{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T07:27:18Z","timestamp":1773300438143,"version":"3.50.1"},"reference-count":25,"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":[[2010,2]]},"abstract":"<jats:p> Superoxide (O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup>) produced by NADPH oxidase regulates Na absorption and renal hemodynamics. Increased NaCl in the thick ascending limb (TAL) stimulates O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation. However, we do not know whether physiological changes in NaCl concentration augment O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation, nor do we know the mediator(s) involved. In other cells, Rac1, a regulatory subunit of NADPH oxidase, is activated by elevated NaCl. We hypothesized that increasing luminal NaCl within the physiological range activates Rac1 and NADPH oxidase and, thereby, increases O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> production. We increased NaCl from 10 to 57 mM in medullary TAL suspensions and used lucigenin to measure O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation and Western blot to measure Rac1 activity. Increasing NaCl stimulated O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation from 1.41 \u00b1 0.16 to 2.71 \u00b1 0.30 nmol O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup>\u00b7min<jats:sup>\u22121<\/jats:sup>\u00b7mg protein<jats:sup>\u22121<\/jats:sup> ( n = 6, P &lt; 0.05). This increase was blocked by the Na-K-2Cl cotransporter inhibitor furosemide and the NADPH oxidase inhibitor apocynin. To examine the role of Rac1 in NaCl-induced O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> production, we measured Rac1 translocation by Western blot. When we added NaCl, Rac1 in the particulate fraction increased from 6.8 \u00b1 0.8 to 11.7 \u00b1 2.4% of total Rac1 ( n = 7, P &lt; 0.05). Then we measured O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation in the presence and absence of the Rac1 inhibitor. In the absence of the Rac1 inhibitor, NaCl increased O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation from 1.07 \u00b1 0.24 to 2.02 \u00b1 0.49 nmol O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup>\u00b7min<jats:sup>\u22121<\/jats:sup>\u00b7mg protein<jats:sup>\u22121<\/jats:sup>, and this increase was completely blocked by the inhibitor. Similarly, in vivo treatment of TALs with adenovirus expressing dominant-negative Rac1 decreased NaCl-induced O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation by 60% compared with control (0.33 \u00b1 0.04 vs. 0.81 \u00b1 0.17 nmol O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup>\u00b7min<jats:sup>\u22121<\/jats:sup>\u00b7mg protein<jats:sup>\u22121<\/jats:sup>, n = 6, P &lt; 0.05). We concluded that physiological increases in NaCl stimulate TAL O<jats:sub>2<\/jats:sub><jats:sup>\u2212<\/jats:sup> generation by activating Rac1. <\/jats:p>","DOI":"10.1152\/ajprenal.00472.2009","type":"journal-article","created":{"date-parts":[[2009,11,18]],"date-time":"2009-11-18T22:17:47Z","timestamp":1258582667000},"page":"F421-F425","source":"Crossref","is-referenced-by-count":31,"title":["Rac1 mediates NaCl-induced superoxide generation in the thick ascending limb"],"prefix":"10.1152","volume":"298","author":[{"given":"Guillermo B.","family":"Silva","sequence":"first","affiliation":[{"name":"Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeffrey L.","family":"Garvin","sequence":"additional","affiliation":[{"name":"Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, and"},{"name":"Department of Physiology, School of Medicine, Wayne State University, Detroit, Michigan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.00407.2005"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1091\/mbc.11.10.3341"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.1978.234.2.F97"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2005.087130"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9629(15)40679-2"},{"key":"B6","first-page":"37","volume":"13","author":"Greger R","year":"1990","journal-title":"Renal Physiol Biochem"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1172\/JCI111314"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1161\/HYPERTENSIONAHA.107.100214"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.1989.256.6.F1007"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.00383.2006"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1161\/01.RES.0000204727.46710.5e"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.00218.2001"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1161\/hy0202.104137"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1016\/j.cardiores.2006.05.003"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1161\/01.HYP.0000113295.31481.36"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1046\/j.1523-1755.2003.00827.x"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.1987.252.3.F374"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1152\/ajpregu.1995.268.5.R1087"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.1982.243.2.F160"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1161\/HYPERTENSIONAHA.108.120212"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.90365.2008"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1152\/ajprenal.00270.2009"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1161\/01.HYP.0000236646.83354.51"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M000026200"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1038\/ncb1071"}],"container-title":["American Journal of Physiology-Renal Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/ajprenal.00472.2009","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T20:07:14Z","timestamp":1567973234000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajprenal.00472.2009"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,2]]},"references-count":25,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2010,2]]}},"alternative-id":["10.1152\/ajprenal.00472.2009"],"URL":"https:\/\/doi.org\/10.1152\/ajprenal.00472.2009","relation":{},"ISSN":["1931-857X","1522-1466"],"issn-type":[{"value":"1931-857X","type":"print"},{"value":"1522-1466","type":"electronic"}],"subject":[],"published":{"date-parts":[[2010,2]]}}}