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

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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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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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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