{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,4,24]],"date-time":"2025-04-24T04:58:23Z","timestamp":1745470703817,"version":"3.40.4"},"reference-count":15,"publisher":"S. Karger AG","issue":"3","license":[{"start":{"date-parts":[[2007,6,15]],"date-time":"2007-06-15T00:00:00Z","timestamp":1181865600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2007,6,15]],"date-time":"2007-06-15T00:00:00Z","timestamp":1181865600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nephron Physiol"],"abstract":"<i>Background:<\/i> Several apical ammonium (NH<sub>4<\/sub><sup>+<\/sup>\/NH<sub>3<\/sub>) transport pathways have been described in medullary thick ascending limb (MTAL) cells. The exact nature and importance of some of these pathways remain controversial. <i>Methods:<\/i> Ammonium transport in primary cultured rabbit MTAL cells was investigated by measuring intracellular pH (pH<sub>i<\/sub>). <i>Results:<\/i> To create physiological conditions, experiments were performed in the symmetrical presence of NH<sub>4<\/sub>Cl, which acidified the cells to pH<sub>i<\/sub> 6.89. When blockers of apical NH<sub>4<\/sub><sup>+<\/sup> transport were used, the cells alkalinized due to a decreased NH<sub>4<\/sub><sup>+<\/sup> loading. The following values (pH units) were observed: bumetanide, +0.05; verapamil, +0.04; Ba<sup>2+<\/sup> and Cs<sup>+<\/sup>, +0.19; tertiapin, +0.09. Tetraethylammonium had no effect. Depolarizing the cells by increasing the K<sup>+<\/sup> concentration alkalinized the cells by 0.16 pH units. Because NH<sub>4<\/sub><sup>+<\/sup> might enter through nonspecific channels, ammonium pulse experiments were performed: an NH<sub>4<\/sub>Cl pulse acidified controls as well as depolarized cells. In contrast, when Ba<sup>2+<\/sup>, Cs<sup>+<\/sup> or tertiapin were present, an NH<sub>4<\/sub>Cl pulse alkalinized the cells. The pharmacological profile of this apical NH<sub>4<\/sub><sup>+<\/sup> transport pathway correlates with the renal outer medullary K<sup>+<\/sup> (ROMK) channel. Indirect immunofluorescence showed the presence of the ROMK protein. <i>Conclusion:<\/i> In these MTAL cells the Ba<sup>2+<\/sup>-sensitive component of NH<sub>4<\/sub><sup>+<\/sup> transport is predominant and consists of permeation of NH<sub>4<\/sub><sup>+<\/sup> through an apical ROMK-related channel.<\/jats:p>","DOI":"10.1159\/000103909","type":"journal-article","created":{"date-parts":[[2007,6,18]],"date-time":"2007-06-18T06:52:54Z","timestamp":1182149574000},"page":"p45-p53","source":"Crossref","is-referenced-by-count":4,"title":["Investigation of the Ba<sup>2+<\/sup>-Sensitive NH<sub>4<\/sub><sup>+<\/sup> Transport Pathways in the Apical Cell Membrane of Primary Cultured Rabbit MTAL Cells"],"prefix":"10.1159","volume":"106","author":[{"given":"Frank","family":"Jans","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Corina","family":"Balut","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marcel","family":"Ameloot","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Patrick","family":"Wouters","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paul","family":"Steels","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2007,6,15]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1146%2Fannurev.ph.56.030194.003203"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1085%2Fjgp.103.5.917"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1007%2FBF01869723"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1038%2F339478a0"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1085%2Fjgp.99.3.435"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1021%2Fbi00578a012"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.1083%2Fjcb.87.3.672"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1159%2F000025957"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1016%2F0005-2736%2891%2990079-N"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1152%2Fphysrev.00051.2003"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.1085%2Fjgp.115.4.391"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.1021%2Fbi981178p"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.1016%2F0014-5793%2895%2901182-E"},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1085%2Fjgp.103.6.1055"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.1097%2F01.ASN.0000025280.02386.9D"}],"container-title":["Nephron Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/103909","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/103909","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,24]],"date-time":"2025-04-24T02:49:59Z","timestamp":1745462999000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000103909"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,6,15]]},"references-count":15,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2007,7,1]]}},"URL":"https:\/\/doi.org\/10.1159\/000103909","archive":["Portico"],"relation":{},"ISSN":["1660-2137"],"issn-type":[{"type":"electronic","value":"1660-2137"}],"subject":[],"published":{"date-parts":[[2007,6,15]]}}}