| Japanese |
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| Title | クロニジンの冠循環に与える影響 -急性狭窄モデルを用いて- |
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| Subtitle | 原著 |
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| Authors | 平野真由美, 嬉野浩行, 張士平, 堤雅俊, 柴田治, 澄川耕二 |
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| Organization | 長崎大学医学部麻酔学教室 |
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| Journal | 循環制御 |
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| Volume | 18 |
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| Number | 2 |
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| Page | 196-202 |
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| Year/Month | 1997/ |
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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」血圧, 心拍数を固定した生体内冠灌流モデルを用い, クロニジンがイヌの冠動脈の血流分布に及ぼす影響を調べ, 更に急性狭窄を作製しその影響を調べた. 局所心筋短縮率はクロニジン(3μg/kg)の静脈内投与により若干減少する傾向が見られたが有意ではなかった. クロニジン非投与群では狭窄による心筋内外層血流比(I/O比)の変化はなかったが, クロニジン投与群ではクロニジン投与時に心筋外層の血流量が増加し, I/O比が低下し, 狭窄により前値に復した. クロニジンの心筋収縮性への影響は小さく, さらに正常心においては心筋血流分布を変化させるが冠狭窄心においてはその作用は現れにくいことが示唆された. |
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| Practice | 基礎医学・関連科学 |
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| Keywords | Clonidine, α2-adrenergic agonist, Cooary circulation, Coronary stenosis |
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| English |
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| Title | Effect of Clonidine on Coronary Circulation in Dogs with Acute Stenosis |
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| Subtitle | |
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| Authors | Mayumi Hirano, Hiroyuki Ureshino, Schiping Zang, Masatoshi Tsutsumi, Osamu Shibata, Koji Sumikawa |
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| Authors(kana) | |
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| Organization | Department of Anesthesia, Nagasaki University School of Medicine |
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| Journal | Circulation Control |
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| Volume | 18 |
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| Number | 2 |
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| Page | 196-202 |
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| Year/Month | 1997/ |
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| Article | Original article |
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| Publisher | Japan Society of Circulation Control |
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| Abstract | The present study was carried out to clarify the effect of clonidine on coronary hemodynamics in dogs with acute stenosis. Fourteen mongrel dogs were anesthetized with α-chloralose, pentobarbital and morphine. Heart was paced at a constant rate (100bpm) after producing a complete AV block. Mean arterial pressure (MAP) was controlled at 80mmHg by using a pressurized blood reservoir connected to femoral artery. A carotid to left circumflex coronary artery (CX) shunt was installed. Total CX flow was measured with electromagnetic flowmeter and flow to inner (I) and outer (O) layer was determined wiht colored microsphere technique. A pair of crystals was implanted in the myocardium supplied by CX to measure the regional myocardial contractility (%SS), After stabilization, dogs were allocated into two groups, i.e., clonidine group and control group. First measurement was made for baseline value in each group and then clonidine group received clonidine, 3μg/kg, followed by second measurement befor having stenosis. In both groups, coronary stenosis was made to the degree that was maximum without decrease in blood flow. Under this condition, in which coronary flow reserve was lost completely, the measurement was made for stenosis value. MAP and HR were kept constant at predetemined value CX flow shoued no significant change in either group. clonidine tended to reduce %SS but not significantly. In control group, there was no change in I/O ratio before and after stenosis. In clonidine group. I/O ratio was significantly reduced by clonidine compared to baseline due to an increase in blood flow to the outer layer. However, the I/O ratio returned to the baseline value under stenosis. The results show that clonidine reduces I/O ratio of myocardial blood flow in normal heart, whereas this effect of clonidine is not observed in stenotic heart. It is suggested that a compensatory mechanism in stenotic heart to cause full dilatation of coronary arterioles would counteract clonidine effect on myocardial circulation. |
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| Practice | Basic medicine |
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| Keywords | Clonidine, α2-adrenergic agonist, Cooary circulation, Coronary stenosis |
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