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Munkvik M, Christersson P, Øyane N, Alsnes IV. M. Munkvik og medarbeidere svarer. Tidsskr Nor Laegeforen 2023; 143:23-0455. [PMID: 37589353 DOI: 10.4045/tidsskr.23.0455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023] Open
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Munkvik M, Christersson P, Øyane N, Alsnes IV. Pasienttilpasset basistilskudd kan true fastlegeordningen. Tidsskr Nor Laegeforen 2023; 143:23-0345. [PMID: 37341414 DOI: 10.4045/tidsskr.23.0345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023] Open
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Munkvik M, Alsnes IV, Ørn S. New Deal for Norwegian medical training. Tidsskr Nor Laegeforen 2021; 141:21-0287. [PMID: 34107656 DOI: 10.4045/tidsskr.21.0287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Abstract
Objectives We aimed to describe the quality improvement measures made by Norwegian general practice (GP) during the COVID-19 pandemic, evaluate the differences in quality improvements based on region and assess the combinations of actions taken. Design Descriptive study. Setting Participants were included after taking part in an online quality improvement COVID-19 course for Norwegian GPs in April 2020. The participants reported whether internal and external measures were in place: COVID-19 sign on entrance, updated home page, access to video consultations and/or electronic written consultations, home office solutions, separate working teams, preparedness for home visits, isolation rooms, knowledge on decontamination, access to sufficient supplies of personal protective equipment (PPE) and COVID-19 clinics. Participants One hundred GP offices were included. The mean number of general practitioners per office was 5.63. Results More than 80% of practices had the following preparedness measures: COVID-19 sign on entrance, updated home page, COVID-19 clinic in the municipality, video and written electronic consultations, knowledge on how to use PPE, and home office solutions for general practitioners. Less than 50% had both PPE and knowledge of decontamination. Lack of PPE was reported by 37%, and 34% reported neither sufficient PPE nor a dedicated COVID-19 clinic. 15% reported that they had an isolation room, but not enough PPE. There were no geographical differences. Conclusions Norwegian GPs in this study implemented many quality improvements to adapt to the COVID-19 pandemic. Overall, the largest potentials for improvement seem to be securing sufficient supply of PPE and establishing an isolation room at their practices.
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Affiliation(s)
| | - Morten Munkvik
- Department of Public Health, University of Stavanger, Stavanger, Norway
| | - W Dana Flanders
- Department of Epidemiology, Emory University, Atlanta, Georgia, USA
| | - Nicolas Øyane
- Centre of Quality Improvement in Medical Practices, Bergen, Norway
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Munkvik M. Gammel hånd og andre nydiagnoser. Tidsskriftet 2020. [DOI: 10.4045/tidsskr.20.0971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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6
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Munkvik M. En lekmanns reiseskildring. Tidsskriftet 2020. [DOI: 10.4045/tidsskr.19.0827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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7
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Munkvik M. Framfor alt ikke feile. Tidsskriftet 2019. [DOI: 10.4045/tidsskr.19.0139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Hortemo KH, Lunde PK, Anonsen JH, Kvaløy H, Munkvik M, Rehn TA, Sjaastad I, Lunde IG, Aronsen JM, Sejersted OM. Exercise training increases protein O-GlcNAcylation in rat skeletal muscle. Physiol Rep 2016; 4:4/18/e12896. [PMID: 27664189 PMCID: PMC5037911 DOI: 10.14814/phy2.12896] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 07/19/2016] [Indexed: 11/24/2022] Open
Abstract
Protein O-GlcNAcylation has emerged as an important intracellular signaling system with both physiological and pathophysiological functions, but the role of protein O-GlcNAcylation in skeletal muscle remains elusive. In this study, we tested the hypothesis that protein O-GlcNAcylation is a dynamic signaling system in skeletal muscle in exercise and disease. Immunoblotting showed different protein O-GlcNAcylation pattern in the prototypical slow twitch soleus muscle compared to fast twitch EDL from rats, with greater O-GlcNAcylation level in soleus associated with higher expression of the modulating enzymes O-GlcNAc transferase (OGT), O-GlcNAcase (OGA), and glutamine fructose-6-phosphate amidotransferase isoforms 1 and 2 (GFAT1, GFAT2). Six weeks of exercise training by treadmill running, but not an acute exercise bout, increased protein O-GlcNAcylation in rat soleus and EDL There was a striking increase in O-GlcNAcylation of cytoplasmic proteins ~50 kDa in size that judged from mass spectrometry analysis could represent O-GlcNAcylation of one or more key metabolic enzymes. This suggests that cytoplasmic O-GlcNAc signaling is part of the training response. In contrast to exercise training, postinfarction heart failure (HF) in rats and humans did not affect skeletal muscle O-GlcNAcylation level, indicating that aberrant O-GlcNAcylation cannot explain the skeletal muscle dysfunction in HF Human skeletal muscle displayed extensive protein O-GlcNAcylation that by large mirrored the fiber-type-related O-GlcNAcylation pattern in rats, suggesting O-GlcNAcylation as an important signaling system also in human skeletal muscle.
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Affiliation(s)
- Kristin Halvorsen Hortemo
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Per Kristian Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | | | - Heidi Kvaløy
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Morten Munkvik
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Tommy Aune Rehn
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ida Gjervold Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Bjørknes College, Oslo, Norway
| | - Ole M Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway Center for Heart Failure Research, University of Oslo, Oslo, Norway
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9
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Hortemo KH, Munkvik M, Lunde PK, Sejersted OM. Multiple causes of fatigue during shortening contractions in rat slow twitch skeletal muscle. PLoS One 2013; 8:e71700. [PMID: 23977116 PMCID: PMC3745421 DOI: 10.1371/journal.pone.0071700] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/08/2013] [Indexed: 01/18/2023] Open
Abstract
Fatigue in muscles that shorten might have other causes than fatigue during isometric contractions, since both cross-bridge cycling and energy demand are different in the two exercise modes. While isometric contractions are extensively studied, the causes of fatigue in shortening contractions are poorly mapped. Here, we investigate fatigue mechanisms during shortening contractions in slow twitch skeletal muscle in near physiological conditions. Fatigue was induced in rat soleus muscles with maintained blood supply by in situ shortening contractions at 37°C. Muscles were stimulated repeatedly (1 s on/off at 30 Hz) for 15 min against a constant load, allowing the muscle to shorten and perform work. Fatigue and subsequent recovery was examined at 20 s, 100 s and 15 min exercise. The effects of prior exercise were investigated in a second exercise bout. Fatigue developed in three distinct phases. During the first 20 s the regulatory protein Myosin Light Chain-2 (slow isoform, MLC-2s) was rapidly dephosphorylated in parallel with reduced rate of force development and reduced shortening. In the second phase there was degradation of high-energy phosphates and accumulation of lactate, and these changes were related to slowing of muscle relengthening and relaxation, culminating at 100 s exercise. Slowing of relaxation was also associated with increased leak of calcium from the SR. During the third phase of exercise there was restoration of high-energy phosphates and elimination of lactate, and the slowing of relaxation disappeared, whereas dephosphorylation of MLC-2s and reduced shortening prevailed. Prior exercise improved relaxation parameters in a subsequent exercise bout, and we propose that this effect is a result of less accumulation of lactate due to more rapid onset of oxidative metabolism. The correlation between dephosphorylation of MLC-2s and reduced shortening was confirmed in various experimental settings, and we suggest MLC-2s as an important regulator of muscle shortening.
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Affiliation(s)
- Kristin Halvorsen Hortemo
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Cardiac Research Centre and Centre for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Morten Munkvik
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Cardiac Research Centre and Centre for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Per Kristian Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Cardiac Research Centre and Centre for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ole M. Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Cardiac Research Centre and Centre for Heart Failure Research, University of Oslo, Oslo, Norway
- * E-mail:
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Rehn TA, Munkvik M, Lunde PK, Sjaastad I, Sejersted OM. Intrinsic skeletal muscle alterations in chronic heart failure patients: a disease-specific myopathy or a result of deconditioning? Heart Fail Rev 2013; 17:421-36. [PMID: 21996779 DOI: 10.1007/s10741-011-9289-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Chronic heart failure (CHF) patients frequently experience impaired exercise tolerance due to skeletal muscle fatigue. Studies suggest that this in part is due to intrinsic alterations in skeletal muscle of CHF patients, often interpreted as a disease-specific myopathy. Knowledge about the mechanisms underlying these skeletal muscle alterations is of importance for the pathophysiological understanding of CHF, therapeutic approach and rehabilitation strategies. We here critically review the evidence for skeletal muscle alterations in CHF, the underlying mechanisms of such alterations and how skeletal muscle responds to training in this patient group. Skeletal muscle characteristics in CHF patients are very similar to what is reported in response to chronic obstructive pulmonary disease (COPD), detraining and deconditioning. Furthermore, skeletal muscle alterations observed in CHF patients are reversible by training, and skeletal muscle of CHF patients seems to be at least as trainable as that of matched controls. We argue that deconditioning is a major contributor to the skeletal muscle dysfunction in CHF patients and that further research is needed to determine whether, and to what extent, the intrinsic skeletal muscle alterations in CHF represent an integral part of the pathophysiology in this disease.
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Affiliation(s)
- T A Rehn
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevaal, Oslo, Norway.
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11
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Slettaløkken G, Rehn TA, Munkvik M, Rud B, Nymark BS, Lunde PK, Sjaastad I, Sejersted OM, Hallén J. Normal training response in skeletal muscle of post-infarction heart failure patients. Eur J Sport Sci 2013. [DOI: 10.1080/17461391.2011.624197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Sjåland C, Lunde PK, Swift F, Munkvik M, Ericsson M, Lunde M, Boye S, Christensen G, Ellingsen Ø, Sejersted OM, Andersson KB. Slowed relaxation and preserved maximal force in soleus muscles of mice with targeted disruption of the Serca2 gene in skeletal muscle. J Physiol 2011; 589:6139-55. [PMID: 21946846 DOI: 10.1113/jphysiol.2011.211987] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Sarcoplasmic reticulum Ca(2+) ATPases (SERCAs) play a major role in muscle contractility by pumping Ca(2+) from the cytosol into the sarcoplasmic reticulum (SR) Ca(2+) store, allowing muscle relaxation and refilling of the SR with releasable Ca(2+). Decreased SERCA function has been shown to result in impaired muscle function and disease in human and animal models. In this study, we present a new mouse model with targeted disruption of the Serca2 gene in skeletal muscle (skKO) to investigate the functional consequences of reduced SERCA2 expression in skeletal muscle. SkKO mice were viable and basic muscle structure was intact. SERCA2 abundance was reduced in multiple muscles, and by as much as 95% in soleus muscle, having the highest content of slow-twitch fibres (40%). The Ca(2+) uptake rate was significantly reduced in SR vesicles in total homogenates. We did not find any compensatory increase in SERCA1 or SERCA3 abundance, or altered expression of several other Ca(2+)-handling proteins. Ultrastructural analysis revealed generally well-preserved muscle morphology, but a reduced volume of the longitudinal SR. In contracting soleus muscle in vitro preparations, skKO muscles were able to fully relax, but with a significantly slowed relaxation time compared to controls. Surprisingly, the maximal force and contraction rate were preserved, suggesting that skKO slow-twitch fibres may be able to contribute to the total muscle force despite loss of SERCA2 protein. Thus it is possible that SERCA-independent mechanisms can contribute to muscle contractile function.
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Affiliation(s)
- Cecilie Sjåland
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, and University of Oslo, Oslo, Norway
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Munkvik M, Lunde PK, Aronsen JM, Birkeland JAK, Sjaastad I, Sejersted OM. Attenuated fatigue in slow twitch skeletal muscle during isotonic exercise in rats with chronic heart failure. PLoS One 2011; 6:e22695. [PMID: 21799933 PMCID: PMC3143175 DOI: 10.1371/journal.pone.0022695] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 07/04/2011] [Indexed: 01/08/2023] Open
Abstract
During isometric contractions, slow twitch soleus muscles (SOL) from rats with chronic heart failure (chf) are more fatigable than those of sham animals. However, a muscle normally shortens during activity and fatigue development is highly task dependent. Therefore, we examined the development of skeletal muscle fatigue during shortening (isotonic) contractions in chf and sham-operated rats. Six weeks following coronary artery ligation, infarcted animals were classified as failing (chf) if left ventricle end diastolic pressure was >15 mmHg. During isoflurane anaesthesia, SOL with intact blood supply was stimulated (1s on 1s off) at 30 Hz for 15 min and allowed to shorten isotonically against a constant afterload. Muscle temperature was maintained at 37°C. In resting muscle, maximum isometric force (F(max)) and the concentrations of ATP and CrP were not different in the two groups. During stimulation, F(max) and the concentrations declined in parallel sham and chf. Fatigue, which was evident as reduced shortening during stimulation, was also not different in the two groups. The isometric force decline was fitted to a bi-exponential decay equation. Both time constants increased transiently and returned to initial values after approximately 200 s of the fatigue protocol. This resulted in a transient rise in baseline tension between stimulations, although this effect which was less prominent in chf than sham. Myosin light chain 2s phosphorylation declined in both groups after 100 s of isotonic contractions, and remained at this level throughout 15 min of stimulation. In spite of higher energy demand during isotonic than isometric contractions, both shortening capacity and rate of isometric force decline were as well or better preserved in fatigued SOL from chf rats than in sham. This observation is in striking contrast to previous reports which have employed isometric contractions to induce fatigue.
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Affiliation(s)
- Morten Munkvik
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, Oslo, Norway
- Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Per Kristian Lunde
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, Oslo, Norway
- Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, Oslo, Norway
- Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jon Arne Kro Birkeland
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, Oslo, Norway
- Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, Oslo, Norway
- Center for Heart Failure Research, University of Oslo, Oslo, Norway
- Department of Cardiology, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Ole M. Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital, Ullevål, Oslo, Norway
- Center for Heart Failure Research, University of Oslo, Oslo, Norway
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Slettaløkken G, Rehn TA, Munkvik M, Rud B, Sökjer-Petersen M, Lunde PK, Sjaastad I, Sejersted OM, Hallén J. Preserved metabolic reserve capacity in skeletal muscle of post-infarction heart failure patients. Scand J Med Sci Sports 2010; 22:199-206. [PMID: 20874858 DOI: 10.1111/j.1600-0838.2010.01226.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It has been proposed that exercise capacity during whole body exercise in post-infarction congestive heart failure (CHF) patients is limited by skeletal muscle function. We therefore investigated the balance between cardiopulmonary and muscular metabolic capacity. CHF patients (n=8) and healthy subjects (HS, n=12) were included. Patients with coronary artery disease (CAD, n=8) were included as a control for medication. All subjects performed a stepwise incremental load test during bicycling (∼24 kg muscle mass), two-legged knee extensor (2-KE) exercise (∼4 kg muscle mass) and one-legged knee extensor (1-KE) exercise (∼2 kg muscle mass). Peak power and peak pulmonary oxygen uptake (VO(2peak) ) increased and muscle-specific VO(2peak) decreased with an increasing muscle mass involved in the exercise. Peak power and VO(2peak) were lower for CHF patients than HS, with values for CAD patients falling between CHF patients and HS. During bicycling, all groups utilized 24-29% of the muscle-specific VO(2peak) as measured during 1-KE exercise, with no difference between the groups. Hence, the muscle metabolic reserve capacity during whole body exercise is not different between CHF patients and HS, indicating that appropriately medicated and stable post-infarction CHF patients are not more limited by intrinsic skeletal muscle properties during whole body exercise than HS.
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Affiliation(s)
- G Slettaløkken
- Norwegian School of Sport Sciences (NSSS), Oslo, Norway.
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Munkvik M, Lunde PK, Sejersted OM. Causes of fatigue in slow-twitch rat skeletal muscle during dynamic activity. Am J Physiol Regul Integr Comp Physiol 2009; 297:R900-10. [PMID: 19625691 DOI: 10.1152/ajpregu.91043.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Skeletal muscle fatigue is most often studied in vitro at room temperature and is classically defined as a decline in maximum force production or power output, exclusively linked to repeated isometric contractions. However, most muscles shorten during normal use, and we propose that both the functional correlate of fatigue, as well as the fatigue mechanism, will be different during dynamic contractions compared with static contractions. Under isoflurane anesthesia, fatigue was induced in rat soleus muscles in situ by isotonic shortening contractions at 37 degrees C. Muscles were stimulated repeatedly for 1 s at 30 Hz every 2 s for a total of 15 min. The muscles were allowed to shorten isotonically against a load corresponding to one-third of maximal isometric force. Maximal unloaded shortening velocity (V(0)), maximum force production (F(max)), and isometric relaxation rate (-dF/dt) was reduced after 100 s but returned to almost initial values at the end of the stimulation protocol. Likewise, ATP and creatine phosphate (CrP) were reduced after 100 s, but the level of CrP was partially restored to initial values after 15 min. The rate of isometric force development, the velocity of shortening, and isotonic shortening were also reduced at 100 s, but in striking contrast, did not recover during the remainder of the stimulation protocol. The regulatory myosin light chain (MLC2s) was dephosphorylated after 100 s and did not recover. Although metabolic changes may account for the changes of F(max), -dF/dt, and V(0), dephosphorylation of MLC2s may be involved in the fatigue seen as sustained slower contraction velocities and decreased muscle shortening.
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Affiliation(s)
- Morten Munkvik
- Institute for Experimental Medical Research, Oslo Univ. Hospital, Ullevål, Kirkeveien 166, N-0407 Oslo, Norway.
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Rehn TA, Borge BA, Lunde PK, Munkvik M, Sneve ML, Grøndahl F, Aronsen JM, Sjaastad I, Prydz K, Kolset SO, Wiig H, Sejersted OM, Iversen PO. Temporary fatigue and altered extracellular matrix in skeletal muscle during progression of heart failure in rats. Am J Physiol Regul Integr Comp Physiol 2009; 297:R26-33. [PMID: 19339678 DOI: 10.1152/ajpregu.90617.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients with congestive heart failure (CHF) experience increased skeletal muscle fatigue. The mechanism underlying this phenomenon is unknown, but a deranged extracellular matrix (ECM) might be a contributing factor. Hence, we examined ECM components and regulators in a rat postinfarction model of CHF. At various time points during a 3.5 mo-period after induction of CHF in rats by left coronary artery ligation, blood, interstitial fluid (IF), and muscles were sampled. Isoflurane anesthesia was employed during all surgical procedures. IF was extracted by wicks inserted intermuscularly in a hind limb. We measured cytokines in plasma and IF, whereas matrix metalloproteinase (MMP) activity and collagen content, as well as the level of glycosaminoglycans and hyaluronan were determined in hind limb muscle. In vivo fatigue protocols of the soleus muscle were performed at 42 and 112 days after induction of heart failure. We found that the MMP activity and collagen content in the skeletal muscles increased significantly at 42 days after induction of CHF, and these changes were time related to increased skeletal muscle fatigability. These parameters returned to sham levels at 112 days. VEGF in IF was significantly lower in CHF compared with sham-operated rats at 3 and 10 days, but no difference was observed at 112 days. We conclude that temporary alterations in the ECM, possibly triggered by VEGF, are related to a transient development of skeletal muscle fatigue in CHF.
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Affiliation(s)
- Tommy A Rehn
- Institute for Experimental Medical Research, Oslo Univ. Hospital-Ullevaal, N-0407 Oslo, Norway.
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Munkvik M, Rehn TA, Hasic A, Slettaløkken G, Hallèn J, Sjaastad I, Sejersted OM, Lunde PK. Training Effects On Skeletal Muscle Calcium Handling In Chronic Heart Failure (CHF) Patients And Controls. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.1129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Hellund JC, Geitung JT, Meo AM, Angelsen JH, Munkvik M, Trondsen E, Buanes T. [Secretin stimulated magnetic resonance cholangiopancreatography in diseases of the biliary and pancreatic ducts]. Tidsskr Nor Laegeforen 2002; 122:691-4. [PMID: 11998731 DOI: pmid/11998731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND MRCP has replaced ERCP as the diagnostic tool in diseases in the biliary and pancreatic ducts. Secretin increases the secretion to ducts, and this has been reported to improve MRCP image quality. MATERIAL AND METHODS We report our experience with S-MRCP in our first 20 patients. Secretin was given intravenously and images were obtained every minute for 10 minutes. These images were compared with MRCP images taken before and after secretin stimulation. RESULTS New information was yielded in 18 cases, i.e. information not observed in previous radiological examinations. INTERPRETATION In diagnostics of dysfunction of the sphincter of Oddi, the method may be useful, given the functional aspect of the procedure where increased pressure in the ducts may lead to pain. It may further improve the diagnostics of pancreatic cancer versus pancreatitis, in pancreas divisum and sclerosing cholangitis. The method is also valuable for clarifying whether there is injury to the pancreatic duct after blunt abdominal trauma. Surgical common bile duct injuries may be better assessed than with any other method. In difficult pancreatic and biliary investigations, S-MRCP seems to be a useful and complication-free supplement to existing diagnostic methods.
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