{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T21:29:02Z","timestamp":1771622942702,"version":"3.50.1"},"reference-count":0,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[1969,8,1]],"date-time":"1969-08-01T00:00:00Z","timestamp":-13219200000},"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":[[1969,8]]},"abstract":"<jats:p>1. The electrical properties of frog slow muscle fibres were investigated with intracellular micropipettes to determine their characteristic length (\u03bb), specific membrane resistance (<jats:italic>R<\/jats:italic><jats:sub>m<\/jats:sub>) and specific membrane capacitance.<\/jats:p><jats:p>2. The value of \u03bb was about 1 cm in fibres of 1\u00b72 cm length. The \u2018short cable model\u2019 was used to calculate <jats:italic>R<\/jats:italic><jats:sub>m<\/jats:sub>. Its mean value was 1\u00b712 \u00d7 10<jats:sup>5<\/jats:sup> ohm cm<jats:sup>2<\/jats:sup>, about 10\u201320 times larger than the value for twitch fibres. The mean value for <jats:italic>C<\/jats:italic><jats:sub>m<\/jats:sub> was 3\u00b724 \u00d7 10<jats:sup>\u22126<\/jats:sup> F\/cm<jats:sup>2<\/jats:sup>.<\/jats:p><jats:p>3. Resting potentials measured immediately after penetration with a single micropipette were about \u2014 80 mV. Lower values can be attributed to the effects of damage or leakage produced by micropipette insertion.<\/jats:p><jats:p>4. Changes in external K concentration produced changes in the initially recorded resting potentials which follow the constant field theory using a ratio of Na: K permeabilities <jats:italic>P<\/jats:italic><jats:sub>Na<\/jats:sub>\/<jats:italic>P<\/jats:italic><jats:sub>K<\/jats:sub> = 0\u00b702. Changes in external Cl concentration produced little or no change in the resting potential or membrane resistance, indicating a low Cl permeability.<\/jats:p><jats:p>5. In agreement with previous work, slow fibres showed a time\u2010dependent decrease in resistance (\u2018delayed rectification\u2019) for membrane potentials more positive than \u2014 60 mV. \u2018Anomalous rectification\u2019 observed in twitch fibres was not seen in slow fibres. In high external K concentrations the resistance of slow fibres is almost unaffected by changes in membrane potential.<\/jats:p><jats:p>6. Increasing the concentration of external Ca (up to isotonic) has two distinct effects on slow fibres. It increases <jats:italic>R<\/jats:italic><jats:sub>m<\/jats:sub> up to ten times, and it improves the stability of trans\u2010membrane recordings, probably by reducing the leakage due to micropipette penetrations. Magnesium does not appear to have either of these effects.<\/jats:p>","DOI":"10.1113\/jphysiol.1969.sp008869","type":"journal-article","created":{"date-parts":[[2014,12,19]],"date-time":"2014-12-19T11:57:48Z","timestamp":1418990268000},"page":"383-401","source":"Crossref","is-referenced-by-count":84,"title":["Resting potential and electrical properties of frog slow muscle fibres. Effect of different external solutions"],"prefix":"10.1113","volume":"203","author":[{"given":"E.","family":"Stefani","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A. B.","family":"Steinbach","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1969,8]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1969.sp008869","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1969.sp008869","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,8]],"date-time":"2023-11-08T20:01:54Z","timestamp":1699473714000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1969.sp008869"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1969,8]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1969,8]]}},"alternative-id":["10.1113\/jphysiol.1969.sp008869"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1969.sp008869","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1969,8]]}}}