| Japanese |
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| Title | 培養心筋細胞肥大におよぼす拍動とβ受容体刺激の影響 |
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| Subtitle | 原著 |
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| Authors | 内貴猛, 林あさこ, 河原剛一 |
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| Organization | 北海道大学電子科学研究所 |
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| Journal | 循環制御 |
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| Volume | 24 |
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| Number | 4 |
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| Page | 378-385 |
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| Year/Month | 2003/ |
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| Article | 原著 |
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| Publisher | 日本循環制御医学会 |
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| Abstract | 「要旨」慢性的な力学的過負荷による心筋細胞肥大の発生メカニズムには未だ不明な点が多い. 本研究では力学的過負荷が加わった状態において, 心拍出量を正常に保つために活性化される交感神経の作用が, 心筋細胞肥大形成におよぼす影響を検討した. 成熟ラット単離心筋細胞を電気刺激しながら培養し, 交感神経伝達物質の添加や細胞収縮力, 収縮頻度の変化が細胞の大きさにおよぼす影響を, 細胞内タンパク量を測定して調べた. その結果, 交感神経作用の1つであるβ受容体刺激によって細胞肥大が誘発され, 細胞収縮(電気刺激)と相乗的な効果を示すことがわかった. さらに, その変化は収縮関連タンパクにも認められ, 力学的負荷に対する適応的な変化である可能性が示唆された. 一方, 電気刺激のみでは収縮関連タンパクのみが有意に増加し, β受容体刺激とは異なるメカニズムの変化が起こることが示唆された. これらの結果より, 交感神経活動亢進によりβ受容体を介した細胞肥大と機械的負荷感受性受容体を介した収縮関連タンパク産生増加による収縮機能変化が同時に起こる可能性が示唆された. |
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| Practice | 基礎医学・関連科学 |
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| Keywords | 心筋細胞肥大, 交感神経, 力学的負荷, β受容体, 心筋細胞収縮性, 電気刺激, Cell hypertrophy, Sympathetic nerve, Mechanical overload, β-receptor, Contractility of myocardial cell, Electrical stimulation |
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| English |
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| Title | Effects of Contraction and Stimulation of β-adrenergic Receptors on the Hypertrophy of Cultured Myocardial Cells |
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| Authors | Takeru Naiki, Asako Hayashi, Koichi Kawahara |
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| Organization | Research Institute for Electronic Science, Hokkaido University |
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| Journal | Circulation Control |
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| Volume | 24 |
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| Number | 4 |
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| Page | 378-385 |
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| Year/Month | 2003/ |
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| Article | Original article |
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| Publisher | Japan Society of Circulation Control |
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| Abstract | Detailed mechanisms underlying the genesis of myocardial cell hypertrophy caused by long-term mechanical overload have not yet been fully understood. In the present study, we investigated effects of the increased sympathetic nervous tone, which is considered to occur in order to maintain the normal cardiac output when the heart is mechanically overloaded, on cell hypertrophy. To do this, myocardial cells isolated from adult rats were cultured under electrical field stimulation, and the effects of an agonist of sympathetic receptors, and the frequency and intensity of cell contraction on the mass of the cells were investigated by measuring the total protein content and the contents of α-actin and β-myosin. The cell hypertrophy was induced by stimulating β-adrenoceptors, and was enhanced by concurrent cell contraction(electrical stimulation). These changes were associated with the increase in the contents of actin and myosin, indicating that the cell hypertrophy induced in the present study may be an adaptive response against the mechanical overload if it would occur in vivo. On the other hand, the cell contraction itself significantly increased the contents of actin and myosin. The present study suggested that the increased sympathetic nervous tone induced hypertrophy by stimulating β-adrenoceptors together with the increase in contractile proteins through mechanoreceptor activation. |
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| Practice | Basic medicine |
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| Keywords | Cell hypertrophy, Sympathetic nerve, Mechanical overload, β-receptor, Contractility of myocardial cell, Electrical stimulation |
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