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Siedlecki P, Ivanova TD, Garland SJ. Cardiovascular response to anticipatory and reactionary postural perturbations in young adults. Exp Physiol 2023; 108:1144-1153. [PMID: 37458232 PMCID: PMC10988459 DOI: 10.1113/ep091173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/03/2023] [Indexed: 09/02/2023]
Abstract
NEW FINDINGS What is the central question of this study? It has been suggested that the cardiovascular responses to a postural perturbation are centrally mediated and reflex mediated. We wanted to know the extent to which the cardiovascular responses to external perturbations could be executed in a feedforward manner, in anticipation of the perturbation. What is the main finding and its importance? We found no anticipatory component driving heart rate and systolic blood pressure responses, suggesting that reflexive mechanisms dominate cardiovascular regulation after a postural perturbation in young adults. ABSTRACT Cardiovascular responses to postural perturbations have been reported, but whether the cardiovascular responses to external perturbations could be executed in anticipation of the perturbation is unknown. The purpose of this study was to determine the effect of anticipated and reactionary perturbations on heart rate (HR) and systolic blood pressure (SBP) responses in healthy young adults. A secondary aim was to determine whether perceived state anxiety scores were correlated with the change in HR response during postural perturbation. Twenty healthy young adults stood on a treadmill and experienced two perturbation conditions (anticipatory vs. reactionary), each with two intensity levels (Step vs. No Step). The HR and SBP were collected continuously. Two-way repeated-measures statistical non-parametric mapping tests were used to compare HR and SBP responses to the perturbations over time (from -3 to +8 s). The results indicated that HR was significantly elevated in the higher intensity perturbations [Step vs. No Step, at 0.56-1.32 s (P < 0.0001) and 1.92-3.44 s (P < 0.0001) post-perturbation], while there were no differences in HR between perturbation types (anticipatory vs. reactionary) or in SBP between perturbation types and intensity levels. The perceived state anxiety scores did not differ between perturbation types and intensity levels but were correlated with the change in HR post-perturbation (P = 0.013). We suggest that reflexive mechanisms dominate cardiovascular regulation after anticipatory and reactionary perturbations. The data highlight the cardiovascular mechanism(s) associated with perturbations that should be considered when assessing postural stability in populations with poor balance performance.
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Affiliation(s)
| | | | - S. Jayne Garland
- Faculty of Health SciencesWestern UniversityLondonOntarioCanada
- Department of Physiology & PharmacologyWestern UniversityLondonOntarioCanada
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2
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Katz A. The role of glycogen phosphorylase in glycogen biogenesis in skeletal muscle after exercise. SPORTS MEDICINE AND HEALTH SCIENCE 2022; 5:29-33. [PMID: 36994178 PMCID: PMC10040329 DOI: 10.1016/j.smhs.2022.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 10/29/2022] [Accepted: 11/08/2022] [Indexed: 11/15/2022] Open
Abstract
Initially it was believed that phosphorylase was responsible for both glycogen breakdown and synthesis in the living cell. The discovery of glycogen synthase and McArdle's disease (lack of phosphorylase activity), together with the high Pi/glucose 1-P ratio in skeletal muscle, demonstrated that glycogen synthesis could not be attributed to reversal of the phosphorylase reaction. Rather, glycogen synthesis was attributable solely to the activity of glycogen synthase, subsequent to the transport of glucose into the cell. However, the well-established observation that phosphorylase was inactivated (i.e., dephosphorylated) during the initial recovery period after prior exercise, when the rate of glycogen accumulation is highest and independent of insulin, suggested that phosphorylase could play an active role in glycogen accumulation. But the quantitative contribution of phosphorylase inactivation was not established until recently, when studying isolated murine muscle preparations during recovery from repeated contractions at temperatures ranging from 25 to 35 °C. Thus, in both slow-twitch, oxidative and fast-twitch, glycolytic muscles, inactivation of phosphorylase accounted for 45%-75% of glycogen accumulation during the initial hours of recovery following repeated contractions. Such data indicate that phosphorylase inactivation may be the most important mechanism for glycogen accumulation under defined conditions. These results support the initial belief that phosphorylase plays a quantitative role in glycogen formation in the living cell. However, the mechanism is not via activation of phosphorylase, but rather via inactivation of the enzyme.
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A century of exercise physiology: key concepts in regulation of glycogen metabolism in skeletal muscle. Eur J Appl Physiol 2022; 122:1751-1772. [PMID: 35355125 PMCID: PMC9287217 DOI: 10.1007/s00421-022-04935-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/15/2022] [Indexed: 01/20/2023]
Abstract
Glycogen is a branched, glucose polymer and the storage form of glucose in cells. Glycogen has traditionally been viewed as a key substrate for muscle ATP production during conditions of high energy demand and considered to be limiting for work capacity and force generation under defined conditions. Glycogenolysis is catalyzed by phosphorylase, while glycogenesis is catalyzed by glycogen synthase. For many years, it was believed that a primer was required for de novo glycogen synthesis and the protein considered responsible for this process was ultimately discovered and named glycogenin. However, the subsequent observation of glycogen storage in the absence of functional glycogenin raises questions about the true role of the protein. In resting muscle, phosphorylase is generally considered to be present in two forms: non-phosphorylated and inactive (phosphorylase b) and phosphorylated and constitutively active (phosphorylase a). Initially, it was believed that activation of phosphorylase during intense muscle contraction was primarily accounted for by phosphorylation of phosphorylase b (activated by increases in AMP) to a, and that glycogen synthesis during recovery from exercise occurred solely through mechanisms controlled by glucose transport and glycogen synthase. However, it now appears that these views require modifications. Moreover, the traditional roles of glycogen in muscle function have been extended in recent years and in some instances, the original concepts have undergone revision. Thus, despite the extensive amount of knowledge accrued during the past 100 years, several critical questions remain regarding the regulation of glycogen metabolism and its role in living muscle.
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Ghosh S, Zulkifli M, Joshi A, Venkatesan M, Cristel A, Vishnu N, Madesh M, Gohil VM. MCU-complex-mediated mitochondrial calcium signaling is impaired in Barth syndrome. Hum Mol Genet 2021; 31:376-385. [PMID: 34494107 DOI: 10.1093/hmg/ddab254] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 02/02/2023] Open
Abstract
Calcium signaling via mitochondrial calcium uniporter (MCU) complex coordinates mitochondrial bioenergetics with cellular energy demands. Emerging studies show that the stability and activity of the pore-forming subunit of the complex, MCU, is dependent on the mitochondrial phospholipid, cardiolipin (CL), but how this impacts calcium-dependent mitochondrial bioenergetics in CL-deficiency disorder like Barth syndrome (BTHS) is not known. Here we utilized multiple models of BTHS including yeast, mouse muscle cell line, as well as BTHS patient cells and cardiac tissue to show that CL is required for the abundance and stability of the MCU-complex regulatory subunit MICU1. Interestingly, the reduction in MICU1 abundance in BTHS mitochondria is independent of MCU. Unlike MCU and MICU1/MICU2, other subunit and associated factor of the uniporter complex, EMRE and MCUR1, respectively, are not affected in BTHS models. Consistent with the decrease in MICU1 levels, we show that the kinetics of MICU1-dependent mitochondrial calcium uptake is perturbed and acute stimulation of mitochondrial calcium signaling in BTHS myoblasts fails to activate pyruvate dehydrogenase, which in turn impairs the generation of reducing equivalents and blunts mitochondrial bioenergetics. Taken together, our findings suggest that defects in mitochondrial calcium signaling could contribute to cardiac and skeletal muscle pathologies observed in BTHS patients.
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Affiliation(s)
- Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Mohammad Zulkifli
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Alaumy Joshi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Manigandan Venkatesan
- Department of Medicine, Cardiology Division, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Allen Cristel
- Department of Medicine, Cardiology Division, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Neelanjan Vishnu
- Department of Medicine, Cardiology Division, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Muniswamy Madesh
- Department of Medicine, Cardiology Division, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
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Blackwood SJ, Jude B, Mader T, Lanner JT, Katz A. Role of nitration in control of phosphorylase and glycogenolysis in mouse skeletal muscle. Am J Physiol Endocrinol Metab 2021; 320:E691-E701. [PMID: 33554777 DOI: 10.1152/ajpendo.00506.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphorylase is one of the most carefully studied proteins in history, but knowledge of its regulation during intense muscle contraction is incomplete. Tyrosine nitration of purified preparations of skeletal muscle phosphorylase results in inactivation of the enzyme and this is prevented by antioxidants. Whether an altered redox state affects phosphorylase activity and glycogenolysis in contracting muscle is not known. Here, we investigate the role of the redox state in control of phosphorylase and glycogenolysis in isolated mouse fast-twitch (extensor digitorum longus, EDL) and slow-twitch (soleus) muscle preparations during repeated contractions. Exposure of crude muscle extracts to H2O2 had little effect on phosphorylase activity. However, exposure of extracts to peroxynitrite (ONOO-), a nitrating/oxidizing agent, resulted in complete inactivation of phosphorylase (half-maximal inhibition at ∼200 µM ONOO-), which was fully reversed by the presence of an ONOO- scavanger, dithiothreitol (DTT). Incubation of isolated muscles with ONOO- resulted in nitration of phosphorylase and marked inhibition of glycogenolysis during repeated contractions. ONOO- also resulted in large decreases in high-energy phosphates (ATP and phosphocreatine) in the rested state and following repeated contractions. These metabolic changes were associated with decreased force production during repeated contractions (to ∼60% of control). In contrast, repeated contractions did not result in nitration of phosphorylase, nor did DTT or the general antioxidant N-acetylcysteine alter glycogenolysis during repeated contractions. These findings demonstrate that ONOO- inhibits phosphorylase and glycogenolysis in living muscle under extreme conditions. However, nitration does not play a significant role in control of phosphorylase and glycogenolysis during repeated contractions.NEW & NOTEWORTHY Here we show that exogenous peroxynitrite results in nitration of phosphorylase as well as inhibition of glycogenolysis in isolated intact mouse skeletal muscle during short-term repeated contractions. However, repeated contractions in the absence of exogenous peroxynitrite do not result in nitration of phosphorylase or affect glycogenolysis, nor does the addition of antioxidants alter glycogenolysis during repeated contractions. Thus phosphorylase is not subject to redox control during repeated contractions.
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Affiliation(s)
- Sarah J Blackwood
- Åstrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, GIH, Stockholm, Sweden
| | - Baptiste Jude
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden
| | - Theresa Mader
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden
| | - Abram Katz
- Åstrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, GIH, Stockholm, Sweden
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Cabrera-Aguilera I, Falcones B, Calvo-Fernández A, Benito B, Barreiro E, Gea J, Farré R, Almendros I, Farré N. The conventional isoproterenol-induced heart failure model does not consistently mimic the diaphragmatic dysfunction observed in patients. PLoS One 2020; 15:e0236923. [PMID: 32730329 PMCID: PMC7392250 DOI: 10.1371/journal.pone.0236923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/16/2020] [Indexed: 11/25/2022] Open
Abstract
Heart failure (HF) impairs diaphragm function. Animal models realistically mimicking HF should feature both the cardiac alterations and the diaphragmatic dysfunction characterizing this disease. The isoproterenol-induced HF model is widely used, but whether it presents diaphragmatic dysfunction is unknown. However, indirect data from research in other fields suggest that isoproterenol could increase diaphragm function. The aim of this study was to test the hypothesis that the widespread rodent model of isoproterenol-induced HF results in increased diaphragmatic contractility. Forty C57BL/6J male mice were randomized into 2 groups: HF and healthy controls. After 30 days of isoproterenol infusion to establish HF, in vivo diaphragmatic excursion and ex vivo isolated diaphragm contractibility were measured. As compared with healthy controls, mice with isoproterenol-induced HF showed the expected changes in structural and functional echocardiographic parameters and lung edema. isoproterenol-induced HF increased in vivo diaphragm excursion (by ≈30%, p<0.01) and increased by ≈50% both ex vivo peak specific force (p<0.05) and tetanic force (p<0.05) at almost all 10–100 Hz frequencies (p<0.05), with reduced fatigue resistance (p<0.01) when compared with healthy controls. Expression of myosin genes encoding the main muscle fiber types revealed that Myh4 was higher in isoproterenol-induced HF than in healthy controls (p<0.05), suggesting greater distribution of type IIb fibers. These results show that the conventional isoproterenol-induced HF model increases diaphragm contraction, a finding contrary to what is observed in patients with HF. Therefore, this specific model seems limited for translational an integrative HF research, especially when cardio-respiratory interactions are investigated.
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Affiliation(s)
- Ignacio Cabrera-Aguilera
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- Heart Diseases Biomedical Research Group, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
- Department of Human Movement Sciences, School of Kinesiology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile
| | - Bryan Falcones
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Alicia Calvo-Fernández
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Heart Failure Unit, Department of Cardiology, Hospital del Mar, Barcelona, Spain
| | - Begoña Benito
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Cardiology Department, Hospital Universitari Vall d'Hebron, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - Esther Barreiro
- Respiratory Department, Hospital del Mar and Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Joaquim Gea
- Respiratory Department, Hospital del Mar and Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Ramon Farré
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Isaac Almendros
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Núria Farré
- Heart Diseases Biomedical Research Group, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Heart Failure Unit, Department of Cardiology, Hospital del Mar, Barcelona, Spain
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Gorrell E, Shemery A, Kowalski J, Bodziony M, Mavundza N, Titus AR, Yoder M, Mull S, Heemstra LA, Wagner JG, Gibson M, Carey O, Daniel D, Harvey N, Zendlo M, Rich M, Everett S, Gavini CK, Almundarij TI, Lorton D, Novak CM. Skeletal muscle thermogenesis induction by exposure to predator odor. J Exp Biol 2020; 223:jeb218479. [PMID: 32165434 PMCID: PMC7174837 DOI: 10.1242/jeb.218479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/02/2020] [Indexed: 01/07/2023]
Abstract
Non-shivering thermogenesis can promote negative energy balance and weight loss. In this study, we identified a contextual stimulus that induces rapid and robust thermogenesis in skeletal muscle. Rats exposed to the odor of a natural predator (ferret) showed elevated skeletal muscle temperatures detectable as quickly as 2 min after exposure, reaching maximum thermogenesis of >1.5°C at 10-15 min. Mice exhibited a similar thermogenic response to the same odor. Ferret odor induced a significantly larger and qualitatively different response from that of novel or aversive odors, fox odor or moderate restraint stress. Exposure to predator odor increased energy expenditure, and both the thermogenic and energetic effects persisted when physical activity levels were controlled. Predator odor-induced muscle thermogenesis is subject to associative learning as exposure to a conditioned stimulus provoked a rise in muscle temperature in the absence of the odor. The ability of predator odor to induce thermogenesis is predominantly controlled by sympathetic nervous system activation of β-adrenergic receptors, as unilateral sympathetic lumbar denervation and a peripherally acting β-adrenergic antagonist significantly inhibited predator odor-induced muscle thermogenesis. The potential survival value of predator odor-induced changes in muscle physiology is reflected in an enhanced resistance to running fatigue. Lastly, predator odor-induced muscle thermogenesis imparts a meaningful impact on energy expenditure as daily predator odor exposure significantly enhanced weight loss with mild calorie restriction. This evidence signifies contextually provoked, centrally mediated muscle thermogenesis that meaningfully impacts energy balance.
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Affiliation(s)
- Erin Gorrell
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Ashley Shemery
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Jesse Kowalski
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Miranda Bodziony
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Nhlalala Mavundza
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Amber R Titus
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Mark Yoder
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Sarah Mull
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Lydia A Heemstra
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Jacob G Wagner
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Megan Gibson
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Olivia Carey
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Diamond Daniel
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Nicholas Harvey
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Meredith Zendlo
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Megan Rich
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Scott Everett
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Chaitanya K Gavini
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Tariq I Almundarij
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
- Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Qassim University, PO Box 6622, Buraidah 51452, Saudi Arabia
| | - Diane Lorton
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Colleen M Novak
- School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
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