| Objective:A rat model of pulmonary fibrosis was induced by bleomycin.We observe the expression of phosphorylated protein kinase B and hypoxia inducible factor 1 alpha in lung tissue of rats with pulmonary fibrosis,and study the possible mechanism of exogenous hydrogen sulfide resistance to pulmonary fibrosis.Methods:According to the random number method,60 healthy adult female SD rats were divided into 4 groups: group A(blank control group),group B(group BLM),group C(group BLM+ prednisone),group D(group BLM+H2S),15 rats in each group.In group B,group C and group D,we injected bleomycin(5mg/kg)into rat trachea to establish pulmonary fibrosis model and add equal volume saline in A group.The first day after modeling,prednisone acetate suspension was injected into the stomach of group C rats every day,and the concentration of prednisone acetate suspension was 0.56mgmg·kg-1·d-1 in rats.Intraperitoneal injection of Na HS solution(H2S donor)in the D group of rats every day,the concentration of Na HS solution is 28 umol·kg-1·d-1 Intraperitoneal injection of normal saline in group A and B rats every day.Five rats were killed at random in each group,at seventh days,fourteenth days and twenty-eighth days.The left lung tissue was taken into 10% formalin solution and fixed for HE staining and Masson staining.We observed the changes of alveolitis and pulmonary fibrosis by optical microscope.The right lung was cryogenic in liquid nitrogen and placed in-80 ℃ refrigerator for preservation.It was used for immunohistochemistry and Western-blot method to detect the expression level of p-AKT and HIF-1α protein.Results:1.HE staining and Masson stainingIn group A,the structure of lung tissue was clear,no edema,thickening,inflammation and fibrosis.Group B: On the seventh day,the lung tissue was disorganized,alveolar septum edema,widening,and inflammatory cell exudation in the alveoli.On the fourteenth day,there was still inflammatory exudation in the lung tissue,thickening of alveolar septum in the lung tissue,fibroblast proliferation and collagen fiber deposition,and fibrosis began.At twenty-eighth days,the alveolar structure of the lung tissue was destroyed and disappeared,and a small amount of inflammatory cells were infiltrated,and a large amount of collagen was deposited,which showed severe pulmonary fibrosis like changes.Group C and group D were compared with that of group B,and the pulmonary fibrosis and the degree of inflammation were reduced at all times.2.Expression of p-AKT and HIF-1α(immunohistochemistry and Western-Blot)(1)The expression of p-AKT and HIF-1α in group A was not significant at all times.In group B,group C and group D,the expression of p-AKT and HIF-1 α in each period was compared,and the expression was significant at seventh days and fourteenth days.(2)In the seventh and 14 days,group B,C and D were compared with the A group,and the expression of p-AKT and HIF-1α was higher than that of the A group,the difference was statistically significant(p < 0.05).Compared with group B,the expression of p-AKT and HIF-1α in group C and D was lower than that in group B,and the difference was statistically significant(p < 0.05).Conclussions:1.Exogenous H2S can reduce the degree of bronchitis and pulmonary fibrosis caused by bleomycin.2.Exogenous H2S can inhibit the expression of p-AKT and HIF-1α in the early stage of pulmonary fibrosis,and thus play an anti-pulmonary fibrosis effect. |
