Effect of temperature and coronary flow on the metabolic and mechanical function of the isolated rat heart.
Effect of temperature and coronary flow on the metabolic and mechanical function of the isolated rat heart.
复制标题
温度和冠脉流量对离体大鼠心脏代谢和机械功能的影响。
DOI：
10.1159/000175871
复制
发表时间：
1993
期刊：
影响因子：
1.9
通讯作者：
Osbakken,MD
中科院分区：
文献类型：
--
作者：
Blum,H;Ivanics,T;Zhang,D;Wroblewski,K;Osbakken,MD
许多心脏代谢中间体，即三磷酸腺苷（ATP）、H+、磷酸肌酸（PCr）、无机磷酸盐（Pi）、二磷酸腺苷（ADP），以及这些中间体的相关功能，ATP水解的吉布斯自由能（ΔG）和磷酸化比率[ATP/(ADP·Pi)]，被认为可以调节线粒体氧化磷酸化速率以符合机械需求。在Langendorff模式灌注的12个Sprague-Dawley大鼠心脏中，评估了低温和灌注压改变对这些参数的影响。在心脏温度为20 ~ 37℃，冠状动脉灌注压力为20 ~ 145 cm H2O时，获得31p核磁共振（NMR）谱。在整个干预期间，冠状动脉血流在0.5 ~ 15ml/min之间变化。在不同温度和灌注压力下测定心率（HR）、左室收缩压（LVSP）和冠状动脉比容积流量（SCF）。在所有温度下，产品HR × LVSP与灌注压力直接相关。温度依赖性可由总活化能72.7kJ/M表示。在恒温实验中，SCF和HR × LVSP随灌注压的降低呈线性下降。对上述代谢中间体与心功能之间关系的定量评价将这些中间体定义为除H+外的非调节性中间体。
A number of cardiac metabolic intermediates, namely, adenosine triphosphate (ATP), H+, phosphocreatine (PCr), inorganic phosphate (Pi), adenosine diphosphate (ADP), and related functions of these intermediates, Gibbs’ free energy of ATP hydrolysis (ΔG) and phosphorylation ratio [ATP/(ADP·Pi)], are thought to adjust mitochondrial oxidative phosphorylation rates to conform to mechanical demand. The effects of hypothermia and altered perfusion pressure on these parameters were evaluated in 12 hearts from Sprague-Dawley rats perfused in the Langendorff mode.31P-nuclear magnetic resonance (NMR) spectra were obtained at cardiac temperatures between 20 and 37 °C, and coronary perfusion pressures between 20 and 145 cm H2O. Coronary flow varied between 0.5 and 15ml/min throughout this range of intervention. Heart rate (HR), left ventricular systolic pressure (LVSP), and specific volumetric coronary flow (SCF) were determined for each temperature and perfusion pressure. The product HR × LVSP directly correlated with perfusion pressure at all temperatures. The temperature dependence could be represented by an overall activation energy of 72.7kJ/M.In the constant temperature experiment, SCF and HR × LVSP fell linearly with decreasing perfusion pressure. Quantitative evaluation of the relationship between cardiac function and the metabolic intermediates described above defined these intermediates as nonregulatory with the possible exception of H+.