Effect of continuous positive airway pressure on myocardial structure and plasma NO and ET in mini pigs with obstructive sleep apnea syndrome / 第二军医大学学报

ABSTRACT

Objective: To investigate the effect of continuous positive airway pressure (CPAP) on serum NO and plasma ET and myocardial structure in mini pigs with obstructive sleep apnea syndrome (OSAS). Methods: Twenty-four male mini pigs were evenly randomized into 4 groups normal control group (group A), OSAS model group (group B), CPAP treated group (group C) and positive control group (group D). Animals in group A were not treated and those in the other 3 groups were treated with intermittent hypobaric hypoxia 6 h daily for 22 d. Animals in groups C was also given further CPAP treatment 6 h daily for 30 d. The animals in group D were raised for 30 d and were sacrificed together with those in group C; the animals in group A and group B were sacrificed simultaneously. Sleep monitoring and determination of serum NO and plasma ET were performed before execution and pathological examination of myocardial structure after execution. Results: The apnea-hypopnea index (AHI) of group C was significantly lower than those of group B and D and higher than that of group A (P<0.05); the SpO 2 of group C was significantly higher than those of group B and D (P<0.05), and was similar to that of group A. The levels of NO in group A, B, C, and D were (0.221±0.062), (0.115±0.061), (0.110±0.033), (0.077±0.043) μmol/L, respectively, and the levels of ET were (40.2±4.8), (99.8±22.4), (67.1±18.5), and (103.7±30.1) pg/ml, respectively. Group C had significantly higher NO level and lower ET level compared with group D (P<0.05). The ET level in group C was significantly lower than that in group B (P<0.05). Pathological examination showed that the myocardial structure in group B, C, and D all had hypoxia and ischemia damage compared with group A; the damage in group C was slighter than that in group B and D, but severer than that in group A. Conclusion: Thirty day-treatment with CPAP can improve the sleeping indices, plasma ET and serum NO level, and myocardial structure of OSAS mini pigs.