{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T17:36:00Z","timestamp":1784223360409,"version":"3.55.0"},"reference-count":0,"publisher":"American Physiological Society","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Cell Physiology"],"published-print":{"date-parts":[[1989,9,1]]},"abstract":"<jats:p> The role of G proteins in cholinergic suppression of Ca2+-activated K current was studied in isolated canine colonic myocytes with the whole cell voltage-clamp technique. Acetylcholine (ACh; 10.0 microM) caused a 64 +\/- 2.4% depression in the Ca2+-dependent component of the outward current evoked at potentials between -45 and -15 mV when GTP (0.1 microM) was included in the pipette-filling solution. This effect was reversed within 2-4 min on washout of ACh. Without GTP in the filling solution, ACh caused a 15 +\/- 2.5% depression in outward current in 60% of the cells tested. When the non-hydrolyzable GTP analogues, GTP gamma S (0.1 mM) or 5'-guanylylimidodiphosphate (GppNHp; 0.1 mM) were used, the decrease in outward current was greater (85 +\/- 4.2 and 78 +\/- 6.5%, respectively), and it was not reversed on withdrawal of ACh. Dialysis of the cell interior with pipette solution containing pertussis toxin (1 ng\/ml) for 30 min had no effect on the whole cell currents evoked on depolarization, but it abolished the effect of ACh on Ca2+-dependent outward current. These data suggest that coupling of muscarinic receptors to the inhibition of Ca2+-activated K channels is mediated by pertussis toxin-sensitive G proteins in colonic smooth muscle cells. G protein-mediated inhibition is distinctly different from the opening of muscarinic-regulated K channels in other cell types. <\/jats:p>","DOI":"10.1152\/ajpcell.1989.257.3.c596","type":"journal-article","created":{"date-parts":[[2017,12,24]],"date-time":"2017-12-24T15:25:37Z","timestamp":1514129137000},"page":"C596-C600","source":"Crossref","is-referenced-by-count":37,"title":["G proteins mediate suppression of Ca2+-activated K current by acetylcholine in smooth muscle cells"],"prefix":"10.1152","volume":"257","author":[{"given":"W. C.","family":"Cole","sequence":"first","affiliation":[{"name":"Department of Physiology, University of Nevada School of Medicine,Reno 89557."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. M.","family":"Sanders","sequence":"additional","affiliation":[{"name":"Department of Physiology, University of Nevada School of Medicine,Reno 89557."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","container-title":["American Journal of Physiology-Cell Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.physiology.org\/doi\/pdf\/10.1152\/ajpcell.1989.257.3.C596","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,17]],"date-time":"2024-06-17T19:48:41Z","timestamp":1718653721000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.physiology.org\/doi\/10.1152\/ajpcell.1989.257.3.C596"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1989,9,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1989,9,1]]}},"alternative-id":["10.1152\/ajpcell.1989.257.3.C596"],"URL":"https:\/\/doi.org\/10.1152\/ajpcell.1989.257.3.c596","relation":{},"ISSN":["0363-6143","1522-1563"],"issn-type":[{"value":"0363-6143","type":"print"},{"value":"1522-1563","type":"electronic"}],"subject":[],"published":{"date-parts":[[1989,9,1]]}}}