游泳对慢性低氧高二氧化碳大鼠一氧化氮代谢的影响

摘要

BACKGROUND: Sports could increase the nitric oxide (NO) production of vessels for normal organism and patients with cardiac diseases [2], while sports have an active role in metabolism of NO when chronic hypoxia.OBJECTIVE: To study the effects of swimming exercise on NO metabolism and mean pulmonary artery pressure(mPAP) in rats exposed chronically to hypoxia-hypercapnia.SETTING, PARTICIPANTS and INTERVENTIONS: The study was made in the Institute of Cot Pulmonale, Wenzhou Medical College. Thirty-one Sprague-Dawley(SD) rats were randomly divided into two groups: normal control group( n = 10) and chronic hypoxia-hypercapnia group( n = 21) .After four weeks of exposure to hypoxia-hypercapnia, the latter group was suhdivided into hypoxia-hypercapnia(HH) control group( n = 8) and swimming exercise (SE) group ( n = 13 ). Contents of nitrate/nitrite in plasma, and pulmonary and right ventricular homogenates were measured with colorimetric analysis. L-citrulline was determined with liquid scintillometer, and the activity of NO synthase(induced NOS, total NOS, constitutive NOS) in pulmonary and right ventricular homogenates was counted.RESULTS: The NO2/NO3 contents and cNOS activity in plasma, and pulmonary and right ventricular homogenate in the SE group were markedly higher than those in the HH group. Moreover, mPAP in the SE group [(19.62±1.32) mm Hg] was obviously lower than that in the HH group [(15.19+1.11) mm Hg](q=12.632, P ＜0.01).CONCLUSION: Swimming exercise could increase NO production and lower the mPAP of the rats exposed chronically to hypoxia-hypercapnia.%背景:运动锻炼能提高正常机体和心血管疾病患者血管一氧化氮的生成能力,但运动锻炼对慢性低氧时一氧化氮代谢有积极的影响.目的:探讨游泳锻炼对慢性低氧高二氧化碳大鼠一氧化氮代谢及肺动脉平均压(mean pulmonary artery pressuse,mPAP)的影响.设计:随机对照的实验研究.地点、材料和干预:实验在温州医学院肺心病研究室完成.实验选用31只SD大鼠随机分成正常对照组(10只)与模型组(21只).模型组低氧4周后,又随机分为模型对照组(8只)与游泳锻炼组(13只).采用比色法测定血浆、肺组织、右心室组织一氧化氮代谢产物(NO2-/NO3-)的含量,液体闪烁仪测定[3H]-瓜氨酸的生成量,计算肺组织、右心室组织组织型NOS(tissue NOS,tNOS)、诱导型NOS(induced NOS,iNOS)和原生型NOS(constitutive NOS,cNOS)的活性.主要观察指标:游泳对慢性低氧高二氧化碳在大鼠mPAP、右心室质量,血浆、肺组织、右心室组织NO2-/NO3-含量、NOS活性的影响.结果:游泳锻炼组的血浆、肺与右心室组织的NO2-/NO3-的含量和cNOS的活性明显高于模型对照组;同时,游泳锻炼组的mPAP[(19.62±1.32)mm Hg]显著低于模型对照组[(15.19±1.11)mm Hg](q=12.632,P＜0.01).结论:游泳锻炼有促使一氧化氮生成增加和降低肺动脉压的作用.