{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,3,19]],"date-time":"2025-03-19T11:13:54Z","timestamp":1742382834690},"reference-count":0,"publisher":"American Physiological Society","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Renal Physiology"],"published-print":{"date-parts":[[1989,2,1]]},"abstract":"<jats:p> We used intracellular pH-sensitive and voltage microelectrodes to examine the effects of depolarization on intracellular pH (pHi) in isolated perfused proximal tubules from the tiger salamander Ambystoma tigrinum. Tubules were depolarized by raising [K+] in the bath (b) or lumen (l), or by adding Ba2+ (1 mM) to the bath or lumen, always in nominally HCO3-free solutions. Increasing [K+]b from 2.5 to 50 mM caused the basolateral membrane to depolarize by an average of 45 mV, and pHi to increase by 0.23 over 3 min. Similar alkalinization was observed when basolateral Ba2+ (1 mM) was used to depolarize the cell at constant extracellular [K+], suggesting that the alkalinization observed during exposure to elevated [K+]b results from depolarization rather than an increase in [K+]b. The initial rate of depolarization-induced alkalinization (DIA) was proportional to the magnitude of the depolarization, regardless of whether tubules were depolarized by elevated [K+]b, elevated [K+]l, or by basolateral Ba2+. An exception was the initial rate of the alkalinization caused by 1 mM luminal Ba2+, which was more than 10-fold greater than that predicted from the depolarization. The voltage and pHi responses to basolateral Ba2+ were smaller in some tubules than others, as were the responses to elevated [K+]l. Tubules with small responses to 1 mM [Ba2+]b had large responses to 50 mM [K+]l, whereas tubules with large responses to 1 mM [Ba2+]b had small responses to 50 mM [K+]l. This variability can be accounted for by differences in the luminal K+ conductance. The DIA was partially inhibited by removal of Na+ from only the lumen or only the bath, but completely inhibited by bilateral Na+ removal. We conclude that the depolarization-induced alkalinization results from additive effects of Na+-dependent processes at both the luminal and basolateral membranes. <\/jats:p>","DOI":"10.1152\/ajprenal.1989.256.2.f342","type":"journal-article","created":{"date-parts":[[2017,12,22]],"date-time":"2017-12-22T21:05:13Z","timestamp":1513976713000},"page":"F342-F353","source":"Crossref","is-referenced-by-count":6,"title":["Depolarization-induced alkalinization in proximal tubules. I. Characteristics and dependence on Na+"],"prefix":"10.1152","volume":"256","author":[{"given":"A. W.","family":"Siebens","sequence":"first","affiliation":[{"name":"Department of Physiology, Yale University School of Medicine, NewHaven, Connecticut 06510."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W. F.","family":"Boron","sequence":"additional","affiliation":[{"name":"Department of Physiology, Yale University School of Medicine, NewHaven, Connecticut 06510."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","container-title":["American Journal of Physiology-Renal Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/ajprenal.1989.256.2.F342","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T19:08:00Z","timestamp":1567969680000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajprenal.1989.256.2.F342"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1989,2,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1989,2,1]]}},"alternative-id":["10.1152\/ajprenal.1989.256.2.F342"],"URL":"https:\/\/doi.org\/10.1152\/ajprenal.1989.256.2.f342","relation":{},"ISSN":["1931-857X","1522-1466"],"issn-type":[{"value":"1931-857X","type":"print"},{"value":"1522-1466","type":"electronic"}],"subject":[],"published":{"date-parts":[[1989,2,1]]}}}