title: Divergent outcomes of fructose consumption on exercise capacity of rats: friend or foe.
abstract: To test the hypothesis that high fructose (HF) consumption divergently affects exercise capability as a function of feeding duration, rats were fed a normal (as control) diet or a normal caloric diet with HF for 3, 6, 10, and 30 days, respectively, and then were run on a treadmill. Results show that running distance and work were significantly increased, which was associated with greater exercise oxygen consumption in rats fed HF for 3 (HF-3D) and 6 days, but were decreased in rats fed HF for 30 days (HF-30D) compared with rats in their respective control groups. Shear stress-induced vasodilation (SSID) in isolated plantaris muscle arterioles was significantly greater in the HF-3D group than the control group. The difference in SSID between the two groups was abolished byNω-nitro-l-arginine methyl ester (L-NAME), suggesting a nitric oxide (NO)-mediated response. Expression of phosphorylated/activated endothelial NO synthase (eNOS) and release of nitrite/NO were significantly increased in vessels of animals in the HF-3D group than controls. In contrast, arterioles isolated from the hypertensive rats in the HF-30D group displayed significantly attenuated NO-mediated SSID accompanied with greater production of superoxide compared with vessels of control animals. Additionally, the NO-dependent modulation of myocardial oxygen consumption (MV̇o2) was also impaired in the HF-30D group, and was prevented by blocking superoxide production with apocynin, an inhibitor that also normalized the reduced SSID in the HF-30D group. In conclusion, short-term (3-6 days) HF feeding enhances exercise potential via an increase in endothelial sensitivity to shear stress, which stimulates eNOS to release NO, leading to better tissue perfusion and utilization of oxygen. However, long-term (30 days) HF feeding initiates endothelial dysfunction by superoxide-dependent mechanisms to compromise exercise performance.NEW & NOTEWORTHYThe evidence that short-term fructose intake potentiates exercise capacity by nitric oxide-mediated mechanisms yields an optimal fructose feeding frame in which beneficial effects of fructose have been acquired while detrimental effects have not yet been manifested. This highlights the significance of exercise physiology in providing constructive regimens to improve physical performance.
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York.
authors.forename: Angela
authors.initials: A
authors.lastname: Sun
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York.
authors.forename: An
authors.initials: A
authors.lastname: Huang
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kertowidjojo
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York.
authors.forename: Su
authors.initials: S
authors.lastname: Song
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Hintze
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York dong_sun@nymc.edu.
authors.forename: Dong
authors.initials: D
authors.lastname: Sun
mesh_terms: D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D005632:Fructose / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D033081:Shear Strength / Q000187:drug effects / Q000502:physiology; D013481:Superoxides / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D013481:Superoxides; D005632:Fructose; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D019331:NG-Nitroarginine Methyl Ester
keywords: exercise; fructose; nitric oxide; oxygen consumption; shear stress-induced vasodilation