Myocardial oxygenation in isolated hearts predicted by an anatomically realistic microvascular transport model
Myocardial oxygenation in isolated hearts predicted by an anatomically realistic microvascular transport model
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DOI：
10.1152/ajpheart.00380.2003
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发表时间：
2003-11-01
影响因子：
4.8
通讯作者：
Feigl, EO
中科院分区：
文献类型：
--
作者：
Beard, DA;Schenkman, KA;Feigl, EO
引入了心脏组织中氧输送的解剖学真实模型，用于分析从离体灌注豚鼠心脏测量的数据。该模型的构建是为了根据可用的形态测量数据来匹配心脏组织的微血管解剖结构。模拟三维系统（分为不同的微血管、间质和实质空间）中的传输。该模型用于解释平均心脏组织肌红蛋白饱和度的实验数据，并揭示缓冲液灌注和红细胞灌注的离体心脏之间组织氧合的差异。测量的平均肌红蛋白饱和度的解释很大程度上取决于灌注液的氧含量（例如，含红细胞灌注液与无细胞灌注液）。模型计算与平均组织肌红蛋白饱和度、测量的平均肌红蛋白和静脉氧张力的实验值相匹配，可用于预测细胞内氧张力的分布。计算表明，当缓冲液与 95% 的氧气平衡以提供超过 600 mmHg 的动脉氧张力时，大约 20% 的组织处于缺氧状态，氧张力 < 0.5 mmHg。添加红细胞使血细胞比容仅为 5%，可以防止组织缺氧。假设通常的缓冲液灌注 Langendorff 心脏准备对于流量范围内的流量来说是充分氧合的，这是不正确的
An anatomically realistic model for oxygen transport in cardiac tissue is introduced for analyzing data measured from isolated perfused guinea pig hearts. The model is constructed to match the microvascular anatomy of cardiac tissue based on available morphometric data. Transport in the three-dimensional system ( divided into distinct microvascular, interstitial, and parenchymal spaces) is simulated. The model is used to interpret experimental data on mean cardiac tissue myoglobin saturation and to reveal differences in tissue oxygenation between buffer-perfused and red blood cell-perfused isolated hearts. Interpretation of measured mean myoglobin saturation is strongly dependent on the oxygen content of the perfusate ( e. g., red blood cell-containing vs. cell-free perfusate). Model calculations match experimental values of mean tissue myoglobin saturation, measured mean myoglobin, and venous oxygen tension and can be used to predict distributions of intracellular oxygen tension. Calculations reveal that similar to 20% of the tissue is hypoxic with an oxygen tension of < 0.5 mmHg when the buffer is equilibrated with 95% oxygen to give an arterial oxygen tension of over 600 mmHg. The addition of red blood cells to give a hematocrit of only 5% prevents tissue hypoxia. It is incorrect to assume that the usual buffer-perfused Langendorff heart preparation is adequately oxygenated for flows in the range of