{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T00:19:08Z","timestamp":1785370748304,"version":"3.55.0"},"reference-count":33,"publisher":"The Company of Biologists","issue":"16","license":[{"start":{"date-parts":[[2021,8,15]],"date-time":"2021-08-15T00:00:00Z","timestamp":1628985600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/www.biologists.com\/user-licence-1-1\/"}],"funder":[{"DOI":"10.13039\/501100011958","name":"Danmarks Frie Forskningsfond","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100011958","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"crossref","award":["19-15-00163"],"award-info":[{"award-number":["19-15-00163"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100016971","name":"Lomonosov Moscow State University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100016971","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2021,8,15]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n               <jats:p>To provide the first description of the exact location of primary pacemaker of the squamate heart, we used sharp microelectrode impalements and optical mapping of isolated sinus venosus preparations from Burmese pythons. We located the dominant pacemaker site at the base of the right leaflet of the sinoatrial valve (SAV), but latent pacemakers were also identified in a circular region around the SAV. Acetylcholine (10\u22125\u00a0mol\u00a0l\u22121) or noradrenaline (10\u22126\u00a0mol\u00a0l\u22121) induced shifts of the leading pacemaker site to other points near the SAV. The ionic currents of most of the cardiomyocytes isolated enzymatically from the SAV region resembled those of typical working myocytes from the sinus venosus. However, seven cells lacked the background inward rectifier current (IK1) and had a time-dependent hyperpolarization-induced inward current identified as the \u2018funny\u2019 pacemaker current (If). Therefore, the region proximal to SAV demonstrates pacemaking activity and contains cells that resemble the electrophysiological properties of mammalian pacemaker myocytes.<\/jats:p>","DOI":"10.1242\/jeb.242778","type":"journal-article","created":{"date-parts":[[2021,7,28]],"date-time":"2021-07-28T08:58:53Z","timestamp":1627462733000},"source":"Crossref","is-referenced-by-count":6,"title":["The snake heart pacemaker is localized near the sinoatrial valve"],"prefix":"10.1242","volume":"224","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5751-8853","authenticated-orcid":false,"given":"Denis V.","family":"Abramochkin","sequence":"first","affiliation":[{"name":"Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye Gory, 1, 12, 119234 Moscow, Russia"},{"name":"Laboratory of Cardiac Electrophysiology, National Medical Research Center for Cardiology, 3rd Cherepkovskaya, 15a, 121552 Moscow, Russia"},{"name":"Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova, 1a, 117997 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3075-4834","authenticated-orcid":false,"given":"Vladislav S.","family":"Kuzmin","sequence":"additional","affiliation":[{"name":"Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye Gory, 1, 12, 119234 Moscow, Russia"},{"name":"Laboratory of Cardiac Electrophysiology, National Medical Research Center for Cardiology, 3rd Cherepkovskaya, 15a, 121552 Moscow, Russia"},{"name":"Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova, 1a, 117997 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3303-1095","authenticated-orcid":false,"given":"Vladimir","family":"Matchkov","sequence":"additional","affiliation":[{"name":"MEMBRANES, Department of Biomedicine, Faculty of Health, University of Aarhus, 8000 Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6496-0527","authenticated-orcid":false,"given":"Andrey A.","family":"Kamensky","sequence":"additional","affiliation":[{"name":"Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye Gory, 1, 12, 119234 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4350-3682","authenticated-orcid":false,"given":"Tobias","family":"Wang","sequence":"additional","affiliation":[{"name":"Section of Zoophysiology, Institute of Biology, University of Aarhus, 8000C Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"237","published-online":{"date-parts":[[2021,8,24]]},"reference":[{"key":"2021082409550352800_JEB242778C1","doi-asserted-by":"publisher","first-page":"883","DOI":"10.1007\/s00360-015-0925-5","article-title":"Seasonal acclimatization of the cardiac potassium currents (IK1 and IKr) in an arctic marine teleost, the navaga cod (Eleginus navaga)","volume":"185","author":"Abramochkin","year":"2015","journal-title":"J. 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