title: The mouse sino-atrial node expresses both the type 2 and type 3 Ca(2+) release channels/ryanodine receptors.
abstract: Ca(2+) released from intracellular Ca(2+) stores is shown to be involved in pacemaker activity in the sino-atrial (SA)-node. However, little is known about the molecular identity of the Ca(2+) release channel/ryanodine receptor (RYR) involved in pacemaker activity. We examined the mRNA distribution of three different RYR isoforms (RYR1, RYR2, and RYR3) in the mouse SA-node. RNase protection assay and in situ hybridization revealed that RYR2 mRNA expresses widely in the heart including the SA-node, while RYR3 mRNA expression is limited to the SA-node and to the right atrium. Thus, not only RYR2 but also RYR3 may participate in pacemaker activity.
authors.affiliation: Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Japan. h-masumiya.bip@mri.tmd.ac.jp
authors.forename: Haruko
authors.initials: H
authors.lastname: Masumiya
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Myriam
authors.initials: M
authors.lastname: Hemberger
authors.forename: Hikaru
authors.initials: H
authors.lastname: Tanaka
authors.forename: Koki
authors.initials: K
authors.lastname: Shigenobu
authors.forename: S R Wayne
authors.initials: SR
authors.lastname: Chen
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Furukawa
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D006325:Heart Atria / Q000378:metabolism; D017403:In Situ Hybridization; D051379:Mice; D008969:Molecular Sequence Data; D018408:Patch-Clamp Techniques; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012433:Ryanodine / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics* / Q000378:metabolism; D012849:Sinoatrial Node / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D019837:Ryanodine Receptor Calcium Release Channel; D012433:Ryanodine; D002118:Calcium