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Mikłosz A, Łukaszuk B, Chabowski A, Górski J. Treadmill Running Changes Endothelial Lipase Expression: Insights from Gene and Protein Analysis in Various Striated Muscle Tissues and Serum. Biomolecules 2021; 11:biom11060906. [PMID: 34204548 PMCID: PMC8234415 DOI: 10.3390/biom11060906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/04/2021] [Accepted: 06/16/2021] [Indexed: 11/16/2022] Open
Abstract
Endothelial lipase (EL) is an enzyme capable of HDL phospholipids hydrolysis. Its action leads to a reduction in the serum high-density lipoprotein concentration, and thus, it exerts a pro-atherogenic effect. This study examines the impact of a single bout exercise on the gene and protein expression of the EL in skeletal muscles composed of different fiber types (the soleus—mainly type I, the red gastrocnemius—mostly IIA, and the white gastrocnemius—predominantly IIX fibers), as well as the diaphragm, and the heart. Wistar rats were subjected to a treadmill run: (1) t = 30 [min], V = 18 [m/min]; (2) t = 30 [min], V = 28 [m/min]; (3) t = 120 [min], V = 18 [m/min] (designated: M30, F30, and M120, respectively). We established EL expression in the total muscle homogenates in sedentary animals. Resting values could be ordered with the decreasing EL protein expression as follows: endothelium of left ventricle > diaphragm > red gastrocnemius > right ventricle > soleus > white gastrocnemius. Furthermore, we observed that even a single bout of exercise was capable of inducing changes in the mRNA and protein level of EL, with a clearer pattern observed for the former. After 30 min of running at either exercise intensity, the expression of EL transcript in all the cardiovascular components of muscles tested, except the soleus, was reduced in comparison to the respective sedentary control. The protein content of EL varied with the intensity and/or duration of the run in the studied whole tissue homogenates. The observed differences between EL expression in vascular beds of muscles may indicate the muscle-specific role of the lipase.
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Affiliation(s)
- Agnieszka Mikłosz
- Department of Physiology, Medical University of Bialystok, 12-222 Bialystok, Poland; (B.Ł.); (A.C.)
- Correspondence: ; Tel.: +48-85-746-55-85
| | - Bartłomiej Łukaszuk
- Department of Physiology, Medical University of Bialystok, 12-222 Bialystok, Poland; (B.Ł.); (A.C.)
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, 12-222 Bialystok, Poland; (B.Ł.); (A.C.)
| | - Jan Górski
- Department of Basic Sciences, Lomza State University of Applied Sciences, 18-400 Lomza, Poland;
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Zabielski P, Błachnio-Zabielska AU, Wójcik B, Chabowski A, Górski J. Effect of plasma free fatty acid supply on the rate of ceramide synthesis in different muscle types in the rat. PLoS One 2017; 12:e0187136. [PMID: 29095868 PMCID: PMC5667851 DOI: 10.1371/journal.pone.0187136] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 10/13/2017] [Indexed: 01/06/2023] Open
Abstract
Ceramide is a key compound in sphingolipid metabolism. Dynamics of ceramide synthesis is important in the several biological processes, such as induction of apoptosis or insulin resistance. So far, its de novo synthesis rate was evaluated indirectly, based on the content of the compound, its intermediates and the activity of respective enzymes. The aim of the present study was to directly measure ceramide synthesis rate (FSR) in different muscle types under varied plasma FFA supply in rat with the use of [U-13C] palmitate tracer and LC/MS/MS. The experiments were carried out on male Wistar rats, divided into three groups: 1-control, 2-with elevated plasma free fatty acid (FFA) concentration by means of intralipid and heparin, 3-with reduced plasma FFA concentration by means of nicotinic acid. The stable plasma FFA concentration and plasma [U-13C] palmitate enrichment was maintained for two hours by simultaneous infusion of the tracer and the respective compounds. At the end of the experiment, samples of blood from the abdominal aorta, the heart, diaphragm, soleus and white section of the gastrocnemius were taken. Muscle sphinganine, sphingosine and ceramide content and enrichment and plasma palmitate enrichment was measured with the use of LC/MS/MS. Plasma FFA concentration and composition was measured by means of gas-liquid chromatography. Under basal conditions ceramide FSR in the heart and the diaphragm was higher than in the soleus and the white gastrocnemius. Elevation in the plasma FFA concentration increased the FSR and ceramide content in each muscle, which correlated with increased HOMA-IR. The highest FSR was noted in the heart. Reduction in the plasma FFA concentration decreased ceramide FSR in each muscle type, which was accompanied by marked reduction in HOMA-IR. It is concluded that ceramide FSR depends on both the muscle type and the plasma FFA supply and is correlated with whole body insulin sensitivity under varying plasma FFA supply.
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Affiliation(s)
- Piotr Zabielski
- Department of Physiology, Medical University of Białystok, Białystok, Poland
- Department of Medical Biology, Medical University of Białystok, Białystok, Poland
- * E-mail:
| | - Agnieszka Urszula Błachnio-Zabielska
- Department of Physiology, Medical University of Białystok, Białystok, Poland
- Department of Hygiene, Epidemiology and Metabolic Disorders, Medical University of Białystok, Białystok, Poland
| | - Beata Wójcik
- Department of Physiology, Medical University of Białystok, Białystok, Poland
| | - Adrian Chabowski
- Department of Physiology, Medical University of Białystok, Białystok, Poland
| | - Jan Górski
- Department of Physiology, Medical University of Białystok, Białystok, Poland
- Medical Institute, Łomża State University of Applied Sciences, Łomża, Poland
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Lukaszuk B, Miklosz A, Zendzian-Piotrowska M, Wojcik B, Gorski J, Chabowski A. Changes in the Diaphragm Lipid Content after Administration of Streptozotocin and High-Fat Diet Regime. J Diabetes Res 2017; 2017:3437169. [PMID: 29234684 PMCID: PMC5694988 DOI: 10.1155/2017/3437169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/06/2017] [Accepted: 07/18/2017] [Indexed: 12/15/2022] Open
Abstract
The diaphragm is a dome-shaped skeletal muscle indispensable for breathing. Its activity contributes up to 70% of the total ventilatory function at rest. In comparison to other skeletal muscles, it is distinguished by an oxidative phenotype and uninterrupted cyclic contraction pattern. Surprisingly, the research regarding diaphragm diabetic phenotype particularly in the light of lipid-induced insulin resistance is virtually nonexistent. Male Wistar rats were randomly allocated into 3 groups: control, streptozotocin-induced (STZ) type-1 diabetes, and rodents fed with high-fat diet (HFD). Additionally, half of the animals from each group were administered with myriocin, a robust, selective inhibitor of ceramide synthesis and, therefore, a potent agent ameliorating insulin resistance. Diaphragm lipid contents were evaluated using chromatography. Fatty acid transporter expression was determined by Western blot. The STZ and HFD rats had increased concentration of lipids, namely, ceramides (CER) and diacylglycerols (DAG). Interestingly, this coincided with an increased concentration of long-chain (C ≥ 16) saturated fatty acid species present in both the aforementioned lipid fractions. The CER/DAG accumulation was accompanied by an elevated fatty acid transporter expression (FATP-1 in HFD and FATP-4 in STZ). Surprisingly, we observed a significantly decreased triacylglycerol content in the diaphragms of STZ-treated rats.
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Affiliation(s)
- Bartlomiej Lukaszuk
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Agnieszka Miklosz
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | | | - Beata Wojcik
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Jan Gorski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
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Qaisar R, Bhaskaran S, Van Remmen H. Muscle fiber type diversification during exercise and regeneration. Free Radic Biol Med 2016; 98:56-67. [PMID: 27032709 DOI: 10.1016/j.freeradbiomed.2016.03.025] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/01/2016] [Accepted: 03/24/2016] [Indexed: 01/15/2023]
Abstract
The plasticity of skeletal muscle can be traced down to extensive metabolic, structural and molecular remodeling at the single fiber level. Skeletal muscle is comprised of different fiber types that are the basis of muscle plasticity in response to various functional demands. Resistance and endurance exercises are two external stimuli that differ in their duration and intensity of contraction and elicit markedly different responses in muscles adaptation. Further, eccentric contractions that are associated with exercise-induced injuries, elicit varied muscle adaptation and regenerative responses. Most adaptive changes are fiber type-specific and are highly influenced by diverse structural, metabolic and functional characteristics of individual fiber types. Regulation of signaling pathways by reactive oxygen species (ROS) and oxidative stress also plays an important role in muscle fiber adaptation during exercise. This review focuses on cellular and molecular responses that regulate the adaptation of skeletal muscle to exercise and exercise-related injuries.
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Affiliation(s)
- Rizwan Qaisar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA
| | - Shylesh Bhaskaran
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA.
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Abstract
During dynamic exercise, the healthy pulmonary system faces several major challenges, including decreases in mixed venous oxygen content and increases in mixed venous carbon dioxide. As such, the ventilatory demand is increased, while the rising cardiac output means that blood will have considerably less time in the pulmonary capillaries to accomplish gas exchange. Blood gas homeostasis must be accomplished by precise regulation of alveolar ventilation via medullary neural networks and sensory reflex mechanisms. It is equally important that cardiovascular and pulmonary system responses to exercise be precisely matched to the increase in metabolic requirements, and that the substantial gas transport needs of both respiratory and locomotor muscles be considered. Our article addresses each of these topics with emphasis on the healthy, young adult exercising in normoxia. We review recent evidence concerning how exercise hyperpnea influences sympathetic vasoconstrictor outflow and the effect this might have on the ability to perform muscular work. We also review sex-based differences in lung mechanics.
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Affiliation(s)
- Andrew William Sheel
- The School of Kinesiology, The University of British Columbia, Vancouver, Canada.
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Borzykh AA, Kuzmin IV, Mart’ianov AA, Borovik AS, Sharova AP, Tarasova OS, Vinogradova OL. Changes of rat respiratory and locomotory muscles during aerobic exercise training in continuous and interval regimens. Biophysics (Nagoya-shi) 2012. [DOI: 10.1134/s0006350912050053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Dempsey JA, Adams L, Ainsworth DM, Fregosi RF, Gallagher CG, Guz A, Johnson BD, Powers SK. Airway, Lung, and Respiratory Muscle Function During Exercise. Compr Physiol 2011. [DOI: 10.1002/cphy.cp120111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Hepburn H, Fletcher J, Rosengarten TH, Coote JH. Cardiac vagal tone, exercise performance and the effect of respiratory training. Eur J Appl Physiol 2005; 94:681-9. [PMID: 15906077 DOI: 10.1007/s00421-005-1355-y] [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] [Accepted: 02/14/2005] [Indexed: 10/25/2022]
Abstract
Heart rate variability (HRV) at rest and heart rate recovery after exercise reflect cardiac vagal activity. The aim of this study was to determine whether increasing HRV during involuntary respiratory training induced by rebreathing air using a Hepburn heart and lung exerciser (HHALE) could, like exercise, improve vagal tone. Eighteen subjects (36-88 years) underwent a 6-week control period, then a 6-week training period with the HHALE following which half continued training for 6 weeks and half ceased training. Measurements were made of HRV, work at 60% predicted heart rate max for 15 min, heart rate recovery after exercise, resting blood pressure, heart rate, vital capacity and forced expiratory volume. After the first 6-week HHALE training, there was a significant increase of 13.2 +/- 5.7 nu in the high frequency peak of the power spectrum of HRV at rest, whereas, the low frequency peak decreased. Similarly, exercise performance showed a significant improvement of 0.031 +/- 0.012 J per heartbeat from a pre-training 0.128 +/- 0.022. Also, heart rate recovery after exercise significantly faster (drop in the first 20 s improving by 3.3 +/- 1.5 beats from a pre-training 12.9 +/- 1.6). The subgroup that continued training maintained or slightly improved these values. In those that ceased training the speed of heart rate recovery at the end of the exercise test returned to pre-trained levels, whereas, other responses were either maintained or decreased slightly. We conclude that training with the HHALE can, without additional exercise, increase cardiac vagal tone and exercise performance.
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Affiliation(s)
- H Hepburn
- Department of Physiology, The Medical School, The University of Birmingham, Birmingham, B15 2TT, UK
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9
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Nair-Shalliker V, Kee AJ, Joya JE, Lucas CA, Hoh JF, Hardeman EC. Myofiber adaptational response to exercise in a mouse model of nemaline myopathy. Muscle Nerve 2004; 30:470-80. [PMID: 15372535 DOI: 10.1002/mus.20138] [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: 11/09/2022]
Abstract
In some muscle diseases, such as muscular dystrophy, exercise can increase muscle damage and alter myofiber adaptation. We determined whether this is also true for the congenital muscle disease nemaline myopathy using our mouse model of this disease. Nemaline mice expressing a mutant alpha-tropomyosinslow protein [alpha-Tmslow(Met9Arg)] in skeletal muscle underwent 4 weeks of treadmill exercise. Exercise increased slow/oxidative myofibers, but different fibers were involved in these transformations in nemaline mice. Despite similar expression of the mutant alpha-Tmslow protein in muscles of the nemaline mouse, muscles responded in a unique manner that did not reflect fiber-type composition. For example, the particular fibers involved in fast-to-slow transformation were specific for each muscle examined. In contrast to the muscular dystrophies, exercise did not result in muscle damage nor did it cause an increase in rod-containing fibers; however, the fiber-type distribution of rod-containing fibers was altered in a muscle-specific fashion. That exercise did not exacerbate the pathology (i.e., nemaline rod formation) supports its use in nemaline myopathy patients. This study shows that fibers of a similar type respond to increased activity differently in different muscles and suggests that fibers of similar type may be functionally distinct in different muscles.
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Affiliation(s)
- Visalini Nair-Shalliker
- Muscle Development Unit, Children's Medical Research Institute, Westmead, NSW 2145, Australia
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10
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Ekmark M, Grønevik E, Schjerling P, Gundersen K. Myogenin induces higher oxidative capacity in pre-existing mouse muscle fibres after somatic DNA transfer. J Physiol 2003; 548:259-69. [PMID: 12598590 PMCID: PMC2342785 DOI: 10.1113/jphysiol.2002.036228] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 11/19/2002] [Accepted: 01/21/2003] [Indexed: 11/08/2022] Open
Abstract
Muscle is a permanent tissue, and in the adult pronounced changes can occur in pre-existing fibres without the formation of new fibres. Thus, the mechanisms responsible for phenotype transformation in the adult might be distinct from mechanisms regulating muscle differentiation during muscle formation and growth. Myogenin is a muscle-specific, basic helix-loop-helix transcription factor that is important during early muscle differentiation. It is also expressed in the adult, where its role is unknown. In this study we have overexpressed myogenin in glycolytic fibres of normal adult mice by electroporation and single-cell intracellular injection of expression vectors. Myogenin had no effects on myosin heavy chain fibre type, but induced a considerable increase in succinate dehydrogenase and NADH dehydrogenase activity, with some type IIb fibres reaching the levels observed histochemically in normal type IIx and IIa fibres. mRNA levels for malate dehydrogenase were similarly altered. The size of the fibres overexpressing myogenin was reduced by 30-50 %. Thus, the transfected fibres acquired a phenotype reminiscent of the phenotype obtained by endurance training in man and other animals, with a higher oxidative capacity and smaller size. We conclude that myogenin can alter pre-existing glycolytic fibres in the intact adult animal.
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Affiliation(s)
- Merete Ekmark
- Department of Biology, University of Oslo, PO Box 1051, Blindern, N-0316 Oslo, Norway
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Wahrmann JP, Fulla Y, Rieu M, Kahn A, Dinh-Xuan AT. Altered myosin isoform expression in rat skeletal muscles induced by a changed thyroid state. ACTA PHYSIOLOGICA SCANDINAVICA 2002; 176:233-43. [PMID: 12392503 DOI: 10.1046/j.1365-201x.2002.01012.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of our study was to find out, which are the thyroid linked mechanisms responsible for the changes in myosin isoform composition which accompany endurance training (ET) in rodents. We studied the interaction between ET and altered sedentary group with no thyroid treatment or Se group. Six groups of rats were compared: (1) a trained group with no thyroid treatment or T group; (2) a thyroid state in rats; (3) a sedentary group rendered hypothyroid with 6-n-propyl thio uracil (H); (4) a sedentary group rendered hyperthyroid with T3 (150 microg kg(-1) every other day for 4 weeks) (St); (5) trained rats rendered hyperthyroid with T3 (150 microg kg(-1) every other day for 4 weeks) (Tt) and (6) a trained group kept euthyroid with T3 (150 ng kg(-1) every other day for 4 weeks) (Te). In each group myosin isoform composition was determined in five muscles, three locomotor muscles: (1) extensor digitorum longus, (2) superficial lateral gastrocnemius, (3) deep medial gastrocnemius, (4) an antigravity muscle, the soleus and (5) a rhytmic respiratory muscle, the crural diaphragm. Different muscles responded in a specific way to variations of the thyroid state and training.
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Affiliation(s)
- J P Wahrmann
- IC U567 Unité de Recherches en Physiologie et Pathologie Génetiques et Moléculaires de l'INSERM Université ParisV, Paris, France
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12
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Abstract
Interest in the adaptive strategies of respiratory muscles in response to exercise training has grown in recent years. Animal studies have clearly demonstrated that regular endurance exercise training results in small but significant increases in oxidative and antioxidant enzyme activities in both inspiratory and expiratory muscles. Further, exercise training has been shown to promote a shift in the fast myosin heavy chain isoforms (e.g. from type IIb to IId) within the costal diaphragm of endurance-trained rodents. Human studies using numerous respiratory muscle training programmes have shown that respiratory muscle training results in an increased work capacity of the ventilatory musculature. However, the issue of whatever respiratory muscle training improves whole body endurance capacity remains controversial. Although some authors have reported that ventilatory muscle training results in improved whole body exercise, many investigators argue that respiratory muscle performance does not limit high intensity exercise tolerance or influence maximum oxygen table uptake (VO2max). The explanation for the divergent findings is unclear but may be due to variance in the exercise tasks used to evaluate exercise endurance. This is an interesting area for future research.
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Affiliation(s)
- S K Powers
- Center for Exercise Science, University of Florida, Gainesville, USA
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Babcock MA, Pegelow DF, Johnson BD, Dempsey JA. Aerobic fitness effects on exercise-induced low-frequency diaphragm fatigue. J Appl Physiol (1985) 1996; 81:2156-64. [PMID: 8941541 DOI: 10.1152/jappl.1996.81.5.2156] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We used bilateral phrenic nerve stimulation (BPNS; at 1, 10, and 20 Hz at functional residual capacity) to compare the amount of exercise-induced diaphragm fatigue between two groups of healthy subjects, a high-fit group [maximal O2 consumption (VO2max) = 69.0 +/- 1.8 ml.kg-1.min-1, n = 11] and a fit group (VO2max = 50.4 +/- 1.7 ml.kg-1.min-1, n = 13). Both groups exercised at 88-92% VO2max for about the same duration (15.2 +/- 1.7 and 17.9 +/- 2.6 min for high-fit and fit subjects, respectively, P > 0.05). The supramaximal BPNS test showed a significant reduction (P < 0.01) in the BPNS transdiaphragmatic pressure (Pdi) immediately after exercise of -23.1 +/- 3.1% for the high-fit group and -23.1 +/- 3.8% (P > 0.05) for the fit group. Recovery of the BPNS Pdi took 60 min in both groups. The high-fit group exercised at a higher absolute workload, which resulted in a higher CO2 production (+26%), a greater ventilatory demand (+16%) throughout the exercise, and an increased diaphragm force output (+28%) over the initial 60% of the exercise period. Thereafter, diaphragm force output declined, despite a rising minute ventilation, and it was not different between most of the high-fit and fit subjects. In summary, the high-fit subjects showed diaphragm fatigue as a result of heavy endurance exercise but were also partially protected from excessive fatigue, despite high ventilatory requirements, because their hyperventilatory response to endurance exercise was reduced, their diaphragm was utilized less in providing the total ventilatory response, and possibly their diaphragm aerobic capacity was greater.
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Affiliation(s)
- M A Babcock
- John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin, Madison 53705, USA
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14
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Powers SK, Criswell D. Adaptive strategies of respiratory muscles in response to endurance exercise. Med Sci Sports Exerc 1996; 28:1115-22. [PMID: 8882998 DOI: 10.1097/00005768-199609000-00006] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The purpose of this review is to discuss the adaptive strategies of mammalian respiratory muscles in response to whole-body endurance exercise training. It is now clear that endurance training results in small (i.e., 20-30%) but significant increases in mitochondrial enzyme activity and the activities of key antioxidant enzymes (i.e., superoxide dismutase and glutathione peroxidase) within the rodent diaphragm. Interestingly, the magnitude of this training-induced increase in costal diaphragmatic oxidative and antioxidant enzyme activity is relatively independent of the exercise duration and intensity. Although the crural diaphragm of rodents is also capable of increasing its oxidative and antioxidant capacity in response to endurance training, high-to moderate-intensity exercise of long duration is required to promote these changes. Endurance training also increases the oxidative capacity of other key rodent inspiratory muscles, such as the parasternal intercostals and external intercostals. Furthermore, endurance training results in small (approximately 10%) increased in the oxidative capacity of key abdominal (expiratory) muscles. Whether the improvement in oxidative capacity of respiratory muscles is of significant magnitude to result in improvement in respiratory muscle performance remains an unanswered question.
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Affiliation(s)
- S K Powers
- Center for Exercise Science, University of Florida, Gainesville 32611, USA
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15
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Powers SK, Criswell D, Lieu FK, Dodd S, Silverman H. Diaphragmatic fiber type specific adaptation to endurance exercise. RESPIRATION PHYSIOLOGY 1992; 89:195-207. [PMID: 1439301 DOI: 10.1016/0034-5687(92)90050-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent evidence suggests that exercise training results in a significant improvement in the oxidative capacity of the mammalian diaphragm; however, limited data exist concerning which diaphragmatic fiber types are metabolically altered due to training. To test the hypothesis that exercise training increases the oxidative capacity of diaphragmatic type I and IIa fibers only, we examined the effects of endurance training on the fiber type specific changes in oxidative capacity, cross-sectional area, and capillarity of the costal diaphragm. Female Fischer-344 rats (age ca 180 days) were divided into either sedentary control group (n = 6) or an exercise training group (n = 6). The trained animals exercised for 10 wks on a motor-driven treadmill (60 min.day-1; 5 days.wk-1) at a work rate equal to ca 55-65% VO2max. Capillaries were identified histologically and fiber types determined using ATPase histochemistry. Fiber cross-sectional area (CSA) and succinate dehydrogenase (SDH) activity in individual fibers were measured using a computerized image analysis system. Compared to control animals, training did not increase the capillary to fiber ratio in any diaphragm fiber type (P greater than 0.05); however, training increased capillary density (capillary No./CSA) in type IIa fibers due to a reduction in cell CSA (P less than 0.05). Further, training resulted in significant (P less than 0.05) increases in total diaphragmatic SDH activity (delta increase = 17.5%) and an increase in SDH activity in both type I (delta increase = 14%) and IIa fibers (delta increase = 17.4%). In contrast, training did not alter (P greater than 0.05) SDH activity in type IIb fibers.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S K Powers
- Department of Exercise Science, University of Florida, Gainesville 32611
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Viscor G, Torrella JR, Fouces V, Palomeque J. Skeletal muscle capillarization and fiber types in urban and homing pigeons (Columba livia). ACTA ACUST UNITED AC 1992; 101:751-7. [PMID: 1351450 DOI: 10.1016/0300-9629(92)90354-s] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. Fiber types, capillary supply and other morphometrical parameters were analysed in pectoral, gastrocnemius and pronator muscles of homing and urban pigeons. 2. The two kinds of birds were analysed before and after a restrainment period of at least 5 months. 3. Only slight differences in fiber type frequencies were noted between urban and homing pigeons in control conditions. 4. The effect of restrainment on the different parameters studied was unclear in gastrocnemius and pronator muscles and negligible in M. pectoralis. 5. Mean diffusion distances for oxygen from capillaries were smaller in oxidative fibers; also, vascularization indexes were higher for these fiber types. 6. The contribution of each fiber type to total sectional ara of muscle remains stable in spite of fiber type frequencies heterogeneity.
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Affiliation(s)
- G Viscor
- Departamento de Bioquimica y Fisiologia, Universidad de Barcelona, Facultad de Biologia, Spain
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Sanchez J, Sarue AM, Brunet A, Monod H. Enzymatic adaptations to treadmill training under the influence of naftidrofuryl acid in diaphragm and limb muscles of old rats. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE, DE BIOCHIMIE ET DE BIOPHYSIQUE 1991; 99:129-34. [PMID: 1713485 DOI: 10.3109/13813459109145915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of training and naftidrofuryl treatment were observed in 21-month-old Long-Evans rats. Rats were injected intraperitoneally twice daily for 8 weeks with 7 mg.kg-1 of naftidrofuryl acid (SN, TN), or with 7 mg.kg-1 fumaric acid (SC and TC) or used as solvent. Training groups (TC, TN) started a progressive 8-week training programme of treadmill exercise. The activities of lactate dehydrogenase (LDH), hexokinase (HK), citrate synthase (CS) and 3-hydroxyacyl-Co-A-dehydrogenase (HAD), were measured in Soleus (SOL), Extensor Digitorum Longus (EDL) and Diaphragm (DIA) muscles. The mean VO2max value was 65 ml.min-1.kg-1 for 21-month-old rats. The training protocol induced increases in the mean VO2max values in the TC and TN groups, 71.8 and 74.4 ml.min-1.kg-1. In sedentary groups (SN), naftidrofuryl increased enzymatic activities (HK, CS, HAD) in the three muscles examined. When the animals underwent 8 weeks of physical training, the enzymatic activities (HK, CS, HAD) increased in SOL, EDL and DIA. When training was combined with naftidrofuryl treatment the increases in enzymatic activities were greater than those induced by training alone. However, the total changes did not differ for the sum of the changes produced by each condition alone.
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Affiliation(s)
- J Sanchez
- Laboratoire de Physiologie du Travail-UA 385-CNRS, Faculté de Médecine, Pitié-Salpêtrière, Université Pierre et Marie Curie, Paris, France
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Katsuta S, Kanao Y, Aoyagi Y. Is exhaustive training adequate preparation for endurance performance? EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1988; 58:68-73. [PMID: 3203677 DOI: 10.1007/bf00636605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Our purpose was to test the significance of exhaustive training in aerobic or endurance capacity. The extent of adaptations to endurance training was evaluated by assessing the increase in physical performance capability and oxidative markers in the organs of rats trained by various exercise programs. Rats were trained by treadmill running 5 days.week-1 at 30 m.min-1 for 8 weeks by one of three protocols: T1-60 min.day-1; T2-120 min.day-1; and T3-120 min.day-1 (3 days.week-1) and to exhaustion (2 days.week-1). Groups T2 and T3 ran for longer than T1 in an endurance exercise test (P less than 0.05), in which the animals ran at 30 m.min-1 to exhaustion; no difference was observed between groups T2 and T3. All 3 trained groups showed a similar increase (20-27%) in the fast-twitch oxidative-glycolytic (FOG) fibers with a concomitant decrease in the fast-twitch glycolytic (FG) fiber population in gastrocnemius (p less than 0.05). The capillary supply in gastrocnemius increased with the duration of exercise (p less than 0.05): no difference was found between groups T2 and T3. Likewise, no distinction was seen between groups T2 and T3 in the increase in succinate dehydrogenase activity in gastrocnemius and the heart. These results suggest that the maximal adaptive response to endurance training does not require daily exhaustive exercise.
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Affiliation(s)
- S Katsuta
- Institute of Health and Sports Sciences, University of Tsukuba, Ibaraki, Japan
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