória final positiva de 1 cmH 2 O. Foram obtidas medidas hemodinâmicas e gasométricas antes da toracotomia, antes do clampeamento hilar total, aos 30 e 90 min de reperfusão. A peroxidação lipídica foi estabelecida por meio da determinação das substâncias reativas ...

Endobronchial Perfluorocarbon Reduces Inflammatory Activity before and after Lung Transplantation in an Animal Experimental Model

“…Other tests such as isoprostane quantification may be able to demonstrate much earlier changes in this setting. Similar results have been found in a previous study by Pilla et al [10] in an animal model of ischemic preconditioning. However, studies that used different techniques have found significant differences in oxidative stress in a similar animal model of lung transplantation [9, 37].…”

Oxidative Stress and Lung Ischemia-Reperfusion Injury

“…Because of the pulmonary damage that IR causes, many studies in animal models have focused on the prevention of IR injury and the improvement of lung preservation methods [ 113 – 115 ], such as the use of lung hyperinflation [ 26 , 116 ], hypothermic preservation [ 117 ], different lung preservation solutions [ 118 , 119 ], retrograde pulmonary perfusion [ 118 , 119 ], liquid ventilation [ 120 ], and perfluorocarbon [ 121 , 122 ]. These are in addition to the use of vasodilators [ 123 , 124 ] antioxidants [ 125 ] gene therapy [ 126 ], inhaled nitric oxide [ 89 ], and ischemic preconditioning (PCI) [ 127 ].…”