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Zagatto AM, Bishop DJ, Antunes BM, Beck WR, Malta ES, de Poli RAB, Cavaglieri CR, Chacon-Mikahil MPT, Castro A. Impacts of high-intensity exercise on the metabolomics profile of human skeletal muscle tissue. Scand J Med Sci Sports 2021; 32:402-413. [PMID: 34706104 DOI: 10.1111/sms.14086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/13/2021] [Accepted: 10/25/2021] [Indexed: 01/06/2023]
Abstract
The study aimed to identify and quantify the metabolites profile and metabolic pathways in human muscle tissue engaged during exhaustive high-intensity cycling exercise. Seven healthy physically active men performed a graded exercise test and an exhaustive supramaximal effort at 115% of maximal aerobic power with muscles biopsies performed in rest and immediately after exhaustion for quantifying of muscle metabolites changes by 1 H-NMR spectroscopy. The time until exhaustion (tlim) recorded was 224.7 ± 35.5 s whereas the muscle pH at exhaustion was 6.48 ± 0.05. A total of 54 metabolites were identified and quantified. The most enriched and impacted pathways included: beta oxidation of very long chain fatty acids, mitochondrial electron transport chain, alanine aspartate, and glutamate metabolism, citric acid cycle, arginine biosynthesis, propanoate metabolism, threonine and 2-oxobutanoate degradation and pyruvate metabolism. In addition, the muscle concentrations in Post exercise, compared to Pre increased significantly (p < 0.0398) for fumarate (42.0%), succinate (101.2%), glucose (249.7%), lactate (122.8%), O-acetylcarnitine (164.7%), glycerol (79.3%), AMP (288.2%), 2-oxobutyrate (121.0%), and methanol (58.5%), whereas decreased significantly (p < 0.010) for creatine phosphate (-70.2%), ADP (-56.5%), carnitine (-33.5%), and glutamate (-42.3%). Only the succinate was significantly correlated with tlim (r = -0.76; p = 0.0497). Besides the classical expected contribution of glycolytic and phosphagen energetic pathways, it was demonstrated that the high-intensity exercise is also associated with pathways indicatives of amino acid and fatty acid oxidation metabolisms, highlighting the inverse relation between changes in the intramuscular succinate levels and tlim.
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Affiliation(s)
- Alessandro M Zagatto
- Laboratory of Physiology and Sport Performance (LAFIDE), São Paulo State University (UNESP), Bauru, Brazil
| | - David J Bishop
- Institute for Health and Sport (iHeS), Victoria University, Footscray, Victoria, Australia
| | - Barbara Moura Antunes
- Laboratory of Physiology and Sport Performance (LAFIDE), São Paulo State University (UNESP), Bauru, Brazil
| | - Wladimir R Beck
- Federal University of Sao Carlos (UFSCar), Sao Carlos, Brazil
| | - Elvis S Malta
- Laboratory of Physiology and Sport Performance (LAFIDE), São Paulo State University (UNESP), Bauru, Brazil
| | - Rodrigo A B de Poli
- Laboratory of Physiology and Sport Performance (LAFIDE), São Paulo State University (UNESP), Bauru, Brazil
| | - Claudia R Cavaglieri
- Laboratory of Exercise Physiology, Faculty of Physical Education, University of Campinas (UNICAMP), Campinas, Brazil
| | | | - Alex Castro
- Laboratory of Exercise Physiology, Faculty of Physical Education, University of Campinas (UNICAMP), Campinas, Brazil
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Davis M, Fulton M, Popken A. Effect of hyperthermia and acidosis on equine skeletal muscle mitochondrial oxygen consumption. COMPARATIVE EXERCISE PHYSIOLOGY 2021. [DOI: 10.3920/cep200041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The skeletal muscle of exercising horses develops pronounced hyperthermia and acidosis during strenuous or prolonged exercise, with very high tissue temperature and low pH associated with muscle fatigue or damage. The purpose of this study was to evaluate the individual effects of physiologically relevant hyperthermia and acidosis on equine skeletal muscle mitochondrial function, using ex vivo measurement of oxygen consumption to assess the function of different mitochondrial elements. Fresh triceps muscle biopsies from 6 healthy unfit Thoroughbred geldings were permeabilised to permit diffusion of small molecular weight substrates through the sarcolemma and analysed in a high resolution respirometer at 38, 40, 42, and 44 °C, and pH=7.1, 6.5, and 6.1. Oxygen consumption was measured under conditions of non-phosphorylating (leak) respiration and phosphorylating respiration through Complex I and Complex II. Data were analysed using a one-way repeated measures ANOVA and data are expressed as mean ± standard deviation. Leak respiration was ~3-fold higher at 44 °C compared to 38 °C regardless of electron source (Complex I: 22.88±3.05 vs 8.08±1.92 pmol O2/mg/s), P=0.002; Complex II: 79.14±23.72 vs 21.43±11.08 pmol O2/mg/s, P=0.022), resulting in a decrease in efficiency of oxidative phosphorylation. Acidosis had minimal effect on mitochondrial respiration at pH=6.5, but pH=6.1 resulted in a 50% decrease in mitochondrial oxygen consumption. These results suggest that skeletal muscle hyperthermia decreases the efficiency of oxidative phosphorylation through increased leak respiration, thus providing a specific biochemical basis for hyperthermia-induced muscle fatigue. The effect of myocellular acidosis on mitochondrial respiration was minimal under typical levels of acidosis, but atypically severe acidosis can lead to impairment of mitochondrial function.
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Affiliation(s)
- M.S. Davis
- Department of Physiological Sciences, Oklahoma State University, 264 McElroy Hall, Stillwater, OK 74078, USA
| | - M.R. Fulton
- Department of Physiological Sciences, Oklahoma State University, 264 McElroy Hall, Stillwater, OK 74078, USA
| | - A. Popken
- Department of Physiological Sciences, Oklahoma State University, 264 McElroy Hall, Stillwater, OK 74078, USA
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Liegnell R, Apró W, Danielsson S, Ekblom B, van Hall G, Holmberg HC, Moberg M. Elevated plasma lactate levels via exogenous lactate infusion do not alter resistance exercise-induced signaling or protein synthesis in human skeletal muscle. Am J Physiol Endocrinol Metab 2020; 319:E792-E804. [PMID: 32830552 DOI: 10.1152/ajpendo.00291.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Lactate has been implicated as a potential signaling molecule. In myotubes, lactate incubation increases mechanistic target of rapamycin complex 1 (mTORC1)- and ERK-signaling and induces hypertrophy, indicating that lactate could be a mediator of muscle adaptations to resistance exercise. However, the potential signaling properties of lactate, at rest or with exercise, have not been explored in human tissue. In a crossover design study, 8 men and 8 women performed one-legged resistance exercise while receiving venous infusion of saline or sodium lactate. Blood was sampled repeatedly, and muscle biopsies were collected at rest and at 0, 90, and 180 min and 24 h after exercise. The primary outcomes examined were intracellular signaling, fractional protein synthesis rate (FSR), and blood/muscle levels of lactate and pH. Postexercise blood lactate concentrations were 130% higher in the Lactate trial (3.0 vs. 7.0 mmol/L, P < 0.001), whereas muscle levels were only marginally higher (27 vs. 32 mmol/kg dry wt, P = 0.003) compared with the Saline trial. Postexercise blood pH was higher in the Lactate trial (7.34 vs. 7.44, P < 0.001), with no differences in intramuscular pH. Exercise increased the phosphorylation of mTORS2448 (∼40%), S6K1T389 (∼3-fold), and p44T202/T204 (∼80%) during recovery, without any differences between trials. FSR over the 24-h recovery period did not differ between the Saline (0.067%/h) and Lactate (0.062%/h) trials. This study does not support the hypothesis that blood lactate levels can modulate anabolic signaling in contracted human muscle. Further in vivo research investigating the impact of exercised versus rested muscle and the role of intramuscular lactate is needed to elucidate its potential signaling properties.
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Affiliation(s)
- Rasmus Liegnell
- Department of Physiology, Nutrition and Biomechaniscs, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- Department of Physiology, Nutrition and Biomechaniscs, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Sebastian Danielsson
- Department of Physiology, Nutrition and Biomechaniscs, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Björn Ekblom
- Department of Physiology, Nutrition and Biomechaniscs, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Gerrit van Hall
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Clinical Metabolomics Core Facility, Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institute, Stockholm, Sweden
| | - Marcus Moberg
- Department of Physiology, Nutrition and Biomechaniscs, Swedish School of Sport and Health Sciences, Stockholm, Sweden
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Westermann CM, Dorland L, Wijnberg ID, de Sain-van der Velden MGM, van Breda E, Barneveld A, de Graaf-Roelfsema E, Keizer HA, van der Kolk JH. Amino acid profile during exercise and training in Standardbreds. Res Vet Sci 2010; 91:144-149. [PMID: 20863542 DOI: 10.1016/j.rvsc.2010.08.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 07/29/2010] [Accepted: 08/09/2010] [Indexed: 11/28/2022]
Abstract
The objective of this study is to assess the influence of acute exercise, training and intensified training on the plasma amino acid profile. In a 32-week longitudinal study using 10 Standardbred horses, training was divided into four phases, including a phase of intensified training for five horses. At the end of each phase, a standardized exercise test, SET, was performed. Plasma amino acid concentrations before and after each SET were measured. Training significantly reduced mean plasma aspartic acid concentration, whereas exercise significantly increased the plasma concentrations of alanine, taurine, methionine, leucine, tyrosine and phenylalanine and reduced the plasma concentrations of glycine, ornithine, glutamine, citrulline and serine. Normally and intensified trained horses differed not significantly. It is concluded that amino acids should not be regarded as limiting training performance in Standardbreds except for aspartic acid which is the most likely candidate for supplementation.
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Affiliation(s)
- C M Westermann
- Department of Equine Sciences, Medicine Section, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80152, 3508 TD Utrecht, The Netherlands.
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Hill CA, Harris RC, Kim HJ, Harris BD, Sale C, Boobis LH, Kim CK, Wise JA. Influence of β-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids 2006; 32:225-33. [PMID: 16868650 DOI: 10.1007/s00726-006-0364-4] [Citation(s) in RCA: 276] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 04/20/2006] [Indexed: 11/30/2022]
Abstract
Muscle carnosine synthesis is limited by the availability of beta-alanine. Thirteen male subjects were supplemented with beta-alanine (CarnoSyn) for 4 wks, 8 of these for 10 wks. A biopsy of the vastus lateralis was obtained from 6 of the 8 at 0, 4 and 10 wks. Subjects undertook a cycle capacity test to determine total work done (TWD) at 110% (CCT(110%)) of their maximum power (Wmax). Twelve matched subjects received a placebo. Eleven of these completed the CCT(110%) at 0 and 4 wks, and 8, 10 wks. Muscle biopsies were obtained from 5 of the 8 and one additional subject. Muscle carnosine was significantly increased by +58.8% and +80.1% after 4 and 10 wks beta-alanine supplementation. Carnosine, initially 1.71 times higher in type IIa fibres, increased equally in both type I and IIa fibres. No increase was seen in control subjects. Taurine was unchanged by 10 wks of supplementation. 4 wks beta-alanine supplementation resulted in a significant increase in TWD (+13.0%); with a further +3.2% increase at 10 wks. TWD was unchanged at 4 and 10 wks in the control subjects. The increase in TWD with supplementation followed the increase in muscle carnosine.
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Affiliation(s)
- C A Hill
- School of Sports, Exercise & Health Sciences, University of Chichester, Chichester, UK
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6
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Harris RC, Tallon MJ, Dunnett M, Boobis L, Coakley J, Kim HJ, Fallowfield JL, Hill CA, Sale C, Wise JA. The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino Acids 2006; 30:279-89. [PMID: 16554972 DOI: 10.1007/s00726-006-0299-9] [Citation(s) in RCA: 327] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Accepted: 10/18/2005] [Indexed: 11/28/2022]
Abstract
Beta-alanine in blood-plasma when administered as A) histidine dipeptides (equivalent to 40 mg . kg(-1) bwt of beta-alanine) in chicken broth, or B) 10, C) 20 and D) 40 mg . kg(-1) bwt beta-alanine (CarnoSyn, NAI, USA), peaked at 428 +/- SE 66, 47 +/- 13, 374 +/- 68 and 833 +/- 43 microM. Concentrations regained baseline at 2 h. Carnosine was not detected in plasma with A) although traces of this and anserine were found in urine. Loss of beta-alanine in urine with B) to D) was <5%. Plasma taurine was increased by beta-alanine ingestion but this did not result in any increased loss via urine. Pharmacodynamics were further investigated with 3 x B) per day given for 15 d. Dietary supplementation with I) 3.2 and II) 6.4 g . d(-1) beta-alanine (as multiple doses of 400 or 800 mg) or III) L-carnosine (isomolar to II) for 4 w resulted in significant increases in muscle carnosine estimated at 42.1, 64.2 and 65.8%.
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Affiliation(s)
- R C Harris
- School of Sports, Exercise and Health Sciences, University College Chichester, West Sussex, Chichester, UK.
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7
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STEPHENS TERRYJ, McKENNA MICHAELJ, CANNY BENEDICTJ, SNOW RODNEYJ, McCONELL GLENNK. Effect of sodium bicarbonate on muscle metabolism during intense endurance cycling. Med Sci Sports Exerc 2002. [DOI: 10.1249/00005768-200204000-00009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Stephens TJ, McKenna MJ, Canny BJ, Snow RJ, McConell GK. Effect of sodium bicarbonate on muscle metabolism during intense endurance cycling. Med Sci Sports Exerc 2002; 34:614-21. [PMID: 11932569 DOI: 10.1097/00005768-200204000-00009] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Sodium bicarbonate (NaHCO3) ingestion has been shown to increase both muscle glycogenolysis and glycolysis during brief submaximal exercise. These changes may be detrimental to performance during more prolonged, exhaustive exercise. This study examined the effect of NaHCO3 ingestion on muscle metabolism and performance during intense endurance exercise of approximately 60 min in seven endurance-trained men. METHODS Subjects ingested 0.3 g.kg-1 body mass of either NaHCO3 or CaCO3 (CON) 2 h before performing 30 min of cycling exercise at 77 +/- 1% .VO(2peak) followed by completion of 469 +/- 21 kJ as quickly as possible (approximately 30 min, approximately 80% .VO(2peak)). RESULTS Immediately before, and throughout exercise, arterialized-venous plasma HCO3- concentrations were higher (P < 0.05) whereas plasma and muscle H+ concentrations were lower (P < 0.05) in NaHCO3 compared with CON. Blood lactate concentrations were higher (P < 0.05) during exercise in NaHCO3, but there was no difference between trials in muscle glycogen utilization or muscle lactate content during exercise. Reductions in PCr and ATP and increases in muscle Cr during exercise were also unaffected by NaHCO3 ingestion. Accordingly, exercise performance time was not different between treatments. CONCLUSION NaHCO3 ingestion resulted in a small muscle alkalosis but had no effect on muscle metabolism or intense endurance exercise performance in well-trained men.
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Affiliation(s)
- Terry J Stephens
- Department of Physiology, Monash University, Clayton, 3800 Victoria, Australia
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9
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Abstract
Lactate is known as the end product of anaerobic glycolysis, a pathway that is of key importance during high intensity exercise. Instead of being a waste product lactate is now regarded as a valuable substrate that significantly contributes to the energy production of heart, non-contracting muscles and even brain. The recent cloning of monocarboxylate transporters, a conserved protein family that transports lactate through biological membranes, has given a new insight into the role of lactate in whole body metabolism. This paper reviews current literature on lactate and monocarboxylate transporters with special reference to horses.
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Affiliation(s)
- A R Pösö
- Department of Basic Veterinary Sciences, University of Helsinki, Finland.
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10
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Agüera EI, Muñoz A, Castejón FM, Essén-Gustavsson B. Skeletal muscle fibre characteristics in young and old bulls and metabolic response after a bullfight. JOURNAL OF VETERINARY MEDICINE. A, PHYSIOLOGY, PATHOLOGY, CLINICAL MEDICINE 2001; 48:313-9. [PMID: 11475906 DOI: 10.1046/j.1439-0442.2001.00362.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fibre type composition, activities of enzymes such as citrate synthase (CS), 3-hydroxyacyl coenzyme A dehydrogenase (HAD), lactate dehydrogenase (LDH), as well as glycogen, lactate and pH levels were analysed in muscle biopsies (m. gluteus medius) obtained after bullfighting from 10 young and 10 old bulls. No changes were seen in fibre type composition between groups, but the older bulls had higher HAD and LDH activities. Low glycogen concentrations and low pH values were found in both groups, but the lactate concentration after bullfighting was higher in the older group of bulls. The histochemical stain for glycogen revealed that type IIB fibres in both young and old bulls contained more glycogen than seen in type IIA and type I fibres. These results show that young and old bulls have similar muscle fibre type composition, but the metabolic capacity differs, with a higher glycolytic capacity and lactate production in older bulls. Furthermore, it seems that the physical and emotional stress in connection with a bullfight causes a marked depletion of glycogen, especially of type I and IIA fibres.
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Affiliation(s)
- E I Agüera
- Department of Animal Biology (Physiology), Faculty of Veterinary Medicine, University of Córdoba
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Essén-Gustavsson B, Gottlieb-Vedi M, Lindholm A. Muscle adenine nucleotide degradation during submaximal treadmill exercise to fatigue. Equine Vet J 1999:298-302. [PMID: 10659272 DOI: 10.1111/j.2042-3306.1999.tb05238.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim was to investigate metabolic response in muscle during submaximal treadmill exercise to fatigue, with a special emphasis on adenine nucleotide degradation products such as inosine monophosphate (IMP) in muscle and hypoxanthine, xanthine and uric acid in plasma. Five Standardbred trotters performed treadmill exercise on 2 occasions, once at 7 m/s and once at 10 m/s. Venous blood samples were taken at rest, during exercise and at the end of exercise. Muscle biopsies were taken before and after exercise and muscle temperature was measured before and after exercise. Running time differed among horses and was 48-58 min at 7 m/s and 10-15.5 min at 10 m/s. Both lactate and uric acid concentrations in plasma showed a gradual increase during exercise at both 7 and 10 m/s. At the end of exercise, values for uric acid were higher and values for lactate lower at 7 m/s compared with at 10 m/s. No marked changes were seen in plasma concentrations of hypoxanthine or xanthine with exercise. Muscle glycogen decreased after exercise at both 7 and 10 m/s with a marked depletion seen in some fibres. Muscle lactate concentrations increased after exercise at both 7 m/s and at 10 m/s. No significant changes were seen in adenosine triphosphate (ATP), ADP and AMP concentrations, whereas IMP concentrations increased after exercise at both 7 m/s and at 10 m/s. The results of this study indicate that AMP deamination occurs with submaximal exercise and that development of fatigue may be related to adenine nucleotide degradation in muscle.
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Affiliation(s)
- B Essén-Gustavsson
- Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Abstract
Exercise in horses is associated with a wide variety of physiological changes in fluid, electrolyte and acid base balance. The integration of physiologic and physiochemical mechanisms acts to minimize alterations in pH and enhance removal of carbon dioxide produced by exercising muscles. This article provides a description of the changes that take place during exercise and how these changes affect acid-base balance in the horse.
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Affiliation(s)
- J K Kingston
- Department of Veterinary Clinical Sciences, Washington State University College of Veterinary Medicine, Pullman, USA
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13
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C. Harris R, Dunnett M, Greenhaff PL. Carnosine and taurine contents in individual fibres of human vastus lateralis muscle. J Sports Sci 1998. [DOI: 10.1080/026404198366443] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Räsänen LA, Wiitanen PA, Lilius EM, Hyyppä S, Pösö AR. Accumulation of uric acid in plasma after repeated bouts of exercise in the horse. Comp Biochem Physiol B Biochem Mol Biol 1996; 114:139-44. [PMID: 8759288 DOI: 10.1016/0305-0491(96)00022-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Plasma concentration of uric acid, total peroxyl radical-trapping antioxidative parameter (TRAP), blood lactate concentration and plasma activity of xanthine oxidase (XO) were measured in six Standardbreed trotters after six bouts of exercise with increasing intensity on two separate days three days apart. Blood samples were taken immediately, 5, 10, 15, 30 and 60 min after each heat and 2, 4, and 6 hr after the last heat. Exercise caused an increase in TRAP and in the concentrations of lactate and uric acid. Plasma uric acid concentration increased exponentially with respect to time after the last heat performed maximal speed, indicating a rapid increase in the rate of purine degradation. Plasma XO activity increased during exercise, but the intensity of exercise had only a minor effect on the level of XO activity. In conclusion, these data suggest that a threshold for the plasma accumulation of uric acid in terms of the intensity of exercise may exist and that XO may play a role in the formation of uric acid in horse plasma. Intense exercise causes an increase in the plasma antioxidant capacity that in the horse is mainly caused by the increase in the plasma uric acid concentration.
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Affiliation(s)
- L A Räsänen
- Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, Finland.
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15
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Sewell DA, Harris RC. Adenine nucleotide degradation in the thoroughbred horse with increasing exercise duration. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1992; 65:271-7. [PMID: 1396658 DOI: 10.1007/bf00705093] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Adenine nucleotide (AN) degradation has been shown to occur during intense exercise in the horse and in man, at or close to the point of fatigue. The aim of the study was to compare the concentrations of muscle inosine 5'-monophosphate (IMP) and plasma ammonia (NH3) during intense exercise with the concentrations of muscle and blood lactate. Seven trained thoroughbred horses were used in the study. Each exercised on a treadmill for periods of between 30 s and 150 s, at 11 and/or 12 m.s-1. Blood and muscle samples were taken and analysed for lactate and NH3 and adenosine 5'-triphosphate (ATP), phosphorylcreatine (PCr), IMP, creatine, lactate and glycerol-3-phosphate respectively. Horses showed varying degrees of AN degradation as indicated by plasma [NH3] and muscle [ATP] and [IMP]. Comparisons of [IMP] with muscle [lactate], and plasma [NH3] with that of blood [lactate] indicated a threshold to the start of AN degradation. This threshold corresponded to a lactate content of around 80 mmol.kg-1 dry muscle and 15 mmol.l-1 in blood. We discuss the mechanisms which have been proposed to account for AN degradation and suggest that IMP formation occurs as a result of a sudden rise in the concentration of adenosine 5'-diphosphate (ADP) and consequently the concentration of adenosine 5'-monophosphate. The data suggest a critical pH below which there may be a substantial reduction in the kinetics of ADP rephosphorylation provided by PCr resulting in an increase in [ADP], which is the stimulus to AN degradation during intense exercise.
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Affiliation(s)
- D A Sewell
- Department of Physiology, Animal Health Trust, Newmarket, Suffolk, UK
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16
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Essén-Gustavsson B, Karlström K, Lundström K. Muscle fibre characteristics and metabolic response at slaughter in pigs of different halothane genotypes and their relation to meat quality. Meat Sci 1992; 31:1-11. [DOI: 10.1016/0309-1740(92)90067-e] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/1990] [Revised: 12/28/1990] [Accepted: 01/04/1991] [Indexed: 10/27/2022]
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17
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Marlin DJ, Harris RC. Titrimetric determination of muscle buffering capacity (beta mtitr) in biopsy samples. Equine Vet J 1991; 23:193-7. [PMID: 1884700 DOI: 10.1111/j.2042-3306.1991.tb02753.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In vitro titration of muscle homogenates has been used to assess muscle buffering capacity (beta mtitr) in a variety of species. In the present study, factors likely to affect the estimation of beta mtitr were investigated. Also, values of beta mtitr from normal Thoroughbred horses are presented. A non-linear titration curve was obtained with addition of HCl to muscle homogenates. As a result, beta mtitr is expressed as the mumol H+ required to change the pH of 1g of dry muscle or wet muscle from 7.1 to 6.5. An effect of dilution on the initial pH was found below 40 mg wet muscle per ml homogenising reagent (10 mg dry muscle per ml) and on beta mtitr below 10 mg wet muscle. As a result, 40 mg wet muscle or 10 mg dry muscle per ml was chosen as the minimum concentration for determination of beta mtitr. Incubation of homogenates up to 60 mins did not affect beta mtitr significantly. As a mean, beta mtitr in wet muscle was approximately 25 per cent higher compared to dry muscle. The beta mtitr of dry muscle was increased by approximately 18 per cent when HCO3- was added in an amount equivalent to the calculated HCO3- content of wet muscle at rest. The homogenisation process resulted in complete loss of adenosine triphosphate and phosphocreatine with only small changes in adenosine diphosphate and adenosine monophosphate. It was concluded that the estimates of beta mtitr did not include any contribution from 'dynamic' buffering via rephosphorylation of adenosine diphosphate by phosphocreatine, and in dry muscle it was accounted for mainly through physico-chemical buffering by phosphates, proteins and dipeptides. beta mtitr determined in biopsy samples of muscle from 20 Thoroughbred horses ranged from 100.8 to 131.8 mumol H+/g dry muscle pH 7.1 to 6.5 (mean 121.2, sd +/- 7.4).
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Affiliation(s)
- D J Marlin
- Department of Comparative Physiology, Animal Heath Trust, Newmarket, Suffolk, UK
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18
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Marlin DJ, Harris RC, Gash SP, Snow DH. Carnosine content of the middle gluteal muscle in thoroughbred horses with relation to age, sex and training. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1989; 93:629-32. [PMID: 2569380 DOI: 10.1016/0300-9629(89)90023-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. Muscle biopsies were collected from 85 thoroughbred horses and analysed for carnosine content by an automated HPLC method. 2. No significant sex difference was found between colts, geldings and fillies. 3. There was a trend towards lower muscle carnosine contents with age, which was only significant between 1-year-old untrained horses and 4+ year-old horses (P less than 0.002).
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Affiliation(s)
- D J Marlin
- Department of Comparative Physiology, Animal Health Trust, Suffolk, England, UK
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