{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T18:18:05Z","timestamp":1780078685772,"version":"3.54.0"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1985,1,1]],"date-time":"1985-01-01T00:00:00Z","timestamp":473385600000},"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":[[1985,1]]},"abstract":"<jats:p>The apical membranes of surface cells in the rabbit descending colon possess a significant ionic conductance in parallel to amiloride\u2010blockable Na+ channels. The identity of the ion(s) responsible for the amiloride\u2010insensitive conductance is unknown. The purpose of the present paper was to assess the permeability and net driving forces for K+ and Cl\u2010 across this membrane using conventional and ion\u2010sensitive micro\u2010electrode techniques. Intracellular Cl\u2010 activity (aiCl) averaged 23 +\/\u2010 2 mM with an equilibrium potential (ECl) of \u201038 +\/\u2010 2 mV. This value is less than previous estimates of the electromotive force (e.m.f.) of the amiloride\u2010insensitive pathway (ca. \u201050 mV). Consequently, Cl\u2010 alone cannot account for the amiloride\u2010insensitive conductance. Replacement of Cl\u2010 by gluconate in the serosal solution decreased aiCl to 17 +\/\u2010 2.8 mM. aiCl was lowered to approximately 1 mM by replacement in the mucosal bath or by replacement in both solutions. The results indicate a low Cl\u2010 conductance in the basolateral membrane, in agreement with previous electrophysiological studies of this epithelium. In contrast to Cl\u2010, the chemical driving force for K+ was large enough to support the e.m.f. of the amiloride\u2010insensitive pathway (K+ equilibrium potential, EK = \u201066 mV). The basolateral membrane potential (Vbl), EK and the intracellular K+ activity (aiK) were decreased in parallel following inhibition of the basolateral Na\u2010K pump, providing evidence that Vbl is largely due to a K+ diffusion potential. In the presence of serosal 10(\u20104) M\u2010ouabain, aiK appeared to remain above equilibrium and more than doubled after addition of Ba2+ to the serosal bath. Replacement of the mucosal bathing solution with KCl or gluconate Ringer solution largely restored Vbl and the transepithelial potential (VT) in tissues which had been previously treated with ouabain. The restoration of VT was decreased and the transepithelial resistance (RT) was increased by addition of tetraethylammonium to the mucosal bath. The above results suggest that there are at least four routes for ion movement across the apical membrane of rabbit colon surface epithelial cells. These are: (1) an amiloride\u2010sensitive Na+ channel, (2) a K+ conductance, (3) electroneutral uptake of Cl\u2010 from lumen to cell interior and (4) an active K+ transport mechanism, also from lumen to cell interior.<\/jats:p>","DOI":"10.1113\/jphysiol.1985.sp015560","type":"journal-article","created":{"date-parts":[[2014,12,19]],"date-time":"2014-12-19T06:47:11Z","timestamp":1418971631000},"page":"433-445","source":"Crossref","is-referenced-by-count":24,"title":["Apical membrane potassium and chloride permeabilities in surface cells of rabbit descending colon epithelium."],"prefix":"10.1113","volume":"358","author":[{"given":"N K","family":"Wills","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[1985,1]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1985.sp015560","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1985.sp015560","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,20]],"date-time":"2023-10-20T18:14:10Z","timestamp":1697825650000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1985.sp015560"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1985,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1985,1]]}},"alternative-id":["10.1113\/jphysiol.1985.sp015560"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1985.sp015560","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1985,1]]}}}