Abstract: Objective To observe the effect of chronic intermittent hypoxia in sleep apnea syndrome patients on renin angiotensin system and the protection of angiotensin receptors blocker on cardiovascular system, so as to explore the mechanism which sleep apnea syndrome act on cardiovascular system. Methods Thirty-two healthy male C57BL/6J mice were randomly divided into 4 groups: the CIH group, the telmisartan treatment group, the air control group, and the blank control group, with 8 mice in each group. The period of chronic intermittent hypoxia was lasted for 12 weeks. The blood pressure and blood flow of mouse tail were measured. Results (1) The level of systolic blood pressure in the CIH group was significantly higher than other groups and came down to the lowest after ARB treatment. (2) The level of diastolic blood pressure in ARB treatment group was significantly lower than other groups. (3) The tail blood flow of CIH group was significantly higher than those of the blank control group, the air control group, and the ARB treatment group. Conclusion The chronic intermittent hypoxia might induce high systolic blood pressure, and that ARB could decrease the hypertension caused by CIH. At the same time, CIH could increase the tail blood flow of mouse, and ARB could inverse this influence of CIH.

Key words: Chronic intermittent hypoxia, Sleep apnea syndromes, ARB, Blood pressure