Effects Of Intermittent Hypoxia On Lung Injury And TLR4 Expression In Lungs Of Rats

Objective Intermittent Hypoxia(IH)model in rats was used to simulate the obstructive sleep apnea hypopnea syndrome(OSAHS)in humans,to detect the expression of TLR4 in the lungs,to provide new ideas for further investigation of the correlation between TLR4 and other pulmonary diseases and clinical prevention and treatment of OSAHS.Methods Thirty two male SPF-grade healthy Wistar rats were randomly divided into four groups(eight in each group),which were respectively group A(normal oxygen group,the oxygen concentration is 21%),group B(mild hypoxia group,the oxygen concentration is 15%),group C(moderate hypoxia group,the oxygen concentration is 9%)and group D(severe hypoxia group,the oxygen concentration is 6%).On the 36th day,the lung tissues were taken to observe the morphological changes of the rats under optical microscope,and the expression level of TLR4 of each group with immunohi stochemi stry.Results HE results showed that there were no obvious abnormalities in the lung tissues in group A.The alveoli septa were thickened and lymphocytes were infiltrated in the lung tissues in groups B,C,and D.A small number of macrophages and dust-free cells were found in group B.Dust cells and macrophages were found in groups C and D,and there were significantly increased in group D than in group C.Groups B,C,and D had changes of bronchiolar epithelial cells with different degrees of emphysema.Group D showed inflammatory infiltration of pulmonary interstitial and severe emphysema.Immunohistochemical results showed that there were no TLR4 expression in group A,and TLR4 expression was gradually increased in groups B,C,and D.The expression of TLR4 in group D was the most significant.The differences were statistically significant(P<0.001).Conclusions1.Intermittent hypoxia could cause pathological damages and morphological changes in lung tissues of rats.With the increase of hypoxia,the pathological damages of lung tissues became more serious.2.Intermittent hypoxia led to an increase in the degree of inflammation in the lung tissues of rats,which increased the expression of TLR4 in the lung tissues.With the increase of the degree of hypoxia,TLR4 expression was higher.