{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T23:22:24Z","timestamp":1787959344514,"version":"build-2784847793"},"reference-count":33,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2020,2,10]],"date-time":"2020-02-10T00:00:00Z","timestamp":1581292800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2020,2,10]],"date-time":"2020-02-10T00:00:00Z","timestamp":1581292800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title><jats:p>We investigated effects of the ryanodine receptor (RyR) modulator caffeine on Na<jats:sup>+<\/jats:sup> current (<jats:italic>I<\/jats:italic><jats:sub>Na<\/jats:sub>) activation and inactivation in intact loose-patch clamped murine skeletal muscle fibres subject to a double pulse procedure. <jats:italic>I<\/jats:italic><jats:sub>Na<\/jats:sub> activation was examined using 10-ms depolarising, <jats:italic>V<\/jats:italic><jats:sub>1<\/jats:sub>, steps to varying voltages 0\u201380\u2009mV positive to resting membrane potential. The dependence of the subsequent, <jats:italic>I<\/jats:italic><jats:sub>Na<\/jats:sub> inactivation on <jats:italic>V<\/jats:italic><jats:sub>1<\/jats:sub> was examined by superimposed, <jats:italic>V<\/jats:italic><jats:sub>2<\/jats:sub>, steps to a fixed depolarising voltage. Current-voltage activation and inactivation curves indicated that adding 0.5 and 2\u2009mM caffeine prior to establishing the patch seal respectively produced decreased (within 1\u2009min) and increased (after ~2\u2009min) peak <jats:italic>I<\/jats:italic><jats:sub>Na<\/jats:sub> followed by its recovery to pretreatment levels (after ~40 and ~30\u2009min respectively). These changes accompanied negative shifts in the voltage dependence of <jats:italic>I<\/jats:italic><jats:sub>Na<\/jats:sub> inactivation (within 10\u2009min) and subsequent superimposed positive activation and inactivation shifts, following 0.5\u2009mM caffeine challenge. In contrast, 2\u2009mM caffeine elicited delayed negative shifts in both activation and inactivation. These effects were abrogated if caffeine was added <jats:italic>after<\/jats:italic> establishing the patch seal or with RyR block by 10\u2009\u03bcM dantrolene. These effects precisely paralleled previous reports of persistently (~10\u2009min) increased cytosolic [Ca<jats:sup>2+<\/jats:sup>] with 0.5\u2009mM, and an early peak rapidly succeeded by persistently reduced [Ca<jats:sup>2+<\/jats:sup>] likely reflecting gradual RyR inactivation with \u22651.0\u2009mM caffeine. The latter findings suggested inhibitory effects of even resting cytosolic [Ca<jats:sup>2+<\/jats:sup>] on <jats:italic>I<\/jats:italic><jats:sub>Na<\/jats:sub>. They suggest potentially physiologically significant negative feedback regulation of RyR activity on Na<jats:sub>v<\/jats:sub>1.4 properties through increased or decreased local cytosolic [Ca<jats:sup>2+<\/jats:sup>], Ca<jats:sup>2+<\/jats:sup>-calmodulin and FKBP12.<\/jats:p>","DOI":"10.1038\/s41598-020-59196-9","type":"journal-article","created":{"date-parts":[[2020,2,10]],"date-time":"2020-02-10T11:02:57Z","timestamp":1581332577000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Ryanodine receptor modulation by caffeine challenge modifies Na+ current properties in intact murine skeletal muscle fibres"],"prefix":"10.1038","volume":"10","author":[{"given":"Sahib S.","family":"Sarbjit-Singh","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hugh R.","family":"Matthews","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher L.-H.","family":"Huang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2020,2,10]]},"reference":[{"key":"59196_CR1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-019-09570-7","volume":"10","author":"JB Yoder","year":"2019","unstructured":"Yoder, J. B. et al. Ca 2+ -dependent regulation of sodium channels Na V 1.4 and Na V 1.5 is controlled by the post-IQ motif. Nat. Commun. 10, 1514, https:\/\/doi.org\/10.1038\/s41467-019-09570-7 (2019).","journal-title":"Nat. Commun."},{"key":"59196_CR2","doi-asserted-by":"publisher","first-page":"349","DOI":"10.1113\/jphysiol.2004.081422","volume":"565","author":"KA Young","year":"2005","unstructured":"Young, K. A. & Caldwell, J. H. Modulation of skeletal and cardiac voltage-gated sodium channels by calmodulin. J. Physiol. 565, 349\u201370 (2005).","journal-title":"J. Physiol."},{"key":"59196_CR3","doi-asserted-by":"publisher","first-page":"8846","DOI":"10.1074\/jbc.M806871200","volume":"284","author":"F Potet","year":"2009","unstructured":"Potet, F. et al. Functional Interactions between Distinct Sodium Channel Cytoplasmic Domains through the Action of Calmodulin. J. Biol. Chem. 284, 8846\u201354 (2009).","journal-title":"J. Biol. Chem."},{"key":"59196_CR4","doi-asserted-by":"publisher","first-page":"314","DOI":"10.3389\/fphar.2015.00314","volume":"6","author":"G Loussouarn","year":"2016","unstructured":"Loussouarn, G. et al. Physiological and pathophysiological insights of Nav1.4 and Nav1.5 comparison. Front. Pharmacol. 6, 314, https:\/\/doi.org\/10.3389\/fphar.2015.00314 (2016).","journal-title":"Front. Pharmacol."},{"key":"59196_CR5","doi-asserted-by":"publisher","first-page":"12003","DOI":"10.1073\/pnas.92.26.12003","volume":"92","author":"S Bendahhou","year":"1995","unstructured":"Bendahhou, S., Cummins, T. R., Potts, J. F., Tong, J. & Agnew, W. S. Serine-1321-independent regulation of the mu 1 adult skeletal muscle Na+ channel by protein kinase C. Proc. Natl. Acad. Sci. USA 92, 12003\u201312007 (1995).","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"59196_CR6","doi-asserted-by":"publisher","first-page":"1657","DOI":"10.1016\/j.cell.2014.04.035","volume":"157","author":"M Ben-Johny","year":"2014","unstructured":"Ben-Johny, M. et al. Conservation of Ca2+\/calmodulin regulation across Na and Ca 2+ channels. Cell 157, 1657\u20131670 (2014).","journal-title":"Cell"},{"key":"59196_CR7","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1085\/jgp.200709863","volume":"131","author":"S Biswas","year":"2008","unstructured":"Biswas, S. et al. Calmodulin regulation of Nav1.4 current: role of binding to the carboxyl terminus. J. Gen. Physiol. 131, 197\u2013209 (2008).","journal-title":"J. Gen. Physiol."},{"key":"59196_CR8","doi-asserted-by":"publisher","first-page":"E49","DOI":"10.1161\/01.RES.0000012502.92751.E6","volume":"90","author":"I Desch\u00eanes","year":"2002","unstructured":"Desch\u00eanes, I. et al. Isoform-Specific Modulation of Voltage-Gated Na + Channels by Calmodulin. Circ. Res. 90, E49\u2013E57 (2002).","journal-title":"Circ. Res."},{"key":"59196_CR9","doi-asserted-by":"crossref","first-page":"9474","DOI":"10.1016\/S0021-9258(19)50114-4","volume":"267","author":"T Jayaraman","year":"1992","unstructured":"Jayaraman, T. et al. FK506 binding protein associated with the calcium release channel (ryanodine receptor). J. Biol. Chem. 267, 9474\u20139477 (1992).","journal-title":"J. Biol. Chem."},{"key":"59196_CR10","doi-asserted-by":"publisher","first-page":"4613","DOI":"10.1242\/jcs.02582","volume":"118","author":"J Jones","year":"2005","unstructured":"Jones, J., Reynolds, D., Lai, F. & Blayney, L. Ryanodine receptor binding to FKBP12 is modulated by channel activation state. J. Cell Sci. 118, 4613\u20134619 (2005).","journal-title":"J. Cell Sci."},{"key":"59196_CR11","doi-asserted-by":"publisher","first-page":"1042","DOI":"10.1161\/CIRCRESAHA.110.237867","volume":"108","author":"M Maruyama","year":"2011","unstructured":"Maruyama, M. et al. FKBP12 is a critical regulator of the heart rhythm and the cardiac voltage-gated sodium current in mice. Circ. Res. 108, 1042\u201352 (2011).","journal-title":"Circ. Res."},{"key":"59196_CR12","doi-asserted-by":"publisher","first-page":"C352","DOI":"10.1152\/ajpcell.00021.2009","volume":"297","author":"GN Filatov","year":"2009","unstructured":"Filatov, G. N., Pinter, M. J. & Rich, M. M. Role of Ca(2+) in injury-induced changes in sodium current in rat skeletal muscle. Am. J. Physiol. Cell Physiol. 297, C352\u2013C359 (2009).","journal-title":"Am. J. Physiol. Cell Physiol."},{"key":"59196_CR13","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-018-36386-0.","volume":"9","author":"HR Matthews","year":"2019","unstructured":"Matthews, H. R. et al. Sodium current inhibition following stimulation of exchange protein directly activated by cyclic-3\u2032, 5\u2032-adenosine monophosphate (Epac) in murine skeletal muscle. Sci. Rep. 9, 1927, https:\/\/doi.org\/10.1038\/s41598-018-36386-0. (2019).","journal-title":"Sci. Rep."},{"key":"59196_CR14","doi-asserted-by":"publisher","first-page":"223","DOI":"10.1023\/A:1005496708505","volume":"20","author":"A Herrmann-Frank","year":"1999","unstructured":"Herrmann-Frank, A., L\u00fcttgau, H. C. & Stephenson, D. G. Caffeine and excitation-contraction coupling in skeletal muscle: A stimulating story. Journal of Muscle Research and Cell Motility 20, 223\u2013237 (1999).","journal-title":"Journal of Muscle Research and Cell Motility"},{"key":"59196_CR15","doi-asserted-by":"publisher","first-page":"435","DOI":"10.1113\/jphysiol.1989.sp017770","volume":"416","author":"MW Fryer","year":"1989","unstructured":"Fryer, M. W. & Neering, I. R. Actions of caffeine on fast- and slow- twitch muscles of the rat. J. Physiol. 416, 435\u2013454 (1989).","journal-title":"J. Physiol."},{"key":"59196_CR16","first-page":"502","volume":"46","author":"C Dettbarn","year":"1994","unstructured":"Dettbarn, C., Gyorke, S. & Palade, P. Many agonists induce \u2018quantal\u2019 Ca2+ release or adaptive behavior in muscle ryanodine receptors. Mol Pharmacol 46, 502\u20137 (1994).","journal-title":"Mol Pharmacol"},{"key":"59196_CR17","doi-asserted-by":"publisher","first-page":"C623","DOI":"10.1152\/ajpcell.1998.274.3.C623","volume":"274","author":"MK Pagala","year":"1998","unstructured":"Pagala, M. K. & Taylor, S. R. Imaging caffeine-induced Ca2+ transients in individual fast-twitch and slow-twitch rat skeletal muscle fibers. Am. J. Physiol. 274, C623\u201332 (1998).","journal-title":"Am. J. Physiol."},{"key":"59196_CR18","doi-asserted-by":"publisher","first-page":"11","DOI":"10.1113\/jphysiol.1993.sp019801","volume":"469","author":"SI Head","year":"1993","unstructured":"Head, S. I. Membrane potential, resting calcium and calcium transients in isolated muscle fibres from normal and dystrophic mice. J. Physiol. 469, 11\u201319 (1993).","journal-title":"J. Physiol."},{"key":"59196_CR19","doi-asserted-by":"publisher","first-page":"732","DOI":"10.1016\/S0006-3495(96)79272-X","volume":"71","author":"DR Laver","year":"1996","unstructured":"Laver, D. R. & Curtis, B. A. Response of ryanodine receptor channels to Ca 2+ steps produced by rapid solution exchange. Biophys. J. 71, 732\u2013741 (1996).","journal-title":"Biophys. J."},{"key":"59196_CR20","doi-asserted-by":"publisher","first-page":"751","DOI":"10.1113\/jphysiol.1984.sp015094","volume":"347","author":"W Almers","year":"1984","unstructured":"Almers, W., Roberts, W. M. & Ruff, R. L. Voltage clamp of rat and human skeletal muscle: measurements with an improved loose- patch technique. J. Physiol. 347, 751\u2013768 (1984).","journal-title":"J. Physiol."},{"key":"59196_CR21","doi-asserted-by":"publisher","first-page":"13810","DOI":"10.1074\/jbc.M006104200","volume":"276","author":"F Zhao","year":"2001","unstructured":"Zhao, F., Li, P., Chen, S., Louis, C. & Fruen, B. Dantrolene inhibition of ryanodine receptor Ca2+ release channels. Molecular mechanism and isoform selectivity. J. Biol. Chem. 276, 13810\u201313816 (2001).","journal-title":"J. Biol. Chem."},{"key":"59196_CR22","doi-asserted-by":"publisher","first-page":"885","DOI":"10.1523\/JNEUROSCI.10-03-00885.1990","volume":"10","author":"RL Milton","year":"1990","unstructured":"Milton, R. L. & Caldwell, J. H. Na current in membrane blebs: implications for channel mobility and patch clamp recording. J. Neurosci. 10, 885\u2013893 (1990).","journal-title":"J. Neurosci."},{"key":"59196_CR23","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1152\/physrev.1994.74.1.49","volume":"74","author":"RH Fitts","year":"1994","unstructured":"Fitts, R. H. Cellular mechanisms of muscle fatigue. Physiol. Rev. 74, 49\u201394 (1994).","journal-title":"Physiol. Rev."},{"key":"59196_CR24","doi-asserted-by":"publisher","first-page":"666","DOI":"10.1002\/mus.21155","volume":"39","author":"T Kubota","year":"2009","unstructured":"Kubota, T. et al. New mutation of the Na channel in the severe form of potassium- aggravated myotonia. Muscle Nerve 39, 666\u2013673 (2009).","journal-title":"Muscle Nerve"},{"key":"59196_CR25","doi-asserted-by":"publisher","first-page":"349","DOI":"10.1113\/jphysiol.1995.sp021056","volume":"489","author":"GD Lamb","year":"1995","unstructured":"Lamb, G. D., Junankar, P. R. & Stephenson, D. G. Raised intracellular [Ca2+] abolishes excitation-contraction coupling in skeletal muscle fibres of rat and toad. J. Physiol. 489, 349\u2013362 (1995).","journal-title":"J. Physiol."},{"key":"59196_CR26","doi-asserted-by":"publisher","first-page":"261","DOI":"10.1113\/jphysiol.1983.sp014580","volume":"336","author":"W Almers","year":"1983","unstructured":"Almers, W., Stanfield, P. R. & St\u00fchmer, W. Lateral distribution of sodium and potassium channels in frog skeletal muscle: measurements with a patch-clamp technique. J. Physiol. 336, 261\u201384 (1983).","journal-title":"J. Physiol."},{"key":"59196_CR27","doi-asserted-by":"publisher","first-page":"223","DOI":"10.1113\/jphysiol.1977.sp011855","volume":"268","author":"RH Adrian","year":"1977","unstructured":"Adrian, R. H. & Marshall, M. W. Sodium currents in mammalian muscle. J. Physiol. 268, 223\u2013250 (1977).","journal-title":"J. Physiol."},{"key":"59196_CR28","doi-asserted-by":"publisher","first-page":"261","DOI":"10.1016\/0005-2736(87)90422-6","volume":"897","author":"ST Ohnishi","year":"1987","unstructured":"Ohnishi, S. T. Effects of halothane, caffeine, dantrolene and tetracaine on the calcium permeability of skeletal sarcoplasmic reticulum of malignant hyperthermic pigs. BBA - Biomembr. 897, 261\u2013268 (1987).","journal-title":"BBA - Biomembr."},{"key":"59196_CR29","doi-asserted-by":"publisher","first-page":"85","DOI":"10.1016\/0378-8741(87)90082-1","volume":"20","author":"F Okwuasaba","year":"1987","unstructured":"Okwuasaba, F., Ejike, C. & Parry, O. Comparison of the skeletal muscle relaxant properties of Portulaca oleracea extracts with dantrolene sodium and methoxyverapamil. J. Ethnopharmacol. 20, 85\u2013106 (1987).","journal-title":"J. Ethnopharmacol."},{"key":"59196_CR30","doi-asserted-by":"publisher","first-page":"221","DOI":"10.1085\/jgp.51.2.221","volume":"51","author":"B Hille","year":"1968","unstructured":"Hille, B. Charges and potentials at the nerve surface. Divalent ions and pH. J. Gen. Physiol. 51, 221\u2013236 (1968).","journal-title":"J. Gen. Physiol."},{"key":"59196_CR31","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1098\/rstb.1975.0011","volume":"270","author":"B Hille","year":"1975","unstructured":"Hille, B., Woodhull, A. M. & Shapiro, B. I. Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 270, 301\u2013318 (1975).","journal-title":"Philos. Trans. R. Soc. Lond. B. Biol. Sci."},{"key":"59196_CR32","doi-asserted-by":"publisher","first-page":"C940","DOI":"10.1152\/ajpcell.1998.274.4.C940","volume":"274","author":"CD Balnave","year":"1998","unstructured":"Balnave, C. D. & Allen, D. G. Evidence for Na+\/Ca2+ exchange in intact single skeletal muscle fibers from the mouse. Am. J. Physiol. Cell Physiol. 274, C940\u2013C946 (1998).","journal-title":"Am. J. Physiol. Cell Physiol."},{"key":"59196_CR33","doi-asserted-by":"publisher","first-page":"615","DOI":"10.1113\/jphysiol.1995.sp020839","volume":"486","author":"A Hoya","year":"1995","unstructured":"Hoya, A. & Venosa, R. A. Characteristics of Na(+)- Ca2+ exchange in frog skeletal muscle. J. Physiol. 486, 615\u2013627 (1995).","journal-title":"J. Physiol."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-020-59196-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-020-59196-9","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-020-59196-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,6]],"date-time":"2022-12-06T06:52:11Z","timestamp":1670309531000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-020-59196-9"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,2,10]]},"references-count":33,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["59196"],"URL":"https:\/\/doi.org\/10.1038\/s41598-020-59196-9","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,2,10]]},"assertion":[{"value":"21 August 2019","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"6 January 2020","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"10 February 2020","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no competing interests.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"2199"}}