| Objective: To explore the impact of induced heme oxgenases and exogenous carbon monoxide on function of the non-heart-beating donor lung, and to find out the impact of cold ischemic time on founction of non-heart-beating donor in dog lung transplantaion.Methods: 16 health mongrel dogs, weighing from 12 to 20 kilograms, were randomly divided into four groups: A : control group, lung ischemia/reperfusion( IR) group; B: IR/hemin (H) group ; group C, IR/zinc protoporphyrin(Z) group, and group D, IR/carbon monoxide. The canine models of non - heart - beating lung ischemia-reperfusion were established by bloodletting via femoral artery. The animals were handled as follows: (1) group B: intraperitoneal injection of hemin(5mg/kg/day) was performed for two consecutive days prior to the operation; (2) group C: the administration of hemin was same as that of group B, and ZnPP(10mg/L) was administered in blood while reperfusion. (3) group A and group D was administered the same dosage of physiological saline intraperitoneally, and 20ppm carbon monoxide was administered via oxygenation in group D. All animals were anesthetized by intramuscular injection of sumianxin-Il and ketamine. After harvesting heart and lung block, all lungs were divided into two groups: group I, enduring 1 hour warm ischemia and 2 hours cold ischemia; groups II, enduring 1 hour warm ischemia and 4 hours cold ischemia. Lung was sampled in beginning and after ischemia followed by 120 minutes reperfusion to detect the expression of HO-lmRNA, blood gas analysis, lung artery press, pulmonary water content, and the activities of superoxide dismutase(SOD) and the contents of malondialdehyde (MDA).Lung slices stained by 10% formaldehyde were used to examine the pathological changes under light microscope. The data were processed with SPSS10.0 Results:1. The expression of heme oxygenase-1 in lung: The expression of HO-1 in group B and group C were significantly stronger than that in groupA and group D.2. Blood gas analysis: TWO hours after reperfusion in group B, PO2 were significantly higher (p<0.05) and PCO2 were significantly lower(p<0.05) than other groups in group I and group II. But PO2 and PCO2 in the same group were no difference between group I and group II.3. Pulmonary artery press: Pulmonary artery press in group D were significantly lower than other groups wehter group I or group II.4. Pulmonary water content: The increase of pulmonary water content were significantly lower in group B than in other groups (P<0.05) wehter I group or II group. There was no significant difference in other groups.(p>0.05).5. The activities of superoxide dismutase(SOD) and the contents of MDA: the decrease of lung tissue SOD activity and the increase of MDA content were significantly lower in group B than other groups.6. The pathological changes of lung: Microscopic examination showed that there were severe leukocyte infiltration and edema formation in alveolar space in group A, but the changes were less severe in group B after reperfusion.Conclusion:1. Hemin may induce upregulation of heme oxygenase-1 mRNA.2. The overexpression of heme oxygenase-1 can partly reduce lung reperfusion injury at the early time of reperfusion.3. Non-heart- beating donors (NHBD) with 1 hour of warm ischemia and 2 hours or 4 hours of cold ischemia, there were no difference in lung... |
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