The Influence Of Different PH On Ischemia-reperfusion Injury To Rat Transplanted Lung

Objection1.To approach a better kind of rat orthotopic left pulmonary allograft transplantation model based on the two-cuff-one-stent anastomosis(ITA) technique,which could provide a basic model for further research of ischemia-reperfusion-injury(IRI) in lung transplantation.2.To research the influence of different pH on ischemia-reperfusion(I/R) injury to rat transplanted lung.Methods1.We established rat orthotopic left lung allograft transplantation in which the anastomosis of pulmonary artery,vein and bronchus were performed by using the cuff technique under surgery microscope and evaluated the possibility of the model by achievement ratio of operation,time of operation,and pathologic change.2.Sixty-four male SD rats weighing 250-350g,were randomly divided into donor and recipient groups(n=32),then,underwent left lung transplantation.According to the different pH of donors which was adjusted before reperfusion,the transplanted rat were divided into four groups:group H(pH=7.2±0.02),group I(pH=7.3±0.02),group S (pH=7.4±0.02),group P(pH=7.5±0.02),and group S was regarded as control group. The donor rats were anesthetized with Ketamine(15mg/kg),tracheoatomized and mechanically ventilated.Heparin 1 000IU/kg was injected via nena cava inferior and 4℃LDP solution 40 ml was injected via pulmonary artery.The trachea was then tied and the lungs were removed,and placed in 4℃LDP solution and kept for 4h.The recipient rats were anesthetized,tracheoatomized and mechanically ventilated as donor rats.The left main bronchus,pulmonary artery and vein were liberated and connected to those of the donor left lung using two-cuff-one-stent anastomosis technique.The transplanted left lungs were reperfused when the blood pH of donors were adjusted to the expecting limit using HCl and NaHCO₃.After ventilated and reperfused for 2h,the transplanted lungs were removed for determination of W/D lung weight ratio,MPO activity,MDA,SOD contents and Microscopic examination.TNF-αand IL-8 contents were measured by method of ELISA.ICAM-1 mRNA were measured by method of RT-PCRResults1.32 cases of rat orthotopic left lung allograft transplantation were accomplished.The time of the process from perfusion to the two-cuff-one-stent accomplishment of the donor lung undergoing(20±4) min,and the mean time of the whole operation were taken(80±7) min.Pathologic study found the typical pathologic change of IRI after 2h reperfusion.2.The doner lung was gotten after 2h reperfusion for following detections:MPO activity, MDA,TNF-αand IL-8 contents in lung tissue were lower(P＜0.05) and SOD content was significantly higher in group I than in control group S(P＜0.05),but compared to group S,these indexs had no deviation in group H and group P.There was no significantly difference in W/D lung weight ratio among group H,I,S and P.ICAM-1 mRNA were dramatically lower in group I than that in group S(P＜0.001).Microscopic examination showed that edema and haemorrhage were better in group I than in the other three groups.Conclusion1.By using the improved"two-cuff-one-stent anastomosis technique"and analyzing the model of rat lung transplantation domestic and abroad,we tried to establish the best model of rat orthotopic left lung allograft transplantation which shortened the operation time,simplified the operative difficulty and improved the achievement ratio of operation by a single surgeon with naked eye.The pathologic study showed the typical pathologic change of IRI,which can be applied to study donor lung IRI.2.Reducing reperfusing pH moderately can effectively alleviate edema and exudation of the rat transplanted lung tissue,depressd the expression of proinflammatory factor and improved the fuction of transplanted lung,and can effectively relieve the ischemia-reperfusion injury after lung transplantation.