Mechanism Of Ulinastatin On Acute Respiratory Distress Syndrome Via P38 MAPK Signaling Pathway

Objective:Study the effect of ulinastatin on lipopolysaccharide(LPS)- induced acute respiratory distress syndrome(ARDS) and to explore its possible mechanism of treatment on acute respiratory distress syndrome(ARDS), to provide further theoretical foundation and experimental basis for the clinical application of ulinastatin.Methods:40 healthy, male SD rats were randomly divided into 5 groups: normal control group:in SD rat tail vein injection of 1ml physiological saline. LPS group: in SD rat tail intravenous injection of E.coli endotoxin(LPS) 5mg / kg(diluted with normal saline to1ml), replication model of acute respiratory distress syndrome(ARDS); LPS+UTI group :modeling method ibid, replication model of ARDS after intraperitoneal injection of ulinastatin through left side of abdominal cavity 10 million U / kg(diluted with normal saline to 1 ml) immediately.LPS+SB203580 group: modeling method ibid, copy the model of ARDS after immediately on the right side of the abdominal cavity injection of p38 MAPK inhibitor SB203580(5mg / kg)(dissolved in 0.1 ml, 10% dimethyl sulfoxide,before use with physiological saline and diluted to 1 ml); LPS+UTI+SB203580 combined group: modeling method ibid, replication model of ARDS after immediately on the left and right of the peritoneal side respectively injected Ulinastatin and SB203580(dose calculation method ibid.).After 8 hours and 10% chloral hydrate anesthesia laparotomy abdominal aorta separation, collected from abdominal aorta blood measured Pa O2, enzyme-linked immunosorbent adsorption assay(ELISA) to measure the content of lung tissue cytokine TNF-?, Western blot measured lung tissue phosphorylation of p38 MAPK protein expression levels and lung tissue pathological section and electron microscope slices were compared.Results:1. The general condition of rats: normal control rats freely, crawl quickly escape, a good mental state, even breathing; LPS group rats appear listlessness, shortness of breath,cyanosis, rat hair scattered, walking instability and hear part of rat asthma beeps; LPS +UTI group, LPS+SB203580 group and combination group are better than the LPS group.2. Blood gas analysis results: Pa O2 in LPS group was much lower than that in the normal control group(P<0.01). LPS+UTI group, LPS+SB203580 group,LPS+UTI+SB203580 combined group Pa O2 were higher than LPS group(P < 0.01) and the combined group was significantly increasing.LPS+UTI group Pa O2 were higher than LPS+SB203580 group(P < 0.05).3.Lung tissue TNF-?: in LPS group, the lung tissue TNF-? was significantly higher than that of the normal control group(P <0.01), in LPS+UTI group, LPS+SB203580 group,LPS+UTI+SB203580 combined group, the lung tissue TNF-? levels were significantly lower than those in the LPS group(P < 0.01), with the combination of the two groups is the most significant. In LPS+UTI group the lung tissue TNF-? were lower than LPS+SB203580 group(P < 0.01).4. In lung tissue of each group of p38 MAPK phosphorylation protein expression: the expression of p-p38 MAPK in lung tissue in LPS group was significantly higher than that of normal control group(P<0.01), in LPS+UTI group, LPS+SB203580 group,LPS+UTI+SB203580 combined group, the lung tissue of p-p38 MAPK levels were lower than that of LPS group(P<0.01), the combination of the two groups is the most significant.In LPS+UTI group, the lung tissue of p-p38 MAPK levels were lower than LPS+SB203580 group(P < 0.05).5.Correlation analysis of TNF- alpha, p-p38MAPK: there is a significant correlation between p-p38 MAPK and TNF- ?(r=0.971, P<0.01).6. The lung tissue pathological slices: normal control group: lung tissue structure were clear and complete,no thick alveolar septum uniform; in LPS group:destruction of lung tissue structure, pulmonary stenosis and collapse, alveolar septal thickening, rich in inflammatory cell infiltration, and visible pulmonary microvascular congestion, LPS + UTI group, group LPS+SB203580, LPS+UTI+SB203580 joint group compared to the LPS group, the lung tissue injury mitigated, alveolar septum inflammatory cell infiltration were decreased while alveolar septal thickening.7. Alveolar type II cells electric lens: normal control group: alveolar type II epithelial cell cytoplasm within the lamellar body density is uniform and complete form; LPS group:alveolar type II epithelial cell cytoplasm lamellar bodies emptying significantly, and induced vacuolization; LPS+UTI, LPS+SB203580 group and combined group compared to LPS group,lamellar bodies emptying and vacuolization within the cytoplasm of alveolar type II epithelial cells were relief.Conclusions:In this experiment, p-p38 MAPK and TNF-? were positively correlated, in the model of acute respiratory distress syndrome,TNF-? and p-p38 MAPK expression increased significantly,Pa02 decreased significantly.After Ulinastatin and p38 MAPK specific inhibitor, TNF-? and p-p38 MAPK were reducted and Pa02 was increased.Combined treatment was better than the single treatment.The effect of ulinastatin on curative effect was better than that of SB203580.It can be concluded that the effect of ulinastatin on acute respiratory distress syndrome(ARDS) can protect the lung, and the protective effect of ulinastatin via the effect of p38 MAPK pathway can achieve the protective effect of the treatment of ARDS lung, at the same time the use of ulinastatin and p38 MAPK inhibitor SB203580 in the organization of ARDS can achieve synergistic protective effect. There are other pathways on the anti-inflammatory effect of ulinastatin on ARDS.