分子拡散培養法を用いた培養心筋細胞の成長過程における自律拍動リズムの時間変化

摘要

To understand the detailed mechanisms of arrhythmia and its treatment methods, it is required to elucidate the mechanisms of formation and debacle of cardiac beat at a microscopic level by using appropriate in vitro models of cardiac beating. In this study, we have developed a method for an medium-exchange-free culture of rat cardiac myocytes, and carried out long-term recording of electrical activity of cardiac myocytes from postnatal rat by means of microelectrode-array (MEA) and the new culture method. Figure 6 a) ～ f) is a series of the properties of spontaneous beating (mean beating interval, standard deviation and coefficient of variation) of cardiac myocytes cultured by conventional culture method with alternate-day medium exchange (a ～ c) or newly developed "molecular diffusion culture" method (d ～ f). As shown in these figures, the difference of the beating property between the individual cultures, which is observed in conventional cultures (a) ～ c)), was dramatically reduced in the molecular diffusion cultures (d) ～ f)). In addition, these results also indicated that there is a transient period when all of mean beating interval, standard deviation, and coefficient of variation increase transiently before the formation of stable rhythmic fast beat.%心臓は，多数の心筋細胞の同期拍動とそのタイミングのrn微妙な制御によって，血液ポンプとしての機能を実現してrnいる。この制御機構が破綻した状態が不整脈現象であり，rn現在細胞レベルでその詳細な発生メカニズムの解明，効果rn的な治療法の確立に向けて研究が進められている状況にあrnる。そのような状況で，高空間分解能の光学観察や高時間rn分解能の細胞膜電位計測が適用できる培養心筋細胞集団のrn成長過程を詳細に解析することは，心臓の拍動リズムの形rn成メカニズムを解明するためや，不整脈現象への移行メカrnニズムを解明するための有効な研究手段であると考えられrnる。