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Hentschke VS, Capalonga L, Rossato DD, Perini JL, Alves JP, Quagliotto E, Stefani GP, Karsten M, Pontes M, Dal Lago P. Functional capacity in a rat model of heart failure: impact of myocardial infarct size. Exp Physiol 2017; 102:1448-1458. [DOI: 10.1113/ep086076] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 08/21/2017] [Indexed: 01/09/2023]
Affiliation(s)
- Vítor Scotta Hentschke
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
- Programa de Pós-Graduação em Ciências da Saúde; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Lucas Capalonga
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Douglas Dalcin Rossato
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
- Centro Universitário Franciscano (UNIFRA); Santa Maria Rio Grande do Sul Brazil
| | - Júlia Luíza Perini
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Jadson Pereira Alves
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
- Programa de Pós-Graduação em Ciências da Saúde; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Edson Quagliotto
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Giuseppe Potrick Stefani
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
- Programa de Pós-Graduação em Ciências da Saúde; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Marlus Karsten
- Departamento de Fisioterapia; Universidade do Estado de Santa Catarina (UDESC); Florianópolis Santa Catarina Brazil
| | - Mauro Pontes
- Departamento de Farmacociências; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
| | - Pedro Dal Lago
- Laboratório de Fisiologia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
- Departamento de Fisioterapia; Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre Rio Grande do Sul Brazil
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Maximal oxygen uptake and exercise tolerance are improved in rats with heart failure subjected to low-level laser therapy associated with resistance training. Lasers Med Sci 2016; 32:73-85. [PMID: 27858257 DOI: 10.1007/s10103-016-2088-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/27/2016] [Indexed: 12/19/2022]
Abstract
Exercise tolerance and maximal oxygen uptake (VO2max) are reduced in heart failure (HF). The influence of combined resistance training (RT) and low-level laser therapy (LLLT) on exercise tolerance and VO2max in HF has not yet been explored. The aim of this study was to evaluate the influence of combined RT and LLLT on VO2max and exercise tolerance in rats with HF induced by myocardial infarction (MI). Rats were allocated to sedentary sham (Sed-Sham, n = 12), sedentary heart failure (Sed-HF, n = 9), RT heart failure (RT-HF, n = 7) and RT associated with LLLT heart failure (RT + LLLT-HF, n = 7) groups. After MI or sham surgery, rats underwent a RT and LLLT protocol (applied immediately after RT) for 8 weeks. VO2max and exercise tolerance were evaluated at the end of protocol. HF rats subjected to LLLT combined with RT showed higher VO2basal (41 %), VO2max (40 %), VO2reserve (39 %), run distance (46 %), time to exhaustion (30 %) and maximal velocity (22 %) compared with HF rats that underwent RT alone. LLLT associated with RT improved oxygen uptake and exercise tolerance compared with RT alone in HF rats.
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Lima JW, Hentschke VS, Rossato DD, Quagliotto E, Pinheiro L, Almeida E, Dal Lago P, Lukrafka JL. Chronic electroacupuncture of the ST36 point improves baroreflex function and haemodynamic parameters in heart failure rats. Auton Neurosci 2015; 193:31-7. [PMID: 26032957 DOI: 10.1016/j.autneu.2015.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 04/28/2015] [Accepted: 05/05/2015] [Indexed: 12/20/2022]
Abstract
Electroacupuncture (EA) has been used to treat many diseases, including heart failure (HF). This study aimed to evaluate the effects of chronic stimulation in the ST36 acupuncture point on haemodynamic parameters and baroreflex function in rats with HF. Cardiovascular parameters assessed were heart rate (HR), blood pressure (BP), and the reflex cardiovascular response of HR triggered by stimulation of baroreceptors in animals with HF subsequent to acute myocardial infarction (AMI). Male Wistar rats were divided into three groups: Sham Control - animals without HF and without EA; HF Control group - animals with HF and without EA; and HF EA group - animals with HF that received the EA protocol. Six weeks after surgical induction of AMI, the EA protocol (8 weeks, 5 times a week) was performed. The protocol was applied with EA at the ST36 point, frequency of 2 Hz, pulse of 0.3 ms and intensity of 1-3 mA for 30 min. Haemodynamic parameters and baroreceptor function were assessed. There was no difference between groups in the variables HR, systolic blood pressure (SBP) and diastolic blood pressure (DBP), which were evaluated with awake animals (p>0.05). There was an increase in the mean arterial pressure (MAP) in the HF EA group compared to the HF Control group (p<0.05). The maximum gain of the baroreflex heart rate response (Gain) was higher in the HF EA group than the HF Control and Sham Control groups. Chronic EA in the ST36 point increased the MAP and baroreflex sensitivity in rats with HF.
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Affiliation(s)
- J W Lima
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - V S Hentschke
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - D D Rossato
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil; Centro Universitário Franciscano, Brazil
| | - E Quagliotto
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - L Pinheiro
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - E Almeida
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - P Dal Lago
- Physiology Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil; Department of Physical Therapy, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - J L Lukrafka
- Department of Physical Therapy, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil.
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Alves JP, Nunes RB, Stefani GP, Dal Lago P. Resistance training improves hemodynamic function, collagen deposition and inflammatory profiles: experimental model of heart failure. PLoS One 2014; 9:e110317. [PMID: 25340545 PMCID: PMC4207701 DOI: 10.1371/journal.pone.0110317] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 09/21/2014] [Indexed: 11/30/2022] Open
Abstract
The role of resistance training on collagen deposition, the inflammatory profile and muscle weakness in heart failure remains unclear. Therefore, this study evaluated the influence of a resistance training program on hemodynamic function, maximum strength gain, collagen deposition and inflammatory profile in chronic heart failure rats. Thirty-two male Wistar rats submitted to myocardial infarction by coronary artery ligation or sham surgery were assigned into four groups: sedentary sham (S-Sham, n = 8); trained sham (T-Sham, n = 8); sedentary chronic heart failure (S-CHF, n = 8) and trained chronic heart failure (T-CHF, n = 8). The maximum strength capacity was evaluated by the one maximum repetition test. Trained groups were submitted to an 8-week resistance training program (4 days/week, 4 sets of 10-12 repetitions/session, at 65% to 75% of one maximum repetition). After 8 weeks of the resistance training program, the T-CHF group showed lower left ventricular end diastolic pressure (P<0.001), higher left ventricular systolic pressure (P<0.05), higher systolic blood pressure (P<0.05), an improvement in the maximal positive derivative of ventricular pressure (P<0.05) and maximal negative derivative of ventricular pressure (P<0.05) when compared to the S-CHF group; no differences were observed when compared to Sham groups. In addition, resistance training was able to reduce myocardial hypertrophy (P<0.05), left ventricular total collagen volume fraction (P<0.01), IL-6 (P<0.05), and TNF-α/IL-10 ratio (P<0.05), as well as increasing IL-10 (P<0.05) in chronic heart failure rats when compared to the S-CHF group. Eight weeks of resistance training promotes an improvement of cardiac function, strength gain, collagen deposition and inflammatory profile in chronic heart failure rats.
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Affiliation(s)
- Jadson P. Alves
- Laboratory of Physiology, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Ramiro B. Nunes
- Laboratory of Physiology, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Giuseppe P. Stefani
- Laboratory of Physiology, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Pedro Dal Lago
- Laboratory of Physiology, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Rio Grande do Sul, Brazil
- Department of Physical Therapy, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Rio Grande do Sul, Brazil
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Nunes RB, Alves JP, Kessler LP, Dal Lago P. Aerobic exercise improves the inflammatory profile correlated with cardiac remodeling and function in chronic heart failure rats. Clinics (Sao Paulo) 2013; 68:876-82. [PMID: 23778495 PMCID: PMC3674304 DOI: 10.6061/clinics/2013(06)24] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 02/25/2013] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The aim of the present study was to evaluate the effect of 8 weeks of aerobic exercise training on cardiac functioning and remodeling and on the plasma levels of inflammatory cytokines in chronic heart failure rats. METHODS Wistar rats were subjected to myocardial infarction or sham surgery and assigned to 4 groups: chronic heart failure trained (n=7), chronic heart failure sedentary (n=6), sham trained (n=8) and sham sedentary (n=8). Four weeks after the surgical procedures, the rats were subjected to aerobic training in the form of treadmill running (50 min/day, 5 times per week, 16 m/min). At the end of 8 weeks, the rats were placed under anesthesia, the hemodynamic variables were recorded and blood samples were collected. Cardiac hypertrophy was evaluated using the left ventricular weight/body weight ratio, and the collagen volume fraction was assessed using histology. RESULTS The chronic heart failure trained group showed a reduction in left ventricular end-diastolic pressure, a lower left ventricular weight/body weight ratio and a lower collagen volume fraction compared with the chronic heart failure sedentary group. In addition, exercise training reduced the plasma levels of TNF-α and IL-6 and increased the plasma level of IL-10. CONCLUSION An 8-week aerobic exercise training program improved the inflammatory profile and cardiac function and attenuated cardiac remodeling in chronic heart failure rats.
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Affiliation(s)
- Ramiro B Nunes
- Universidade Federal de Ciências da Saúde de Porto Alegre, Laboratory of Physiology, Porto Alegre/RS, Brazil
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Green HJ, Burnett ME, D'Arsigny CL, Webb KA, McBride I, Ouyang J, O'Donnell DE. Vastus lateralis NA+-K+-ATpase activity, protein, and isoform distribution in chronic obstructive pulmonary disease. Muscle Nerve 2009; 40:62-8. [DOI: 10.1002/mus.21296] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nunes RB, Tonetto M, Machado N, Chazan M, Heck TG, Veiga ABG, Dall'Ago P. Physical exercise improves plasmatic levels of IL-10, left ventricular end-diastolic pressure, and muscle lipid peroxidation in chronic heart failure rats. J Appl Physiol (1985) 2008; 104:1641-7. [DOI: 10.1152/japplphysiol.00062.2008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Chronic heart failure (CHF) is characterized by left ventricular dysfunction, resulting in hemodynamic changes, sustained inflammatory state, as well as increase in oxidative stress. Physical exercise has been described as an important nonpharmacological procedure in the treatment of CHF, contributing to the improvement of the clinical outcomes in this disease. This study evaluated the effects of physical training on hemodynamics, muscle lipid peroxidation, and plasmatic levels of IL-10 in CHF rats. The left coronary artery was ligated to induce CHF, or sham operation was performed in control groups. Rats were assigned to one of four groups: trained CHF (T-CHF, n = 10), sedentary CHF (S-CHF, n = 10), trained sham (T-Sham, n = 10), or sedentary sham (S-Sham, n = 10). Trained animals had carried out a swimming protocol, 60 min/day, 5 days/wk, during 8 wk, whereas sedentary animals remained without training. Eight weeks of physical training promoted an improvement of diastolic function represented by a reduction of the left ventricular end-diastolic pressure in the T-CHF group compared with the S-CHF group ( P < 0.05). Lipid peroxidation evaluated in gastrocnemius muscle using thiobarbituric acid reactive substance assay was higher in the S-CHF group compared with all other groups ( P < 0.05). However, there were no differences between T-CHF compared with S-Sham and T-Sham groups. The plasmatic levels of IL-10 were lower in the S-CHF group compared with all other groups ( P < 0.05). These findings demonstrate that regular physical training using a swimming protocol, with duration of 8 wk, improves the cardiac function and the anti-inflammatory response and reduces muscle cellular damage.
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Regulation of the Na,K-ATPase: Special implications for cardiovascular complications of metabolic syndrome. PATHOPHYSIOLOGY 2007; 14:153-8. [DOI: 10.1016/j.pathophys.2007.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Li J, Gao Z, Kehoe V, Sinoway LI. Interstitial K+ concentration in active muscle after myocardial infarction. Am J Physiol Heart Circ Physiol 2006; 292:H808-13. [PMID: 17012361 PMCID: PMC2291533 DOI: 10.1152/ajpheart.00295.2006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous work demonstrated that Na(+)-K(+) pump activity within skeletal muscle is attenuated in myocardial infarction (MI). This may lead to enhanced interstitial K(+) concentration ([K(+)](o)) in the muscle. We tested the hypothesis that [K(+)](o) rises with muscle contraction and that, in rats with MI, the rate of rise in [K(+)](o) is greater than it is in control animals. Microdialysis probes were inserted in the skeletal muscle of six healthy control and six MI rats. The ends of the probes were then attached to the K(+) electrodes, and [K(+)](o) was continuously measured. Muscle contraction was induced by electrical stimulation of the sciatic nerves for 1 min. Stimulation at 1 and 3 Hz increased muscle [K(+)](o) by 14.2% and 44.7% in controls and by 22.9% and 62.8% in MI rats (P < 0.05 vs. controls), respectively. When ouabain, an inhibitor of Na(+)-K(+) pump, was added to the perfusate, muscle [K(+)](o) rose significantly. This effect of ouabain was significantly attenuated in MI animals. In conclusion, when compared with that in control animals, an increase of [K(+)](o) in exercising muscle is augmented in MI rats, likely due to an attenuation of Na(+)-K(+) pump activity.
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Affiliation(s)
- Jianhua Li
- Division of Cardiology, Pennsylvania State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA.
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Rush JWE, Green HJ, Maclean DA, Code LM. Oxidative stress and nitric oxide synthase in skeletal muscles of rats with post-infarction, compensated chronic heart failure. ACTA ACUST UNITED AC 2005; 185:211-8. [PMID: 16218926 DOI: 10.1111/j.1365-201x.2005.01479.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Involvement of oxidative stress and nitric oxide synthase (NOS) isoforms in skeletal muscle cellular adaptations to chronic heart failure (CHF) is controversial, and possible muscle fibre-type heterogeneity in the oxidative stress and NOS responses to CHF have not been examined. Consequently, we hypothesized that the changes in determinants of elevated oxidative and nitrosylative stress associated with CHF would occur in skeletal muscle and would be similar in predominantly type I slow twitch muscle (soleus) and type II fast twitch muscle (plantaris) of rats. METHODS The purpose of this study was to measure NOS isoforms (endothelial, inducible and neuronal NOS) and antioxidant enzymes (SOD-1, SOD-2, catalase) by protein immunoblot as well as markers of oxidative stress by biochemical assays in soleus and plantaris muscle sections of the rat hind limb. This was performed for control and post-infarction, compensated CHF rats. RESULTS Twelve weeks after coronary artery ligation-induced moderate CHF, soleus exhibited decreased SOD-1, SOD-2 and eNOS, but increased iNOS and nNOS isoforms assessed by immunoblot. This was associated with elevated lipid and DNA oxidative damage assessed by biochemical assays. In contrast, plantaris muscle exhibited no changes in antioxidant enzymes or NOS isoforms, and had lower lipid and DNA oxidative damage. CONCLUSION These observations suggest a heretofore unreported muscle fibre-type-specific response of oxidative stress and NOS isoforms to CHF is of importance in understanding the cellular mechanisms of skeletal muscle dysfunction in CHF.
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MESH Headings
- Adaptation, Physiological
- Animals
- DNA Damage
- Glutathione/blood
- Heart Failure/metabolism
- Heart Failure/pathology
- Heart Failure/physiopathology
- Immunoblotting
- Lipid Peroxidation
- Male
- Muscle Fibers, Fast-Twitch/enzymology
- Muscle Fibers, Fast-Twitch/pathology
- Muscle Fibers, Skeletal/enzymology
- Muscle Fibers, Skeletal/pathology
- Muscle Fibers, Slow-Twitch/enzymology
- Muscle Fibers, Slow-Twitch/pathology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Myocardial Infarction/enzymology
- Myocardial Infarction/pathology
- Myocardial Infarction/physiopathology
- Nitric Oxide Synthase/analysis
- Oxidative Stress
- Peptidyl-Dipeptidase A/analysis
- Peptidyl-Dipeptidase A/metabolism
- Rats
- Rats, Sprague-Dawley
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Affiliation(s)
- J W E Rush
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
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Barr DJ, Green HJ, Lounsbury DS, Rush JWE, Ouyang J. Na+-K+-ATPase properties in rat heart and skeletal muscle 3 mo after coronary artery ligation. J Appl Physiol (1985) 2005; 99:656-64. [PMID: 15817721 DOI: 10.1152/japplphysiol.00343.2004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
This study was designed to determine whether chronic heart failure (CHF) results in changes in Na(+)-K(+)-ATPase properties in heart and skeletal muscles of different fiber-type composition. Adult rats were randomly assigned to a control (Con; n = 8) or CHF (n = 8) group. CHF was induced by ligation of the left main coronary artery. Examination of Na(+)-K(+)-ATPase activity (means +/- SE) 12 wk after the ligation measured, using the 3-O-methylfluorescein phosphatase assay (3-O-MFPase), indicated higher (P < 0.05) levels in soleus (Sol) (250 +/- 13 vs. 179 +/- 18 nmol.mg protein(-1).h(-1)) and lower (P < 0.05) levels in diaphragm (Dia) (200 +/- 12 vs. 272 +/- 27 nmol.mg protein(-1).h(-1)) and left ventricle (LV) (760 +/- 62 vs. 992 +/- 16 nmol.mg protein(-1).h(-1)) in CHF compared with Con, respectively. Na(+)-K(+)-ATPase protein content, measured by the [(3)H]ouabain binding technique, was higher (P < 0.05) in white gastrocnemius (WG) (166 +/- 12 vs. 135 +/- 7.6 pmol/g wet wt) and lower (P < 0.05) in Sol (193 +/- 20 vs. 260 +/- 8.6 pmol/g wet wt) and LV (159 +/- 10 vs. 221 +/- 10 pmol/g wet wt) in CHF compared with Con, respectively. Isoform content in CHF, measured by Western blot techniques, showed both increases (WG; P < 0.05) and decreases (Sol; P < 0.05) in alpha(1). For alpha(2), only increases [red gastrocnemius (RG), Sol, and Dia; P < 0.05] occurred. The beta(2)-isoform was decreased (LV, Sol, RG, and WG; P < 0.05) in CHF, whereas the beta(1) was both increased (WG and Dia; P < 0.05) and decreased (Sol and LV; P < 0.05). For beta(3), decreases (P < 0.05) in RG were observed in CHF, whereas no differences were found in Sol and WG between CHF and Con. It is concluded that CHF results in alterations in Na(+)-K(+)-ATPase that are muscle specific and property specific. Although decreases in Na(+)-K(+)-ATPase content would appear to explain the lower 3-O-MFPase in the LV, such does not appear to be the case in skeletal muscles where a dissociation between these properties was observed.
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Affiliation(s)
- D J Barr
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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Eklund KE, Hageman KS, Poole DC, Musch TI. Impact of aging on muscle blood flow in chronic heart failure. J Appl Physiol (1985) 2005; 99:505-14. [PMID: 15802367 DOI: 10.1152/japplphysiol.00896.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic heart failure (CHF) is manifested principally in the elderly population. Therefore, to understand the causes of exercise intolerance in CHF patients, it is imperative to resolve the effects of aging on muscle blood flow (BF) in CHF. To address this issue, we determined the muscle BF response to submaximal treadmill exercise (20 m/min, 5% grade) in young (Y(CHF): 6-8 mo, 412 +/- 11 g, n = 11) and old (O(CHF): 27-29 mo, 494 +/- 10 g, n = 8) Fischer 344 x Brown Norway rats with similar degrees of myocardial infarction-induced left ventricular (LV) dysfunction [resting LV end-diastolic pressure: Y(CHF) = 24 +/- 2, O(CHF) = 22 +/- 2 mmHg; derivative of LV pressure over time: Y(CHF) = 5,168 +/- 285; O(CHF) = 5,050 +/- 165 mmHg/s; lung weight normalized to body weight: Y(CHF) = 9.14 +/- 0.72; O(CHF) = 8.21 +/- 0.29 mg/g (all P > 0.05)]. The exercising heart rate response was blunted in O(CHF) compared with Y(CHF) rats (Y(CHF) = 454 +/- 8, O(CHF) = 395 +/- 9 beats/min; P < 0.05). BF (radiolabeled microspheres) to the total hindlimb musculature and to each of the 28 individual muscles examined was similar between Y(CHF) and O(CHF) rats under resting conditions. During exercise, BF to five of the hindlimb muscles that normally possess a majority of slow-twitch oxidative and fast-twitch oxidative glycolytic muscle fibers increased significantly less (-25 to -42%) for O(CHF) compared with Y(CHF) rats. In contrast, BF to 14 of the hindlimb muscles that normally possess a majority of fast-twitch glycolytic muscle fibers was increased (+22 to +337%) for O(CHF) vs. Y(CHF) rats, which contributed to a greater mass-specific total hindlimb BF response in O(CHF) rats (Y(CHF) = 78 +/- 5, O(CHF) = 100 +/- 11 ml.min(-1).100 g(-1); P < 0.05) and coincided with greater reductions in BF to the kidneys and splanchnic organs during exercise in O(CHF) vs. Y(CHF). In conclusion, there appears to be a profound age-related redistribution of BF from the highly oxidative to the highly glycolytic muscles of the hindlimb during exercise in O(CHF) compared with Y(CHF) rats. This phenomenon is qualitatively similar to that reported previously for healthy young and old rats.
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Affiliation(s)
- Kevin E Eklund
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, 128 Coles Hall, 1600 Denison Avenue, Manhattan, KS 66505-5802, USA
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Abstract
A failure in membrane excitability, defined as an inability of the sarcolemma and T-tubule to translate the neural discharge command into repetitive action potentials, represents an inviting cause of mechanical disfunction in both health and disease. A failure at this level would precipitate a disturbance in signal transmission between the T-tubule and the calcium release channels of the sarcoplasmic reticulum, resulting in reduced release of Ca2+, lower cytosolic free Ca2+ levels, and depressed myofibrillar activation and force generation. The ability of the sarcolemma and T-tubules to conduct repetitive action potentials is intimately dependent on active transport of Na+ and K+ following an action potential. The active transport of these cations is mediated by the Na+-K+-ATPase, an integral membrane protein that uses the energy from the hydrolysis of 1 ATP to transport 3 Na+ out of the cell and 2 K+ into the cell. A failure to recruit sufficient Na+-K+-ATPase activity during contractile activity could result in a rundown of the transmembrane gradients for Na+ and K+, leading to a loss of membrane excitability. The Na+-K+-ATPase activity depends on the amount and isoform composition of the protein, substrate availability, and acute regulatory factors. Each of these factors is examined as a potential cause of altered activation of the Na+-K+-ATPase activity and loss of membrane excitability in fatigue. Regular exercise represents a potent stimulus for upregulating Na+-K+-ATPase levels and for increasing the ability for cation transport across the sarcolemma and T-tubule membrane. As such, training may be a valuable tool in the management of fatigue in health and disease.
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Affiliation(s)
- Howard J Green
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario
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McDonough P, Behnke BJ, Musch TI, Poole DC. Effects of chronic heart failure in rats on the recovery of microvascular PO2 after contractions in muscles of opposing fibre type. Exp Physiol 2004; 89:473-85. [PMID: 15131070 DOI: 10.1113/expphysiol.2004.027367] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic heart failure (CHF) impairs muscle O2 delivery (QO2) and, at a given O2 uptake (VO2), lowers microvascular O2 pressures (PmvO2: determined by the QO2-to-VO2 ratio), which may impair recovery of high-energy phosphates following exercise. Because CHF preferentially decreases QO2 to slow-twitch muscles, we hypothesized that recovery PmvO2 kinetics would be slowed to a greater extent in soleus (SOL: approximately 84% type I fibres) than in peroneal (PER: approximately 14% type I) muscles of CHF rats. PmvO2 dynamics were determined in SOL and PER muscles of control (CON: n= 6; left ventricular end-diastolic pressure, LVEDP: approximately 3 mmHg), moderate CHF (MOD: n= 7; LVEDP: approximately 11 mmHg) and severe CHF (SEV: n= 4; LVEDP: approximately 25 mmHg) following cessation of electrical stimulation (180 s; 1 Hz). In PER, neither the recovery PmvO2 values nor the mean response time (MRT; a weighted average of the time to 63% of the overall response) were altered by CHF (CON: 66.8 +/- 8.0, MOD: 72.4 +/- 11.8, SEV: 69.1 +/- 9.5 s). In marked contrast, SOL PmvO2, at recovery onset, was reduced significantly in the SEV group ( approximately 6 Torr) and PmvO2 MRT was slowed with increased severity of CHF (CON: 45.1 +/- 5.3, MOD: 63.2 +/- 9.4, SEV: 82.6 +/- 12.3 s; P < 0.05 CON vs. MOD and SEV). These data indicate that CHF slows PmvO2 recovery following contractions and lowers capillary O2 driving pressure in slow-twitch SOL, but not in fast-twitch PER muscle. These results may explain, in part, the slowed recovery kinetics (phosphocreatine and VO2) and pronounced fatigue following muscular work in CHF patients.
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Affiliation(s)
- Paul McDonough
- Departments of Anatomy, Physiology and Kinesiology, 129 Coles Hall, Kansas State University, Manhattan, KS 66506-5802, USA
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Abstract
Clausen, Torben. Na+-K+ Pump Regulation and Skeletal Muscle Contractility. Physiol Rev 83: 1269-1324, 2003; 10.1152/physrev.00011.2003.—In skeletal muscle, excitation may cause loss of K+, increased extracellular K+ ([K+]o), intracellular Na+ ([Na+]i), and depolarization. Since these events interfere with excitability, the processes of excitation can be self-limiting. During work, therefore, the impending loss of excitability has to be counterbalanced by prompt restoration of Na+-K+ gradients. Since this is the major function of the Na+-K+ pumps, it is crucial that their activity and capacity are adequate. This is achieved in two ways: 1) by acute activation of the Na+-K+ pumps and 2) by long-term regulation of Na+-K+ pump content or capacity. 1) Depending on frequency of stimulation, excitation may activate up to all of the Na+-K+ pumps available within 10 s, causing up to 22-fold increase in Na+ efflux. Activation of the Na+-K+ pumps by hormones is slower and less pronounced. When muscles are inhibited by high [K+]o or low [Na+]o, acute hormone- or excitation-induced activation of the Na+-K+ pumps can restore excitability and contractile force in 10-20 min. Conversely, inhibition of the Na+-K+ pumps by ouabain leads to progressive loss of contractility and endurance. 2) Na+-K+ pump content is upregulated by training, thyroid hormones, insulin, glucocorticoids, and K+ overload. Downregulation is seen during immobilization, K+ deficiency, hypoxia, heart failure, hypothyroidism, starvation, diabetes, alcoholism, myotonic dystrophy, and McArdle disease. Reduced Na+-K+ pump content leads to loss of contractility and endurance, possibly contributing to the fatigue associated with several of these conditions. Increasing excitation-induced Na+ influx by augmenting the open-time or the content of Na+ channels reduces contractile endurance. Excitability and contractility depend on the ratio between passive Na+-K+ leaks and Na+-K+ pump activity, the passive leaks often playing a dominant role. The Na+-K+ pump is a central target for regulation of Na+-K+ distribution and excitability, essential for second-to-second ongoing maintenance of excitability during work.
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Affiliation(s)
- Torben Clausen
- Department of Physiology, University of Aarhus, Arhus, Denmark.
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Helwig B, Schreurs KM, Hansen J, Hageman KS, Zbreski MG, McAllister RM, Mitchell KE, Musch TI. Training-induced changes in skeletal muscle Na+-K+ pump number and isoform expression in rats with chronic heart failure. J Appl Physiol (1985) 2003; 94:2225-36. [PMID: 12562669 DOI: 10.1152/japplphysiol.00279.2002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanisms responsible for the decrements in exercise performance in chronic heart failure (CHF) remain poorly understood, but it has been suggested that sarcolemmal alterations could contribute to the early onset of muscular fatigue. Previously, our laboratory demonstrated that the maximal number of ouabain binding sites (B(max)) is reduced in the skeletal muscle of rats with CHF (Musch TI, Wolfram S, Hageman KS, and Pickar JG. J Appl Physiol 92: 2326-2334, 2002). These reductions may coincide with changes in the Na(+)-K(+)-ATPase isoform (alpha and beta) expression. In the present study, we tested the hypothesis that reductions in B(max) would coincide with alterations in the alpha- and beta-subunit expression of the sarcolemmal Na(+)-K(+)-ATPase of rats with CHF. Moreover, we tested the hypothesis that exercise training would increase B(max) along with producing significant changes in alpha- and beta-subunit expression. Rats underwent a sham operation (sham; n = 10) or a surgically induced myocardial infarction followed by random assignment to either a control (MI; n = 16) or exercise training group (MI-T; n = 16). The MI-T rats performed exercise training (ET) for 6-8 wk. Hemodynamic indexes demonstrated that MI and MI-T rats suffered from severe left ventricular dysfunction and congestive CHF. Maximal oxygen uptake (Vo(2 max)) and endurance capacity (run time to fatigue) were reduced in MI rats compared with sham. B(max) in the soleus and plantaris muscles and the expression of the alpha(2)-isoform of the Na(+)-K(+)-ATPase in the red portion of the gastrocnemius (gastrocnemius(red)) muscle were reduced in MI rats. After ET, Vo(2 max) and run time to fatigue were increased in the MI-T group of rats. This coincided with increases in soleus and plantaris B(max) and the expression of the alpha(2)-isoform in the gastrocnemius(red) muscle. In addition, the expression of the beta(2)-isoform of the gastrocnemius(red) muscle was increased in the MI-T rats compared with their sedentary counterparts. This study demonstrates that CHF-induced alterations in skeletal muscle Na(+)-K(+)-ATPase, including B(max) and isoform expression, can be partially reversed by ET.
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Affiliation(s)
- Bryan Helwig
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506-5802, USA
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