High altitude hypoxia aggravates chronic inflammation induced by LPS in rats / 军事医学

ABSTRACT

Objective To investigate the effect of high altitude hypoxia on chronic inflammation in rats.Methods Forty SD rats were randomly divided into 4 groups control group (Con),chronic inflammation group (CI),high altitude hypoxia group (HH),high altitude hypoxia+chronic inflammation group (HH+CI).Rats in CI group were injected with lipopolysaccharide (LPS) (0.5 mg/kg) through the caudal vein twice a week for 4 weeks.Rats in HH+CI group were treated just as CI group was,but together with HH group rats were settled in a hypoxic environment of 6000 m altitude for three days.Pathological changes in lung tissues were observed by hematoxylin eosin stain.The peripheral white blood cell count and classification were measured.The levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in serum and lung tissues were detected by enzyme-linked immunosorbent assay (ELISA).Changes in IL-6 expression in rat lung tissues were observed by Western blotting.Results After LPS and high altitude hypoxia exposure,inflammatory cells infiltration and alveolar capillary expansion were observed in rats' lung tissue.Compared with Con group,not only the peripheral white blood cell count,but also the level of IL-6 and TNF-α in serum and lung tissue increased in CI and HH group(P<0.01).IL-6 expression levels observed by Western blotting were also increased in HH and CI group(P<0.01).High altitude hypoxia and chronic inflammation interacted(P<0.01).The peripheral white blood cell count was higher in HH+CI group than in other groups,and IL-6 and TNF-α expressions in lung tissue were increased(P<0.05).Conclusion An LPS-induced chronic inflammation model in rats is successfully obtained,and high altitude hypoxia could aggravate chronic inflammation.