Sodium modulates inotropic response to hyperosmolarity in isolated working rat heart.
Sodium modulates inotropic response to hyperosmolarity in isolated working rat heart.
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钠调节离体工作大鼠心脏对高渗性的正性肌力反应。
DOI：
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发表时间：
1992
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通讯作者：
O. Better
中科院分区：
文献类型：
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作者：
S. Ben;Y. Edoute;G. Hayam;O. Better
本研究旨在探讨急性变化的灌流液钠浓度和渗透压对左心室（LV）力学在离体工作大鼠心脏模型的影响。具体而言，我们分离了具有不同Na+浓度的等渗灌注液对LV力学的影响。在对照期之后，在该对照期期间，心脏以工作模式用Krebs-Henseleit碳酸氢盐缓冲液（Na+为136 meq/l，Ca 2+为2.6 mM，渗透压为300 mosM）的对照溶液灌注，心脏以半随机顺序经受不同的灌注液（Na+为96-156 meq/l，渗透压为240-380 mosM，使用不同的甘露醇浓度）。记录左室最大压力（PLVP）、左室压力最大时间导数（dP/dtmax）和心输出量（CO）。增加Na+浓度从96至156毫当量/升，使用等渗灌注液，降低PLVP，dP/dtmax，和CO的剂量依赖性方式。对于240、280、320和360 mosM的张力，剂量依赖性行为明显，但对于380 mosM则不明显。在恒定灌注液张力（320 mosM）下，将Na+浓度从96 meq/l增加到136 meq/l，dP/dtmax从6，753 +/- 133降至5，602 +/- 418 mmHg/s（P < 0.001）。重新排列相同的结果以检查灌注液张力与等Na+浓度的影响，表明增加灌注液渗透压对PLVP、dP/dtmax和CO具有剂量依赖性影响。在恒定的116 meq/l Na+浓度下，将灌注液渗透压从240 mosM增加到320 mosM使dP/dtmax从6，116 +/- 132增加到7，274 ± 594 mmHg/s（P < 0.01）。灌注液张力进一步增加至380 mosM，dP/dtmax降低至2，338 +/- 398 mmHg/s（P < 0.001）。（250字处删节）
The present study was designed to examine the effects of acute changes in perfusate Na+ concentrations and osmolarities on left ventricular (LV) mechanics in the isolated working rat heart model. Specifically, we separated the effect of isosmotic perfusates with different Na+ concentrations on LV mechanics. After a control period during which the hearts were perfused in a working mode with a control solution of Krebs-Henseleit bicarbonate buffer (Na+ of 136 meq/l, Ca2+ of 2.6 mM, and osmolarity of 300 mosM), the hearts were subjected to different perfusates (Na+ of 96-156 meq/l and osmolarity of 240-380 mosM, using different mannitol concentrations) in a semirandom order. Peak LV pressure (PLVP), maximal time derivative of LV pressure (dP/dtmax), and cardiac output (CO) were recorded. Increasing Na+ concentrations from 96 to 156 meq/l, using isosmotic perfusates, decreased PLVP, dP/dtmax, and CO in a dose-dependent manner. The dose-dependent behavior was evident for tonicities of 240, 280, 320, and 360 but not for 380 mosM. Increasing Na+ concentration from 96 to 136 meq/l at constant perfusate tonicity (320 mosM) decreased dP/dtmax from 6,753 +/- 133 to 5,602 +/- 418 mmHg/s (P < 0.001). Rearranging the same results to examine the effect of perfusate tonicity with iso-Na+ concentration demonstrated that increasing perfusate osmolarity had a dose-dependent effect on PLVP, dP/dtmax, and CO. At a constant Na+ concentration of 116 meq/l, increasing perfusate osmolarity from 240 to 320 mosM increased dP/dtmax from 6,116 +/- 132 to 7,274 +/- 594 mmHg/s (P < 0.01). Further increase in perfusate tonicity to 380 mosM decreased dP/dtmax to 2,338 +/- 398 mmHg/s (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)