{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T04:17:27Z","timestamp":1777522647248,"version":"3.51.4"},"reference-count":0,"publisher":"American Physiological Society","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Renal Physiology"],"published-print":{"date-parts":[[1990,3,1]]},"abstract":"<jats:p> Experiments were carried out to test whether maneuvers believed to increase intracellular Ca2+ concentration [( Ca2+]cell) inhibit Na transport in cortical collecting tubules (CCTs). Unidirectional Na efflux (JNa1----b) and Na influx (JNab----1) were measured isotopically in isolated perfused renal CCTs of rabbits. The animals were either untreated or pretreated with deoxycorticosterone (DOC) for 1-3 wk. To raise [Ca2+]cell, ionomycin or quinidine were added to, or [Na] reduced in, pertubular fluid. In control DOC-pretreated CCTs JNa1----b tended to saturate as luminal Na concentration was increased, reaching 22.9 +\/- 1.2 pmol.cm-1.s-1 at 145 mM. In addition, in these CCTs, in contrast to non-DOC-treated tubules, the apical cell membrane was not found to be rate limiting for Na reabsorption as neither amphotericin B nor vasopressin further enhanced JNa1----b. In non-DOC-treated CCTs 10(-6) M ionomycin inhibited JNa1----b by 44.7%. When DOC-pretreated CCTs were exposed to either 10(-6)M ionomycin or 10(-4)M quinidine, JNa1----b was inhibited by 27 and 26%, respectively, while JNab----1 remained unchanged. This ionomycin-induced inhibition was Ca dependent. Exposure of DOC-pretreated CCTs to 5 mM Na-Ringer solution (Na replaced by choline or N-methyl-D-glucamine) for 30 min reduced JNa1----b by 18-30%. The inhibition of JNa1----b caused by any of the three maneuvers was fully reversed upon addition of amphotericin B to the luminal fluid. The results are consistent with the view that a sustained increase in [Ca2+]cell reduces Na transport by inhibition of the rate of Na+ entry across the apical cell membrane. <\/jats:p>","DOI":"10.1152\/ajprenal.1990.258.3.f568","type":"journal-article","created":{"date-parts":[[2017,12,22]],"date-time":"2017-12-22T16:37:30Z","timestamp":1513960650000},"page":"F568-F582","source":"Crossref","is-referenced-by-count":5,"title":["Ca2(+)-dependent inhibition of sodium transport in rabbit cortical collecting tubules"],"prefix":"10.1152","volume":"258","author":[{"given":"G.","family":"Frindt","sequence":"first","affiliation":[{"name":"Department of Physiology, Cornell University Medical College, NewYork, New York 10021."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E. E.","family":"Windhager","sequence":"additional","affiliation":[{"name":"Department of Physiology, Cornell University Medical College, NewYork, New York 10021."}],"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.1990.258.3.F568","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T15:12:05Z","timestamp":1567955525000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajprenal.1990.258.3.F568"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,3,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1990,3,1]]}},"alternative-id":["10.1152\/ajprenal.1990.258.3.F568"],"URL":"https:\/\/doi.org\/10.1152\/ajprenal.1990.258.3.f568","relation":{},"ISSN":["1931-857X","1522-1466"],"issn-type":[{"value":"1931-857X","type":"print"},{"value":"1522-1466","type":"electronic"}],"subject":[],"published":{"date-parts":[[1990,3,1]]}}}