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Hemodynamic and Humoral factors in Coronary Collateral Development

冠状动脉侧枝发育中的血流动力学和体液因素

基本信息

批准号：
04454261
负责人：
TOMOIKE Hitonobu
金额：
$ 4.35万
依托单位：
Yamagata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

The effects of pre-existing collateral and the perfusion size on the ischemia-induced collateral development were studied in a canine model. The dogs were instrumented under sterile surgery with pairs of ultrasonic crystals to measure regional wall motion in the territory of the left circumflex(LCX) and left anterior descending coronary arteries. An implantable miniature micromanometer was used to measure left ventricular (LV) pressure. Two to 3weeks after surgery, 2min coronary occlusion (CO) of the LCX was repeated every 32 min automatically using an AM/AM telemetry command system. Regional wall motion and LV pressure were monitored via a FM/FM telemetry system consecutively day and night. The functional state of pre-existing collaterals which estimated by the level of % reduction of regional wall motion at the end of the first 2min CO, ranged from-11 to -141%. The perfusion size of the LCX ranged from 35 to 54%. Number of coronary occlusion needed for collateral development was exponentially related to the functional state of pre-existing collaterals(r=0.77, P<0.01), but not to the perfusion size.When the collateral function was functionally matured in the same model as above, an episode of 2 min coronary occlusion was stopped. After 24 hours'interruption of occlusion stimuli, the functional state of collaterals remained deteriorated. Thus, the presence of ischemic stimuli is important to maintein the developed state of collateral function.To elucidate how the diseased state such as hyperlipidemia(WHHL rabbits) modulates the speed of collateral development, we adopted rabbit for an experimental model.We successfully devised miniaturized sensors for assessing instantaneous coronary bood flow or ventricular pump function. Thus, we are able to study not only regional wall motion, but also humoral factors related to collateral function in purely-bred animal models.

在犬模型中研究了预先存在的侧枝和灌注量对缺血侧枝发育的影响。在无菌手术条件下，用超声晶体对测量左旋（LCX）和左冠状动脉前降支区域壁面运动。采用植入式微型微压计测量左心室（LV）压力。术后2 ~ 3周，采用AM/AM遥测命令系统，每32分钟自动重复2分钟的LCX冠状动脉闭塞（CO）。通过调频/调频遥测系统连续昼夜监测区域壁面运动和左室压力。预存抵押品的功能状态由前2min CO结束时区域壁面运动减少%的水平估计，范围为- 11%至-141%。LCX灌注面积为35% ~ 54%。侧枝发育所需冠状动脉闭塞次数与已有侧枝功能状态呈指数相关（r=0.77， P<0.01），但与灌注大小无关。当与上述模型相同的侧枝功能功能成熟时，停止一次2分钟的冠状动脉闭塞。阻断刺激24小时后，侧络功能状态继续恶化。因此，缺血刺激的存在对于维持侧支功能的发达状态是重要的。为了阐明高脂血症（WHHL兔）等疾病状态如何调节侧支发育的速度，我们采用家兔作为实验模型。我们成功地设计了微型传感器来评估瞬时冠状动脉血流量或心室泵功能。因此，我们不仅可以研究局部壁运动，还可以研究纯种动物模型中与侧支功能相关的体液因素。