{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,26]],"date-time":"2025-09-26T22:12:47Z","timestamp":1758924767646},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1992,6,1]],"date-time":"1992-06-01T00:00:00Z","timestamp":707356800000},"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":[[1992,6]]},"abstract":"<jats:p>1. Smooth muscle cells, enzymatically isolated from the antrum of the guinea\u2010pig stomach, were voltage clamped at room temperature using the whole\u2010cell patch clamp technique. In physiological salt solution (PSS), step depolarization from a holding potential of \u201090 mV elicited inward calcium current (ICa) followed and superimposed by outward potassium current. 2. Outward current was divided into components depending on the presence of extracellular Ca2+ and others which were not activated as a result of Ca2+ influx. Ca(2+)\u2010dependent components were (1) a fast transient component most likely representing Ca(2+)\u2010activated K+ current (IK(Ca)) immediately triggered by the initial peak of ICa and (2) spontaneous transient outward currents (STOCs) apparently reflecting synchronized opening of IK(Ca) channels by cyclic release of Ca2+ from intracellular stores. Ca2+ influx\u2010independent outward current could be divided into two main components: (1) a transient component (I(to)) showing voltage\u2010dependent activation and inactivation and (2) a non\u2010inactivating component (Ini). 3. I(to) activated with a threshold around \u201030 mV, was fully available at \u201090 mV and completely inactivated at \u201010 mV. The time course of both activation and inactivation of I(to) at different potentials could be described by single exponential functions. Time constants of activation decreased from 35 ms at \u201010 mV to 10 ms at +40 mV. The time constant of inactivation was about 2 s and only weakly voltage dependent. Time constants for exponentially developing recovery from inactivation of I(to) ranged from 0.1 s at \u2010100 mV to 10 s at \u201030 mV. I(to) was insensitive to 4\u2010aminopyridine (4\u2010AP, 5 mmol\/l), slightly sensitive to tetraethylammonium (TEA, 10 mmol\/l), but substantially inhibited by caffeine (10 mmol\/l) and Cd2+ (5 mmol\/l). Estimates of the single\u2010channel conductance by current fluctuation analysis indicated a small value of about 2.5 pS. 4. The action of TEA on current elicited from a holding potential of \u201010 mV indicated a major contribution to Ini of a distinct component (Ini,K) that was completely blocked by this substance at a concentration of 10 mmol\/l. Ini was almost unaffected by 4\u2010AP (5 mmol\/l) and caffeine (10 mmol\/l), but strongly suppressed by Cd2+ (5 mmol\/l). Current fluctuation analysis of Ini,K gave a value for the single\u2010channel conductance of about 60 pS. 5. Ca2+ inward current was studied in PSS ([Ca2+]o = 2.5 mmol\/l) using pipette solution in which K+ was replaced by Cs+ to suppress outward K+ currents.(ABSTRACT TRUNCATED AT 400 WORDS)<\/jats:p>","DOI":"10.1113\/jphysiol.1992.sp019170","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T16:12:53Z","timestamp":1418832773000},"page":"387-417","source":"Crossref","is-referenced-by-count":30,"title":["Characterization of membrane currents in single smooth muscle cells from the guinea\u2010pig gastric antrum."],"prefix":"10.1113","volume":"451","author":[{"given":"T","family":"Noack","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P","family":"Deitmer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E","family":"Lammel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1992,6]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1992.sp019170","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1992.sp019170","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T12:29:25Z","timestamp":1698064165000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1992.sp019170"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,6]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1992,6]]}},"alternative-id":["10.1113\/jphysiol.1992.sp019170"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1992.sp019170","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,6]]}}}