摘要
目的研究慢性间歇低氧（CIH）与持续低氧（CH）对大鼠血清及组织器官局部的肾素血管紧张素（RAS）系统的影响，以探讨CIH相关性高血压及低氧性肺动脉高压的发生机制。方法18只SD雄性大鼠按随机数字表法分为CIH组、CH组和对照组共3组，每组6只。CIH组大鼠循环给予氮气和压缩空气（每循环180s，舱内最低氧浓度达6％-8％，维持20—25S，然后恢复至21％，7h／d），CH组持续给予氮气（舱内氧浓度保持8％-12％，7h／d），对照组大鼠常规饲养。结果第6周时CIH大鼠收缩压（SBP）显著高于CH组、对照组（P〈0．05）和实验前水平（P〈0．01）。CIH分别与CH和对照组比较：肾小动脉和肺小动脉中ACE及ACE2水平差异有统计学意义（P〈0．05）；血清和肾组织中AngⅡ显著增高（P〈0．05），Ang．（1—7）则明显降低（P〈0．05）。CH组肺组织AnglI较CIH及对照组增高（P〈0．05），Ang．（1-7）降低（P〈0．05）；SBP与血清及肾AngII水平呈正相关；与Ang．（1—7）水平呈负相关。CIH组肾小动脉及CH组肺小动脉管壁厚度、壁厚度占外径或内径的百分比（WT％）及管壁面积占血管壁总面积的百分比（WA％）分别与其他两组比较均有明显差异（P〈0．05）。肺及肾的小动脉管壁厚度与其相应组织局部的Ang1I呈正相关（r=0．386、0．414，均P〈0．05），与Ang-（1—7）呈负相关（r=-0．401，-0．394，均P〈0．05）。结论CIH与CH两种低氧方式对大鼠血清及各组织局部的RAS系统影响程度及结果存在差异性，CIH主要影响大鼠肾组织及肾小动脉及体循环RAS系统，与血压增高密切相关；CH主要影响肺组织及肺小动脉RAS系统，可能与肺动脉重塑及肺动脉高压有关。
Objective To Investigate the influences of chronic intermittent hypoxia （CIH） and continuous hypoxia （CH） on renin angiotensin system （RAS） in serum and tissues of rats , and therefore to investigate the mechanism of CIH-indueed hypertension and hypoxia induced pulmonary hypertension. Methods Eighteen male Sprague-Dawley（SD） rats were divided into 3 groups： CIH group, CH group and control group（ UC ）. CIH rats were subjected to alternating cycles of hypoxia （6% -8% O2 in N2 for 20-25 s） and normoxia （21% O2 in N2 for 2 rain） every 180 s for 7 h/d. CH rats were consistently given nitrogen （oxygen concentration 8% - 12% in the cabin, 7 h/d） , while the UC rats were not treated. Results Systolic blood pressure （SBP） in the CIH rats at the end of 6th week was significantly elevated compared with baseline SBP （P 〈0. 001） , and that in the CH and the UC rats（P 〈0.05）. At the end of 6th week, the expression of ACE and ACE2 in the renal arteriole was significantly different（ P 〈 0. 05 ） , and the levels of Ang H in serum and kidney tissues were increased . Ang-（1-7） was decreased in the CIH rats compared with the CH and the UC rats （ P 〈 0. 05 ）. The levels of Ang ]] in pulmonary tissues were increased, while the levels of Ang-（1-7） were decreased in the CH rats compared with the CIH and the UC rats （ P 〈 0. 05 ）. SBP showed a positive correlation with Ang ]] in serum and kidney tissues, and a negative correlation with Ang-（1-7） in serum and kidney tissues. There were significant differences in arterial wall thickness, WT%, and WA% of renal arterioles and pulmonary arterioles among the 3 groups. Wall thickness of pulmonary arterioles and kidney arterioles was positively correlated with Ang 11 in pulmonary and kidney tissues（r = 0. 386,0. 414, P 〈 0. 05）, and negatively correlated with Ang-（1-7） （ r = - 0. 401, -0. 394, P 〈 0.05 ）. Conclusion CIH and CH showed different effects on RAS in the serum and the tissues of rats. CIH mainly affected levels of RAS in the serum, kidney tissues and renal arterioles, and was closely related with blood pressure. CH mainly affected the levels of RAS in lung tissues and pulmonary small arteries, which may be related with pulmonary, hypertension and pulmonary arterial remodeling.
出处
《中华结核和呼吸杂志》
CAS
CSCD
北大核心
2012年第1期33-36,共4页
Chinese Journal of Tuberculosis and Respiratory Diseases
基金
湖南省科技厅基金资助项目（06FJ3121）
