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Exercise Training Reverses Age‐induced Coronary Microvascular Dysfunction
Author(s) -
MullerDelp Judy,
Behnke Bradley,
Delp Michael,
Chen Bei,
Ghosh Payal,
Stabley John,
Hotta Kazuki,
Cowan Morgan,
Lucero Tiffani,
Morgan Hannah
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.953.7
Subject(s) - medicine , endocardium , cardiology , diastole , blood flow , coronary circulation , coronary flow reserve , endothelial dysfunction , blood pressure
The risk for diastolic dysfunction increases with advancing age. We tested the hypotheses that 1) microvascular dysfunction underlies age‐related diastolic dysfunction, and 2) exercise training (ET) reverses age‐related microvascular and diastolic dysfunction. Old and young male Fischer 344 rats underwent 10 weeks of daily ET or remained sedentary cage controls. Cardiac function was assessed before and after ET. At the end of training, coronary blood flow was measured at rest and during treadmill exercise. The reactivity of the coronary resistance vasculature was assessed in isolated coronary arterioles. E/a ratio decreased with age and was partially restored by ET. Isovolumic relaxation time increased with age and this increase was reversed by ET. Resting blood flow to the left ventricular (LV) endocardium and the right ventricular free wall was decreased in old rats; however, ET increased resting blood flow to the septum, papillary muscles, LV endocardium and epicardium. Exercise hyperemia was reduced by age in the septum, and the LV endocardium and epicardium, but these age‐related reductions were reversed by ET. Age‐induced impairments of both contractile and relaxation responses of coronary arterioles were reversed by ET. Thus, microvascular dysfunction contributes to development of diastolic dysfunction with advancing age; however, ET at an advanced age reverses microvascular dysfunction and improves diastolic function.