Fogh-Andersen N, Altura B M, Altura B T, Siggaard-Andersen O
Department of Clinical Chemistry, Herlev Hospital, Denmark.
Clin Chem. 1995 Oct;41(10):1522-5.
In several previous experiments to determine the composition of interstitial fluid, the results varied depending on the collecting technique, and the electrolyte concentrations differed from those of a hypothetical ultrafiltrate of plasma. In our approach, since a change of position from standing to supine is accompanied by hemodilution with interstitial fluid, we used the changes in hematocrit and composition of plasma in 20 subjects before and after lying down to calculate the composition of added interstitial fluid. The estimated protein concentration was 20.6 g/L, and the concentrations of total calcium and magnesium were low, in accord with a lower concentration of protein-bound calcium and magnesium. The activity of free cations was also lower, in agreement with a Donnan equilibrium potential of 1 mV across the endothelium. The concentration of leukocytes and platelets decreased according to the hemodilution, implying no escape or mobilization of these elements.
在先前几项确定组织间液成分的实验中，结果因采集技术而异，且电解质浓度与假设的血浆超滤液不同。在我们的方法中，由于从站立位变为仰卧位会伴随组织间液导致的血液稀释，我们利用20名受试者躺下前后血细胞比容和血浆成分的变化来计算添加的组织间液的成分。估计的蛋白质浓度为20.6 g/L，总钙和镁的浓度较低，这与蛋白结合钙和镁浓度较低一致。游离阳离子的活性也较低，这与内皮细胞上1 mV的唐南平衡电位相符。白细胞和血小板的浓度随血液稀释而降低，这意味着这些成分没有逸出或动员。
