{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T03:08:13Z","timestamp":1771643293623,"version":"3.50.1"},"reference-count":0,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[1972,6,1]],"date-time":"1972-06-01T00:00:00Z","timestamp":76204800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Journal of Physiology"],"published-print":{"date-parts":[[1972,6]]},"abstract":"<jats:p>1. The excitatory process travelling along the T\u2010system may be either electrotonic or regenerative. If Na<jats:sup>+<\/jats:sup> dependent action potential is present in the tubular membranes, high frequency of stimulation might cause a Na<jats:sup>+<\/jats:sup> depletion in the tubules sufficient to abolish this process.<\/jats:p><jats:p>2. We tested this hypothesis by recording tension in isolated muscle fibres stimulated tetanically (up to 60 shocks\/sec). In low [Na<jats:sup>+<\/jats:sup>] solutions, output tension was initially similar to that in normal Ringer, but then fell smoothly to a substantially lower value.<\/jats:p><jats:p>3. The activity of individual myofibrils was recorded directly with cin\u00e9\u2010micrographs during isotonic contractions while the fibres were stimulated at high frequencies. In low [Na<jats:sup>+<\/jats:sup>]<jats:sub>o<\/jats:sub> wavy myofibrils appeared in the centre of the fibre and spread towards the periphery, indicating failure of activation. Wavy myofibrils never appeared in normal Ringer.<\/jats:p><jats:p>4. Intracellular action potentials recorded during the tetanic stimulation indicated that the inactivated myofibrils present in low [Na<jats:sup>+<\/jats:sup>] solutions cannot be explained by the changes in size and duration of the action potential.<\/jats:p><jats:p>5. Our results strongly suggest the existence of a regenerative Na<jats:sup>+<\/jats:sup> conductance in the tubular membrane during the inward spread of an excitatory process.<\/jats:p>","DOI":"10.1113\/jphysiol.1972.sp009860","type":"journal-article","created":{"date-parts":[[2014,12,19]],"date-time":"2014-12-19T10:38:05Z","timestamp":1418985485000},"page":"507-523","source":"Crossref","is-referenced-by-count":89,"title":["Sodium dependence of the inward spread of activation in isolated twitch muscle fibres of the frog"],"prefix":"10.1113","volume":"223","author":[{"given":"F.","family":"Bezanilla","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C.","family":"Caputo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"H.","family":"Gonzalez\u2010Serratos","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R. A.","family":"Venosa","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1972,6]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1972.sp009860","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1972.sp009860","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,8]],"date-time":"2023-11-08T10:35:02Z","timestamp":1699439702000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1972.sp009860"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1972,6]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1972,6]]}},"alternative-id":["10.1113\/jphysiol.1972.sp009860"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1972.sp009860","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1972,6]]}}}