title: Partial persistence of exercise-induced myocardial angiogenesis following 4-week detraining in the rat.
abstract: Enhanced angiogenesis, or capillary growth, has a prominent role among the various beneficial effects of exercise training on the myocardium. The aim of the present study is to assess if training-induced increases in capillarity and vascularization persist after 4 weeks of detraining. Adult male rats were trained to run on a treadmill for 10 weeks at approximately 60% VO2max, which did not induce cardiac hypertrophy, but increased (P < 0.05) the soleus/body weight ratio, left ventricle capillarity and von Willebrand-positive cell density (n = 6). In another group of animals (n = 6) subjected to training followed by 4-week detraining, the soleus/body weight ratio returned to normal, with only partial reversal of left ventricle capillarity and von Willebrand-positive cell density. Markers of angiogenesis (VEGF, KDR/VEGF-R2 and HIF-1alpha mRNA, studied by real-time RT-PCR) were upregulated at the end of training, and returned to baseline value after detraining. Electron microscopy highlighted some morphological features in trained hearts (endothelial cell sprouting and bridges and pericyte detachment), suggestive of endothelial cell proliferation and capillary growth that were absent in untrained and detrained hearts. We conclude that the training-induced increase in cardiac capillarity and vascularization are retained for some time upon cessation of the training program even in the absence of angiogenic stimuli.
authors.affiliation: Department of Histology, Embryology and Applied Biology, University of Bologna, Via Belmeloro, 8, Bologna, Italy. marina.marini@unibo.it
authors.forename: Marina
authors.initials: M
authors.lastname: Marini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Falcieri
authors.forename: Vittoria
authors.initials: V
authors.lastname: Margonato
authors.forename: Davide
authors.initials: D
authors.lastname: Treré
authors.forename: Rosa
authors.initials: R
authors.lastname: Lapalombella
authors.forename: Simona
authors.initials: S
authors.lastname: di Tullio
authors.forename: Cosetta
authors.initials: C
authors.lastname: Marchionni
authors.forename: Sabrina
authors.initials: S
authors.lastname: Burattini
authors.forename: Michele
authors.initials: M
authors.lastname: Samaja
authors.forename: Fabio
authors.initials: F
authors.lastname: Esposito
authors.forename: Arsenio
authors.initials: A
authors.lastname: Veicsteinas
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003331:Coronary Vessels / Q000502:physiology* / Q000648:ultrastructure; D006352:Heart Ventricles / Q000378:metabolism / Q000648:ultrastructure; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D010805:Physical Conditioning, Animal; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2