[游泳运动对低氧性肺动脉高压大鼠肺组织中apelin及其受体表达的影响]

Chen Si, Xue Feng, Jin Hai-Long, Chen Lie, Chen Yu, Wang Gao-Feng, Fan Xiao-Fang, Gong Yong-Sheng

Laboratory of Cor Pulmonale, Institute of Hypoxia Medicine, Wenzhou 325035, China.

Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2012 Jan;28(1):5-8.

OBJECTIVE

To study the effects of swimming exercise on the expression of apelin and its receptor (APJ) system in pulmonary tissues of rats with pulmonary hypertension induced by hypoxia.

METHODS

Forty-five male SD rats were randomly divided into control group, hypoxia group (seven-week) and swimming group (four-week swimming group after three-week hypoxia). The animal model of hypoxic pulmonary hypertension was established by exposing the rats to isobaric hypoxic chamber (8 h/d, 6 d/w). The rats of swimming group swam 60 min/day, 7 d/week for 4 weeks after three-week hypoxia. The mean pulmonary arterial pressure (mPAP) and the mean carotid arterial pressure (mCAP) were measured by either right or left cardiac catheterization, and the weight ratio of right ventricule/left ventricle plus septum [RV/(LV + S)] were calculated. The Masson's trichrome stained lung specimens were used by light microscope to examine the vessel wall area/total area (WA/TA), vessel cavity area/total area (CA/TA) and media thickness of pulmonary arterioles (PAMT). Meanwhile, apelin/ APJ expressions were determined by Western blot and immunohistochemistry.

RESULTS

(1) mPAP and RV/(LV + S) of hypoxia group were higher than those of control group by 73.6% and 31.2% (P < 0.01), and mPAP and RV/(LV + S) of swimming group were lower than those of hypoxia group by 21.1%and 8.9 % (P < 0.05), respectively. (2) Masson's trichrome staining revealed that WA/TA and PAMT of hypoxia group were higher than those of control group by 70.8% and 102%. However, WA/TA and PAMT of swimming group were lower than those of hypoxia group by 24.8% and 40.1% (all P < 0.01), respectively. CA/TA of hypoxia group was lower than that of control group by 15.1%, and CA/TA of swimming group was lower than that of hypoxia group by 10.3% (all P < 0.01). (3) Compared with control group, hypoxia group showed up-regulated apelin expression and down-regulated APJ expression in pulmonary tissues (all P < 0.01). Compared with hypoxia group, swimming group showed decreased apelin expression and elevated APJ expression in pulmonary tissues (all P < 0.01). (4) Apelin localized mainly in intracytoplasm of inflammatory cell and tunica adventitia of vessel, and APJ were in vascular intima and tunica externa and plasmalemma of inflammatory cell.

CONCLUSION

The improving effect of swimming exercise on hypoxic pulmonary hypertension in rats could be mediated by regulating the pulmonary apelin/APJ system.

目的

研究游泳运动对低氧诱导的大鼠肺动脉高压肺组织中apelin及其受体（APJ）系统表达的影响。

方法

45只雄性SD大鼠随机分为对照组、低氧组（7周）和游泳组（低氧3周后进行4周游泳训练）。通过将大鼠置于等压低氧舱（8小时/天，6天/周）建立低氧性肺动脉高压动物模型。游泳组大鼠在低氧3周后每天游泳60分钟，每周7天，共4周。通过右心或左心导管插入术测量平均肺动脉压（mPAP）和平均颈动脉压（mCAP），并计算右心室/左心室加室间隔重量比[RV/（LV + S）]。采用Masson三色染色法对肺组织标本进行光镜检查，观察肺小动脉的血管壁面积/总面积（WA/TA）、血管腔面积/总面积（CA/TA）及中膜厚度（PAMT）。同时，采用蛋白质免疫印迹法和免疫组织化学法检测apelin/APJ的表达。

结果

（1）低氧组的mPAP和RV/（LV + S）分别比对照组高73.6%和31.2%（P < 0.01），游泳组的mPAP和RV/（LV + S）分别比低氧组低21.1%和8.9%（P < 0.05）。（2）Masson三色染色显示，低氧组的WA/TA和PAMT分别比对照组高70.8%和102%。然而，游泳组的WA/TA和PAMT分别比低氧组低24.8%和40.1%（均P < 0.01）。低氧组的CA/TA比对照组低15.1%，游泳组的CA/TA比低氧组低10.3%（均P < 0.01）。（3）与对照组相比，低氧组肺组织中apelin表达上调，APJ表达下调（均P < 0.01）。与低氧组相比，游泳组肺组织中apelin表达降低，APJ表达升高（均P < 0.01）。（4）Apelin主要定位于炎症细胞的胞质内和血管外膜，APJ定位于血管内膜、外膜及炎症细胞的质膜。