Impaired aerobic capacity in hypercholesterolemic mice: partial reversal by exercise training

Niebauer, Josef; Maxwell, Andrew J.; Lin, Patrick S.; Tsao, Philip S.; Kosek, Jon C.; Bernstein, Daniel; Cooke, John P.

doi:10.1152/ajpheart.1999.276.4.h1346

Cited by 64 publications

(65 citation statements)

References 32 publications

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“…In the present study, ventricular weights increased more than previously reported in mice and about the same as in rats exercising for 7 wk with the same regimen (42). Other studies in mice report no change (31) or an increase between 10 and 15% in cardiac mass (1,24), after 4 wk of training in C57BL/6J mice, treadmill, voluntary wheel, and swimming exercise, respectively. These studies lack a rigorous control of exercise intensity, and cardiovascular load seemed lower.…”

Section: Discussionsupporting

confidence: 67%

“…Within 6 wk, V O 2 reached a plateau 50% above sedentary controls in female mice and 30% above controls in males. Niebauer et al (31) found that V O 2 max increased 10% in C57BL/6J females after treadmill running for 4 wk, 1 h twice each day, 6 days/wk, at an intensity of ϳ85% of V O 2 max . Increments of 5-6% in C57BL/6J males (37) and 12% occurred in male Hsd:ICR house mice (40) after 6 wk of treadmill running and 7-8 wk of voluntary wheel running, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…V O 2 max in untrained mice has been reported to range from ϳ80 to 260 ml ⅐ kg Ϫ1 ⅐ min Ϫ1 , and RER at V O 2 max from 0.91 to 1.28 (13,14,31,32,36,38,40). However, there are differences in these studies regarding test protocols, equipment, body masses, strains, age, sex, and how accustomed the mice were to the methods.…”

Section: Discussionmentioning

confidence: 99%

“…3, allometric scaling greatly enhances comparison of V O 2 in animals with different weights. Reports of long-term running in mice have reported decreased (34,40,44) or unchanged (1,19,31,33,37,39) body mass, whereas swimming yielded an increase (24). In a survey of 100 recent transgenic mice studies at PubMed, body mass ranged between 17 and 74 g and age between 26 days and 12 mo.…”

Section: Discussionmentioning

confidence: 99%

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Intensity-controlled treadmill running in mice: cardiac and skeletal muscle hypertrophy

Kemi

Loennechen

Wisløff

et al. 2002

Journal of Applied Physiology

237

265

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. Intensity-controlled treadmill running in mice: cardiac and skeletal muscle hypertrophy. J Appl Physiol 93: 1301-1309. First published May 24, 2002 10.1152/japplphysiol.00231.2002-Whereas novel pathways of pathological heart enlargement have been unveiled by thoracic aorta constriction in genetically modified mice, the molecular mechanisms of adaptive cardiac hypertrophy remain virtually unexplored and call for an effective and wellcharacterized model of physiological mechanical loading. Experimental procedures of maximal oxygen consumption (V O2 max) and intensity-controlled treadmill running were established in 40 female and 36 male C57BL/6J mice. An inclination-dependent V O2 max with 0.98 test-retest correlation was found at 25°treadmill grade. Running for 2 h/day, 5 days/wk, in intervals of 8 min at 85-90% of V O2 max and 2 min at 50% (adjusted to weekly V O2 max testing) increased V O2 max to a plateau 49% above sedentary females and 29% in males. Running economy improved in both sexes, and echocardiography indicated significantly increased left ventricle posterior wall thickness. Ventricular weights increased by 19-29 and 12-17% in females and males, respectively, whereas cardiomyocyte dimensions increased by 20-32, and 17-23% in females and males, respectively; skeletal muscle mass increased by 12-18%. Thus the model mimics human responses to exercise and can be used in future studies of molecular mechanisms underlying these adaptations. maximal oxygen uptake; work economy; respiratory exchange ratio; cardiomyocyte; allometric scaling SEVERAL NOVEL SIGNALING PATHWAYS of pathological cardiac hypertrophy have been unveiled in the powerful model of mechanical overloading by thoracic aorta constriction in genetically modified mice (8,22). Thus far, the molecular mechanisms of adaptive cardiac hypertrophy in response to physiological stimuli remain virtually unexplored because of a paucity of effective and well-controlled experimental models in this species. Ideally, the outcome should mimic typical results of exercise training in humans, e.g., increased maximal oxygen uptake (V O 2 max ) and work economy (21). In healthy individuals, increased exercise capacity is dependent on functional and structural adaptations in skeletal muscle, blood vessels, and heart. Cardiac adaptation includes increased ventricular chamber volumes and weights, cardiomyocyte hypertrophy, increased cardiac output, and improved contractile function measured in isolated cardiomyocytes and in the intact heart (2, 3).At present, there are few well-controlled endurance training studies in mice. Training is usually carried out as voluntary exercise regimens, with little control of exercise intensity and the individual's fitness level. Voluntary wheel running is most frequently used. V O 2 max has been shown to increase by 12-30% after a 7-to 12-wk period of free wheel running (11,40). The latter study also demonstrated a 6% decreased respiratory exchange ratio (RER) at V O 2 max in trained mice. Exercise capacity and adaptations have al...

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Section: Discussionsupporting

confidence: 67%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Intensity-controlled treadmill running in mice: cardiac and skeletal muscle hypertrophy

Kemi

Loennechen

Wisløff

et al. 2002

Journal of Applied Physiology

237

265

View full text Add to dashboard Cite

show abstract

“…Although the atherosclerotic lesions are progressive and may become severe, their functional effect on blood flow and physiology is largely unknown. Cardiovascular reserve relevant to exercise performance is reduced (Niebauer et al, 1999), and we have previously shown a 55% increase in aortic and mitral flow velocities and a 59% increase in heart-weight to body-weight ratio at 1 year of age (Hartley et al, 2000) consistent with volume overload hypertrophy. However, the effect and significance of systemic and coronary arterial lesions and of the cardiac hypertrophy on coronary blood flow and coronary flow reserve in ApoE −/− mice is unknown.…”

Section: Introductionmentioning

confidence: 71%

Effects of Isoflurane on Coronary Blood Flow Velocity in Young, Old and ApoE−/− Mice Measured by Doppler Ultrasound

Hartley

Reddy

Madala

et al. 2007

Ultrasound in Medicine & Biology

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The commonly used anesthetic agent, isoflurane (ISO), is a potent coronary vasodilator which could potentially be used in the assessment of coronary reserve, but its effects on coronary blood flow in mice are unknown. Coronary reserve is reduced by age, coronary artery disease, and other cardiac pathologies in man, and some of these conditions can now be modeled in mice. Accordingly, we used Doppler ultrasound to measure coronary flow velocity in mice anesthetized at low (1%) and at high (2.5%) levels of ISO to generate baseline (B) and elevated hyperemic (H) and Y and between A and O were significant (P < 0.01), while the differences in hyperemic velocities were not (P > 0.05). H/B was higher in old mice due to decreased baseline flow rather than increased hyperemic flow velocity. In contrast ApoE −/− mice have increased baseline and hyperemic velocities perhaps due to coronary lesions. The differences in baseline velocities between young and old mice could be due to age-related changes in basal metabolism or to differential sensitivity to isoflurane. We conclude that Doppler ultrasound combined with coronary vasodilation via isoflurane could provide a convenient and noninvasive method to estimate coronary reserve in mice, but also that care must be taken when assessing coronary flow in mice under isoflurane anesthesia because of its potent coronary vasodilator properties.

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The effect of exercise training on endothelial function in postmenopausal women with breast cancer under aromatase inhibitor therapy

et al. 2022

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Background: Breast cancer is the leading non-cardiovascular cause of death in women. In endocrine receptor positive women, aromatase inhibitors (AI) are the therapy of choice despite the fact that a decrease in systemic estrogen levels may result in endothelial dysfunction and eventually in cardiovascular disease. In this study, we assessed whether exercise training (ET), which has repeatedly shown to lead to an improvement of endothelial dysfunction, will also exert this effect in postmenopausal women with AI treated breast cancer. Methods: Thirty two postmenopausal women with AI treated breast cancer were randomized to an intervention group (ET; 6 months, supervised training plus 6 months without intervention) or control group of usual care (UC; 12 months without intervention plus initial exercise counseling). Endothelial function was assessed via Reactive Hyperemia Index (RHI) measured non-invasively with the EndoPAT-System at baseline, 6 and 12 months.Results: After 6 months of supervised ET, changes in maximal exercise capacity were significantly greater in ET than in UC (∆W: 24.1 ± 11.5 vs. 1.1 ± 8.2 watts; p < 0.001). Even though 43.8% of all participants had endothelial dysfunction at baseline, there were no significant group differences in the changes of RHI between ET (∆RHI: −0.1 ± 1.04) and UC (0.02 ± 0.75; p = 0.323) after 6 months. Conclusion:Even though ET led to significantly greater improvement in exercise capacity in postmenopausal women with AI treated breast cancer than exercise counseling only, it did not exert any measurable effects on endothelial dysfunction.

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Impaired aerobic capacity in hypercholesterolemic mice: partial reversal by exercise training

Cited by 64 publications

References 32 publications

Intensity-controlled treadmill running in mice: cardiac and skeletal muscle hypertrophy

Intensity-controlled treadmill running in mice: cardiac and skeletal muscle hypertrophy

Effects of Isoflurane on Coronary Blood Flow Velocity in Young, Old and ApoE−/− Mice Measured by Doppler Ultrasound

The effect of exercise training on endothelial function in postmenopausal women with breast cancer under aromatase inhibitor therapy

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