{"corpus_id":85005053,"paper_sha":"7014dc89d568cf2d8c51b41a9754cb27f331bfb0","doi":"10.1085/JGP.50.7.1929","arxiv_id":null,"pmid":6050974,"pmcid":"2225760","mag_id":2082412365,"dblp_id":null,"acl_id":null,"title":"Relative Ion Permeabilities in the Crayfish Giant Axon Determined from Rapid External Ion Changes","year":1967,"publication_date":"1967-08-01","venue":"The Journal of General Physiology","journal":{"name":"The Journal of General Physiology","pages":"1929 - 1953","volume":"50"},"journal_issn":null,"journal_title":null,"publication_types":["JournalArticle"],"pubmed_pub_types":["Journal Article"],"s2_fields_of_study":["Biology","Medicine","Chemistry"],"reference_count":43,"citation_count":67,"influential_citation_count":4,"is_open_access":true,"arxiv_categories":null,"arxiv_license":null,"arxiv_journal_ref":null,"mesh_headings":[{"d":"Animals","mj":false,"ui":"D000818"},{"d":"Axons","mj":false,"qs":[{"q":"drug effects","mj":true,"ui":"Q000187"}],"ui":"D001369"},{"d":"Biological Transport","mj":false,"ui":"D001692"},{"d":"Cell Membrane Permeability","mj":false,"qs":[{"q":"drug effects","mj":true,"ui":"Q000187"}],"ui":"D002463"},{"d":"Chlorides","mj":false,"qs":[{"q":"pharmacology","mj":true,"ui":"Q000494"}],"ui":"D002712"},{"d":"Crustacea","mj":false,"qs":[{"q":"physiology","mj":false,"ui":"Q000502"}],"ui":"D003445"},{"d":"Electrophysiology","mj":false,"qs":[{"q":"instrumentation","mj":false,"ui":"Q000295"}],"ui":"D004594"},{"d":"Membrane Potentials","mj":false,"qs":[{"q":"drug effects","mj":true,"ui":"Q000187"}],"ui":"D008564"},{"d":"Models, Theoretical","mj":false,"ui":"D008962"},{"d":"Potassium","mj":false,"qs":[{"q":"pharmacology","mj":true,"ui":"Q000494"}],"ui":"D011188"},{"d":"Sodium","mj":false,"qs":[{"q":"pharmacology","mj":true,"ui":"Q000494"}],"ui":"D012964"}],"chemicals":[{"n":"Chlorides","ui":"D002712","reg":"0"},{"n":"Sodium","ui":"D012964","reg":"9NEZ333N27"},{"n":"Potassium","ui":"D011188","reg":"RWP5GA015D"}],"comments_corrections":null,"source_flags":5,"s2_open_access_pdf_url":"https://rupress.org/jgp/article-pdf/50/7/1929/1244017/1929.pdf","s2_open_access_landing_url":"https://www.semanticscholar.org/paper/7014dc89d568cf2d8c51b41a9754cb27f331bfb0","s2_open_access_license":"CCBYNCSA","s2_open_access_status":"BRONZE","pmc_open_access_pdf_url":null,"pmc_open_access_landing_url":null,"pmc_open_access_license":null,"pmc_open_access_status":null,"unpaywall_open_access_pdf_url":null,"unpaywall_open_access_landing_url":null,"unpaywall_open_access_license":null,"unpaywall_open_access_status":null,"abstract":"The changes in membrane potential of isolated, single crayfish giant axons following rapid shifts in external ion concentrations have been studied. At normal resting potential the immediate change in membrane potential after a variation in external potassium concentration is quite marked compared to the effect of an equivalent chloride change. If the membrane is depolarized by a maintained potassium elevation, the immediate potential change due to a chloride variation becomes comparable to that of an equivalent potassium change. There is no appreciable effect on membrane potential when external sodium is varied, at normal or at a depolarized membrane potential. Starting from the constant field equation, expressions for the permeability ratios P Cl/P K, P Na/P K, and for intracellular potassium and chloride concentrations are derived. At normal resting membrane potential, P Cl/P K is 0.13 but at a membrane potential of -53 mv (external potassium level increased about five times) it is 0.85. The intracellular concentrations of potassium and chloride are estimated to be 233 and 34 mM, respectively, and it is pointed out that this is not compatible with ions distributed in a Nernst equilibrium across the membrane. It is also stressed that the information given by a plot of membrane potential vs. the logarithm of external potassium concentrations is very limited and rests upon several important assumptions.","claims":[{"public_id":"cl_e00cad66ff634d5b145aa573e2a13c60","status":"active","text":"A plot of membrane potential versus the logarithm of external potassium concentrations provides only limited information and depends on several important assumptions.","confidence":0.94,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_e00cad66ff634d5b145aa573e2a13c60"},{"public_id":"cl_23265c7525734694d5715d9f0e329b16","status":"active","text":"At the normal resting membrane potential, the estimated permeability ratio P Cl/P K is 0.13, increasing to 0.85 at -53 mV when external potassium is raised about 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