[Effect of NADPH oxidase activity inhibitor apocynin on blood pressure in rats exposed to chronic intermittent hypoxia and the possible mechanisms].

OBJECTIVE: To investigate the effect of NADPH oxidase activity inhibitor apocynin on the blood pressure of rats exposed to chronic intermittent hypoxia (CIH).

METHODS: Thirty healthy male SD rats were randomly divided into 3 groups of 10 each, a CIH group, an apocynin treatment group and a control group. The systolic blood pressure (SBP) was measured with tail-cuff method. RT-PCR and Western blot were used to examine mRNA and protein expression of NADPH oxidase subunit p22phox. The level of MDA, SOD, NO and .O(2)(-) were detected by colorimetric method.

RESULTS: Compared to the normal group, the expression of p22phox mRNA and protein were significantly increased in CIH group (q = 3.202, 6.522, P < 0.05). There were no statistic difference of p22phox mRNA and protein expression between CIH group and apocynin treatment group (P > 0.05). Compared with those of CIH group, the levels of MDA, .O(2)(-) and the systolic blood pressure decreased significantly (P < 0.05), while SOD and NO activity increased significantly (q = 6.960, 4.385, P < 0.05) in apocynin treatment group.

CONCLUSIONS: These results indicate that NADPH oxidase up-expression is closely associated with hypertension in OSAHS. Inhibition of NADPH oxidase activity may be hopefully served as a useful strategy for prevention and treatment of OSAHS-induced hypertension.