{"id":17934,"date":"2025-08-29T09:20:22","date_gmt":"2025-08-29T07:20:22","guid":{"rendered":"https:\/\/www.nanion.de\/?post_type=resource_library&#038;p=17934"},"modified":"2025-08-29T09:20:22","modified_gmt":"2025-08-29T07:20:22","slug":"2025-blebbistatin-reduces-calcium-buffering-in-cardiomyocytes-consequences-for-cellular-electrophysiology","status":"publish","type":"resource_library","link":"https:\/\/nanion.com\/zh-hans\/resource_library\/2025-blebbistatin-reduces-calcium-buffering-in-cardiomyocytes-consequences-for-cellular-electrophysiology\/","title":{"rendered":"2025 &#8211; Blebbistatin reduces calcium buffering in cardiomyocytes: Consequences for cellular electrophysiology"},"content":{"rendered":"<p>Blebbistatin is an excitation\u2013contraction uncoupling agent commonly used in cardiac optical mapping; however, it has been reported to influence cardiac myofilament Ca<sup>2+<\/sup>\u00a0sensitivity. As primary contributors to Ca<sup>2+<\/sup>\u00a0buffering within cardiomyocytes, cardiac myofilaments play a critical role, and even minor disruptions in intracellular Ca<sup>2+<\/sup>\u00a0buffering significantly alter the free Ca<sup>2+<\/sup>\u00a0concentration. In this study, we investigated the effect of blebbistatin, a myosin II ATPase inhibitor, on intracellular Ca<sup>2+<\/sup>\u00a0buffering and cellular electrophysiology in induced pluripotent stem cell-derived atrial cardiomyocytes. Simultaneous whole-cell ruptured patch-clamp and fluorescence microscopy techniques were used to assess intracellular Ca<sup>2+<\/sup>\u00a0handling, in addition to automated high-throughput patch-clamp to investigate ion channel function. Comprehensive analysis of Ca<sup>2+<\/sup>\u00a0buffering revealed that blebbistatin (10 \u00b5mol\/l) causes a significant increase in buffer dissociation constant, suggesting decreased affinity of Ca<sup>2+<\/sup>\u00a0buffers. Furthermore, systolic and diastolic Ca<sup>2+<\/sup>\u00a0levels, sarcoplasmic reticulum Ca<sup>2+<\/sup>\u00a0leak and the incidence of spontaneous Ca<sup>2+<\/sup>\u00a0release events were significantly higher upon blebbistatin treatment. Although there was lack of impact on\u00a0<i>I<\/i><sub>Na<\/sub>\u00a0and\u00a0<i>I<\/i><sub>Ca,L<\/sub>\u00a0peak density, Ca<sup>2+<\/sup>-dependent inactivation of\u00a0<i>I<\/i><sub>Ca,L<\/sub>\u00a0was significantly enhanced, and\u00a0<i>I<\/i><sub>K1<\/sub>\u00a0density was significantly smaller after blebbistatin. Importantly, these effects were reversed after chelation of intracellular Ca<sup>2+<\/sup>\u00a0with EGTA. Our observations indicate that blebbistatin reduces Ca<sup>2+<\/sup>\u00a0buffering, which, in turn, causes changes in cellular electrophysiology in cardiomyocytes.<\/p>\n","protected":false},"featured_media":0,"template":"","products_tags":[42],"resource_type":[75],"application_areas":[53,76,77],"therapeutic_areas":[54,143],"target_categories":[],"target_families":[],"targets":[],"resource_keyword":[],"class_list":["post-17934","resource_library","type-resource_library","status-publish","hentry","products_tags-syncropatch-384","resource_type-publication","application_areas-assay-development-and-validation","application_areas-drug-discovery","application_areas-cell-ipscs-profiling","therapeutic_areas-cardiac-safety-cipa","therapeutic_areas-assay-development-and-validation"],"acf":[],"_links":{"self":[{"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/resource_library\/17934","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/resource_library"}],"about":[{"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/types\/resource_library"}],"wp:attachment":[{"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/media?parent=17934"}],"wp:term":[{"taxonomy":"products_tags","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/products_tags?post=17934"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/resource_type?post=17934"},{"taxonomy":"application_areas","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/application_areas?post=17934"},{"taxonomy":"therapeutic_areas","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/therapeutic_areas?post=17934"},{"taxonomy":"target_categories","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/target_categories?post=17934"},{"taxonomy":"target_families","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/target_families?post=17934"},{"taxonomy":"targets","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/targets?post=17934"},{"taxonomy":"resource_keyword","embeddable":true,"href":"https:\/\/nanion.com\/zh-hans\/wp-json\/wp\/v2\/resource_keyword?post=17934"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}