The Experimental Study Of Protective Effect Of Ligustrazine On Lung Ischemia Reperfusion Injury

Part I : Establishment of the"non-vessel endothelium cuff"model in rat left orthotopic lung allograft transplantationObjective:To try to establish a more simple and available rat left orthotopic lung allograft transplantation mode1 for short period research.Methods:20 couples of SD rats were randomly divided into two groups:experiment group(n =10)and control group(n=10).All rats in experiment group were operated for left orthotopic lung allograft transplantation by using"non-vessel endothelium cuff"technique. All rats in control group were operated for left orthotopic lung allograft transplantation by using"vessel endothelium cuff"technique. When the transplanted lung had been reperfused for 4 h, the right hilus of lung was occluded. Just before and 30 minutes after occluded, systemic PaO2 and PaCO2 were determined in blood samples from left lung veins and blood supply of the transplanted lung tissue was observed.Result: Among 10 couples transplanted rats in experiment group, 8 survived at the end point, the transplantation success rate was 80% and the cuff procedure success rate was 100%. Among 10 couples transplanted rats in control group, 4 survived at the end point, the transplantation success rate was 40% and the cuff procedure success rate was 60%. The right hilus of lung had been occluded for 30 min, in the experiment group Pa02 was 68.8±2.5 mmHg, PaC02 was 53.3±4.3 mmHg , blood supply of the transplanted lung tissue was well and in control group Pa02 was 59.8±3.1 mmHg, PaC02 was 60.1±2.6 mmHg, the transplanted lung tissue was congestion and dull, two cases were died. The content of Pa02 and PaC02 decreased in experiment group compared with those in control group (p<0.05).Conclusion : Rat left orthotopic lung allograft transplantation model with"non-vessel endothelium cuff"technique is easy to do and acceptable for short period research. Part II : The experimental study of protective effect of ligustrazine on lung ischemia reperfusion injuryObjective:To investigate the possible protective mechanisms of ligustrazine on lung ischemia reperfusion injury in rats.Methods:20 couples of SD rats were randomly divided into two groups:experiment group(LPD+ Ligustrazine, n =10)and control group(LPD, n=10).All rats were operated for left orthotopic lung allograft transplantation by using"non-vessel endothelium cuff"technique. When the transplanted lung had been reperfused for 4 h, the right hilus of lung was occluded. Just before and 30 min after occluded, systemic PaO2 and PaCO2 were determined in blood samples from left lung veins. We take samples of left lung and measure the content of malondialdehyde (MDA), wet-dry weight ratio(W/D), platelet activating factor(PAF) and intercellular adhesion molecule(ICAM-1).Observation of lung tissue with optical microscope and electron microscope are also performed.Result: Before the right hilus of lung was occluded, in the experiment group Pa02 was 94.1±8.8 mmHg, PaC02 was 38.9±4.5 mmHg and in control group Pa02 was 93.6±6.7 mmHg, PaC02 was 39.8±1.1 mmHg. The right hilus of lung had been occluded for 30 min, in the experiment group Pa02 was 78.8±2.5 mmHg, PaC02 was 48.3±1.3 mmHg and in control group Pa02 was 69.8±4.1 mmHg, PaC02 was 57.1±3.6 mmHg. During research of effects on the experiment group, the content of W/D was 5.18±0.13, MDA was 1.23±0.11 nmol/ml, PAF was 2.08±0.16 ug/L, ICAM-1 was 6.58±0.44 .In control group, the content of W/D was 5.91±0.13,MDA was 1.44±0.13 nmol/ml, PAF was 2.33±0.15 ug/L,ICAM-1 was 8.71±0.54. The content of MDA ,W/D,PAF and ICAM-1 decreased in experiment group compared with those in control group (p<0.05, respectively).Under optical microscope, normal group displayed the intact structure of lung septa and alveoli without obvious polymorph nuclear cells infiltration. Control group showed the inflammation cells infiltration, red blood cells extravasations in swollen lung septa and impaired alveoli. Attenuated histological changes occurred in experiment group. Under electron microscope, vacuoles of type I and type II lung epithelial cells in control group increased remarkably, while microvilli decreased apparently, as compared with experiment group. But we couldn't find those in normal group.Conclusion:Ligustrazine could play protective role in lung ischemia reperfusion by decreasing the content of PAF and ICAM-1, WBC accumulating and inhabiting free radicals response.