{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T03:44:00Z","timestamp":1774323840549,"version":"3.50.1"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1978,6,1]],"date-time":"1978-06-01T00:00:00Z","timestamp":265507200000},"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":[[1978,6]]},"abstract":"<jats:p>1. The blocking effects of Ba+ and H+ on the inward K current during anomalous rectification of the giant egg membrane of the starfish, Mediaster aequalis, were studied using voltage clamp techniques. 2. External Ba2+ at a low concentration (10\u2010\u2010100 micron) suppresses the inward K current; the extent of suppression, expressed as the ratio of currents with and without Ba2+, can be described by a conventional bimolecular adsorption isotherm, K\/(K + [Ba2+]o), K being an apparent dissociation constant. 3. The dissociation constant, K, decreases as the membrane potential V becomes more negative and can be expressed by K(V) = K(0) exp (zmuFV\/RT), where K(0) is the K at V = 0, z is the charge of the blocking ion, and mu is a parameter for the membrane potential dependence of Ba2+ blockage. The value of mu ranges between 0.64 and 0.68. 4. Upon a sudden change in membrane potential the change in the blocking effect of Ba2+ follows first order kinetics; the forward rate constant is membrane\u2010potential\u2010dependent whereas the backward constant is potential\u2010independent. 5. The blocking effect of Ba2+ appears to be independent of the activation of K channels during anomalous rectification. 6. The blocking effect of Ba2+ depends on V alone, in contrast to the activation of the K channel during anomalous rectification which depends on V\u2010\u2010VK. 7. In these respects, the effect of Ba2+ is equivalent to the introduction of inactivation into the anomalous rectification. 8. SI2+ and Ca2+ show small but observable blocking effects only at much higher concentrations (about 10\u2010\u201020 mM). 9. The inward K current is suppressed when the external pH is reduced below 6.0. The blocking effect of H+ shows no significant potential dependence. The concentration dependence suggests that three H+ ions simultaneously titrate the acidic groups of each channel (pK = 5.3\u2010\u20105.4). 10. The implications of these results are discussed in terms of molecular models of the potassium channel of anomalous rectification and possible mechanisms of K channel inactivation.<\/jats:p>","DOI":"10.1113\/jphysiol.1978.sp012338","type":"journal-article","created":{"date-parts":[[2014,12,19]],"date-time":"2014-12-19T07:57:09Z","timestamp":1418975829000},"page":"167-185","source":"Crossref","is-referenced-by-count":170,"title":["Blocking effects of barium and hydrogen ions on the potassium current during anomalous rectification in the starfish egg."],"prefix":"10.1113","volume":"279","author":[{"given":"S","family":"Hagiwara","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S","family":"Miyazaki","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W","family":"Moody","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J","family":"Patlak","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1978,6]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1978.sp012338","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1978.sp012338","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,5]],"date-time":"2023-11-05T18:45:49Z","timestamp":1699209949000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1978.sp012338"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1978,6]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1978,6]]}},"alternative-id":["10.1113\/jphysiol.1978.sp012338"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1978.sp012338","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1978,6]]}}}