{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T09:49:58Z","timestamp":1789552198251,"version":"build-2803163510"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1994,2,15]],"date-time":"1994-02-15T00:00:00Z","timestamp":761270400000},"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":[[1994,2,15]]},"abstract":"<jats:p>1. In Rana oocytes, measurements with chloride\u2010sensitive microelectrodes show that the mean intracellular chloride activity (34.8 +\/\u2010 6.3 mM, n = 79) is three times higher than that expected for the passive distribution of chloride ions across the outer membrane (12.4 mM, mean membrane potential \u201043 +\/\u2010 8.8 mV, n = 79). 2. Reuptake of chloride into oocytes depleted by prolonged exposure to chloride\u2010free saline takes place against the electrochemical gradient. 3. Chloride reuptake does not take place in sodium\u2010free solution or in a sodium\u2010substituted potassium\u2010free solution. It is inhibited by bumetanide (10(\u20105) M) in the bathing medium. 4. The overall stoichiometry of the transport mechanism deduced from simultaneous measurements of intracellular sodium and chloride using ion\u2010selective electrodes is 1Na+:1K+:2Cl\u2010. 5. Ammonium ions substitute for potassium on the cotransporter. 6. In oocytes smaller than 0.9 mm in diameter, exposure to external ammonium causes an alkaline shift in intracellular pH as the NH3 enters and takes up H+ to form NH4+. We propose that chloride\u2010dependent NH4+ transport contributes to the accumulation of NH4+ and causes the \u2018postexposure\u2019 acidification as the intracellular NH4+ releases H+ to form NH3 which is then lost from the cell. 7. In larger oocytes ammonium exposure produces a rapid reduction in pHi which may be explained in part by cotransport\u2010mediated uptake of NH4+. Evidence is also provided for a second chloride\u2010dependent NH4+ transport mechanism and a chloride\u2010independent process.<\/jats:p>","DOI":"10.1113\/jphysiol.1994.sp020048","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T12:55:47Z","timestamp":1418820947000},"page":"45-57","source":"Crossref","is-referenced-by-count":19,"title":["Endogenous Na(+)\u2010K+ (or NH4+)\u20102Cl\u2010 cotransport in Rana oocytes; anomalous effect of external NH4+ on pHi."],"prefix":"10.1113","volume":"475","author":[{"given":"E","family":"Keicher","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R","family":"Meech","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[1994,2,15]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1994.sp020048","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1994.sp020048","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,24]],"date-time":"2023-10-24T01:02:50Z","timestamp":1698109370000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1994.sp020048"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,2,15]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1994,2,15]]}},"alternative-id":["10.1113\/jphysiol.1994.sp020048"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1994.sp020048","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,2,15]]}}}