{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,5]],"date-time":"2025-10-05T16:50:32Z","timestamp":1759683032769},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1993,11,1]],"date-time":"1993-11-01T00:00:00Z","timestamp":752112000000},"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":[[1993,11]]},"abstract":"<jats:p>1. The effects of isoprenaline (Iso) on Ca2+ channel current in enzymatically isolated single cells of the guinea\u2010pig taenia caeci were examined using the standard whole\u2010cell voltage\u2010clamp method. 2. Iso potentiated the voltage\u2010dependent Ca2+ current; the threshold and maximally effective concentration of Iso to increase Ca2+ current were 3\u201010 nM and 1\u20103 microM, respectively. The average increase in Ca2+ current produced by 3 microM Iso was 42 +\/\u2010 6% (mean +\/\u2010 S.E.M.) and the response could be obtained repeatedly in the same cell. The concentration\u2010response relationship could be fitted by a binding model with a Hill coefficient of 1 and a dissociation constant of 42 nM. 3. The effect of Iso on Ca2+ current was voltage dependent. Although potentiation of Ca2+ current by Iso was obvious between \u201030 and +10 mV, it was small or absent around +20 to +30 mV. Iso had little effect on the relationship between inactivation of the Ca2+ current and voltage obtained using a double\u2010pulse protocol. 4. External application of forskolin, an adenylyl cyclase activator, or internal perfusion of cAMP or dibutyryl cAMP from the recording pipette, did not increase Ca2+ current and potentiation of Ca2+ current by Iso was observed repeatedly and was unchanged. 5. Internal perfusion of GTP gamma S or GDP beta S increased or did not affect the Ca2+ current and potentiation of Ca2+ current by Iso was unchanged and could be recorded repeatedly for about 20 min after rupture of the cell membrane. In addition, treatment of cells with the potent protein kinase C inhibitor, chelerythrine, had no effect on Ca2+ current or on potentiation of Ca2+ current by Iso. 6. These results suggest that the Ca2+ current in guinea\u2010pig taenia caeci cells is potentiated by isoprenaline via mechanisms which do not involve either a cAMP pathway, a G\u2010protein pathway or a protein kinase C pathway. The receptor involved appeared to be an atypical adrenoreceptor not blocked by either alpha\u2010 or beta\u2010receptor blocking agents.<\/jats:p>","DOI":"10.1113\/jphysiol.1993.sp019916","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T13:42:06Z","timestamp":1418823726000},"page":"563-582","source":"Crossref","is-referenced-by-count":24,"title":["Effect of isoprenaline on Ca2+ channel current in single smooth muscle cells isolated from taenia of the guinea\u2010pig caecum."],"prefix":"10.1113","volume":"471","author":[{"given":"K","family":"Muraki","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T B","family":"Bolton","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Y","family":"Imaizumi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Watanabe","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1993,11]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1993.sp019916","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1993.sp019916","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,24]],"date-time":"2023-10-24T23:58:18Z","timestamp":1698191898000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1993.sp019916"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1993,11]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1993,11]]}},"alternative-id":["10.1113\/jphysiol.1993.sp019916"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1993.sp019916","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1993,11]]}}}