The Protective Effect Of Raffinose-low Potassium Dextran (LPD) Solution To Transpanted Lung In Rats

Part Ⅰ Protective effect of raffinose-low potassium dextran solution on isolated lung in ratsObjective To explore the protective effect of raffinose-low potassium dextran (R-LPD) solution on isolated donor lung in different periods through pathologic and molecular channel.Methods Forty eight SD rats were randomly divided into 2 groups of A(LPD) and B(R-LPD) with 24 rats each.The two groups were then respectively allocated into 4 subgroups according to different preservative periods of 4,8,12 and 24h after flusion.Wet/dry weight ratio (W/D),malondialdehyde(MDA),myeloperoxidase(MPO) and superoxide dismutase(SOD) were measured and pulmonary structure was observed by HE staining.Results For both groups,W/D、MPO、MDA、SOD were increasing as lung preservative period in vivo was prolonging.Intragroup comparison:8h VS 4h and 12h VS 8h,all parameters had no statistical difference.But In group A, W/D、MPO、MDA、 SOD in 24h were higher than those in 12h (P<0.01);In group B, MDA,MPO and SOD were higher after 24-hour preservation than those after 12-hour preservation (P<0.01).Interclass comparison:after 4 and 8-hour preservation, all parameters of the two groups mad no significant difference.Untill lung preservative period reached 12-hour, SOD was higher in group B than this in group A (P<0.05).Moreover,before 12-hour preservation, the two groups did not show inflammatory injury,only manifested slight inflammatory reaction through histologic observation. After 24-hour preservation,W/D,MDA and MPO were lower,but SOD was higher in group B than those in group A (P<0.05 or P<0.01). Destructive pulmonary structure,alveolar interstitial edema and irreversible inflamatory damage were markedly seen in group A; while,lear tissue architecture and slight inflammatory reaction were observed in group B.Conclusions In the process of extracorporeal lung cold storation in rats,the two perfusions made no differences before 8-hour preservation;the protective effect of (R-LPD) solution surpass LPD solution slightly when preservative period reached 12-hour. Untill isolated lung preservative period reached 24-hour,the protective effect of R-LPD solution was more evident than LPD solution.Part Ⅱ The research on protective effect of raffinose-low potassium dextran solution on transpanted lung in ratsObjective To investigate the protective effect and possible mechanisim of raffinose-low potassium dextran (R-LPD) solution on lung ischemia reperfusion injury and whether protective effects of LPD containing different concentrations of raffinose are differential.Methods Forty eight rats were randomly divided into 4 groups(n=12 each,six donors and six receptors respectively):groupⅠ-LPD;groupⅡ,Ⅲ,Ⅳ-LPD containing 10,20,30 mmol/L of raffinose. In the process of establishing the orthotopic unilateral left lung allograft animal model in rats,donor lungs were flushed with LPD, or R-LPD (containing 10,20,30 mmol/L of raffinose) and stored for 4 hours at 4℃.After 2 hours of reperfusion, the recipient’s arterial blood from the donor lung’s pulmonary vein was taken and blood gases were measured. Then the animals were put to death; and the upper third of the left lungs were taken to assay the wet/dry weight ratio,the middle third of the left lungs taken for the histologic study using light microscopy,other parts of the donor lungs were frozen in liquid nitrogen and assayed for malondialdehyde(MDA),myeloperoxidase(MPO) superoxide dismutase(SOD) and the expression of TNF-α,IL-10、and ICAM-1 mRNA in lung tissue through RT-PCR method.Results In Ⅱ、Ⅲ、Ⅳ groups, the PaO2 in arterial blood、the concentrations of SOD and the expression of IL-10 mRNA in the lung tissue were significantly higher than those in group Ⅰ.But the PaCO2,W/D ratio,the concentrations of MPO and MDA, the expression of TNF-α,ICAM-1 mRNA in the lung tissue of the Ⅱ、Ⅲ、 Ⅳ groups were significantly lower than those in Ⅰ group. All indexes have no statistical significance between group Ⅱ and group Ⅲ. The PaO2 in arterial blood、the concentrations of SOD and the expression of IL-10 mRNA in the lung tissue were significantly higher in group Ⅳ than those in Ⅱ,Ⅲ groups.But the PaCO2,W/D ratio, the concentrations of MPO and MDA, the expression of TNF-α,ICAM-1 mRNA in the lung tissue of the group Ⅳ were significantly lower than those in Ⅱ,Ⅲ groups. Histological appearances such as lung edema,exudate and damage showed less lung tissue damage in Ⅱ、Ⅲ、Ⅳ groups. Lung tissue in four groups shows pathological injury in different leveles,but group Ⅰ presents most seriously.Group Ⅳ appears most slightly of the four groups.Conclusions Raffinose-low potassium dextran (LPD) solution can alleviate LIRI after lung transplantation in this model, protective effect of R-LPD (containing 30 mmol/L of raffinose) is more apparent than R-LPD (containing 1.0,20 mmol/L of raffinose).The possible mechanism is concerned with alleviating lung edema,enhancing ability of cleaning oxygen radicals, alleviating lipid peroxidation,inibiting releasing inflammatory factors, supressing activation of neutrophilic granulocytes.