{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T23:44:37Z","timestamp":1790811877463,"version":"4.1.0"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1992,9,1]],"date-time":"1992-09-01T00:00:00Z","timestamp":715305600000},"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":[[1992,9]]},"abstract":"<jats:p>1. The processes regulating intracellular calcium in the outer segments of salamander rods have been investigated. The main preparation used was the isolated rod loaded with the Ca(2+)\u2010sensitive photoprotein aequorin, from which outer segment membrane current and free [Ca2+]i could be recorded simultaneously. Two other preparations were also used: outer segment membrane current was recorded from intact, isolated rods using a suction pipette, and from detached outer segments using a whole\u2010cell pipette. 2. Measurements of free intracellular [Ca2+] in Ringer solution were obtained from two aequorin\u2010loaded rods. Mean [Ca2+]i in darkness was 0.41 microM, and after a bright flash [Ca2+]i fell to below detectable levels ( &lt; 0.3 microM). No release of intracellular Ca2+ by a bright flash of light could be detected ( &lt; 0.2 microM). 3. Application of the phosphodiesterase inhibitor 3\u2010isobutyl\u20101\u2010methylxanthine (IBMX) caused an increase in the size of the light\u2010sensitive current and a rise in [Ca2+]i, but application of IBMX either when the light\u2010sensitive channels had been closed by a bright light or in the absence of external Ca2+ caused no detectable rise in [Ca2+]i. It is concluded that IBMX increases [Ca2+]i by opening light\u2010sensitive channels, and does not release Ca2+ from stores within the outer segment. 4. Removal of external Na+ caused a rise in [Ca2+]i to around 2 microM and completely suppressed the light\u2010sensitive current. 5. The Na(+)\u2010Ca2+, K+ exchange current in aequorin\u2010loaded rods was activated in first\u2010order manner by internal free calcium, with a mean Michaelis constant, KCa, of 1.6 microM. 6. The KCa of the Na(+)\u2010Ca2+, K+ exchange was increased by elevating internal [Na+]. 7. The Michaelis relation between [Ca2+]i and the activity of the Na(+)\u2010Ca2+, K+ exchange was used to calculate the change in [Ca2+]i occurring during the response to a bright light. In aequorin\u2010loaded rods in Ringer solution the mean change in free [Ca2+]i after a bright flash was 0.34 microM. In these rods 10% of the dark current was carried by Ca2+. 8. Most of the calcium entering the outer segment was taken up rapidly and reversibly by buffer systems. The time constant of equilibration between free and rapidly bound Ca2+ was less than 20 ms. No slow component of calcium uptake was detected. 9. Two components of calcium buffering could be distinguished in the outer segments of aequorin\u2010loaded rods.(ABSTRACT TRUNCATED AT 400 WORDS)<\/jats:p>","DOI":"10.1113\/jphysiol.1992.sp019293","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T15:34:42Z","timestamp":1418830482000},"page":"111-142","source":"Crossref","is-referenced-by-count":141,"title":["Calcium homeostasis in the outer segments of retinal rods from the tiger salamander."],"prefix":"10.1113","volume":"455","author":[{"given":"L","family":"Lagnado","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L","family":"Cervetto","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P A","family":"McNaughton","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[1992,9]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1992.sp019293","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1992.sp019293","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T14:12:40Z","timestamp":1698070360000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1992.sp019293"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,9]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1992,9]]}},"alternative-id":["10.1113\/jphysiol.1992.sp019293"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1992.sp019293","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,9]]}}}