Hypoxia training attenuates left ventricular remodeling in rabbit with myocardial infarction

• Published in: Journal of geriatric cardiology : JGC Vol. 11; no. 3; pp. 237 - 244
• Main Authors: Wan, Chun-Xiao, Lan, Yun-Feng, Jiang, Hui, Huang, Jie, Li, Rui-Sheng, Bi, Sheng, Li, Jian-An
• Format: Journal Article
• Language: English
• Published: China Rehabilitation Medicine Center, Chinese PLA General Hospital, Beijing 100853, China%Department of Healthcare, Hainan Branch of Chinese PLA General Hospital, Sanya 572000, Hainan Province, China%Research and Technology Service Center, 302 Hospital of PLA, Beijing 100039, China%Rehabilitation Medicine Center, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China 01.09.2014; Science Press
• Subjects: VEGF; 低氧; 心室重构; 心肌梗死; 血管内皮生长因子; 血管密度; 训练; 雄兔; Hypobaric hypoxia; Myocardial infarction; Infarct size; Left ventricular remodelling; Vascular endothelial growth factor
• ISSN: 1671-5411
• DOI: 10.11909/j.issn.1671-5411.2014.03.002

Objective Previous studies showed that hypoxia preconditioning could protect cardiac function against subsequent myo-cardial infarction injury. However, the effect of hypoxia on left ventricular after myocardial infarction is still unclear. This study therefore aims to investigate the effects of hypoxia training on left ventricular remodeling in rabbits post myocardial infarction. Methods Adult male rabbits were randomly divided into three groups： group SO （sham operated）, group MI （myocardial infarc-tion only） and group MI-HT （myocardial infarction plus hypoxia training）. Myocardial infarction was induced by left ventricular branch ligation. Hypoxia training was performed in a hypobaric chamber （having equivalent condition at an altitude of 4000 m, FiO214.9%） for 1 h/day, 5 days/week for four weeks. At the endpoints, vascular endothelial growth factor （VEGF） in the plasma was measured. Infarct size and capillary density were detected by histology. Left ventricular remodeling and function were as-sessed by echocardiography.Results After the 4-week experiment, compared with the group SO, plasma VEGF levels in groups MI （130.27 ± 18.58 pg/mL,P〈 0.01） and MI-HT （181.93 ± 20.29 pg/mL,P〈 0.01） were significantly increased. Infarct size in Group MI-HT （29.67% ± 7.73%） was deceased remarkably, while its capillary density （816.0 ± 122.2/mm2） was significantly increased. For both groups MI and MI-HT, left ventricular end-diastolic and end-systolic dimensions were increased whereas left ventricular ejection fraction was decreased. However, compared with group MI, group MI-HT diminished left ventricular end-diastolic （15.86 ± 1.09 mm,P〈 0.05） and end-systolic dimensions （12.10 ± 1.20 mm,P〈 0.01） significantly and im-proved left ventricular ejection fraction （54.39 ± 12.74 mm,P〈 0.05）.ConclusionHypoxia training may improve left ven-tricular function and reduce remodeling via angiogenesis in rabbits with MI.