Abstract: Objectives To develop a sleep intermittent hypoxia (SIH) and emphysema rat model and to explore whether SHE results in more severe hepatic oxidative stress and inflammation than emphysema alone or sleep intermittent hypoxia alone .Methods Sixty male Wistar rats were assigned to 4 groups with 15 per group according to the exposure conditions. Group A (control group), sham smoke exposure(smoke exposure, exposed to smoke of 15 cigarettes twice everyday, 8weeks) and sham SIH exposure (5% O2, 8hours); Group B (Emphysema group), smoke exposure and sham SIH exposure; Group C (SIH group), sham smoke exposure and SIH exposure ; Group D (Emphysema and SIH group), smoke exposure and SIH exposure . At the end of exposure, 5 rats in each group were randomly selected for arterial blood gas analysis. In the rest 10 rats in each group, We also obtained tissue blocks of liver for pathologic scoring and measurements of liver oxidative stress (measuring hepatic oxidative stress enzymes, superoxide dismutase (SOD) activity, catalase (CAT) activity and malondialdehyde (MDA) concentration)and liver inflammation (measuring hepatic inflammatory factor interleukin -6 (IL-6) protein and tumor necrosis factor a (TNF-a) protein).Results Characteristics of emphysema were obvious in group B and D.Group B and D had higher mean linear intercept (MLI) values than group A and C (all P <0.05). group B and D had lower mean alveolar number (MAN) values than group A and C. MAN values in group D were the lowest (all P <0.05).SOD and CAT values were lower and MDA values were higher in group B, C and D than group A(all P <0.05)). SOD and CAT values were the lowest in group D ,MDA values were the highest in group D (all P <0.05); Histological scores of liver , IL-6 and TNF-α values were higher in group B, C and D than group A , group D were the highest (all P <0.05) .Conclusions Emphysema and SIH have synergistic action in causing of hepatic oxidative stress and inflammation.

Key words: emphysema1, intermittent hypoxemia2, liver3, oxidative stress4, inflammation5