{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,2]],"date-time":"2025-11-02T09:33:16Z","timestamp":1762075996725},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1992,12,1]],"date-time":"1992-12-01T00:00:00Z","timestamp":723168000000},"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":[[1992,12]]},"abstract":"<jats:p>1. Voltage\u2010clamped isolated smooth muscle cells from guinea\u2010pig urinary bladder were studied with 3.6 mM extracellular Ca2+ at 36 degrees C. The fluorescence of the Ca(2+)\u2010sensitive dye Indo\u20101 was used to monitor the cytosolic calcium concentration ([Ca2+]i) and its changes ([Ca2+]i transient). Fast application of caffeine (10 mM) to the cell was used to release the intracellular Ca2+ from a \u2018caffeine\u2010sensitive Ca2+ store\u2019. 2. At the holding potential \u201060 mV, a short (1 s) caffeine application increased [Ca2+]i within less than 1 s from the resting 118 +\/\u2010 22 nM to 1490 +\/\u2010 332 nM. Following the caffeine wash\u2010out, [Ca2+]i fell from this peak to a subresting level of 47 +\/\u2010 12 nM, i.e. an \u2018undershoot\u2019 of [Ca2+]i occurred. Subsequent caffeine\u2010induced [Ca2+]i transients had attenuated peaks suggesting that the caffeine\u2010sensitive Ca2+ store had lost a part of the releasable Ca2+. 3. In the continuous presence of caffeine, [Ca2+]i decayed from its peak to control resting [Ca2+]i values. The wash\u2010out of caffeine following prolonged (10\u201030 s) treatment also resulted in [Ca2+]i undershoot. Subsequent caffeine\u2010induced [Ca2+]i transients were largely abolished as if the caffeine\u2010sensitive Ca2+ store had lost a large part of releasable Ca2+. During the undershoot, hyperpolarization to \u2010100 mV did not affect [Ca2+]i. In most cells studied, recovery of [Ca2+]i from the undershoot to the resting level required depolarizations inducing Ca2+ influx through L\u2010type Ca2+ channels. 4. Block of plasmalemmal Ca(2+)\u2010ATPase (PMCa) with extracellular La3+ (3 mM) did not modify the decay of the [Ca2+]i transients induced by depolarization or by a 1 s caffeine application suggesting that decay rate of both is not limited by PMCa rate. La3+ abolished the undershoot of [Ca2+]i. In the continuous presence of caffeine, La3+ largely prevented the decay of [Ca2+]i. 5. When the depolarizing steps from \u201060 to 0 mV (160 ms duration) were applied during the period of [Ca2+]i undershoot, the half\u2010time of decay of the corresponding [Ca2+]i transients was up to three times faster than in control. Repetitive depolarizations restored the rate of decay and [Ca2+]i recovered to the resting value. Both processes recovered along a similar time course. 6. Application of the phosphodiesterase inhibitor 3\u2010isobutyl\u20101\u2010methylxanthine (IBMX; 0.1 mM) or of 8\u2010Br\u2010cAMP (0.1 mM) did not mimic the above caffeine effects suggesting that stimulation of sarcoplasmic reticulum (SR) Ca(2+)\u2010ATPase (SERCa) by cAMP\u2010dependent phosphorylation is not the underlying mechanism.(ABSTRACT TRUNCATED AT 400 WORDS)<\/jats:p>","DOI":"10.1113\/jphysiol.1992.sp019408","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T15:13:14Z","timestamp":1418829194000},"page":"99-117","source":"Crossref","is-referenced-by-count":38,"title":["Caffeine\u2010induced release and reuptake of Ca2+ by Ca2+ stores in myocytes from guinea\u2010pig urinary bladder."],"prefix":"10.1113","volume":"458","author":[{"family":"Ganitkevich VYa","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G","family":"Isenberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1992,12]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1992.sp019408","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1992.sp019408","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T13:51:14Z","timestamp":1698069074000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1992.sp019408"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,12]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1992,12]]}},"alternative-id":["10.1113\/jphysiol.1992.sp019408"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1992.sp019408","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,12]]}}}