Study On Acute Lung Injury Of Rats After Being Drowned In Freshwater And Correlation Between Expression Of IL-8 And IL-10 In Lung Tissue

Objective To investigate the mechanism of lung injury from the level of molecular pathology and angle of pro-inflammation/anti-pro-inflammation by observing change of pathology-morphologic in rats after being drowned in water from Yellow River, and detecting expression of IL-8, IL-10 in lung tissue and correlation between them to provide academic evidence for further exploring new clinical technique of early therapy after being drowned. Methods Eighty healthy Wistar rats were selected and divided into three groups randomly: control group, drowning group and non-drowning group. Animals in the last group were killed after being drowned for 2min then survival 3m, 3h, 12h, 24h and 40h, respectively. Model of animals were established by putting rats in a container with slippy inner wall and half-full of water in it, letting them swimming freely till died of being drowned. Each rat from different groups was killed by breaking its neck except drowning group, then BW and SO₂ was detected, and its chest was cut open rapidly, lung was taken out and weight was measured accurately to count lung coefficient. Its lung appearance was observed and lung tissue was fixed with formalin, which was made into pathology slices with HE staining, and pathology change of the lungtissue was observed;Expression of IL-8 and IL-10 in lung tissue was detected with Immunocytochemistry, and correlation between them was analyzed . Results (1) Lung coefficient of rats from control group was 0.68±0.22, and their SO2 was 96.50%±1.90%;It rose remarkably 1.58±0.14 in drowning group, and their SO2 decreased to the bottom 23.50%±3.40%;In non-downing group, lung coefficient of rats, which were killed after being downed then survival 3m still increased evidently 0.86±0.21, SO2 decreased greatly to 45.60%±5.95%, and there was significant difference compared with control group(P<0.05).Lung coefficient decreased gradually as time past with no prominent difference compared with that of in control group till 3h;SO2 tended to increase gradually to the level of control group after 6h, and there was no prominent difference between them(P<0.05).(2) Lung volume of control-group-rats was normal without bleeding or effusion at their surface, structure of lung was also normal under light microscope;Volume enlarged significantly with severe bleeding at their surface in drowning-group-rats. Under light microscope, it can be seen that alveolus cavity enlarge with large amount of erythrocyte and leukocyte in it, interval between alveolus widen, and capillary vessel broaden with blood in it;Volume of rats was still larger after 3m-3h in non-drowning group with some extent of bleeding and effusion. Alveolus enlarge and its interval edema with some alveolus atrophy while others emphysema under light microscope. Volume tended to normal gradually after 6h with bleeding and effusion decreased too, edema andinflammatory effusion obviously abated under light microscope,.(3) There was a trifle of IL-8 in lung of control-group-rats, and the rate of its expression was 20%;It rose to 80% in lung of drowning-group-rats, and it increased significantly to 100% after being drowned then survival 3m-3h, but it decreased gradually after 6h, and which decreased to 40% till 40h with prominent difference (P<0.05).(4) There was some quantity of IL-10 in lung of control-group-rats, and the rate of its expression was 50%;It decreased to 40% in drowning-group-rats;It decreased evidently to 20% after being drowned then survival 3m-3h in non-drowning-group-rats, but it started to elevate after 6h, and reached to the highest point after 24h(80%), then gradually returned to normal level till 40h with prominent difference (P<0.05).(5) With the gradual weak expression of IL-8, expression of IL-10 has a gradual trend to boost. As a whole, there was negative correlation between IL-8 and IL-10(r=-0.707, P<0.05) with significant difference .Conclusion (1) Animals may get acute lung injury and Anoxemia after being drowned in water from Yellow River.(2) There was high expression of proinflammation eytokines IL-8 in the lung at the early state of acute lung injury, and there was positive correlation with degree of lung injury. It suggests that IL-8 might participate in the acute lung injury after being drowned .(3) Without any outside precaution, the degree of lung injury and generalclinical behavior tend to alleviate, meanwhile, expression of antiinflammation cytodines IL-10 increased, which suggests that IL-10 might have protective role on organism by adjusting reaction of proinflammation/ antiproinflammation . (4) It has positive meanings to rectify the off-balanced state of proinflammation/ antiproinflammation betimes after being drowned in clinical remedy for the drowned.