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.

Objective To obtain the recombinant corticotropin releasing hormone (CRH) protein with soluble, high purity protein through optimizing prokaryotic expression condition and purifying glutathione thiol transferase (GST)-CRH protein. Methods To detect the expression of soluble CRH protein through grope of the host strain GST-CRH temperature of induction expression, the host strain concentration (OD600), IPTG concentration and induction time, the purification of GST-CRH was performed by GST-CRH agarose gel. Western Blot assay was used for the expression identification of the target protein. Results The optimal conditions for the induction of CRH protein were determined: temperature of 30 ℃, IPTG induced concentration 0.1 mmol/L, bacteria density (OD600) 0.8, the induction time of 8 hours, purified GST-CRH>95% fusion protein was obtained. Conclusion The optimal expression conditions of GST-CRH are obtained, and the soluble protein of high purity GST-CRH is also obtained.