| Japanese |
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| Title | Deltorphin(opioidδ-agonist)がGuinea pig摘出灌流心臓に及ぼす影響 |
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| Subtitle | 原著 |
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| Authors | 藤田智*1, 中江裕理*2, 土田英昭*2, 長瀬博*3, 遠藤孝*3, 並木昭義*2 |
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| Organization | *1北海道恵愛会南一条病院麻酔科, *2札幌医科大学医学部麻酔科, *3東レ(株)基礎研究所 |
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| Journal | 循環制御 |
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| Volume | 19 |
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| Number | 2 |
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| Page | 237-241 |
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| Year/Month | 1998/ |
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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」Opioidのδ-agonistであるdeltorphinは, guinea pigの摘出灌流心臓において, 細胞外液のカルシウム濃度が一定の状態で, 左室圧, 冠流量に影響を与えないものの, 酸素消費量を減少させた. さらに, 細胞内カルシウム濃度をIndo-1を使って測定したところDeltorphinは細胞内カルシウム濃度を低下させるものの, 心筋のカルシウム感受性を変化させて, 左室圧を維持した. これらの作用は, Opioidのδ-antagonistであるnaltribenでは部分的にしか拮抗されなかった. この結果から, 麻薬系鎮痛薬の循環に対する抑制の少なさの原因の一つにδ-receptorが関与してい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 | Deltorphin, Intracellural calcium, Isolated heart, Calcium sensitivity |
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| English |
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| Title | The Effects of Deltorphin (δ-opioid agonist) on the Isolated Guinea Pig Heart |
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| Authors | Satoshi Fujita*, Yuri Nakae**, Hideaki Tsuchida*2, Hiroshi Nagase*3, Takashi Endo*3, Akiyoshi Namiki*2 |
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| Organization | *1Department of Anesthesiology, Hokkaido Keiaikai Minami 1 Jyo Hospital, *2Department of Anesthesiology, Sapporo Medical University School of Medicine, *3Basic Research Lab. Toray Inc |
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| Journal | Circulation Control |
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| Volume | 19 |
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| Number | 2 |
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| Page | 237-241 |
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| Year/Month | 1998/ |
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| Article | Original article |
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| Publisher | Japan Society of Circulation Control |
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| Abstract | Introduction : [D-Ala2]-deltorphin (DTP) is a synthetic opioid peptide that acts predominantly as a δ agonist. There is a controversy whether opioid receptors of the δ subtype that are found in cardiac tissue have a role in cardiac function and it is unclear if there is any direct myocardial effect of various opioid peptides when they are perfused. We explored the effect of 10-7 M DTP on altering the left ventricular pressure (LVP) /intracellular Ca2+ transient relationship in intact, beating hearts. Methods : The hearts of 5 anesthetized guinea pigs were isolated and perfused at constant pressure (55mmHg)with a Kreb's solution (2.5mM CaCl2). Heart rate (HR), coronary flow (CF) and LVP were monitored. LV surface Ca2+ transients were measured by the ratio of fluorescence emission at F386/F456 nm with the free Ca2+ fluorescent indicator indo 1. After insertion of a saline filled balloon to measure LVP, and loading and washout of 6μM indo 1 AM, hearts were exposed to Kreb's solution containing 0.3 to 4.5mM CaCl2 and LVP and Ca2+ transients were recorded before (control) and after perfusion of DTP. After correcting for autofluorescence and mitochondrial uptake, the emitted fluorescence ratio, F386/F456, indicated relative but proportional changes in diastolic (d) and systolic (s) free Ca2+. Data were expressed as sCa2+ and dCa2+ as a function of CaCl2, and sLVPmax (control) as a function of sCa2+max transients (control). Results : As a function of extracellular CaCl2, DTP decreased sCa2+max by 7.5% but increased dCa2+ max by 6.6% (measured at 2.5mM CaCl2) so that s-dCa2+max (total) decreased by 40%, indicating markedly reduced total Ca2+ for a given extracellular CaCl2. But DTP increased sLVPmax at sCa2+max by 20%, indicating enhanced contractile effort for a given sCa2+ by DTP. The figure shows that when sLVPmax for DTP was normalized to control sLVPmax at sCa2+max (F386/F456) (i.e. to 1) there was a 7.3% leftward shift in the sLVPmax/sCa2+max relationship at 50% sLVPmax. This is indicative of enhanced myofibrillar responsiveness to Ca2+ in the presence of DTP compared to control. |
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| Practice | Basic medicine |
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| Keywords | Deltorphin, Intracellural calcium, Isolated heart, Calcium sensitivity |
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