Coronary circulation in pressure-overloaded cardiac hypertrophy
Project/Area Number |
63570379
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Circulatory organs internal medicine
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Research Institution | TOHOKU UNIVERSITY |
Principal Investigator |
ISOYAMA Shogen TOHOKU UNIVERSITY HOSPITAL INSTRUCTOR, 医学部附属病院, 助手 (10133943)
|
Project Period (FY) |
1988 – 1989
|
Project Status |
Completed (Fiscal Year 1989)
|
Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1988: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
Keywords | Cardiac hypertrophy / Pressure overload / Coronary flow reserve / Coronary vascular resistance / Regression process / Rat / Aortic constriction / Isolated hearts / ランゲンドルフ標本 / 冠潅流 |
Research Abstract |
Using a rat model of ascending aortic banding and debaseding, we examined how the duration of pressure-overload affects reversibility in coronary circulation abnormalities after relief of pressure-overload. Four-week banding increased left ventricular dry weight/body weight ratio to 158<plus-minus>8% of that of sham-operated controls. In isolated non-working hearts perfused with crystalloid solution, peak mean coronary flow rate (CFR) was measured after brief ischemia. CFR and CFR/dry tissue weight significantly decreased (75<plus-minus>5 and 54<plus-minus>3% of that of controls at 100 mm Hg of coronary perfusion pressure; 75<plus-minus>5 and 54<plus-minus>4% at 150 mm Hg, respectively). Four weeks after debanding, CFR and CFR/dry tissue weight increased to similar levels in controls. On the other hand, 10-week banding produced the same degree of myocardial hypertrophy and decreases in CFR and CFr/dry tissue weight as in 4-week banded rats. Four weeks after debaseding, CTR had not changed. CFR/dry tissue weight increased due to regression of myocardial hypertrophy, but was significantly lower than that in rats debaseded after 4-week banding. Thus, the duration of pressure-overload does not affect the degree of coronary circulation abnormalities in the progression process, but does affect it in the regressio
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Report
(3 results)
Research Products
(21 results)