Evaluation of extra- and intracellular apparent diffusion coefficient of sodium in rat skeletal muscle: Effects of prolonged ischemia
Evaluation of extra- and intracellular apparent diffusion coefficient of sodium in rat skeletal muscle: Effects of prolonged ischemia
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DOI：
10.1002/mrm.21568
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Bansal, Navin
中科院分区：
文献类型：
--
作者：
Babsky, Andriy M.;Topper, Stephen;Bansal, Navin
利用在体H-1和Na-23核磁共振波谱(MRS)研究了大鼠骨骼肌全脑缺血时水和钠表观扩散系数(ADC)变化的机制。Na+和水的ADC应该具有相似的特征，因为钠是以水阳离子的形式存在于组织中的。移动剂TmDOTP5-用于分离胞内和胞外钠(分别为Na-i(+)和Na-e(+))信号。分别于缺血前、缺血后1、2、3、4h测定组织含水量、组织总钠(Na-t(+)、Na-i(+)、Na+、ADC)。与一般的认知相反，缺血前Na-i(+)和Na-e(+)的ADC是相同的。因此，缺血引起的Na-t(+)ADC的变化不能用相对细胞内或细胞外空间大小的简单变化来解释。缺血2-4小时后，Na-t(+)和Na-e(+)ADC降低，而水和Na-i(+)ADC无明显变化。由于Na+浓度较高，Na-t(+)和Na-e(+)ADC之间存在相关性。同样，水与Na+、ADC之间的相关性也被观察到，因为细胞占据了骨骼肌80%的组织空间。由于Na+/K+-ATPase功能的停止，Ischernia还引起Na-i(+)的增加和Na-e(+)的信号强度的降低。
The mechanism of water and sodium apparent diffusion coefficient (ADC) changes in rat skeletal muscle during global ischemia was examined by in vivo H-1 and Na-23 magnetic resonance spectroscopy (MRS). The ADCs of Na+ and water are expected to have similar characteristics because sodium is present as an aqua-cation in tissue. The shift reagent, TmDOTP5-, was used to separate intra- and extracellular sodium (Na-i(+) and Na-e(+), respectively) signals. Water, total tissue sodium (Na-t(+), Na-i(+), and Na+, ADCs were measured before and 1, 2, 3, and 4 hr after ischemia. Contrary to the general perception, Na-i(+) and Na-e(+) ADCs were identical before ischemia. Thus, ischemia-induced changes in Na-t(+) ADC cannot be explained by a simple change in the size of relative intracellular or extracellular space. Na-t(+) and Na-e(+) ADCs decreased after 2-4 hr of ischemia, while water and Na-i(+) ADC remained unchanged. The correlation between Na-t(+) and Na-e(+) ADCs was observed because of high Na+, concentration. Similarly, the correlation between water and Na+, ADCs was observed because cells occupy 80% of the tissue space in the skeletal muscle. Ischernia also caused an increase in the Na-i(+) and an equal decrease in Na-e(+) signal intensity due to cessation of Na+/K+-ATPase function.