| Budget Amount *help |
¥12,100,000 (Direct Cost: ¥12,100,000)
Fiscal Year 2002: ¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 2001: ¥5,900,000 (Direct Cost: ¥5,900,000)
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| Research Abstract |
Selective acute left heart failure(ALHF) had been induced by injecting the technopolymer(mic-rosphere : 20 micron in diameter) into the left main coronary artery in mongrael dogs. The dogs were devided into four groups as follows ; (1)control study group to observe ALHF course (G-1), (2)dogs with circulatory support by ventricular assist device (VAD) via left atrial cannula (G-2), (3)dogs with VAD via left ventricular cannula, supported with fixed pulsatile driven with native heart (G-3), and (4) dogs like as G-3, but simultaneous driven with native heart (G-4). We studied left ventricular (LV) mechanics analyzing LV loop, which had been investigated from the first year of this research program, and have been analyzed the myocardial deformation by microscopic/electron microscopic methods and mRNA changes in beta-adrenergic receptors, angiotensin II type-1 receptors as well as parameters (Bcl-xl/Bax) evaluating cellular apotosis
Intramyocardial edem and myocardial derangements were micro
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scopically observeed in G-land G-2, but G-3 showed alomost normal findings like as pre-support. In electron microscopic studies, various sized mitochondria were observed in G-1/2, but normal sizes in G-3 with no myofibril derangements. These cellular findings were calculated using imaze analysis system by computer, resulted in comfirming the evidences with statistics. Immnunobinding assy studies showed elevated signals in beta-1-adrenalin receptor in G-3 which myocardial inotropic power might be attenuated to recovery, and mRNA of angiotensin 2 type-1 receptor was also elevated in G-2 revealing the elevated afterload inspite of VAD. Bcl-xl/Bax did not change in any stitua-tions, resulted in being unable to judge cellular apotosis during 4 hours VAD support
Comclusions : (1)VAD with apical cannula keeps normal cellular anatomy, (2)signals in beta-1-adrenalin receptor are increased in VAD with apical cannula, suggesting the reserved inotropic power within VAD support, (3)signals of angiotensin 2 type-1 receptor are increased in VAD with atrial cannula, sugesting the elevated afterload, anr (4)myocardial apotosis was not prevented enough during four circulatory support with VAD Less
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