Improve Donor Lung Function In Experimental Research

1. Establishment of the isolated lung transplantation and reperfusion model in rats.Objectives: To establish a simple, reliable and economical lung transplantation model in rats for the study of improving the function of donor lung. Methods: The donor lung blocks were harvested and flushed with the low-potassium-dextran(LPD) solution through the main pulmonary artery and stored at 4℃for 18 hours. The donor lung was connected to the recipient rat with conduit and pump. During circulation, the venous blood from the right superior vena cava of the donor rat was perfused through the pulmonary artery into the donor lung by means of a double -head roller pump. The donor rat lung was ventilated with an O₂ fraction of 100% at a tidal volume of 5.0 ml/rat and a rate of 50 breaths/min. Reperfusion was performed at 37℃for 60 minutes. PvO2, PvCO2, Hb, PH, PaO2, PaCO2 were obtained by blood gas analysis of the blood inflow to and out flow from the donor lung at 15-mininute intervals and mean pulmonary artery pressure(PaP) and peak airway pressure(PawP) were measured in the same time. Results: The ricipient rat can transpose arterial blood into venous blood well with small fluctuate of PvO2, PvCO2, Hb, PH(P＞0.05). The donor lung can maintain good oxygenation and compliance in the early phase of reperfusion. But with the time passed by, the reperfusion injury was observed according to the lower lung function and compliance with the decreasing PaO2, the increasing PaCO₂,PaP and PawP (P＜0.05或P＜0.01). Conclusions: The isolated rat lung transplantation and reperfusion model can imitate the donor lung peffusion and it was simple, reliable, and economical. The model can be used for the study of improving the function of the donor lung. Objectives: With an isolated, whole venous blood-perfused, ventilated rat lung model, we studied the effects of ulinastatin on the donor lung of rat after long time, cold ischemic preservation. Methods: Forty-eight rats were randomly divided into four groups(â… ,â…¡,â…¢,â…£). All lungs were flushed with low-potassium-dextran(LPD) solution, harvested en bloc,stored inflated at 4℃for 18 hours, and reperfused for 1 hour except groupâ… . In groupâ… (n=6), donor lungs were flushed, harvested, and reperfused immediately without storage. In groupâ…¡(n=6), donor lungs were stored, and reperfused. In groupâ…¢(n=6), donor lungs were treated with ulinastatin of 5,000 units/kg during flush and reperfusion. In groupâ…£(n=6), donor lungs were treated with ulinastatin of 10,000/kg units during flush and reperfusion. PaO2, PaP, PawP were measured at every 15 minutes intervals during repeffusion. After repeffusion, the lung tissue wet-to-dry(W/D) ratio, MDA, myeloperoxidase(MPO) activity, interlukin-8(IL-8) and ultrastructure were obtained. Results: The decreased PaO2 and increased PAP, PawP were observed with the reperfusion time passed by in groupâ…¡,â…¢,â…£. However, the level of decreased PaO2 and increased PaEPawP in groupâ…¢,â…£were lighter than those in groupâ…¡(P＜0.05或P＜0.01 ). After reperfusion the W/T, MDA, MPO, IL-8 were decreased evidently in groupâ…¢,â…£than in groupâ…¡. After reperfusion, PaO2 were higher in groupâ…£than groupâ…¢(P＜0.05), PaP, PawP, W/T, MDA, MPO, IL-8 were lower in groupâ…£than groupâ…¢(P＜0.01 or P＜0.05). Histological evaluation revealed less injury in groupâ…¢,â…£than groupâ…¡. Conclusions: Using ulinastatin during flush and repel-fusion can effectively inhibit accumulation of neutrophils, lysis of proteinase, lipid superoxidation, and interleukin-8, thus improving the respiratory function of donor lungs.3. Study of effects of administering a second rinse solution before reperfusion on the rat donor lung.Objectives: With an isolated,whole venous blood-perfused, ventilated rat lung model, we studied the effects of administering a second rinse solution before reperfusion on the rat donor lung after long time, cold ischemic preservation. Methods: Twenty-four rats were randomly divided into control group(n=6) and trial group(n=6). Donor lungs of control group were flushed with low-potassium-dextran(LPD) solution, harvested en bloc, stored inflated at 4℃for 18 hours, then the right hilum were ligated and the right lung was resected for measurement of MDA, MPO, IL-8, the left lungs were reperfused with venous blood for 30 minutes. Donor lungs of trial group were treated the same as control group except that donor lungs were flushed with low-potassium-dextran(LPD) solution again before reperfusion with blood. PaO2, PaP, PawP were measured at every 10 minutes intervals during reperfusion. After reperfusion, the lung tissue wet-to-dry(W/D) ratio, MDA, myeloperoxidase(MPO) activity, interlukin-8(IL-8) and ultrastructure were obtained. Results: The W/T, MDA, MPO, IL-8 were decreased evidently in right lung of trial group than in control group(P＜0.01). After reperfusion of 20 minutes, PaO2 were higher in trial group than in control group(P＜0.01), and PaP, PawP were lower in trial group than in control group(P＜0.01). After reperfusion, The W/T, MDA, MPO, IL-8 were decreased evidently in left lung of trial group than in control group(P＜0.01). Histological evaluation of the test group revealed less injury. Conclusions: A second flush with LPD solution before reperfusion can decrease MDA, MPO, IL-8 and thus improve the function of donor lungs.