Separate effects of ischemia, hypoxia, and contractility on thallium-201 kinetics in rabbit myocardium.
Separate effects of ischemia, hypoxia, and contractility on thallium-201 kinetics in rabbit myocardium.
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缺血、缺氧和收缩力对兔心肌中 201 铊动力学的单独影响。
DOI：
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发表时间：
1986
影响因子：
9.3
通讯作者：
C. Apstein
中科院分区：
文献类型：
--
作者：
J. Leppo;P. B. Macneil;A. Moring;C. Apstein
在42只离体等容收缩兔心上，观察了缺氧、缺血及收缩力改变对~（201）Tl动力学的影响。在A组中，研究了三个亚组（n = 7），即正常血流和氧合，缺氧和正常血流，或缺血血流和正常灌注液氧含量。在B组中，研究了三个亚组（n = 7），所有心脏都有正常的血流，但收缩状态被异丙肾上腺素增强或被低钙血症损害。在所有实验中使用无血红蛋白的缓冲液灌注液，并使用动脉和冠状窦流出物的多次定时收集来模拟30分钟恒定摄取期间的心肌同位素活性，随后进行30分钟的示踪剂清除。在缺血期间，与正常血流动力学参数相比，缺氧和低钙血症峰值产生压力和峰值正和负dP/dt均显著降低（p <0.01）。正如预期，异丙肾上腺素显著升高这些参数（p <0.04）。心肌201 TI动力学充分利用双指数模型具有快速和缓慢的组件。只有缺血性心脏的201 TI摄取和清除速率常数显著低于正常心脏（p <0.001）。平均值（+/- s.d.）对于其余心脏组，201 TI的心肌摄取和清除率（%/min）在4.86 +/- 0.87和7.18 +/- 1.45之间变化。因此，心肌201 TI动力学似乎是由冠状动脉流量占主导地位，可能不反映代谢和收缩状态的显着改变。这些数据表明，正常的201 TI摄取受损或过度收缩的细胞，接受正常的流量，可能不代表正常的细胞功能。
The effects of hypoxia and ischemia, as well as altered contractility, on thallium-201 (201TI) kinetics were evaluated in 42 isolated isovolumetrically contracting rabbit hearts. In Group A, three subgroups (n = 7 each) were studied that had either normal flow and oxygenation, hypoxia and normal flow, or ischemic flow and normal perfusate oxygen content. In Group B, three subgroups (n = 7 each) were studied and all hearts had normal flow but the contractile state was either enhanced with isoproterenol or impaired by hypocalcemia. A hemoglobin-free buffer perfusate was used in all experiments and multiple timed collections of arterial and coronary sinus effluent were used to model myocardial isotope activity during 30 min of constant uptake followed by 30 min of tracer clearance. During ischemia, hypoxia and hypocalcemia peak developed pressure and peak positive and negative dP/dt were all significantly reduced when compared to normal hemodynamic parameters (p less than 0.01). As expected, isoproterenol significantly elevated these parameters (p less than 0.04). Myocardial 201TI kinetics were adequately described utilizing a bi-exponential model having a fast and slow component. Only ischemic hearts had significantly lower rate constants for 201TI uptake and clearance than normal hearts (p less than 0.001). The mean (+/- s.d.) myocardial uptake and clearance rates for 201TI (%/min) varied between 4.86 +/- 0.87 and 7.18 +/- 1.45 for the remaining groups of hearts. Therefore, myocardial 201TI kinetics appear to be dominated by coronary flow and may not reflect marked alterations in the metabolic and contractile state. These data suggest that normal 201TI uptake in impaired or hypercontractile cells, receiving normal flow, may not represent normal cellular function.
冠状动脉流量减少对体外大鼠心脏制剂中铊 201 积累和释放的影响。
DOI：
10.1016/s0002-9149(83)80150-7
发表时间：
1983
期刊：
The American journal of cardiology
影响因子：
--
作者：
Goldhaber,SZ;Newell,JB;Ingwall,JS;Pohost,GM;Alpert,NM;Fossel,ET
通讯作者：
Fossel,ET