title: Exercise Training Reverses Structural Microvascular Rarefaction and Improves Endothelium-Dependent Microvascular Reactivity in Rats with Diabetes.
abstract: We evaluated structural microvascular alterations in the skeletal muscle and left ventricle, as well as endothelium-dependent microvascular reactivity in the skeletal muscle, of diabetic rats subjected to long-term aerobic exercise training.
  
  
  
  Diabetes was experimentally induced by a combination of a high-fat diet with a single low dose of streptozotocin (35 mg/kg, i.p.). Animals with diabetes were divided into sedentary (DM+SED) and training groups (DM+TR) and compared with rats without diabetes (CON). We then measured maximal exercise capacity, fasting glucose and insulin, endothelium-dependent microvascular reactivity in skeletal muscle, and structural alterations of microvasculature in the skeletal and cardiac muscles.
  
  
  
  Diabetes induced microvascular rarefaction and reduced endothelium-dependent microvascular reactivity. Physical exercise completely reversed microvascular rarefaction in the skeletal muscle (1.85 ± 0.05 vs. 1.17 ± 0.03 capillary/fiber ratio, P < 0.05) and in the left ventricle (0.48 ± 0.66 vs. 0.25 ± 0.01 Vv[cap]/Vv[fib] ratio, P < 0.05) compared with the DM+SED group and normalized the microcirculatory responses to acetylcholine in skeletal muscle (CON 38.76 ± 5.60 vs. DM+TR 30.47% ± 5.77%). As expected, exercise training increased the maximal velocity and exercise tolerance compared with the DM+SED (P < 0.05) and CON (P < 0.05) groups. Exercise training also reduced fasting glucose (P < 0.05) compared with DM+SED and normalized insulin levels compared with CON.
  
  
  
  Our results suggest that long-term physical exercise reverses skeletal and cardiac muscle microvascular rarefaction, as well as impaired endothelium-dependent microvascular reactivity, induced by diabetes in rats.
authors.affiliation: 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Marcus V
authors.initials: MV
authors.lastname: Machado
authors.affiliation: 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Rômulo L
authors.initials: RL
authors.lastname: Martins
authors.affiliation: 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Juliana
authors.initials: J
authors.lastname: Borges
authors.affiliation: 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Bárbara R
authors.initials: BR
authors.lastname: Antunes
authors.affiliation: 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Vanessa
authors.initials: V
authors.lastname: Estato
authors.affiliation: 2 Laboratory of Inflammation, Oswaldo Cruz Institute, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Aline B
authors.initials: AB
authors.lastname: Vieira
authors.affiliation: 1 Laboratory of Cardiovascular Investigation, FIOCRUZ , Rio de Janeiro, Brazil .
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tibiriçá
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000473:pathology* / Q000628:therapy*; D059305:Diet, High-Fat; D004730:Endothelium, Vascular / Q000473:pathology; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008833:Microcirculation; D055806:Microvessels / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D010805:Physical Conditioning, Animal; D051381:Rats; D057185:Sedentary Behavior; D014664:Vasodilation
chemical_list: D001786:Blood Glucose; D007328:Insulin