Study on thioredoxin in vascular system of rats exposed in different degree of chronic intermittent hypoxia

Abstract

Objective To approach the possible role of oxidative stress in pathogenesis of hypertension caused by obstructive sleep apnea syndrome, we detected the mRNA expression of thioredoxin(TRX) in aortic endothelial system of rats exposed in different degree of intermittent hypoxia. Methods 160 Wistar rats were randomly assigned to 5 groups: 5% IH,7. 5% IH, 10% IH, 10% continuous hypoxia and normoxia control groups. Selected 8 rats from each group randomly and killed on the second, fourth, sixth and eighth weeks respectively. Then detect the mRNA expression of TRX in aortic endothelial system by real-time PCR. Results On the fourth, sixth and eighth weeks, artery systolic blood pressure (SBP) of IH groups increased significantly compared with those before the experiment and those of CH and NC groups at the same time( P <0. 05). With the extending of exposure time, the mRNA expression of TRX showed a rising trend, and the level in 5% IH were significantly higher than those of 10% IH, continuous hypoxia and control groups on the sixth weeks( P <0. 01). On the eighth weeks, the mRNA expression in 5% IH group was higher than those of NC group( P <0. 01) and IH3 group ( P <0. 05). Conclusions Intermittent hypoxia of obstructive sleep apnea mode could induce mRNA expression of TRX in endothelial system rising, which correlated with the degree of IH. It showed that TRX played critical role in the pathogenesis of cardiovascular diseases in chronic intermittent hypoxia. Key words: Intermittent hypoxia; Oxidative stress; Thioredoxin