The Canine’s In-vitro-lung Ischemia-reperfusion Injury Of Dynamic Perfusion And Static Preservation

Objective:Using canine to manufacture and prepare in-vitro-lung model, through the cardiopulmonary bypass system perfusion pulmonary artery, Direct pulmonary artery perfusion And static cold preservation in-vitro-lung. observing the occurrence of the reaction in-vitro-lung injury above three conditions, explore the protective effect and possible mechanisms of in-vitro-lung injury, explore the best method of lung preservation.Methods:To manufacture and prepare in-vitro-lung model,30health ordinary canines were randomly divided into three groups which10in each group:cardiopulmonary bypass perfusion pulmonary artery preservation group, Direct pulmonary artery perfusion save group and the low temperature soaked preservation group. From cardiopulmonary bypass pulmonary artery perfusion preservation group (n=10),in-vitro-lung connected to extracorporeal perfusion system and the Bronchus connected to ventilator to maintain ventilation, intermittently perfuse the low temperature of protective solution of lung within6hours by the cardiopulmonary bypass through pulmonary artery and reperfuse the low-temperature of oxygen-containing autologous blood within2hours.From Direct pulmonary artery perfusion save group (n=10), in-vitro-lung directly connected to protective solution of lung and perfused with high levels of gap of pressure which close to pulmonary artery pressure, the Bronchus connected to ventilator to maintain ventilation, intermittently perfuse the low temperature of protective solution of lung within6 hours and reperfuse the low-temperature of oxygen-containing autologous blood within2hours.From the low temperature soaked preservation group, in-vitro-lung soaked the low temperature of protective solution of lung within6hours, perfuse alone in0,60,120,180,240,300,360min time after operation. When Oh after ischemia and lh,2h,3h,4h,5h,6h,7h,8h after reperfusion and preservation in each group, take the lung tissue detection of activity of superoxide dismutase (SOD), content of malondialdehyde (MDA) and activity of myeloperoxidase (MPO) and observe morphology changes of lung tissue in the light microscope.Results:①Expression of SOD of three groups of animals are all higher than Oh after ischemia (P<0.05) in each time point of lh-3h after reperfusion and preservation, but it in cardiopulmonary bypass perfusion pulmonary artery preservation group is higher than it in Direct pulmonary artery perfusion save the group and the low temperature soaked preservation group,there is no difference among the three groups (P>0.05). Decrease was not significantly different (P>0.05) among the three groups and within three groups in each time point of5h-7h after reperfusion and preservation. Compared with Oh after ischemia and autologous blood before perfusion (7h after preservation), SOD value of2h after intermittently reperfuse the low-temperature of oxygen-containing autologous blood (8h after preservation)were significantly increased (P<0.05). But with the extension of time of the preservation, activity of expression of SOD maintain a certain level in cardiopulmonary bypass perfusion preservation group,is not significant decline, activity of4h is still higher (P<0.01). Throughout the period of preservation (8h), there is significant difference among the three groups, SOD value in cardiopulmonary bypass perfusion preservation group is higher than Direct pulmonary artery perfusion save the group and the low temperature soaked preservation group (P<0.05). SOD value in Direct pulmonary artery perfusion save the group is slightly higher than it in the low temperature soaked preservation group, but there is not statistically significant.②Compared with before ischemia, three groups of MDA,MPO values after perfusion and preservation increased,but compared with Oh before ischemia, at each time point of three groups of MDA,MPO values after preservation, difference was not significant (P>0.05). The mean of MDA value in cardiopulmonary bypass perfusion preservation group is lower than it in Direct pulmonary artery perfusion save the group and the low temperature soaked preservation group. The mean of MPO value in cardiopulmonary bypass perfusion preservation group and Direct pulmonary artery perfusion save the group is lower than it in the low temperature soaked preservation group. Difference of The mean of MPO and MDA value among the three groups is not significant (P>0.05)③Histopathological changes of lung tissue of canine among the three groups:in the lung tissue of canine of three groups, alveolar structure is complete, the alveolar septa is normal, a small amount of inflammatory cells is partially visible when0h-3h after preservation of ung tissue of canine. Cell structure is clear and no significant swelling; cell boundaries is clear, lung interval is a little edema, there is no significant difference among the three groups. With the extension of time of preservation, pathological changes of lung tissue of the three groups is gradually aggravate,but damage of organizational structure in cardiopulmonary bypass perfusion preservation group is worse than Direct pulmonary artery perfusion save the group and the low temperature soaked preservation group.Conclusion:That in-vitro-lung intermittently perfused and preserved with cardiopulmonary bypass system perfusion pulmonary artery keep constant temperature, constant pressure and low constant flow can be a long time at a high level to maintain the activity of SOD, increase the ability that lung tissue scavenging oxygen free radical, can weaken the inflammatory response.It’s protect Lung function effect better than Direct pulmonary artery perfusion save the group and the low temperature soaked preservation group. cardiopulmonary bypass perfusion pulmonary artery precise control perfusion as lung protective strategy has a protective effect on lung ischemia-reperfusion injury. It is can be used by donor lung preservation in the lung transplantion.