Kozeny G A, Murdock D K, Euler D E, Hano J E, Scanlon P J, Bansal V K, Vertuno L L
Am Heart J. 1985 Feb;109(2):290-6. doi: 10.1016/0002-8703(85)90596-4.
Effects of acute changes in osmolality and sodium concentration (Na) on myocardial contractility (MC) were examined in anesthetized dogs. Using a carotid to left anterior descending bypass, 4 cc of NaCl and/or dextrose of varying osmolality as injected and the percentage of change in MC measured. At Na = O mEq/L, a positive inotropic response occurred, which varied inversely as osmolality increased from 300 (MC = 100 +/- 23%) to 700 mOsm/L (MC = 39 +/- 10%, p less than 0.01). Similar ranges of positive responses of lesser magnitude were noted at Na = 75 mEq/L. At Na = 150, 190, or 350 mEq/L, similar increments in osmolality caused an increasingly negative inotropic response. An inverse relationship between Na and MC was noted with osmolality held constant. Injections of the nonionic contrast agent, P297, in 5% dextrose or 0.9% NaCl, resulted in 28 +/- 3% or -17 +/- 4% (p less than 0.01) change in MC, respectively. Sodium concentration and osmolality have independent effects on MC. Hyperosmolality/hypernatremia causes a negative inotropic response while hyponatremia causes a positive one.
在麻醉犬身上研究了渗透压和钠浓度（Na）的急性变化对心肌收缩力（MC）的影响。通过颈动脉至左前降支搭桥，注入4毫升不同渗透压的氯化钠和/或葡萄糖，并测量MC的变化百分比。在Na = 0 mEq/L时，出现正性肌力反应，随着渗透压从300（MC = 100±23%）增加到700 mOsm/L（MC = 39±10%，p<0.01），该反应呈反比变化。在Na = 75 mEq/L时，也观察到幅度较小的类似正反应范围。在Na = 150、190或350 mEq/L时，渗透压的类似增加导致负性肌力反应越来越明显。在渗透压保持恒定的情况下，观察到Na与MC之间呈反比关系。在5%葡萄糖或0.9%氯化钠中注射非离子型造影剂P297，分别导致MC变化28±3%或-17±4%（p<0.01）。钠浓度和渗透压对MC有独立影响。高渗/高钠血症导致负性肌力反应，而低钠血症导致正性肌力反应。
