The influence of food restriction on bone in young female rats with voluntary wheel running over 5 weeks

Evidence suggests that mitochondrial dysfunction and oxidant production, in association with an accumulation of oxidative damage, contribute to the aging process. Regular physical activity can delay the onset of morbidity, increase mean lifespan, and reduce the risk of developing several pathological states. No studies have examined age-related changes in oxidant production and oxidative stress in both subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria in combination with lifelong exercise. Therefore, we investigated whether long-term voluntary wheel running in Fischer 344 rats altered hydrogen peroxide (H2O2) production, antioxidant defenses, and oxidative damage in cardiac SSM and IFM. At 10–11 wk of age, rats were randomly assigned to one of two groups: sedentary and 8% food restriction (sedentary; n = 20) or wheel running and 8% food restriction (runners; n = 20); rats were killed at 24 mo of age. After the age of 6 mo, running activity was maintained at an average of 1,145 ± 248 m/day. Daily energy expenditure determined by doubly labeled water technique showed that runners expended on average ∼70% more energy per day than the sedentary rats. Long-term voluntary wheel running significantly reduced H2O2 production from both SSM (−10.0%) and IFM (−9.6%) and increased daily energy expenditure (kJ/day) significantly in runners compared with sedentary controls. Additionally, MnSOD activity was significantly lowered in SSM and IFM from wheel runners, which may reflect a reduction in mitochondrial superoxide production. Activities of the other major antioxidant enzymes (glutathione peroxidase and catalase) and glutathione levels were not altered by wheel running. Despite the reduction in mitochondrial oxidant production, no significant differences in oxidative stress levels (4-hydroxy-2-nonenal-modified proteins, protein carbonyls, and malondialdehyde) were detected between the two groups. The health benefits of chronic exercise may be, at least partially, due to a reduction in mitochondrial oxidant production; however, we could not detect a significant reduction in several selected parameters of oxidative stress.

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Comparison of changes in electrical activity, in isolated and in vivo hearts, induced by voluntary exercise in female rats

10.1101/2020.11.16.385021 ◽

2020 ◽

Author(s):

Rachel Stones ◽

Mark Drinkhill ◽

Ed White

Keyword(s):

Exercise Training ◽

Electrical Activity ◽

Wheel Running ◽

Left Ventricular ◽

Voluntary Exercise ◽

Female Rats ◽

Heart Weight ◽

Voluntary Wheel Running ◽

Voluntary Wheel

AbstractRegular mild exercise is recommended to the general population as beneficial to health. Regular exercise typically leads to structural and electrical remodelling of the heart but in human studies it is difficult to relate the extrinsic and intrinsic influences on intact hearts to changes seen at the single cell level. In this study we wished to test whether changes in electrical activity in intact hearts, in response to voluntary wheel running exercise training, were consistent with our previous observations in single cardiac myocytes and whether these changes resulted in altered susceptibility to arrhythmic stimuli.Female rats performed 5 weeks of voluntary wheel running. Implanted telemetry transmitters were used to measure electrocardiograms (ECGs) and determine heart rate variability (HRV) in conscious, unrestrained, trained (TRN) and sedentary (SED) animals. In isolated hearts, left ventricular epicardial monophasic action potentials (MAPs) were recorded and the responses to potentially arrhythmic interventions were assessed.Exercise training caused cardiac hypertrophy, as indexed by a significantly greater heart weight to body weight ratio. Consistent with previous measurements of action potential duration in single myocytes, MAPs were significantly longer at 50%, 75% and 90% repolarization. Arrhythmic susceptibility was not different between SED and TRN hearts. Trained animals displayed significantly altered HRV by week 5, in a manner consistent with reduced sympathetic tone, however resting ECG parameters, including those most associated with repolarisation duration, were unaltered. We conclude that intrinsic changes to cellular cardiac electrophysiology, induced by mild voluntary exercise, are not attenuated by the electronic loading that occurs in intact hearts. However, in vivo, extrinsic neuro-hormonal control of the heart may minimize the effects of intrinsic alterations in electrical activity.

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Interrelationship of CB1R and OBR pathways in regulation of metabolic, neuroendocrine, and behavioral responses to food restriction and voluntary wheel running

Journal of Applied Physiology ◽

10.1152/japplphysiol.01303.2013 ◽

2014 ◽

Vol 117 (2) ◽

pp. 97-104 ◽

Cited By ~ 3

Author(s):

Abdoulaye Diane ◽

Donna F. Vine ◽

James C. Russell ◽

C. Donald Heth ◽

W. David Pierce ◽

...

Keyword(s):

Physical Activity ◽

Body Weight ◽

Food Restriction ◽

Leptin Receptor ◽

Wheel Running ◽

Behavioral Responses ◽

Voluntary Wheel Running ◽

Cannabinoid 1 Receptor ◽

Clinical Measures ◽

Voluntary Wheel

We hypothesized the cannabinoid-1 receptor and leptin receptor (ObR) operate synergistically to modulate metabolic, neuroendocrine, and behavioral responses of animals exposed to a survival challenge (food restriction and wheel running). Obese-prone (OP) JCR:LA- cp rats, lacking functional ObR, and lean-prone (LP) JCR:LA- cp rats (intact ObR) were assigned to OP-C and LP-C (control) or CBR1-antagonized (SR141716, 10 mg/kg body wt in food) OP-A and LP-A groups. After 32 days, all rats were exposed to 1.5-h daily meals without the drug and 22.5-h voluntary wheel running, a survival challenge that normally culminates in activity-based anorexia (ABA). Rats were removed from the ABA protocol when body weight reached 75% of entry weight (starvation criterion) or after 14 days (survival criterion). LP-A rats starved faster (6.44 ± 0.24 days) than LP-C animals (8.00 ± 0.29 days); all OP rats survived the ABA challenge. LP-A rats lost weight faster than animals in all other groups ( P < 0.001). Consistent with the starvation results, LP-A rats increased the rate of wheel running more rapidly than LP-C rats ( P = 0.001), with no difference in hypothalamic and primary neural reward serotonin levels. In contrast, OP-A rats showed suppression of wheel running compared with the OP-C group ( days 6–14 of ABA challenge, P < 0.001) and decreased hypothalamic and neural reward serotonin levels ( P < 0.01). Thus there is an interrelationship between cannabinoid-1 receptor and ObR pathways in regulation of energy balance and physical activity. Effective clinical measures to prevent and treat a variety of disorders will require understanding of the mechanisms underlying these effects.

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Effects of Voluntary Wheel Running on Cardiac Function in Female Rats Receiving Chemical Ovariectomy

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000273104.40566.2d ◽

2007 ◽

Vol 39 (Supplement) ◽

pp. S53

Author(s):

David S. Hydock ◽

Chia-Ying Lien ◽

Carole M. Schneider ◽

Reid Hayward

Keyword(s):

Cardiac Function ◽

Wheel Running ◽

Female Rats ◽

Voluntary Wheel Running ◽

Voluntary Wheel

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Effects of Goserelin Acetate and Voluntary Wheel Running on Bone Morphology in Female Rats

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000321803.40381.d0 ◽

2008 ◽

Vol 40 (Supplement) ◽

pp. S82

Author(s):

Traci Parry ◽

David S. Hydock ◽

Urszula T. Iwaniec ◽

Russell T. Turner ◽

Chia-Ying Lien ◽

...

Keyword(s):

Wheel Running ◽

Female Rats ◽

Bone Morphology ◽

Voluntary Wheel Running ◽

Goserelin Acetate ◽

Voluntary Wheel

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Voluntary wheel running attenuates ethanol withdrawal-induced increases in seizure susceptibility in male and female rats

Pharmacology Biochemistry and Behavior ◽

10.1016/j.pbb.2012.07.012 ◽

2012 ◽

Vol 103 (1) ◽

pp. 18-25 ◽

Cited By ~ 10

Author(s):

Leslie L. Devaud ◽

Shawn A. Walls ◽

Walter D. McCulley ◽

Alan M. Rosenwasser

Keyword(s):

Wheel Running ◽

Ethanol Withdrawal ◽

Female Rats ◽

Seizure Susceptibility ◽

Voluntary Wheel Running ◽

Male And Female ◽

Male And Female Rats ◽

Voluntary Wheel

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Introduction Of A High-fat/sucrose Diet Modulates Voluntary Wheel Running Activity In Adult Female Rats

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000518089.56749.c4 ◽

2017 ◽

Vol 49 (5S) ◽

pp. 440

Author(s):

Jon-Philippe K. Hyatt ◽

Lindsay Caprio ◽

Elisa J. Bienenstock ◽

Jung A. Kim ◽

Gary E. McCall

Keyword(s):

Adult Female ◽

Wheel Running ◽

Female Rats ◽

High Fat ◽

Voluntary Wheel Running ◽

Running Activity ◽

Wheel Running Activity ◽

Sucrose Diet ◽

Voluntary Wheel

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Effects of voluntary wheel running on cardiac function and myosin heavy chain in chemically gonadectomized rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00801.2007 ◽

2007 ◽

Vol 293 (6) ◽

pp. H3254-H3264 ◽

Cited By ~ 27

Author(s):

David S. Hydock ◽

Chia-Ying Lien ◽

Carole M. Schneider ◽

Reid Hayward

Keyword(s):

Physical Activity ◽

Cardiac Function ◽

Myosin Heavy Chain ◽

Heavy Chain ◽

Cardiac Dysfunction ◽

Wheel Running ◽

Female Rats ◽

Voluntary Wheel Running ◽

Developed Pressure ◽

Voluntary Wheel

Reducing testosterone and estrogen levels with a luteinizing hormone-releasing hormone agonist such as Zoladex (i.e., chemical gonadectomy) is a common treatment for many prostate and breast cancer patients, respectively. There are reports of surgical gonadectomy inducing cardiac dysfunction, and exercise has been shown to be cardioprotective under these circumstances. Minimal research has been done investigating the effects of chemical gonadectomy and increased physical activity on cardiac function. The purpose of this investigation was to examine the effects of chemical gonadectomy and physical activity on cardiac function. Male (M) and female (F) Sprague-Dawley rats received either Zoladex treatment (Zol) that suppressed gonadal function for 8 wk or control implants (Con) and either were allowed unlimited access to voluntary running wheels (WR) or remained sedentary (Sed) throughout the treatment period. In vivo and ex vivo left ventricle (LV) function were then assessed, and myosin heavy chain (MHC) expression was analyzed to help explain LV functional differences. Hearts from M Sed+Zol exhibited significantly lower aortic blood flow velocity, developed pressure, and maximal rate of pressure development and higher β-MHC expression than M Sed+Con. Hearts from F Sed+Zol exhibited significantly lower LV wall thicknesses, fractional shortening, and developed pressure and higher β-MHC expression than F Sed+Con. This cardiac dysfunction was not evident in hearts from M or F WR+Zol, and this was associated with a preservation of the MHC isoform distribution. Thus an 8-wk chemical gonadectomy with Zoladex promoted cardiac dysfunction in male and female rats, and voluntary wheel running protected against this cardiac dysfunction.

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Preconditioning by voluntary wheel running attenuates later neuropathic pain via Nrf2 antioxidant signaling in rats

10.1101/2021.07.21.452532 ◽

2021 ◽

Author(s):

Suzanne M Green-Fulgham ◽

Michael E Harland ◽

Jayson B Ball ◽

Heather D'Angelo ◽

Renee A Dreher ◽

...

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Nerve Injury ◽

Nuclear Translocation ◽

Wheel Running ◽

Sciatic Nerve Injury ◽

Female Rats ◽

Voluntary Wheel Running ◽

Injury Site ◽

Voluntary Wheel

Animal and human studies have shown that exercise prior to nerve injury prevents later chronic pain, but the mechanisms of such preconditioning remain elusive. Given that exercise acutely increases formation of free radicals, triggering antioxidant compensation, we hypothesized that voluntary running preconditioning would attenuate neuropathic pain by supporting redox homeostasis after sciatic nerve injury in male and female rats. We show that 6 weeks of voluntary wheel running suppresses neuropathic pain development induced by chronic constriction injury (CCI) across both sexes. This protection was associated with reduced nitrotyrosine immunoreactivity-a marker for peroxynitrite-at the sciatic nerve injury site. Our data suggest that prior voluntary wheel running does not reduce production of peroxynitrite precursors, as expression levels of inducible nitric oxide synthase and NADPH oxidase 2 were unchanged. Instead, voluntary wheel running increased superoxide scavenging by elevating expression of superoxide dismutases 1 and 2. Prevention of neuropathic pain was further associated with activation of the master transcriptional regulator of the antioxidant response, nuclear factor E2-related factor 2 (Nrf2). Six weeks of prior voluntary wheel running increased Nrf2 nuclear translocation at the sciatic nerve injury site; in contrast, 3 weeks of prior wheel running, which failed to prevent neuropathic pain, had no effect on Nrf2 nuclear translocation. The protective effects of prior voluntary wheel running were mediated by Nrf2, as suppression was abolished across both sexes when Nrf2 activation was blocked during the running phase. This study provides insight into the mechanisms by which physical activity may prevent neuropathic pain.

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