不同频率间歇低氧大鼠心脏炎症状态及抗氧化干预的研究

Heart inflammatory status of rat in different frequency of intermittent hypoxia and its study of tempol intervention

目的 通过观察不同间歇低氧（intermittent hypoxia,IH）模式下和抗氧化干预后大鼠心肌组织炎症标志物白介素6（IL-6）、IL-8、肿瘤坏死因子α（TNF-α）和C反应蛋白（CRP）水平的变化,探讨阻塞性睡眠呼吸暂停低通气综合征（OSAHS）与心血管疾病的联系和影响机制,以及抗氧化剂4-羟基-2,2,6,6-四甲基哌啶（Tempol）的干预作用.方法 48只成年雄性Wistar大鼠采用随机排列表法分为6组,包括4个不同频率IH组（IH1组、IH2组、IH3组、IH4组）、1个持续常氧对照组（SC组）及1个Tempol干预组（IH3T组）,每组8只大鼠.各组分别给予相应的低氧暴露,暴露6周后处死大鼠,立即分离心脏.采用酶联免疫吸附法测定心肌组织匀浆CRP、IL-6、IL-8及TNF-α水平.结果 ①所有IH组大鼠的心肌组织炎症标志物CRP、TNF-α、IL-8水平均高于SC组（P＜0.05）.各IH组组间比较显示,低氧频率较高的IH3和IH4组的IL-6、CRP、TNF-α、IL-8水平高于低氧频率较低的IH1和IH2组（P＜0.05）,提示随着低氧程度的加重,这4种炎症标志物水平也不断升高.②IH3T组的IL-6、IL-8、TNF-α及CRP水平仍然高于SC组（P＜0.05）,但是与IH3组相比,其IL-8、TNF-α及CRP水平降低（P＜0.05）.结论 ①慢性IH程度是影响大鼠心肌组织炎症标志物IL-6、IL-8、TNF-α及CRP水平的重要因素,其水平可随低氧程度的加重而升高,提示OSAHS可能是一个慢性炎症过程,炎症因子在OSAHS合并心血管疾病的发生发展中起着重要作用.②经Tempol干预后,IH大鼠心肌组织炎症标志物IL-6、IL-8、TNF-α及CRP水平有不同程度的下降,表明抗氧化干预能缓解IH所致氧化应激对大鼠心肌组织带来的损害,但并不能完全逆转这种损害.

Objective To explore the relationship and influencing mechanism in obstructive sleep apnea hypopnea syndrome （OSAHS） combined cardiovascular disease, and to investigate the preventive effect of Tempol （4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-N-oxyl） by observing the changes of inflammation markers interleukin-6 （IL-6）, IL-8, tumor necrosis factor-a （TNF-a）, and C-reactive protein （CRP） of cardiac muscular tissue in rats exposed to continuous normal oxygen and varying degrees of intermittent hypoxia （IH） circumstances as well as treated with antioxidant intervention. Methods 48 male Wistar rats were divided into six groups by random arrangement table method, including four different frequency IH groups （IH1 group, IH2 group,IH3 group,and IH4 group）, a sustained normal oxygen control group （SC group）,and a tempol intervention group （IH3T group）,each group had eight rats. Each group were given corresponding hypoxia exposure. After exposure of six weeks, the rats were executed, and the hearts were separated immediately. CRP, IL-6, IL-8, and TNF-a in cardiac muscular tissue homogenate were tested by enzyme-linked immune sorbent assay. Results （1） The inflammation marker levels of CRP,TNF-a,and IL-8 in the cardiac muscular tissue of rats were significantly elevated in all of IH groups compared with SC group （ P d0.05）. The comparison among each IH group showed that the levels of IL-6,CRP,TNF-a,and IL-8 in IH3 and IH4 group which had higher frequency of IH were significantly elevated compared with IH1 and IH2 group which had lower frequency of IH, it prompted that the levels of these four inflammation markers in the cardiac muscular tissue of IH rats would be lifted with the increasing degree of IH. OThe levels of IL-6, IL-8 ,CRP,and TNF-a in IH3T group were higher than those in SC group （ P d0.05）,but lower than those in IH3 group （ P d0.05）. Conclusions （]）The degree of chronic IH could be an important factor influencing the inflammation marker levels of IL-6, IL-8,TNF-a, and CRP in the cardiac muscular tissue of rats, the levels of these inflammation markers are lifted with the increasing degree of IH, it presents that OSAHS may be a chronic inflammatory process, and inflammation markers may play an important role in the occurrence and development of OSAHS combined cardiovascular disease. （2）After tempol intervention, the levels of IL-6,IL-8,TNF-a, and CRP in the cardiac muscular tissue of IH rats decrease, which shows that anti-oxygen may remit the damage of cardiac muscular tissue in rats that is caused by oxidate stress resulted from IH, however, this kind of damage could not be totally reversed.