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Early Deconditioning of Human Skeletal Muscles and the Effects of a Thigh Cuff Countermeasure. Int J Mol Sci 2021; 22:ijms222112064. [PMID: 34769492 PMCID: PMC8584355 DOI: 10.3390/ijms222112064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 01/12/2023] Open
Abstract
Muscle deconditioning is a major consequence of a wide range of conditions from spaceflight to a sedentary lifestyle, and occurs as a result of muscle inactivity, leading to a rapid decrease in muscle strength, mass, and oxidative capacity. The early changes that appear in the first days of inactivity must be studied to determine effective methods for the prevention of muscle deconditioning. To evaluate the mechanisms of muscle early changes and the vascular effect of a thigh cuff, a five-day dry immersion (DI) experiment was conducted by the French Space Agency at the MEDES Space Clinic (Rangueil, Toulouse). Eighteen healthy males were recruited and divided into a control group and a thigh cuff group, who wore a thigh cuff at 30 mmHg. All participants underwent five days of DI. Prior to and at the end of the DI, the lower limb maximal strength was measured and muscle biopsies were collected from the vastus lateralis muscle. Five days of DI resulted in muscle deconditioning in both groups. The maximal voluntary isometric contraction of knee extension decreased significantly. The muscle fiber cross-sectional area decreased significantly by 21.8%, and the protein balance seems to be impaired, as shown by the reduced activation of the mTOR pathway. Measurements of skinned muscle fibers supported these results and potential changes in oxidative capacity were highlighted by a decrease in PGC1-α levels. The use of the thigh cuff did not prevent muscle deconditioning or impact muscle function. These results suggest that the major effects of muscle deconditioning occur during the first few days of inactivity, and countermeasures against muscle deconditioning should target this time period. These results are also relevant for the understanding of muscle weakness induced by muscle diseases, aging, and patients in intensive care.
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2
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Tikunova SB, Cuesta A, Price M, Li MX, Belevych N, Biesiadecki BJ, Reiser PJ, Hwang PM, Davis JP. 3-Chlorodiphenylamine activates cardiac troponin by a mechanism distinct from bepridil or TFP. J Gen Physiol 2018; 151:9-17. [PMID: 30442775 PMCID: PMC6314390 DOI: 10.1085/jgp.201812131] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/02/2018] [Indexed: 01/14/2023] Open
Abstract
Cardiac troponin activators could be beneficial in systolic heart failure. Tikunova et al. demonstrate that, unlike previously known calcium sensitizers, the small molecule 3-chlorodiphenylamine does not activate isolated cardiac troponin C but instead activates the intact troponin complex. Despite extensive efforts spanning multiple decades, the development of highly effective Ca2+ sensitizers for the heart remains an elusive goal. Existing Ca2+ sensitizers have other targets in addition to cardiac troponin (cTn), which can lead to adverse side effects, such as hypotension or arrhythmias. Thus, there is a need to design Ca2+-sensitizing drugs with higher affinity and selectivity for cTn. Previously, we determined that many compounds based on diphenylamine (DPA) were able to bind to a cTnC–cTnI chimera with moderate affinity (Kd ∼10–120 µM). Of these compounds, 3-chlorodiphenylamine (3-Cl-DPA) bound most tightly (Kd of 10 µM). Here, we investigate 3-Cl-DPA further and find that it increases the Ca2+ sensitivity of force development in skinned cardiac muscle. Using NMR, we show that, like the known Ca2+ sensitizers, trifluoperazine (TFP) and bepridil, 3-Cl-DPA is able to bind to the isolated N-terminal domain (N-domain) of cTnC (Kd of 6 µM). However, while the bulky molecules of TFP and bepridil stabilize the open state of the N-domain of cTnC, the small and flexible 3-Cl-DPA molecule is able to bind without stabilizing this open state. Thus, unlike TFP, which drastically slows the rate of Ca2+ dissociation from the N-domain of isolated cTnC in a dose-dependent manner, 3-Cl-DPA has no effect on the rate of Ca2+ dissociation. On the other hand, the affinity of 3-Cl-DPA for a cTnC–TnI chimera is at least an order of magnitude higher than that of TFP or bepridil, likely because 3-Cl-DPA is less disruptive of cTnI binding to cTnC. Therefore, 3-Cl-DPA has a bigger effect on the rate of Ca2+ dissociation from the entire cTn complex than TFP and bepridil. Our data suggest that 3-Cl-DPA activates the cTn complex via a unique mechanism and could be a suitable scaffold for the development of novel treatments for systolic heart failure.
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Affiliation(s)
- Svetlana B Tikunova
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH
| | - Andres Cuesta
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH
| | - Morgan Price
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH
| | - Monica X Li
- Departments of Medicine and Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Natalya Belevych
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH
| | | | - Peter J Reiser
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH
| | - Peter M Hwang
- Departments of Medicine and Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH
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3
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Ochala J, Sun YB. Novel myosin-based therapies for congenital cardiac and skeletal myopathies. J Med Genet 2016; 53:651-4. [PMID: 27412953 PMCID: PMC5099184 DOI: 10.1136/jmedgenet-2016-103881] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/15/2016] [Indexed: 12/13/2022]
Abstract
The dysfunction in a number of inherited cardiac and skeletal myopathies is primarily due to an altered ability of myofilaments to generate force and motion. Despite this crucial knowledge, there are, currently, no effective therapeutic interventions for these diseases. In this short review, we discuss recent findings giving strong evidence that genetically or pharmacologically modulating one of the myofilament proteins, myosin, could alleviate the muscle pathology. This should constitute a research and clinical priority.
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Affiliation(s)
- Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, King's College London, London, UK
| | - Yin-Biao Sun
- Randall Division of Cell and Molecular Biophysics, British Heart Foundation Centre of Research Excellence, King's College London, London, UK
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4
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Pineda-Sanabria SE, Robertson IM, Sun YB, Irving M, Sykes BD. Probing the mechanism of cardiovascular drugs using a covalent levosimendan analog. J Mol Cell Cardiol 2016; 92:174-84. [PMID: 26853943 PMCID: PMC4831045 DOI: 10.1016/j.yjmcc.2016.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/24/2016] [Accepted: 02/02/2016] [Indexed: 01/16/2023]
Abstract
One approach to improve contraction in the failing heart is the administration of calcium (Ca2 +) sensitizers. Although it is known that levosimendan and other sensitizers bind to troponin C (cTnC), their in vivo mechanism is not fully understood. Based on levosimendan, we designed a covalent Ca2 + sensitizer (i9) that targets C84 of cTnC and exchanged this complex into cardiac muscle. The NMR structure of the covalent complex showed that i9 binds deep in the hydrophobic pocket of cTnC. Despite slightly reducing troponin I affinity, i9 enhanced the Ca2 + sensitivity of cardiac muscle. We conclude that i9 enhances Ca2 + sensitivity by stabilizing the open conformation of cTnC. These findings provide new insights into the in vivo mechanism of Ca2 + sensitization and demonstrate that directly targeting cTnC has significant potential in cardiovascular therapy. A Ca2 + sensitizer, i9 was designed that forms a covalent bond with C84 of cTnC. i9 stabilized the open state of the N-domain of cTnC. The structure of the covalent cTnC-cTnI-i9 complex was solved by NMR. The structure showed that i9 binds deep in the hydrophobic pocket of cTnC. Despite slightly reducing cTnI affinity, i9 enhanced the Ca2 + sensitivity of cardiac muscle.
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Affiliation(s)
- Sandra E Pineda-Sanabria
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Ian M Robertson
- Randall Division of Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK
| | - Yin-Biao Sun
- Randall Division of Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK
| | - Malcolm Irving
- Randall Division of Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK
| | - Brian D Sykes
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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5
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Abstract
Various human diseases can disrupt the balance between muscle contraction and relaxation. Sarcomeric modulators can be used to readjust this balance either indirectly by intervening in signalling pathways or directly through interaction with the muscle proteins that control contraction. Such agents represent a novel approach to treating any condition in which striated muscle function is compromised, including heart failure, cardiomyopathies, skeletal myopathies and a wide range of neuromuscular conditions. Here, we review agents that modulate the mechanical function of the sarcomere, focusing on emerging compounds that target myosin or the troponin complex.
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6
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Kischel P, Bastide B, Muller M, Dubail F, Offredi F, Jin JP, Mounier Y, Martial J. Expression and functional properties of four slow skeletal troponin T isoforms in rat muscles. Am J Physiol Cell Physiol 2005; 289:C437-43. [PMID: 15788488 DOI: 10.1152/ajpcell.00365.2004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the expression and functional properties of slow skeletal troponin T (sTnT) isoforms in rat skeletal muscles. Four sTnT cDNAs were cloned from the slow soleus muscle. Three isoforms were found to be similar to sTnT1, sTnT2, and sTnT3 isoforms described in mouse muscles. A new rat isoform, with a molecular weight slightly higher than that of sTnT3, was discovered. This fourth isoform had never been detected previously in any skeletal muscle and was therefore called sTnTx. From both expression pattern and functional measurements, it appears that sTnT isoforms can be separated into two classes, high-molecular-weight (sTnT1, sTnT2) and low-molecular-weight (sTnTx, sTnT3) isoforms. By comparison to the apparent migration pattern of the four recombinant sTnT isoforms, the newly described low-molecular-weight sTnTx isoform appeared predominantly and typically expressed in fast skeletal muscles, whereas the higher-molecular-weight isoforms were more abundant in slow soleus muscle. The relative proportion of the sTnT isoforms in the soleus was not modified after exposure to hindlimb unloading (HU), known to induce a functional atrophy and a slow-to-fast isoform transition of several myofibrillar proteins. Functional data gathered from replacement of endogenous troponin complexes in skinned muscle fibers showed that the sTnT isoforms modified the Ca2+activation characteristics of single skeletal muscle fibers, with sTnT2 and sTnT1 conferring a similar increase in Ca2+affinity higher than that caused by low-molecular-weight isoforms sTnTx and sTnT3. Thus we show for the first time the presence of sTnT in fast muscle fibers, and our data show that the changes in neuromuscular activity on HU are insufficient to alter the sTnT expression pattern.
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Affiliation(s)
- P Kischel
- Laboratoire de Biologie Moléculaire et Génie Génétique, Allée de la Chimie 3, Campus du Sart-Tilman, Bât. B6, 4000 Liège, Belgium.
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7
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Stevens L, Bozzo C, Nemirovskaya T, Montel V, Falempin M, Mounier Y. Contractile properties of rat single muscle fibers and myosin and troponin isoform expression after hypergravity. J Appl Physiol (1985) 2003; 94:2398-405. [PMID: 12576410 DOI: 10.1152/japplphysiol.00808.2002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effects of 19 days of hypergravity (HG) were investigated on the biochemical and physiological properties of the slow soleus muscle and its fast agonist, the plantaris. HG was induced by rotational centrifugation that led to a 2-G gravity level. The HG rats were characterized by a slower body growth than control, whereas the soleus muscle mass was increased by 15%. Using electrophoretic techniques, we showed that the distribution of myosin heavy chain and troponin T isoforms was not modified after HG in both soleus and plantaris. In contrast, the isoform expression pattern of two troponin subunits, troponin I and troponin C, was changed in a slow-to-fast manner only in the soleus. From tension-pCa relationships, changes in Ca(2+) activation threshold by 0.18 pCa unit indicated a decrease in Ca(2+) sensitivity and an increase in the slope of the curve, attesting to a higher cooperativity along the thin filament after HG. Comparison of our HG data with previous results in microgravity conditions indicated that muscle characteristics, except muscle mass, did not evolve linearly from 0 to 2 G.
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Affiliation(s)
- Laurence Stevens
- Laboratory of Neuromuscular Plasticity, Institut Fédératif de Recherche en Protéomique 118, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq cedex, France.
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8
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Stevens L, Bastide B, Kischel P, Pette D, Mounier Y. Time-dependent changes in expression of troponin subunit isoforms in unloaded rat soleus muscle. Am J Physiol Cell Physiol 2002; 282:C1025-30. [PMID: 11940518 DOI: 10.1152/ajpcell.00252.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study focuses on the effects of mechanical unloading of rat soleus muscle on the isoform patterns of the three troponin (Tn) subunits: troponin T (TnT), troponin I (TnI), and troponin C (TnC). Mechanical unloading was achieved by hindlimb unloading (HU) for time periods of 7, 15, and 28 days. Relative concentrations of slow and fast TnT, TnI, and TnC isoforms were assessed by electrophoretic and immunoblot analyses. HU induced profound slow-to-fast isoform transitions of all Tn subunits, although to different extents and with different time courses. The effectiveness of the isoform transitions was higher for TnT than for TnI and TnC. Indeed, TnI and TnC encompassed minor partial exchanges of slow isoforms with their fast counterparts, whereas the expression pattern of fast TnT isoforms (TnTf) was largely increased after HU. Moreover, slow and fast isoforms of the different Tn were not affected in the same manner by HU. This suggests that the slow and fast counterparts of the Tn subunit isoforms are regulated independently in response to HU. The changes in TnTf composition occurred in parallel with previously demonstrated transitions within the pattern of the fast myosin heavy chains in the same muscles.
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Affiliation(s)
- Laurence Stevens
- Laboratoire de Plasticité Neuromusculaire, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d' Ascq, France.
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9
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Abusamhadneh E, Abbott MB, Dvoretsky A, Finley N, Sasi S, Rosevear PR. Interaction of bepridil with the cardiac troponin C/troponin I complex. FEBS Lett 2001; 506:51-4. [PMID: 11591369 DOI: 10.1016/s0014-5793(01)02790-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We have investigated the binding of bepridil to calcium-saturated cardiac troponin C in a cardiac troponin C/troponin I complex. Nuclear magnetic resonance spectroscopy and [(15)N,(2)H]cardiac troponin C permitted the mapping of bepridil-induced amide proton chemical shifts. A single bepridil-binding site in the regulatory domain was found with an affinity constant of approximately 140 microM(-1). In the presence of cardiac troponin I, bepridil binding to the C domain of cardiac troponin C was not detected. The pattern of bepridil-induced chemical shifts is consistent with stabilization of more open regulatory domain conformational states. A similar pattern of chemical shift perturbations was observed for interaction of the troponin I cardiac-specific amino-terminus with the cardiac troponin C regulatory domain. These results suggest that both bepridil and the cardiac-specific amino-terminus may mediate an increase in calcium affinity by interacting with and stabilizing open regulatory domain conformations. Chemical shift mapping suggests a possible role for inactive calcium-binding site I in the modulation of calcium affinity.
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Affiliation(s)
- E Abusamhadneh
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, College of Medicine, 231 Albert B. Sabin Way, Cincinnati, OH 45267, USA
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10
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Watanabe Y, Kimura J. Blocking effect of bepridil on Na+/Ca2+ exchange current in guinea pig cardiac ventricular myocytes. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 85:370-5. [PMID: 11388640 DOI: 10.1254/jjp.85.370] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We examined the effect of bepridil, a class IV antiarrhythmic drug, on Na+/Ca2+ exchange current (I(NCX)) in single guinea pig cardiac ventricular cells using the whole-cell voltage clamp technique. I(NCX) was recorded by ramp pulses from the holding potential of -60 mV in the presence of 140 mM Na+ and 1 mM Ca2+ in the external solution and 20 mM Na+ and 119 nM free Ca2+ (7 mM Ca2+ and 20 mM BAPTA) in the internal solution. Bepridil suppressed I(NCX) in a concentration-dependent manner. The IC50 value was 8.1 microM with a Hill coefficient of 0.8. Intracellular treatment with trypsin via the pipette solution attenuated the blocking effect of bepridil, suggesting that the inhibitory site is on the cytosolic side of the Na+/Ca2+ exchanger. In the absence of albumin in the external solution, 10 microM bepridil inhibited I(NCX) by 46+/-7% (n = 8), while bepridil blocked it by 28+/-8% (n = 6) in the presence of albumin. Bepridil inhibited I(NCX) in a supra-therapeutic concentration range.
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Affiliation(s)
- Y Watanabe
- Department of Ecology and Clinical Therapeutics, School of Nursing, Fukushima Medical University, Japan.
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11
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Kischel P, Bastide B, Stevens L, Mounier Y. Expression and functional behavior of troponin C in soleus muscle fibers of rat after hindlimb unloading. J Appl Physiol (1985) 2001; 90:1095-101. [PMID: 11181625 DOI: 10.1152/jappl.2001.90.3.1095] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Troponin C (TnC) plays a key role in the regulation of muscle contraction, thereby modulating the Ca(2+)-activation characteristics of skinned muscle fibers. This study was performed to assess the effects of a 15-day hindlimb unloading (HU) period on TnC expression and its functional behavior in the slow postural muscles of the rat. We investigated the TnC isoform expression in whole soleus muscles and in single fibers. The latter were also checked for their Ca(2+) activation characteristics and sensitivity to bepridil, a Ca(2+) sensitizer molecule. This drug has been described as exerting a differential effect on slow and fast fibers, depending on the TnC isoform. With regard to TnC expression, three populations were found in control muscle fibers: slow, hybrid slow, and hybrid fast fibers, with the TnC fast being always coexpressed with TnC slow. In the whole muscle, TnC fast expression increased after HU because of the increase in the proportion of hybrid fast fibers. The HU hybrid fast fibers had properties similar to those of control hybrid fast fibers. The fibers that remained slow after HU exhibited similar bepridil and Sr(2+) properties as control slow fibers. Therefore, in these fibers, the changes could not be related to the TnC molecule.
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Affiliation(s)
- P Kischel
- Laboratoire de Plasticité Neuromusculaire, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France.
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12
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Kischel P, Bastide B, Potter JD, Mounier Y. The role of the Ca(2+) regulatory sites of skeletal troponin C in modulating muscle fibre reactivity to the Ca(2+) sensitizer bepridil. Br J Pharmacol 2000; 131:1496-502. [PMID: 11090126 PMCID: PMC1572481 DOI: 10.1038/sj.bjp.0703727] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The Ca(2+)-sensor protein troponin C (TnC) exerts a key role in the regulation of muscle contraction, and constitutes a target for Ca(2+) sensitizer compounds, such as bepridil, known to increase its apparent Ca(2+) affinity. Moreover, bepridil has been reported to exert a differential effect in slow and fast skeletal muscle fibres, which express the slow/cardiac and fast TnC isoform, respectively. 2. The role of the TnC isoform in establishing the differential effect of bepridil was assessed in slow soleus and fast tibialis rat skinned fibres, by extraction of endogenous TnC and consecutive reconstitution with either slow or fast recombinant TnC. A mutant (VG2), lacking the regulatory site II, was also used to distinguish the role of each regulatory site. 3. Fast tibialis fibres reconstituted with cardiac TnC exhibited a typical slow bepridil reactivity, while slow soleus fibres reincorporated with fast TnC displayed a typically fast reactivity to bepridil. These results indicated that the differential effect of bepridil in slow and fast fibres is related to the TnC isoform predominantly expressed in a fibre. 4. Experiments with the VG2 mutant demonstrated that BPD can achieve an increase in the Ca(2+) affinity in the absence of a functional site II. Thus, site I was necessary for the BPD effect to be independent of the Ca(2+) concentration. Moreover, the amplitude of the reinforcement in the Ca(2+) affinity, induced by the binding of bepridil to the TnC molecule, is dependent on the number of functional regulatory sites, the larger affinity reinforcement being detected when only one regulatory site (either site I or II) is functional.
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MESH Headings
- Animals
- Bepridil/pharmacology
- Binding Sites/genetics
- Calcium/metabolism
- Calcium/pharmacology
- DNA, Recombinant/genetics
- DNA, Recombinant/metabolism
- Dose-Response Relationship, Drug
- In Vitro Techniques
- Male
- Mice
- Muscle Fibers, Fast-Twitch/drug effects
- Muscle Fibers, Fast-Twitch/physiology
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/physiology
- Muscle Fibers, Slow-Twitch/drug effects
- Muscle Fibers, Slow-Twitch/physiology
- Muscle, Skeletal/chemistry
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/physiology
- Mutation
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Rabbits
- Rats
- Rats, Wistar
- Strontium/pharmacology
- Troponin C/genetics
- Troponin C/metabolism
- Vasodilator Agents/pharmacology
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Affiliation(s)
- P Kischel
- Laboratoire de Plasticité Neuromusculaire, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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