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Robergs R, O’Malley B, Torrens S, Siegler J. The missing hydrogen ion, part-2: Where the evidence leads to. SPORTS MEDICINE AND HEALTH SCIENCE 2024; 6:94-100. [PMID: 38463661 PMCID: PMC10918345 DOI: 10.1016/j.smhs.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 12/19/2023] [Accepted: 01/09/2024] [Indexed: 03/12/2024] Open
Abstract
The purpose of this manuscript was to present the evidence for why cells do not produce metabolic acids. In addition, evidence that opposes common viewpoints and arguments used to support the cellular production of lactic acid (HLa) or liver keto-acids have been provided. Organic chemistry reveals that many molecules involved in cellular energy catabolism contain functional groups classified as acids. The two main acidic functional groups of these molecules susceptible to ∼H+ release are the carboxyl and phosphoryl structures, though the biochemistry and organic chemistry of molecules having these structures reveal they are produced in a non-acidic ionic (negatively charged) structure, thereby preventing pH dependent ∼H+ release. Added evidence from the industrial production of HLa further reveals that lactate (La-) is produced followed by an acidification step that converts La- to HLa due to pH dependent ∼H+ association. Interestingly, there is a plentiful list of other molecules that are classified as acids and compared to HLa have similar values for their H+ dissociation constant (pKd). For many metabolic conditions, the cumulative turnover of these molecules is far higher than for La-. The collective evidence documents the non-empirical basis for the construct of the cellular production of HLa, or any other metabolic acid.
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Affiliation(s)
- Robert Robergs
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Kelvin Grove, Queensland, 4059, Australia
| | - Bridgette O’Malley
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Kelvin Grove, Queensland, 4059, Australia
| | - Sam Torrens
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Kelvin Grove, Queensland, 4059, Australia
| | - Jason Siegler
- ASU Health Futures Center, College of Health Solutions, Arizona State University, 6161 East Mayo Blvd, Phoenix, 85054, Arizona, USA
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Mukai K, Ohmura H, Takahashi Y, Ebisuda Y, Yoneda K, Miyata H. Physiological and skeletal muscle responses to high-intensity interval exercise in Thoroughbred horses. Front Vet Sci 2023; 10:1241266. [PMID: 38026631 PMCID: PMC10679931 DOI: 10.3389/fvets.2023.1241266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/19/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction The purpose of this study was to determine whether acute high-intensity interval exercise or sprint interval exercise induces greater physiological and skeletal muscle responses compared to moderate-intensity continuous exercise in horses. Methods In a randomized crossover design, eight trained Thoroughbred horses performed three treadmill exercise protocols consisting of moderate-intensity continuous exercise (6 min at 70% VO2max; MICT), high-intensity interval exercise (6 × 30 s at 100% VO2max; HIIT), and sprint interval exercise (6 × 15 s at 120% VO2max; SIT). Arterial blood samples were collected to measure blood gas variables and plasma lactate concentration. Biopsy samples were obtained from the gluteus medius muscle before, immediately after, 4 h, and 24 h after exercise for biochemical analysis, western blotting and real-time RT-PCR. Effects of time and exercise protocol were analyzed using mixed models (p < 0.05). Results Heart rate and plasma lactate concentration at the end of exercise were higher in HIIT and SIT than those in MICT (heart rate, HIIT vs. MICT, p = 0.0005; SIT vs. MICT, p = 0.0015; lactate, HIIT vs. MICT, p = 0.0014; SIT vs. MICT, p = 0.0003). Arterial O2 saturation and arterial pH in HIIT and SIT were lower compared with MICT (SaO2, HIIT vs. MICT, p = 0.0035; SIT vs. MICT, p = 0.0265; pH, HIIT vs. MICT, p = 0.0011; SIT vs. MICT, p = 0.0023). Muscle glycogen content decreased significantly in HIIT (p = 0.0004) and SIT (p = 0.0016) immediately after exercise, but not in MICT (p = 0.19). Phosphorylation of AMP-activated protein kinase (AMPK) in HIIT showed a significant increase immediately after exercise (p = 0.014), but the increase was not significant in MICT (p = 0.13) and SIT (p = 0.39). At 4 h after exercise, peroxisome proliferator-activated receptor γ co-activator-1α mRNA increased in HIIT (p = 0.0027) and SIT (p = 0.0019) and vascular endothelial growth factor mRNA increased in SIT (p = 0.0002). Discussion Despite an equal run distance, HIIT and SIT cause more severe arterial hypoxemia and lactic acidosis compared with MICT. In addition, HIIT activates the AMPK signaling cascade, and HIIT and SIT elevate mitochondrial biogenesis and angiogenesis, whereas MICT did not induce any significant changes to these signaling pathways.
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Affiliation(s)
- Kazutaka Mukai
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Hajime Ohmura
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Yuji Takahashi
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Yusaku Ebisuda
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Japan
| | - Koki Yoneda
- Biological Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Hirofumi Miyata
- Biological Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
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Aguilar LAB, Field CL, J Delaune A, Aflalo RA, Atkins A, Clauss TM. RETROSPECTIVE REVIEW OF PROPOFOL ANESTHESIA IN MULTIPLE ELASMOBRANCH SPECIES AT GEORGIA AQUARIUM, 2010-2022. J Zoo Wildl Med 2023; 54:326-331. [PMID: 37428695 DOI: 10.1638/2022-0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2023] [Indexed: 07/12/2023] Open
Abstract
General anesthesia is often required in elasmobranch species for medical procedures. A variety of anesthetic drugs have been administered to elasmobranchs with wide variability in efficacy and safety. A retrospective review of 47 anesthetic procedures using IV propofol in eight different elasmobranch species at the Georgia Aquarium from 2010 to 2022 was performed. Cases involving seven sand tiger sharks (Carcharias taurus), four largetooth sawfish (Pristis perotteti), one longcomb sawfish (Pristis zijsron), four blacktip reef sharks (Carcharhinus melanopterus), three silvertip sharks (Carcharhinus albimarginatus), one sandbar shark (Carcharhinus plumbeus), five cownose rays (Rhinoptera bonasus), and one blotched fantail stingray (Taeniura meyeni) were evaluated. Induction dose of IV propofol (median: 2.5; 25-75%: 2.3-3.0; range: 1.7-4.0 mg/kg), time to desired effect (median: 4.0; 25-75%: 2.0-5.0; range: 0.5-15.0 min) and anesthetic duration (median: 76.0; 25-75%: 61.5-119.0; range: 27-216 min) were reported in all species. In six procedures (12.7%), maintenance of desired anesthetic plane required a supplemental dose of propofol IV (1 mg/kg) or addition of tricaine methanesulfonate (70 mg/L) as an immersion bath. The most common side effects were apnea and prolonged recovery. The IV propofol was efficacious and provided a procedural plane of anesthesia for a clinically relevant period of time in the majority of elasmobranch species, but observation for and management of complications is warranted.
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Affiliation(s)
| | - Cara L Field
- The Marine Mammal Center, Fort Cronkhite, Sausalito, CA 94965, USA
| | | | - Roxane A Aflalo
- Animal Health Department, Georgia Aquarium, Atlanta, GA 30313, USA
| | - Adrienne Atkins
- Animal Health Department, Georgia Aquarium, Atlanta, GA 30313, USA
| | - Tonya M Clauss
- Animal Health Department, Georgia Aquarium, Atlanta, GA 30313, USA
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Li S, Zhang H, Zhu M, Kuang Z, Li X, Xu F, Miao S, Zhang Z, Lou X, Li H, Xia F. Electrochemical Biosensors for Whole Blood Analysis: Recent Progress, Challenges, and Future Perspectives. Chem Rev 2023. [PMID: 37262362 DOI: 10.1021/acs.chemrev.1c00759] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Whole blood, as one of the most significant biological fluids, provides critical information for health management and disease monitoring. Over the past 10 years, advances in nanotechnology, microfluidics, and biomarker research have spurred the development of powerful miniaturized diagnostic systems for whole blood testing toward the goal of disease monitoring and treatment. Among the techniques employed for whole-blood diagnostics, electrochemical biosensors, as known to be rapid, sensitive, capable of miniaturization, reagentless and washing free, become a class of emerging technology to achieve the target detection specifically and directly in complex media, e.g., whole blood or even in the living body. Here we are aiming to provide a comprehensive review to summarize advances over the past decade in the development of electrochemical sensors for whole blood analysis. Further, we address the remaining challenges and opportunities to integrate electrochemical sensing platforms.
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Affiliation(s)
- Shaoguang Li
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Hongyuan Zhang
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Man Zhu
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Zhujun Kuang
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Xun Li
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Fan Xu
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Siyuan Miao
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Zishuo Zhang
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Xiaoding Lou
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Hui Li
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Fan Xia
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
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Caslin HL, Abebayehu D, Pinette JA, Ryan JJ. Lactate Is a Metabolic Mediator That Shapes Immune Cell Fate and Function. Front Physiol 2021; 12:688485. [PMID: 34733170 PMCID: PMC8558259 DOI: 10.3389/fphys.2021.688485] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/22/2021] [Indexed: 12/12/2022] Open
Abstract
Lactate and the associated H+ ions are still introduced in many biochemistry and general biology textbooks and courses as a metabolic by-product within fast or oxygen-independent glycolysis. However, the role of lactate as a fuel source has been well-appreciated in the field of physiology, and the role of lactate as a metabolic feedback regulator and distinct signaling molecule is beginning to gain traction in the field of immunology. We now know that while lactate and the associated H+ ions are generally immunosuppressive negative regulators, there are cell, receptor, mediator, and microenvironment-specific effects that augment T helper (Th)17, macrophage (M)2, tumor-associated macrophage, and neutrophil functions. Moreover, we are beginning to uncover how lactate and H+ utilize different transporters and signaling cascades in various immune cell types. These immunomodulatory effects may have a substantial impact in cancer, sepsis, autoimmunity, wound healing, and other immunomodulatory conditions with elevated lactate levels. In this article, we summarize the known effects of lactate and H+ on immune cells to hypothesize potential explanations for the divergent inflammatory vs. anti-inflammatory effects.
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Affiliation(s)
- Heather L Caslin
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States.,Department of Biology, Virginia Commonwealth University, Richmond, VA, United States
| | - Daniel Abebayehu
- Department of Biology, Virginia Commonwealth University, Richmond, VA, United States.,Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Julia A Pinette
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States
| | - John J Ryan
- Department of Biology, Virginia Commonwealth University, Richmond, VA, United States
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Robergs RA. Quantifying H + exchange from muscle cytosolic energy catabolism using metabolite flux and H + coefficients from multiple competitive cation binding: New evidence for consideration in established theories. Physiol Rep 2021; 9:e14728. [PMID: 33904663 PMCID: PMC8077081 DOI: 10.14814/phy2.14728] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/18/2020] [Accepted: 01/03/2021] [Indexed: 11/30/2022] Open
Abstract
The purpose of this investigation was to present calculations of fractional H+ exchange (~H+e ) from the chemical reactions of non-mitochondrial energy catabolism. Data of muscle pH and metabolite accumulation were based on published research for intense exercise to contractile failure within ~3 min, from which capacities and time profiles were modeled. Data were obtained from prior research for multiple competitive cation dissociation constants of metabolites and the chemical reactions of non-mitochondrial energy catabolism, and pH dependent calculations of ~H+e from specific chemical reactions. Data revealed that the 3 min of intense exercise incurred a total ATP turnover of 142.5 mmol L-1 , with a total intramuscular ~H+ exchange (-'ve = release) of -187.9 mmol L-1 . Total ~H+ metabolic consumption was 130.6 mmol L-1 , revealing a net total ~H+e (~H+te ) of -57.3 mmol L-1 . Lactate production had a ~H+te of 44.2 mmol L-1 (for a peak accumulation = 45 mmol L-1 ). The net ~H+te for the sum of the CK, AK, and AMPD reactions was 36.33 mmol L-1 . The ~H+te from ATP turnover equaled -47.5 mmol L-1 . The total ~H+ release to lactate ratio was 4.3 (187.9/44). Muscle ~H+ release during intense exercise is up to ~4-fold larger than previously assumed based on the lactic acid construct.
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Affiliation(s)
- Robert A. Robergs
- School of Exercise and Nutrition SciencesFaculty of HealthQueensland University of TechnologyKelvin GroveQLDAustralia
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7
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Baumann L, Studhalter M. [Lactic Acidosis and Other Misunderstandings]. PRAXIS 2020; 109:979-983. [PMID: 32933388 DOI: 10.1024/1661-8157/a003508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lactic Acidosis and Other Misunderstandings Abstract. Lactic acidosis is a frequently encountered clinical problem in intensive care medicine. Nevertheless, many of the underlying biochemical processes are insufficiently understood, which leads to various misconceptions. Physiologically, lactate is an important, continuously produced carrier of energy and by no means a metabolic 'waste product'. Lactate is the corresponding base to lactic acid and is produced directly from pyruvate. In this reaction H+ is consumed and therefore lactate production itself cannot be directly responsible for the simultaneously arising acidosis. An elevated lactate level allows no conclusions about the underlying pathophysiological process, and, more importantly, it is not an appropriate marker for tissue oxygenation.
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8
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Meyerspeer M, Boesch C, Cameron D, Dezortová M, Forbes SC, Heerschap A, Jeneson JA, Kan HE, Kent J, Layec G, Prompers JJ, Reyngoudt H, Sleigh A, Valkovič L, Kemp GJ. 31 P magnetic resonance spectroscopy in skeletal muscle: Experts' consensus recommendations. NMR IN BIOMEDICINE 2020; 34:e4246. [PMID: 32037688 PMCID: PMC8243949 DOI: 10.1002/nbm.4246] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/01/2019] [Accepted: 12/02/2019] [Indexed: 05/07/2023]
Abstract
Skeletal muscle phosphorus-31 31 P MRS is the oldest MRS methodology to be applied to in vivo metabolic research. The technical requirements of 31 P MRS in skeletal muscle depend on the research question, and to assess those questions requires understanding both the relevant muscle physiology, and how 31 P MRS methods can probe it. Here we consider basic signal-acquisition parameters related to radio frequency excitation, TR, TE, spectral resolution, shim and localisation. We make specific recommendations for studies of resting and exercising muscle, including magnetisation transfer, and for data processing. We summarise the metabolic information that can be quantitatively assessed with 31 P MRS, either measured directly or derived by calculations that depend on particular metabolic models, and we give advice on potential problems of interpretation. We give expected values and tolerable ranges for some measured quantities, and minimum requirements for reporting acquisition parameters and experimental results in publications. Reliable examination depends on a reproducible setup, standardised preconditioning of the subject, and careful control of potential difficulties, and we summarise some important considerations and potential confounders. Our recommendations include the quantification and standardisation of contraction intensity, and how best to account for heterogeneous muscle recruitment. We highlight some pitfalls in the assessment of mitochondrial function by analysis of phosphocreatine (PCr) recovery kinetics. Finally, we outline how complementary techniques (near-infrared spectroscopy, arterial spin labelling, BOLD and various other MRI and 1 H MRS measurements) can help in the physiological/metabolic interpretation of 31 P MRS studies by providing information about blood flow and oxygen delivery/utilisation. Our recommendations will assist in achieving the fullest possible reliable picture of muscle physiology and pathophysiology.
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Affiliation(s)
- Martin Meyerspeer
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
- High Field MR CenterMedical University of ViennaViennaAustria
| | - Chris Boesch
- DBMR and DIPRUniversity and InselspitalBernSwitzerland
| | - Donnie Cameron
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- C. J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CentreLeidenthe Netherlands
| | - Monika Dezortová
- MR‐Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental MedicinePragueCzech Republic
| | - Sean C. Forbes
- Department of Physical TherapyUniversity of FloridaGainesvilleFloridaUSA
| | - Arend Heerschap
- Department of Radiology and Nuclear MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - Jeroen A.L. Jeneson
- Department of RadiologyAmsterdam University Medical Center|site AMCAmsterdamthe Netherlands
- Cognitive Neuroscience CenterUniversity Medical Center GroningenGroningenthe Netherlands
- Center for Child Development and Exercise, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Hermien E. Kan
- C. J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CentreLeidenthe Netherlands
- Duchenne CenterThe Netherlands
| | - Jane Kent
- Department of KinesiologyUniversity of Massachusetts AmherstMAUSA
| | - Gwenaël Layec
- Department of KinesiologyUniversity of Massachusetts AmherstMAUSA
- Institute for Applied Life SciencesUniversity of MassachusettsAmherstMAUSA
| | | | - Harmen Reyngoudt
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of Myology AIM‐CEAParisFrance
| | - Alison Sleigh
- Wolfson Brain Imaging CentreUniversity of CambridgeCambridgeUK
- Wellcome Trust‐MRC Institute of Metabolic ScienceUniversity of CambridgeCambridgeUK
- NIHR/Wellcome Trust Clinical Research FacilityCambridge University Hospitals NHS Foundation TrustCambridgeUK
| | - Ladislav Valkovič
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), RDM Cardiovascular Medicine, BHF Centre of Research ExcellenceUniversity of OxfordOxfordUK
- Department of Imaging MethodsInstitute of Measurement Science, Slovak Academy of SciencesBratislavaSlovakia
| | - Graham J. Kemp
- Department of Musculoskeletal Biology and Liverpool Magnetic Resonance Imaging Centre (LiMRIC)University of LiverpoolLiverpoolUK
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Hedges CP, Bishop DJ, Hickey AJR. Voluntary wheel running prevents the acidosis-induced decrease in skeletal muscle mitochondrial reactive oxygen species emission. FASEB J 2018; 33:4996-5004. [PMID: 30596520 DOI: 10.1096/fj.201801870r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Decreases in pH (acidosis) in vitro can alter skeletal muscle mitochondrial function [respiration and reactive oxygen species (ROS) emission]. However, because skeletal muscles readily adapt to exercise, the effects of acidosis may be different on sedentary vs. trained muscle. The aim of this work was to compare the effects of pH on skeletal muscle mitochondrial function between sedentary vs. exercise-trained male Sprague-Dawley rats ( n = 10 in each cohort). Rates of mitochondrial respiration and ROS emission were determined from the soleus muscle of both cohorts over a physiologic range of pH values (pH 6.2-7.1). Exercise-trained rats had 14% higher mean muscle buffering capacities; 46 and 40% greater enzyme activity of citrate synthase and lactate dehydrogenase, respectively; and greater activity of respiratory complexes I-IV. ADP-stimulated respiration with complex I and II substrates was ∼25% greater in exercise-trained rats but was unaffected by pH in either cohort. In both cohorts, lowering pH decreased respiration only in complex I- and complex II-supported nonphosphorylating (leak) state. However, as pH decreased, ROS emissions in complex I- and complex II-supported leak state decreased only in sedentary rats; in exercise-trained rats, ROS emissions in this state remained constant. We hypothesize that this effect may result from modulation at complex III, which declined 47% per unit pH in sedentary rats, in comparison to 23% in exercise-trained rats. Taken together, these data suggest that pH regulates mitochondrial respiratory complexes and that exercise training can decrease the effects of pH on skeletal muscle mitochondrial function.-Hedges, C. P., Bishop, D. J., Hickey, A. J. R. Voluntary wheel running prevents the acidosis-induced decrease in skeletal muscle mitochondrial reactive oxygen species emission.
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Affiliation(s)
- Christopher P Hedges
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, The University of Auckland, Auckland, New Zealand.,Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia; and
| | - David J Bishop
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia; and.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Anthony J R Hickey
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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10
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Faghy MA, Lomax M, Brown PI. Active recovery strategy and lactate clearance in elite swimmers. J Sports Med Phys Fitness 2018; 59:1487-1491. [PMID: 30468357 DOI: 10.23736/s0022-4707.18.09228-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Swimming requires sustained high performance, with limited recovery between heats, recovery strategies are essential to performance but are often self-regulated and sub-optimal. Accordingly, we investigated a physiologically determined recovery protocol. METHODS Fifteen (m=9, f=6) international junior age group swimmers participated in this study. The average age of the participants was 15.8±1.5 years. All participants completed a lactate elevation protocol (8 x 50 m sprints), followed by one of three recovery strategies: 1) velocity at lactate threshold (VLT); 2) coach prescribed protocol (COA); and 3) national governing body recommendations (NGB) and thereafter a 200-m time trial. RESULTS [lac-]B was similar between trials at baseline (pooled data: 1.3±0.4 mmol.l-1, P>0.05) but increased following 8x50 m sprints (pooled data 9.5±3.5 mmol.l-1, P<0.05) and reduced in all conditions (mean reduction 6.4±1.7 mmol.l-1). [lac-]B remained elevated following NGB (5.6±0.8 mmol.l-1, P<0.05) compared with COA (2.3±1.7 mmol.l-1) and VLT (1.7±1.2 mmol.l-1) but was blunted during the 200-m time trial in VLT (6.4±1.7 mmol.l-1, P<0.05). Time trial performance was similar between trials; VLT (2.24±0.12 min), COA (2.23±0.14 min) and NGB (2.22±0.13 min, P>0.05). CONCLUSIONS Despite similar performance, individually prescribed recovery strategy with a physiological basis will preserve repeated exercise performance performed on the same day.
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Affiliation(s)
- Mark A Faghy
- Human Science Research Centre, University of Derby, Derby, UK -
| | - Mitch Lomax
- Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, UK
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11
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A Fluorescent Biosensors for Detection Vital Body Fluids' Agents. SENSORS 2018; 18:s18082357. [PMID: 30042294 PMCID: PMC6111579 DOI: 10.3390/s18082357] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/13/2018] [Accepted: 07/20/2018] [Indexed: 12/18/2022]
Abstract
The clinical applications of sensing tools (i.e., biosensors) for the monitoring of physiologically important analytes are very common. Nowadays, the biosensors are being increasingly used to detect physiologically important analytes in real biological samples (i.e., blood, plasma, urine, and saliva). This review focuses on biosensors that can be applied to continuous, time-resolved measurements with fluorescence. The material presents the fluorescent biosensors for the detection of neurotransmitters, hormones, and other human metabolites as glucose, lactate or uric acid. The construction of microfluidic devices based on fluorescence uses a variety of materials, fluorescent dyes, types of detectors, excitation sources, optical filters, and geometrical systems. Due to their small size, these devices can perform a full analysis. Microfluidics-based technologies have shown promising applications in several of the main laboratory techniques, including blood chemistries, immunoassays, nucleic-acid amplification tests. Of the all technologies that are used to manufacture microfluidic systems, the LTCC technique seems to be an interesting alternative. It allows easy integration of electronic and microfluidic components on a single ceramic substrate. Moreover, the LTCC material is biologically and chemically inert, and is resistant to high temperature and pressure. The combination of all these features makes the LTCC technology particularly useful for implementation of fluorescence-based detection in the ceramic microfluidic systems.
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12
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Qian Q. Reply to Robergs et al. Physiology (Bethesda) 2018; 33:13. [PMID: 29212887 DOI: 10.1152/physiol.00034.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 10/30/2017] [Indexed: 11/22/2022] Open
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Kolker Baravik I, Capua E, Ainbinder E, Naaman R. Sensing Cellular Metabolic Activity via a Molecular-Controlled Semiconductor Resistor. ACS OMEGA 2017; 2:8550-8556. [PMID: 30023585 PMCID: PMC6045411 DOI: 10.1021/acsomega.7b01702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/09/2017] [Indexed: 05/08/2023]
Abstract
Over the last decade, we have developed a molecular-controlled semiconductor resistor (MOCSER) device that is highly sensitive to variations in its surface potentials. This device was applied as a molecular sensor both in the gas phase and in solutions. The device is based on an AlGaAs/GaAs structure. In the current work, we developed an electronic biosensor for real-time, label-free monitoring of cellular metabolic activity by culturing HeLa cells directly on top of the device's conductive channel. Several properties of GaAs make it attractive for developing biosensors, among others its high electron mobility and ability to control the device's properties by proper epitaxial growing. However, GaAs is very reactive and sensitive to oxidation in aqueous solutions, and its arsenic residues are highly toxic. Nevertheless, we have managed to overcome this inherent chemical instability by developing a surface-protecting layer using polymerized (3-mercaptopropyl)-trimethoxysilane (MPTMS). To improve cell adhesion and biocompatibility, the MPTMS-coated devices were further modified with an additional layer of (3-aminopropyl)-trimethoxysilane (APTMS). HeLa cells were found to grow successfully on these devices, and MOCSER devices cultured with these cells were stable and sensitive to cellular metabolic activity. The sensitivity of the MOCSER device results from the sensing of extracellular acidification in the microenvironment of the cell-MOCSER interspace. We have found that this sensitivity is maintained only when the device is partially covered with the cellular layer, whereas at full coverage the sensitivity is lost. This phenomenon is related to the negatively charged cellular membrane potentials that lead to a reduction in the channel's conductivity. We propose that the coated MOCSER device can be applied for real-time and continuous monitoring of cellular viability and activity.
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Affiliation(s)
- Ilina Kolker Baravik
- Department
of Chemical and Biological Physics and Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Eyal Capua
- Department
of Chemical and Biological Physics and Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Elena Ainbinder
- Department
of Chemical and Biological Physics and Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ron Naaman
- Department
of Chemical and Biological Physics and Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot 76100, Israel
- E-mail: (R.N.)
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14
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Robergs RA. Competitive cation binding computations of proton balance for reactions of the phosphagen and glycolytic energy systems within skeletal muscle. PLoS One 2017; 12:e0189822. [PMID: 29267370 PMCID: PMC5739460 DOI: 10.1371/journal.pone.0189822] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/02/2017] [Indexed: 01/11/2023] Open
Abstract
Limited research and data has been published for the H+ coefficients for the metabolites and reactions involved in non-mitochondrial energy metabolism. The purpose of this investigation was to compute the fractional binding of H+, K+, Na+ and Mg2+ to 21 metabolites of skeletal muscle non-mitochondrial energy metabolism, resulting in 104 different metabolite-cation complexes. Fractional binding of H+ to these metabolite-cation complexes were applied to 17 reactions of skeletal muscle non-mitochondrial energy metabolism, and 8 conditions of the glycolytic pathway based on the source of substrate (glycogen vs. glucose), completeness of glycolytic flux, and the end-point of pyruvate vs. lactate. For pH conditions of 6.0 and 7.0, respectively, H+ coefficients (-‘ve values = H+ release) for the creatine kinase, adenylate kinase, AMP deaminase and ATPase reactions were 0.8 and 0.97, -0.13 and -0.02, 1.2 and 1.09, and -0.01 and -0.66, respectively. The glycolytic pathway is net H+ releasing, regardless of lactate production, which consumes 1 H+. For glycolysis fueled by glycogen and ending in either pyruvate or lactate, H+ coefficients for pH 6.0 and 7.0 were -3.97 and -2.01 (pyruvate), and -1.96 and -0.01 (lactate), respectively. When starting with glucose, the same conditions result in H+ coefficients of -3.98 and -2.67, and -1.97 and –0.67, respectively. The most H+ releasing reaction of glycolysis is the glyceraldehyde-3-phosphate dehydrogenase reaction, with H+ coefficients for pH 6.0 and 7.0 of -1.58 and -0.76, respectively. Incomplete flux of substrate through glycolysis would increase net H+ release due to the absence of the pyruvate kinase and lactate dehydrogenase reactions, which collectively result in H+ coefficients for pH 6.0 and 7.0 of 1.35 and 1.88, respectively. The data presented provide an extensive reference source for academics and researchers to accurately profile the balance of protons for all metabolites and reactions of non-mitochondrial energy metabolism, and reveal the greater role of glycolysis in net H+ release than previously assumed. The data can also be used to improve the understanding of the cause of metabolic acidosis, and reveal mechanistic connections between H+ release within and from muscle and the electrochemical neutrality concepts that further refine acid-base balance in biological solutions.
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Affiliation(s)
- Robert Andrew Robergs
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Kelvin Grove, Queensland, Australia
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15
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Wang X, Li J, Cong J, Chen X, Zhu X, Zhang L, Gao F, Zhou G. Preslaughter Transport Effect on Broiler Meat Quality and Post-mortem Glycolysis Metabolism of Muscles with Different Fiber Types. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:10310-10316. [PMID: 29110475 DOI: 10.1021/acs.jafc.7b04193] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Preslaughter transport has been reported to decrease the quality of breast meat but not thigh meat of broilers. However, tissue-specific difference in glycogen metabolism between breast and thigh muscles of transported broilers has not been well studied. We thus investigated the differences in meat quality, adenosine phosphates, glycolysis, and bound key enzymes associated with glycolysis metabolism in skeletal muscles with different fiber types of preslaughter transported broilers during summer. Compared to a 0.5 h transport, a 3 h transport during summer decreased ATP content, increased AMP content and AMP/ATP ratio, and accelerated glycolysis metabolism via the upregulation of glycogen phosphorylase expression accompanied by increased activities of bound glycolytic enzymes (hexokinase, pyruvate kinase, and lactate dehydrogenase) in pectoralis major muscle, which subsequently increased the likelihood of pale, soft, and exudative-like breast meat. On the other hand, a 3 h transport induced only a moderate glycolysis metabolism in tibialis anterior muscle, which did not cause any noticeable changes in the quality traits of the thigh meat.
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Affiliation(s)
- Xiaofei Wang
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
- College of Science, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Jiaolong Li
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Jiahui Cong
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Xiangxing Chen
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Xudong Zhu
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
- College of Science, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Lin Zhang
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Feng Gao
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
| | - Guanghong Zhou
- College of Animal Science and Technology, Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China
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16
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Hundshammer C, Düwel S, Köcher SS, Gersch M, Feuerecker B, Scheurer C, Haase A, Glaser SJ, Schwaiger M, Schilling F. Deuteration of Hyperpolarized 13
C-Labeled Zymonic Acid Enables Sensitivity-Enhanced Dynamic MRI of pH. Chemphyschem 2017; 18:2422-2425. [DOI: 10.1002/cphc.201700779] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Indexed: 01/15/2023]
Affiliation(s)
- Christian Hundshammer
- Department of Nuclear Medicine; Klinikum rechts der Isar; Technical University of Munich; Ismaninger Str. 22 81675 München Germany
- Department of Chemistry; Technical University of Munich; Lichtenbergstr. 4 85748 Garching Germany
| | - Stephan Düwel
- Department of Nuclear Medicine; Klinikum rechts der Isar; Technical University of Munich; Ismaninger Str. 22 81675 München Germany
- Department of Chemistry; Technical University of Munich; Lichtenbergstr. 4 85748 Garching Germany
- Institute of Medical Engineering; Technical University of Munich; Boltzmannstr. 11 85748 Garching Germany
| | - Simone S. Köcher
- Department of Chemistry; Technical University of Munich; Lichtenbergstr. 4 85748 Garching Germany
- Institute of Energy and Climate Research (IEK-9); Forschungszentrum Jülich, Ostring O10 52425 Jülich Germany
| | - Malte Gersch
- Department of Chemistry; Technical University of Munich; Lichtenbergstr. 4 85748 Garching Germany
| | - Benedikt Feuerecker
- Department of Nuclear Medicine; Klinikum rechts der Isar; Technical University of Munich; Ismaninger Str. 22 81675 München Germany
| | - Christoph Scheurer
- Department of Chemistry; Technical University of Munich; Lichtenbergstr. 4 85748 Garching Germany
| | - Axel Haase
- Institute of Medical Engineering; Technical University of Munich; Boltzmannstr. 11 85748 Garching Germany
| | - Steffen J. Glaser
- Department of Chemistry; Technical University of Munich; Lichtenbergstr. 4 85748 Garching Germany
| | - Markus Schwaiger
- Department of Nuclear Medicine; Klinikum rechts der Isar; Technical University of Munich; Ismaninger Str. 22 81675 München Germany
| | - Franz Schilling
- Department of Nuclear Medicine; Klinikum rechts der Isar; Technical University of Munich; Ismaninger Str. 22 81675 München Germany
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17
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Revenga-Parra M, Martínez-Periñán E, Moreno B, Pariente F, Lorenzo E. Rapid taurine and lactate biomarkers determination with disposable electrochemical detectors. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.04.100] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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18
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Chan D, Barsan MM, Korpan Y, Brett CM. L-lactate selective impedimetric bienzymatic biosensor based on lactate dehydrogenase and pyruvate oxidase. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.02.050] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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19
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Bravo I, Revenga-Parra M, Pariente F, Lorenzo E. Reagent-Less and Robust Biosensor for Direct Determination of Lactate in Food Samples. SENSORS 2017; 17:s17010144. [PMID: 28098753 PMCID: PMC5298717 DOI: 10.3390/s17010144] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/20/2016] [Accepted: 01/11/2017] [Indexed: 11/23/2022]
Abstract
Lactic acid is a relevant analyte in the food industry, since it affects the flavor, freshness, and storage quality of several products, such as milk and dairy products, juices, or wines. It is the product of lactose or malo-lactic fermentation. In this work, we developed a lactate biosensor based on the immobilization of lactate oxidase (LOx) onto N,N′-Bis(3,4-dihydroxybenzylidene) -1,2-diaminobenzene Schiff base tetradentate ligand-modified gold nanoparticles (3,4DHS–AuNPs) deposited onto screen-printed carbon electrodes, which exhibit a potent electrocatalytic effect towards hydrogen peroxide oxidation/reduction. 3,4DHS–AuNPs were synthesized within a unique reaction step, in which 3,4DHS acts as reducing/capping/modifier agent for the generation of stable colloidal suspensions of Schiff base ligand–AuNPs assemblies of controlled size. The ligand—in addition to its reduction action—provides a robust coating to gold nanoparticles and a catalytic function. Lactate oxidase (LOx) catalyzes the conversion of l-lactate to pyruvate in the presence of oxygen, producing hydrogen peroxide, which is catalytically oxidized at 3,4DHS–AuNPs modified screen-printed carbon electrodes at +0.2 V. The measured electrocatalytic current is directly proportional to the concentration of peroxide, which is related to the amount of lactate present in the sample. The developed biosensor shows a detection limit of 2.6 μM lactate and a sensitivity of 5.1 ± 0.1 μA·mM−1. The utility of the device has been demonstrated by the determination of the lactate content in different matrixes (white wine, beer, and yogurt). The obtained results compare well to those obtained using a standard enzymatic-spectrophotometric assay kit.
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Affiliation(s)
- Iria Bravo
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Faraday, 9, Campus UAM, Cantoblanco, 28049 Madrid, Spain.
| | - Mónica Revenga-Parra
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Faraday, 9, Campus UAM, Cantoblanco, 28049 Madrid, Spain.
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Félix Pariente
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Encarnación Lorenzo
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Faraday, 9, Campus UAM, Cantoblanco, 28049 Madrid, Spain.
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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20
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Inoue DS, Panissa VLG, Monteiro PA, Gerosa-Neto J, Rossi FE, Antunes BMM, Franchini E, Cholewa JM, Gobbo LA, Lira FS. Immunometabolic Responses to Concurrent Training: The Effects of Exercise Order in Recreational Weightlifters. J Strength Cond Res 2016; 30:1960-7. [PMID: 26626027 DOI: 10.1519/jsc.0000000000001281] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Inoue, DS, Panissa, VLG, Monteiro, PA, Gerosa-Neto, J, Rossi, FE, Antunes, BMM, Franchini, E, Cholewa, JM, Gobbo, LA, and Lira, FS. Immunometabolic responses to concurrent training: the effects of exercise order in recreational weightlifters. J Strength Cond Res 30(7): 1960-1967, 2016-The relationship between immunometabolic response and performance is not well understood. This study evaluated the influence of concurrent strength and high-intensity aerobic sequence of exercise order between sessions on strength performance, metabolic, and inflammatory response. Eleven recreational weightlifters underwent the following 2 randomized sessions: (a) strength-aerobic exercise order (SA) and (b) aerobic-strength exercise order (AS). Blood samples were collected before (Pre) and immediately after the first exercise (Post-1) and the second exercise (Post-2) of each session. The SA condition presented a higher number of repetitions (SA: 54 ± 15 vs. AS: 43 ± 12) and total volume (SA: 7,265 ± 2,323 vs. AS: 5,794 ± 1846 kg) than the AS condition (both p = 0.001). Glucose was higher in Pre when compared with post-1 in both orders (p ≤ 0.05); changes in lactate were time-dependent in the different orders (p ≤ 0.05); however, AS post-2 lactate was lower when compared with SA post-2 (p ≤ 0.05). Interleukin-6 levels showed time-dependent changes for both exercise orders (p ≤ 0.05). Tumor necrosis factor alpha (TNF-α) level was increased only in AS post-1 (AS: pre = 21.91 ± 35.47, post-1 = 26.99 ± 47.69 pg·ml vs. SA: pre = 25.74 ± 43.64, post-1 = 29.74 ± 46.05 pg·ml, p ≤ 0.05). These results suggest that concurrent training order exhibits different immunometabolic responses and, at least in part, can be associated with the acute decline in strength performance induced by concurrent exercise. Our results point to a possible role of TNF-α (post-1 AS condition) as a trigger to restore the energy demand by providing substrates to help maintain contractile activity in skeletal muscle.
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Affiliation(s)
- Daniela S Inoue
- 1Exercise and Immunometabolism Research Group, Department of Physical Education, São Paulo State University, Presidente Prudente, São Paulo, Brazil; 2Department of Sport, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil; 3Center and Prescription Motor Activity Laboratory, Department of Physical Education, Sáo Paulo State University, Presidente Prudente, São Paulo, Brazil; and 4Department of Kinesiology, Coastal Carolina University, Conway, South Carolina
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21
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McGinley C, Bishop DJ. Influence of training intensity on adaptations in acid/base transport proteins, muscle buffer capacity, and repeated-sprint ability in active men. J Appl Physiol (1985) 2016; 121:1290-1305. [DOI: 10.1152/japplphysiol.00630.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/03/2016] [Accepted: 10/06/2016] [Indexed: 11/22/2022] Open
Abstract
McGinley C, Bishop DJ. Influence of training intensity on adaptations in acid/base transport proteins, muscle buffer capacity, and repeated-sprint ability in active men. J Appl Physiol 121: 1290–1305, 2016. First published October 14, 2016; doi: 10.1152/japplphysiol.00630.2016 .—This study measured the adaptive response to exercise training for each of the acid-base transport protein families, including providing isoform-specific evidence for the monocarboxylate transporter (MCT)1/4 chaperone protein basigin and for the electrogenic sodium-bicarbonate cotransporter (NBCe)1. We investigated whether 4 wk of work-matched, high-intensity interval training (HIIT), performed either just above the lactate threshold (HIITΔ20; n = 8), or close to peak aerobic power (HIITΔ90; n = 8), influenced adaptations in acid-base transport protein abundance, nonbicarbonate muscle buffer capacity (βmin vitro), and exercise capacity in active men. Training intensity did not discriminate between adaptations for most proteins measured, with abundance of MCT1, sodium/hydrogen exchanger (NHE) 1, NBCe1, carbonic anhydrase (CA) II, and CAXIV increasing after 4 wk, whereas there was little change in CAIII and CAIV abundance. βmin vitro also did not change. However, MCT4 protein content only increased for HIITΔ20 [effect size (ES): 1.06, 90% confidence limits × / ÷ 0.77], whereas basigin protein content only increased for HIITΔ90 (ES: 1.49, × / ÷ 1.42). Repeated-sprint ability (5 × 6-s sprints; 24 s passive rest) improved similarly for both groups. Power at the lactate threshold only improved for HIITΔ20 (ES: 0.49; 90% confidence limits ± 0.38), whereas peak O2 uptake did not change for either group. Detraining was characterized by the loss of adaptations for all of the proteins measured and for repeated-sprint ability 6 wk after removing the stimulus of HIIT. In conclusion, 4 wk of HIIT induced improvements in each of the acid-base transport protein families, but, remarkably, a 40% difference in training intensity did not discriminate between most adaptations.
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Affiliation(s)
- Cian McGinley
- College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia; and
| | - David J. Bishop
- College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia; and
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
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22
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Rathee K, Dhull V, Dhull R, Singh S. Biosensors based on electrochemical lactate detection: A comprehensive review. Biochem Biophys Rep 2015; 5:35-54. [PMID: 28955805 PMCID: PMC5600356 DOI: 10.1016/j.bbrep.2015.11.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/08/2015] [Accepted: 11/10/2015] [Indexed: 01/19/2023] Open
Abstract
Lactate detection plays a significant role in healthcare, food industries and is specially necessitated in conditions like hemorrhage, respiratory failure, hepatic disease, sepsis and tissue hypoxia. Conventional methods for lactate determination are not accurate and fast so this accelerated the need of sensitive biosensors for high-throughput screening of lactate in different samples. This review focuses on applications and developments of various electrochemical biosensors based on lactate detection as lactate being essential metabolite in anaerobic metabolic pathway. A comparative study to summarize the L-lactate biosensors on the basis of different analytical properties in terms of fabrication, sensitivity, detection limit, linearity, response time and storage stability has been done. It also addresses the merits and demerits of current enzyme based lactate biosensors. Lactate biosensors are of two main types – lactate oxidase (LOD) and lactate dehydrogenase (LDH) based. Different supports tried for manufacturing lactate biosensors include membranes, polymeric matrices-conducting or non-conducting, transparent gel matrix, hydrogel supports, screen printed electrodes and nanoparticles. All the examples in these support categories have been aptly discussed. Finally this review encompasses the conclusion and future emerging prospects of lactate sensors. Different enzymes used in lactate bio sensing have been studied. Support used for fabrication biosensors have been discussed. The linearity range, response time, detection limit, etc. have been studied. Merits and demerits of different supports are also discussed.
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Affiliation(s)
- Kavita Rathee
- Department of Biochemistry, Maharshi Dayanand University, Rohtak 124001, India
| | - Vikas Dhull
- Department of Bio & Nano Technology, Guru Jambheshwar University of Science & Technology, Hisar 125001, India
| | - Rekha Dhull
- Department of Biochemistry, Maharshi Dayanand University, Rohtak 124001, India
| | - Sandeep Singh
- Department of Biochemistry, Maharshi Dayanand University, Rohtak 124001, India
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23
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Divakaruni AS, Paradyse A, Ferrick DA, Murphy AN, Jastroch M. Analysis and interpretation of microplate-based oxygen consumption and pH data. Methods Enzymol 2015; 547:309-54. [PMID: 25416364 DOI: 10.1016/b978-0-12-801415-8.00016-3] [Citation(s) in RCA: 323] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Breakthrough technologies to measure cellular oxygen consumption and proton efflux are reigniting the study of cellular energetics by increasing the scope and pace with which discoveries are made. As we learn the variation in metabolism between cell types is large, it is helpful to continually provide additional perspectives and update our roadmap for data interpretation. In that spirit, this chapter provides the following for those conducting microplate-based oxygen consumption experiments: (i) a description of the standard parameters for measuring respiration in intact cells, (ii) a framework for data analysis and normalization, and (iii) examples of measuring respiration in permeabilized cells to follow up results observed with intact cells. Additionally, rate-based measurements of extracellular pH are increasingly used as a qualitative indicator of glycolytic flux. As a resource to help interpret these measurements, this chapter also provides a detailed accounting of proton production during glucose oxidation in the context of plate-based assays.
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Affiliation(s)
- Ajit S Divakaruni
- Department of Pharmacology, University of California, San Diego, California, USA.
| | - Alexander Paradyse
- Department of Pharmacology, University of California, San Diego, California, USA
| | | | - Anne N Murphy
- Department of Pharmacology, University of California, San Diego, California, USA
| | - Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
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24
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Kemp GJ, Ahmad RE, Nicolay K, Prompers JJ. Quantification of skeletal muscle mitochondrial function by 31P magnetic resonance spectroscopy techniques: a quantitative review. Acta Physiol (Oxf) 2015; 213:107-44. [PMID: 24773619 DOI: 10.1111/apha.12307] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 12/30/2013] [Accepted: 04/23/2014] [Indexed: 12/16/2022]
Abstract
Magnetic resonance spectroscopy (MRS) can give information about cellular metabolism in vivo which is difficult to obtain in other ways. In skeletal muscle, non-invasive (31) P MRS measurements of the post-exercise recovery kinetics of pH, [PCr], [Pi] and [ADP] contain valuable information about muscle mitochondrial function and cellular pH homeostasis in vivo, but quantitative interpretation depends on understanding the underlying physiology. Here, by giving examples of the analysis of (31) P MRS recovery data, by some simple computational simulation, and by extensively comparing data from published studies using both (31) P MRS and invasive direct measurements of muscle O2 consumption in a common analytical framework, we consider what can be learnt quantitatively about mitochondrial metabolism in skeletal muscle using MRS-based methodology. We explore some technical and conceptual limitations of current methods, and point out some aspects of the physiology which are still incompletely understood.
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Affiliation(s)
- G. J. Kemp
- Department of Musculoskeletal Biology, and Magnetic Resonance and Image Analysis Research Centre; University of Liverpool; Liverpool UK
| | - R. E. Ahmad
- Department of Musculoskeletal Biology, and Magnetic Resonance and Image Analysis Research Centre; University of Liverpool; Liverpool UK
| | - K. Nicolay
- Biomedical NMR; Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven the Netherlands
| | - J. J. Prompers
- Biomedical NMR; Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven the Netherlands
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25
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Pike Winer LS, Wu M. Rapid analysis of glycolytic and oxidative substrate flux of cancer cells in a microplate. PLoS One 2014; 9:e109916. [PMID: 25360519 PMCID: PMC4215881 DOI: 10.1371/journal.pone.0109916] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 09/01/2014] [Indexed: 12/15/2022] Open
Abstract
Cancer cells exhibit remarkable alterations in cellular metabolism, particularly in their nutrient substrate preference. We have devised several experimental methods that rapidly analyze the metabolic substrate flux in cancer cells: glycolysis and the oxidation of major fuel substrates glucose, glutamine, and fatty acids. Using the XF Extracellular Flux analyzer, these methods measure, in real-time, the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) of living cells in a microplate as they respond to substrates and metabolic perturbation agents. In proof-of-principle experiments, we analyzed substrate flux and mitochondrial bioenergetics of two human glioblastoma cell lines, SF188s and SF188f, which were derived from the same parental cell line but proliferate at slow and fast rates, respectively. These analyses led to three interesting observations: 1) both cell lines respired effectively with substantial endogenous substrate respiration; 2) SF188f cells underwent a significant shift from glycolytic to oxidative metabolism, along with a high rate of glutamine oxidation relative to SF188s cells; and 3) the mitochondrial proton leak-linked respiration of SF188f cells increased significantly compared to SF188s cells. It is plausible that the proton leak of SF188f cells may play a role in allowing continuous glutamine-fueled anaplerotic TCA cycle flux by partially uncoupling the TCA cycle from oxidative phosphorylation. Taken together, these rapid, sensitive and high-throughput substrate flux analysis methods introduce highly valuable approaches for developing a greater understanding of genetic and epigenetic pathways that regulate cellular metabolism, and the development of therapies that target cancer metabolism.
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Affiliation(s)
- Lisa S Pike Winer
- Seahorse Bioscience Inc., North Billerica, Massachusetts, United States of America
| | - Min Wu
- Seahorse Bioscience Inc., North Billerica, Massachusetts, United States of America
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Lactate biosensors: current status and outlook. Anal Bioanal Chem 2013; 406:123-37. [PMID: 24037614 DOI: 10.1007/s00216-013-7307-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/10/2013] [Accepted: 08/13/2013] [Indexed: 10/26/2022]
Abstract
Many research efforts over the last few decades have been devoted to sensing lactate as an important analytical target in clinical care, sport medicine, and food processing. Therefore, research in designing lactate sensors is no longer in its infancy and now is more directed toward viable sensors for direct applications. In this review, we provide an overview of the most immediate and relevant developments toward this end, and we discuss and assess common transduction approaches. Further, we critically describe the pros and cons of current commercial lactate sensors and envision how future sensing design may benefit from emerging new technologies.
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Leung HM, Schafer R, Pagel MM, Robey IF, Gmitro AF. Multimodality pH imaging in a mouse dorsal skin fold window chamber model. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2013; 8574. [PMID: 27688523 DOI: 10.1117/12.2005472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Upregulate levels of expression and activity of membrane H+ ion pumps in cancer cells drives the extracellular pH (pHe,) to values lower than normal. Furthermore, disregulated pH is indicative of the changes in glycolytic metabolism in tumor cells and has been shown to facilitate extracellular tissue remodeling during metastasis Therefore, measurement of pHe could be a useful cancer biomarker for diagnostic and therapy monitoring evaluation. Multimodality in-vivo imaging of pHe in tumorous tissue in a mouse dorsal skin fold window chamber (DSFWC) model is described. A custom-made plastic window chamber structure was developed that is compatible with both imaging optical and MR imaging modalities and provides a model system for continuous study of the same tissue microenvironment on multiple imaging platforms over a 3-week period. For optical imaging of pHe, SNARF-1 carboxylic acid is injected intravenously into a SCID mouse with an implanted tumor. A ratiometric measurement of the fluorescence signal captured on a confocal microscope reveals the pHe of the tissue visible within the window chamber. This imaging method was used in a preliminary study to evaluate sodium bicarbonate as a potential drug treatment to reverse tissue acidosis. For MR imaging of pHe the chemical exchange saturation transfer (CEST) was used as an alternative way of measuring pHe in a DSFWC model. ULTRAVIST®, a FDA approved x-ray/CT contrast agent has been shown to have a CEST effect that is pH dependent. A ratiometric analysis of water saturation at 5.6 and 4.2 ppm chemical shift provides a means to estimate the local pHe.
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Affiliation(s)
- Hui Min Leung
- University of Arizona, College of Optical Sciences; University of Arizona, Department of Medical Imaging
| | | | - Mark M Pagel
- University of Arizona, Department of Medical Imaging; University of Arizona, Biomedical Engineering; University of Arizona, Arizona Cancer Center
| | - Ian F Robey
- University of Arizona, Arizona Cancer Center
| | - Arthur F Gmitro
- University of Arizona, College of Optical Sciences; University of Arizona, Department of Medical Imaging; University of Arizona, Biomedical Engineering
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Lomax M. The Effect of Three Recovery Protocols on Blood Lactate Clearance After Race-Paced Swimming. J Strength Cond Res 2012; 26:2771-6. [DOI: 10.1519/jsc.0b013e318241ded7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Meyerspeer M, Robinson S, Nabuurs CI, Scheenen T, Schoisengeier A, Unger E, Kemp GJ, Moser E. Comparing localized and nonlocalized dynamic 31P magnetic resonance spectroscopy in exercising muscle at 7 T. Magn Reson Med 2012; 68:1713-23. [PMID: 22334374 PMCID: PMC3378633 DOI: 10.1002/mrm.24205] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 01/11/2012] [Accepted: 01/19/2012] [Indexed: 12/31/2022]
Abstract
By improving spatial and anatomical specificity, localized spectroscopy can enhance the power and accuracy of the quantitative analysis of cellular metabolism and bioenergetics. Localized and nonlocalized dynamic (31)P magnetic resonance spectroscopy using a surface coil was compared during aerobic exercise and recovery of human calf muscle. For localization, a short echo time single-voxel magnetic resonance spectroscopy sequence with adiabatic refocusing (semi-LASER) was applied, enabling the quantification of phosphocreatine, inorganic phosphate, and pH value in a single muscle (medial gastrocnemius) in single shots (T(R) = 6 s). All measurements were performed in a 7 T whole body scanner with a nonmagnetic ergometer. From a series of equal exercise bouts we conclude that: (a) with localization, measured phosphocreatine declines in exercise to a lower value (79 ± 7% cf. 53 ± 10%, P = 0.002), (b) phosphocreatine recovery shows shorter half time (t(1/2) = 34 ± 7 s cf. t(1/2) = 42 ± 7 s, nonsignificant) and initial postexercise phosphocreatine resynthesis rate is significantly higher (32 ± 5 mM/min cf. 17 ± 4 mM/min, P = 0.001) and (c) in contrast to nonlocalized (31)P magnetic resonance spectroscopy, no splitting of the inorganic phosphate peak is observed during exercise or recovery, just an increase in line width during exercise. This confirms the absence of contaminating signals originating from weaker-exercising muscle, while an observed inorganic phosphate line broadening most probably reflects variations across fibers in a single muscle.
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Affiliation(s)
- Martin Meyerspeer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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Lessons to learn about postmortem metabolism using the AMPKγ3R200Q mutation in the pig. Meat Sci 2011; 89:244-50. [DOI: 10.1016/j.meatsci.2011.04.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 04/28/2011] [Accepted: 04/28/2011] [Indexed: 11/19/2022]
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Vinnakota KC, Kushmerick MJ. Point: Muscle lactate and H+ production do have a 1:1 association in skeletal muscle. J Appl Physiol (1985) 2011; 110:1487-9; discussion 1497. [DOI: 10.1152/japplphysiol.01506.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Kalyan C. Vinnakota
- Biotechnology and Bioengineering Center
- Department of Physiology Medical College of Wisconsin Milwaukee, Wisconsin
| | - Martin J. Kushmerick
- Departments of Radiology and
- Bioengineering and
- Physiology and Biophysics University of Washington Seattle, Washington
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Vinnakota KC, Rusk J, Palmer L, Shankland E, Kushmerick MJ. Common phenotype of resting mouse extensor digitorum longus and soleus muscles: equal ATPase and glycolytic flux during transient anoxia. J Physiol 2010; 588:1961-83. [PMID: 20308252 DOI: 10.1113/jphysiol.2009.185934] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Rates of ATPase and glycolysis are several times faster in actively contracting mouse extensor digitorum longus muscle (EDL) than soleus (SOL), but we find these rates are not distinguishable at rest. We used a transient anoxic perturbation of steady state energy balance to decrease phosphocreatine (PCr) reversibly and to measure the rates of ATPase and of lactate production without muscle activation or contraction. The rate of glycolytic ATP synthesis is less than the ATPase rate, accounting for the continual PCr decrease during anoxia in both muscles. We fitted a mathematical model validated with properties of enzymes and solutes measured in vitro and appropriate for the transient perturbation of these muscles to experimental data to test whether the model accounts for the results. Simulations showed equal rates of ATPase and lactate production in both muscles. ATPase controls glycolytic flux by feedback from its products. Adenylate kinase function is critical because a rise in [AMP] is necessary to activate glycogen phosphorylase. ATPase is the primary source of H+ production. The sum of contributions of the 13 reactions of the glycogenolytic and glycolytic network to total proton load is negligible. The stoichiometry of lactate and H+ production is near unity. These results identify a default state of energy metabolism for resting muscle in which there is no difference in the metabolic phenotype of EDL and SOL. Therefore, additional control mechanisms, involving higher ATPase flux and [Ca2+], must exist to explain the well-known difference in glycolytic rates in fast-twitch and slow-twitch muscles in actively contracting muscle.
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Affiliation(s)
- Kalyan C Vinnakota
- University of Washington, Mail Box 357115, Department of Radiology, 1959 NE Pacific Avenue, HSC AA010, Seattle, WA 09105-7115, USA
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Marcinek DJ, Kushmerick MJ, Conley KE. Lactic acidosis in vivo: testing the link between lactate generation and H+ accumulation in ischemic mouse muscle. J Appl Physiol (1985) 2010; 108:1479-86. [PMID: 20133437 DOI: 10.1152/japplphysiol.01189.2009] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The link between lactate generation and cellular acidosis has been questioned based on the possibility of H+ generation, independent of lactate production during glycolysis under physiological conditions. Here we test whether glycolytic H+ generation matches lactate production over a physiological pH and lactate range using ischemia applied to the hindlimb of a mouse. We measured the H+ generation and ATP level in vivo using 31P-magnetic resonance spectroscopy and chemically determined intracellular lactate level in the hindlimb muscles. No significant change was found in ATP content by chemical analysis (P>0.1), in agreement with the stoichiometric decline in phosphocreatine (20.2+/-1.2 mM) vs. rise in Pi (18.7+/-2.0 mM), as measured by 31P-magnetic resonance spectroscopy. A substantial drop in pH from 7.0 to 6.7 and lactate accumulation to 25 mM were found during 25 min of ischemia. The rise in H+ generation closely agreed with the accumulation of lactate, as shown by a close correlation with a slope near identity (0.98; r2=0.86). This agreement between glycolytic H+ production and elevation of lactate is confirmed by an analysis of the underlying reactions involved in glycolysis in vivo and supports the concept of lactic acidosis under conditions that substantially elevate lactate and drop pH. However, this link is expected to fail with conditions that deplete phosphocreatine, leading to net ATP hydrolysis and nonglycolytic H+ generation. Thus both direct measurements and an analysis of the stoichiometry of glycolysis in vivo support lactate acidosis as a robust concept for physiological conditions of the muscle cell.
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Affiliation(s)
- David J Marcinek
- Department of Radiology, Box 357115, University of Washington Medical Center, Seattle, WA 98195-7115, USA
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Macedo DV, Lazarim FL, Catanho da Silva FO, Tessuti LS, Hohl R. Is lactate production related to muscular fatigue? A pedagogical proposition using empirical facts. ADVANCES IN PHYSIOLOGY EDUCATION 2009; 33:302-307. [PMID: 19948679 DOI: 10.1152/advan.00039.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The cause-effect relationship between lactic acid, acidosis, and muscle fatigue has been established in the literature. However, current experiments contradict this premise. Here, we describe an experiment developed by first-year university students planned to answer the following questions: 1) Which metabolic pathways of energy metabolism are responsible for meeting the high ATP demand during high-intensity intermittent exercise? 2) Which metabolic pathways are active during the pause, and how do they influence phosphocreatine synthesis? and 3) Is lactate production related to muscular fatigue? Along with these questions, students received a list of materials available for the experiment. In the classroom, they proposed two protocols of eight 30-m sprints at maximum speed, one protocol with pauses of 120 s and the other protocol with pauses of 20 s between sprints. Their performances were analyzed through the velocity registered by photocells. Blood lactate was analyzed before the first sprint and after the eighth sprint. Blood uric acid was analyzed before exercise and 15 and 60 min after exercises. When discussing the data, students concluded that phosphocreatine restoration is time dependent, and this fact influenced the steady level of performance in the protocol with pauses of 120 s compared with the performance decrease noted in the protocol with pauses of 20 s. As the blood lactate levels showed similar absolute increases after both exercises, the students concluded that lactate production is not related to the performance decrement. This activity allows students to integrate the understanding of muscular energy pathways and to reconsider a controversial concept with facts that challenge the universality of the hypothesis relating lactate production to muscular fatigue.
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Affiliation(s)
- Denise Vaz Macedo
- Exercise Biochemistry Laboratory, Biochemistry Department, Biology Institute, State University of Campinas, Campinas, São Paulo, Brazil.
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Böning D, Maassen N. Point:Counterpoint: Lactic acid is/is not the only physicochemical contributor to the acidosis of exercise. J Appl Physiol (1985) 2008; 105:358-9. [DOI: 10.1152/japplphysiol.00162.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
The cell-to-cell lactate shuttle was introduced in 1984 and has been repeatedly supported by studies using a variety of experimental approaches. Because of its large mass and metabolic capacity, skeletal muscle is probably the major component of the lactate shuttle in terms of both production and consumption. Muscles exercising in a steady state are avid consumers of lactate, using most of the lactate as an oxidative fuel. Cardiac muscle is highly oxidative and readily uses lactate as a fuel. Lactate is a major gluconeogenic substrate for the liver; the use of lactate to form glucose increases when blood lactate concentration is elevated. Illustrative of the widespread shuttling of lactate, even the brain takes up lactate when the blood level is increased. Recently, an intracellular lactate shuttle has also been proposed. Although disagreements abound, current evidence suggests that lactate is the primary end-product of glycolysis at cellular sites remote from mitochondria. This lactate could subsequently diffuse to areas adjacent to mitochondria. Evidence is against lactate oxidation within the mitochondrial matrix, but a viable hypothesis is that lactate could be converted to pyruvate by a lactate oxidation complex with lactate dehydrogenase located on the outer surface of the inner mitochondrial membrane. In another controversial area, the role of lactic acid in acid-base balance has been hotly debated in recent times. Careful analysis reveals that lactate, not lactic acid, is the substrate/product of metabolic reactions. One view is that lactate formation alleviates acidosis, whereas another is that lactate is a causative factor in acidosis. Surprisingly, there is little direct mechanistic evidence regarding cause and effect in acid-base balance. However, there is insufficient evidence to discard the term "lactic acidosis."
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Affiliation(s)
- L Bruce Gladden
- Department of Kinesiology, Auburn University, Auburn, AL 36849-5323, USA.
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Esquivel AO, Dawe EJ, Sala-Mercado JA, Hammond RL, Bir CA. The Physiologic Effects of a Conducted Electrical Weapon in Swine. Ann Emerg Med 2007; 50:576-83. [PMID: 17719136 DOI: 10.1016/j.annemergmed.2007.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 05/04/2007] [Accepted: 05/04/2007] [Indexed: 10/22/2022]
Abstract
STUDY OBJECTIVE By using an animal model, we determine whether repeated exposures to a conducted electrical weapon could have physiologic consequences. METHODS Exposures to the Stinger S-400 conducted electrical weapon were applied to 10 healthy, anesthetized, Yorkshire-cross, male swine by attaching probes from the cartridge to the sternal notch and anterolateral thorax at a distance of 21.5 cm. The standard pulse generated by the Stinger S-400 during the normal application was applied 20 times during 31 minutes. To evaluate the health effects of the exposures, key physiologic characteristics were evaluated, including arterial pH, PCO2, PO2, blood lactate, cardiac output, ECG, pulse rate, mean arterial pressure, central venous pressure, pulmonary artery pressure and airway pressure, and the cardiac marker troponin I. RESULTS There were notable changes in pH, PCO2, blood lactate, cardiac output, and mean arterial pressure after 1 or more sets of exposures, all of which normalized during the next few hours. Troponin I, PO2, pulse rate, mean arterial pressure, central venous pressure, pulmonary artery pressure, and airway pressure did not change markedly during or after the shocks. Three premature ventricular contractions occurred in one animal; all other ECG results were normal. CONCLUSION Repeated exposures to a conducted electrical weapon result in respiratory acidosis, metabolic vasodilation, and an increase in blood lactate level. These effects were transient in this study, with full recovery by 4 hours postexposure. The Stinger S-400 appears to have no serious adverse physiologic effects on healthy, anesthetized swine.
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Affiliation(s)
- Amanda O Esquivel
- Biomedical Engineering, College of Engineering, Wayne State University, Detroit, MI 48201, USA
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Meyerspeer M, Kemp GJ, Mlynárik V, Krššák M, Szendroedi J, Nowotny P, Roden M, Moser E. Direct noninvasive quantification of lactate and high energy phosphates simultaneously in exercising human skeletal muscle by localized magnetic resonance spectroscopy. Magn Reson Med 2007; 57:654-60. [PMID: 17390348 PMCID: PMC4876926 DOI: 10.1002/mrm.21188] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel method based on interleaved localized 31P- and 1H MRS is presented, by which lactate accumulation and the accompanying changes in high energy phosphates in human skeletal muscle can be monitored simultaneously during exercise and recovery. Lactate is quantified using a localized double quantum filter suppressing the abundant lipid signals while taking into account orientation dependent signal modulations. Lactate concentration after ischemic exercise directly quantified by DQF 1H spectroscopy was 24 +/- 3 mmol/L cell water, while 22 +/- 3 mmol/L was expected on the basis of 31P MRS acquired simultaneously. Lactate concentration in a sample of porcine meat was estimated to be 40 +/- 7 mmol/L by means of DQF quantitation, versus 39 +/- 5 mmol/L by biochemical methods. Excellent agreement is shown between lactate concentrations measured noninvasively by 1H MRS, measured biochemically ex vivo, and inferred indirectly in vivo from changes in pH, P(i), and PCr as obtained from 31P MRS data.
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Affiliation(s)
- Martin Meyerspeer
- MR Centre of Excellence, Medical University of Vienna, Austria
- Center for Biomedical Engineering and Physics, Medical University of Vienna, Austria
| | - Graham J. Kemp
- Division of Metabolic and Cellular Medicine, School of Clinical Science, Faculty of Medicine, University of Liverpool, United Kingdom
| | - Vladimir Mlynárik
- MR Centre of Excellence, Medical University of Vienna, Austria
- Center for Biomedical Engineering and Physics, Medical University of Vienna, Austria
| | - Martin Krššák
- MR Centre of Excellence, Medical University of Vienna, Austria
- Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna, Austria
| | - Julia Szendroedi
- Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna, Austria
- Karl-Landsteiner Institute of Endocrinology and Metabolism, Vienna, Austria
| | - Peter Nowotny
- Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna, Austria
| | - Michael Roden
- Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna, Austria
- Karl-Landsteiner Institute of Endocrinology and Metabolism, Vienna, Austria
- 1st Med. Department, Hanusch Hospital Vienna, Austria
| | - Ewald Moser
- MR Centre of Excellence, Medical University of Vienna, Austria
- Center for Biomedical Engineering and Physics, Medical University of Vienna, Austria
- Department of Diagnostic Radiology, Medical University of Vienna, Austria
- Correspondence to: Ewald Moser, MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, A-1090 Vienna, Austria.
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Kemp G. Muscle cell volume and pH changes due to glycolytic ATP synthesis. J Physiol 2007; 582:461-5; author reply 467-70. [PMID: 17446216 PMCID: PMC2075294 DOI: 10.1113/jphysiol.2007.134643] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Whipp BJ. Physiological mechanisms dissociating pulmonary CO2 and O2 exchange dynamics during exercise in humans. Exp Physiol 2006; 92:347-55. [PMID: 17185348 DOI: 10.1113/expphysiol.2006.034363] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
During moderate exercise (below the lactate threshold, (thetaL)), muscle CO(2) production ( Q(CO2)) kinetics are monoexponential, with a time constant (tau) similar to that of O(2) consumption. Following a delay incorporating the muscle-lung vascular transit time, Q(CO2) is expressed at the lungs (V(CO2)) with an appreciably longer tau, reflecting the influence of intervening high-capacitance CO(2) stores. Above (thetaL), kinetics become complex, resulting from the conflation of the differing rates of HCO(3)(-) breakdown and degrees of compensatory hyperventilation with that of the underlying aerobic component. During incremental exercise, the increased rate of relative to pulmonary O(2) uptake (V(CO2)) can be used to quantify (thetaL) validly if aerobic and hyperventilatory sources can be ruled out, i.e. (thetaL) is then attributable to the decrease in muscle and blood [HCO(3)(-)]. In many cases, however, very rapid incrementation of work rate and/or prior depletion of CO(2) stores (by volitional or anticipatory hyperventilation) can yield a 'false positive' non-invasive estimation of (thetaL) ('pseudo-threshold') resulting from a slowing of the rate of wash-in of transient CO(2) stores.
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Affiliation(s)
- Brian J Whipp
- Institute of Membrane and Systems Biology, University of Leeds, Leeds LS2 9JT, UK.
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Böning D, Klarholz C, Himmelsbach B, Hütler M, Maassen N. Causes of differences in exercise-induced changes of base excess and blood lactate. Eur J Appl Physiol 2006; 99:163-71. [PMID: 17115177 DOI: 10.1007/s00421-006-0328-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2006] [Indexed: 11/25/2022]
Abstract
It has been concluded from comparisons of base excess (BE) and lactic acid (La) concentration changes in blood during exercise-induced acidosis that more H+ than La- leave the muscle and enter interstitial fluid and blood. To examine this, we performed incremental cycle tests in 13 untrained males and measured acid-base status and [La] in arterialized blood, plasma, and red cells until 21 min after exhaustion. The decrease of actual BE (-deltaABE) was 2.2 +/- 0.5 (SEM) mmol l(-1) larger than the increase of [La]blood at exhaustion, and the difference rose to 4.8 +/- 0.5 mmol l(-1) during the first minutes of recovery. The decrease of standard BE (SBE), a measure of mean BE of interstitial fluid (if) and blood, however, was smaller than the increase of [La] in the corresponding volume (delta[La](if+blood)) during exercise and only slightly larger during recovery. The discrepancy between -deltaABE and delta[La]blood mainly results from the Donnan effect hindering the rise of [La]erythrocyte to equal values like [La]plasma. The changing Donnan effect during acidosis causes that Cl- from the interstitial fluid enter plasma and erythrocytes in exchange for HCO3(-). A corresponding amount of La- remains outside the blood. SBE is not influenced by ion shifts among these compartments and therefore is a rather exact measure of acid movements across tissue cell membranes, but changes have been compared previously to delta[La]blood instead to delta[La](if+blood). When performing correct comparisons and considering Cl-/HCO3(-) exchange between erythrocytes and extracellular fluid, neither the use of deltaABE nor of deltaSBE provides evidence for differences in H+ and La- transport across the tissue cell membranes.
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Affiliation(s)
- Dieter Böning
- Institute of Sports Medicine, Charité, University Medicine Berlin, Arnimallee 22, 14195, Berlin, Germany.
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Philp A, Macdonald AL, Watt PW. Lactate--a signal coordinating cell and systemic function. ACTA ACUST UNITED AC 2006; 208:4561-75. [PMID: 16326938 DOI: 10.1242/jeb.01961] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Since its first documented observation in exhausted animal muscle in the early 19th century, the role of lactate (lactic acid) has fascinated muscle physiologists and biochemists. Initial interpretation was that lactate appeared as a waste product and was responsible in some way for exhaustion during exercise. Recent evidence, and new lines of investigation, now place lactate as an active metabolite, capable of moving between cells, tissues and organs, where it may be oxidised as a fuel or reconverted to form pyruvate or glucose. The questions now to be asked concern the effects of lactate at the systemic and cellular level on metabolic processes. Does lactate act as a metabolic signal to specific tissues, becoming a metabolite pseudo-hormone? Does lactate have a role in whole-body coordination of sympathetic/parasympathetic nerve system control? And, finally, does lactate play a role in maintaining muscle excitability during intense muscle contraction? The concept of lactate acting as a signalling compound is a relatively new hypothesis stemming from a combination of comparative, cell and whole-organism investigations. It has been clearly demonstrated that lactate is capable of entering cells via the monocarboxylate transporter (MCT) protein shuttle system and that conversion of lactate to and from pyruvate is governed by specific lactate dehydrogenase isoforms, thereby forming a highly adaptable metabolic intermediate system. This review is structured in three sections, the first covering pertinent topics in lactate's history that led to the model of lactate as a waste product. The second section will discuss the potential of lactate as a signalling compound, and the third section will identify ways in which such a hypothesis might be investigated. In examining the history of lactate research, it appears that periods have occurred when advances in scientific techniques allowed investigation of this metabolite to expand. Similar to developments made first in the 1920s and then in the 1980s, contemporary advances in stable isotope, gene microarray and RNA interference technologies may allow the next stage of understanding of the role of this compound, so that, finally, the fundamental questions of lactate's role in whole-body and localised muscle function may be answered.
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Affiliation(s)
- Andrew Philp
- Department of Sport and Exercise Sciences, Chelsea School Research Centre, Welkin Performance Laboratories, Eastbourne, BN20 7SP, UK.
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Kemp G, Böning D, Beneke R, Maassen N. Explaining pH Change in Exercising Muscle: Lactic acid, Proton Consumption, and Buffering vs. Strong Ion Difference. Am J Physiol Regul Integr Comp Physiol 2006; 291:R235-7; author reply R238-9. [PMID: 16760335 DOI: 10.1152/ajpregu.00662.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The development of acidosis during intense exercise has traditionally been explained by the increased production of lactic acid, causing the release of a proton and the formation of the acid salt sodium lactate. On the basis of this explanation, if the rate of lactate production is high enough, the cellular proton buffering capacity can be exceeded, resulting in a decrease in cellular pH. These biochemical events have been termed lactic acidosis. The lactic acidosis of exercise has been a classic explanation of the biochemistry of acidosis for more than 80 years. This belief has led to the interpretation that lactate production causes acidosis and, in turn, that increased lactate production is one of the several causes of muscle fatigue during intense exercise. This review presents clear evidence that there is no biochemical support for lactate production causing acidosis. Lactate production retards, not causes, acidosis. Similarly, there is a wealth of research evidence to show that acidosis is caused by reactions other than lactate production. Every time ATP is broken down to ADP and Pi, a proton is released. When the ATP demand of muscle contraction is met by mitochondrial respiration, there is no proton accumulation in the cell, as protons are used by the mitochondria for oxidative phosphorylation and to maintain the proton gradient in the intermembranous space. It is only when the exercise intensity increases beyond steady state that there is a need for greater reliance on ATP regeneration from glycolysis and the phosphagen system. The ATP that is supplied from these nonmitochondrial sources and is eventually used to fuel muscle contraction increases proton release and causes the acidosis of intense exercise. Lactate production increases under these cellular conditions to prevent pyruvate accumulation and supply the NAD+ needed for phase 2 of glycolysis. Thus increased lactate production coincides with cellular acidosis and remains a good indirect marker for cell metabolic conditions that induce metabolic acidosis. If muscle did not produce lactate, acidosis and muscle fatigue would occur more quickly and exercise performance would be severely impaired.
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Robergs RA, Ghiasvand F, Parker D. Reply: The Wandering Argument Favoring a Lactic Acidosis. Am J Physiol Regul Integr Comp Physiol 2006. [DOI: 10.1152/ajpregu.00081.2006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Lindinger MI, Kowalchuk JM, Heigenhauser GJF. Applying physicochemical principles to skeletal muscle acid-base status. Am J Physiol Regul Integr Comp Physiol 2005; 289:R891-4; author reply R904-910. [PMID: 16105823 DOI: 10.1152/ajpregu.00225.2005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Robergs RA, Ghiasvand F, Parker D. Lingering construct of lactic acidosis. Am J Physiol Regul Integr Comp Physiol 2005. [DOI: 10.1152/ajpregu.00117.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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