同期拍動とギャップ結合の関係　―共焦点レーザー顕微鏡による心筋細胞内力ルシウム動態の観察―

• 木村 永一

  札幌医科大学薬理教室

• 小山田 正人

  札幌医科大学第二病理学教室

• 森 道夫

  札幌医科大学第二病理学教室

• 大鹿 英世

  札幌医科大学薬理教室

書誌事項

タイトル別名

• Gap-junction in spontaneously contracting cultured neonatal rat cardiac myocytes

抄録

We studied the expression and localization of the major cardiac gap junction protein connexin 43 (Cx43) during the establishment of a synchronized contraction in confluently cultured neonatal rat cardiac myocytes, combined with a functional assay of gap junctional intercellular ccaniunication (GJIC) by using the microinjection-dye transfer method. We analyzed, by Fotonic Sensor, effects of heptanol on synchronized contraction of primary neonatal rat cardiac myocytes cultured at confluent density. We also examined the effect of heptanol on the changes in GJIC, on the expression and localization of Cx43, and on intracellular Ca²⁺ fluctuations by confocal laser scanning microscopy of myocytes loaded with the fluorescent Ca²⁺ indicator fluo 3.<BR> Monitoring of the beating rate and synchronization by Fotonic Sensor showed that the contractile rate increased with culture time, and that a synchronized contraction was gradually formed. GJIC was also increased with culture time and correlated well with the total area of Cx43-positive spots and the amount of Cx43 protein. At day 6 of culture, numerous myocytes exhibited spontaneous, synchronous contractions, excellent dye coupling and synchronized intracellular Ca²⁺ fluctuations. At the concentrations of 2.0 and 2.5 mmol/L, heptanol reversely inhibited synchronized contraction, WIC and synchronization of intracellular Ca²⁺ fluctuations in the myocytes without preventing contraction and changes of intracellular Ca²⁺ in individual cells. Brief exposure (5-20 min) to heptanol (2.0 mmol/L) did not cause detectable changes in the expression and localization of Cx43, despite strong inhibition of WIC. These results suggest that GJIC plays an important role in synchronous intracellular Ca²⁺ fluctuations, which facilitate synchronized contraction of cardiac myocytes.

収録刊行物

• 日本薬理学雑誌

  日本薬理学雑誌 106 (supplement), 67-71, 1995

  公益社団法人 日本薬理学会

キーワード

• Pharmacology

詳細情報

• CRID: 1390001204270765312
• NII論文ID: 10008631270
• NII書誌ID: AN00198335
• DOI: 10.1254/fpj.106.supplement_67
• ISSN: 13478397
• ISSN: 00155691
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可