Henthorn T K, Avram M J, Frederiksen M C, Atkinson A J
J Pharmacol Exp Ther. 1982 Aug;222(2):389-94.
The kinetics of inulin and gallamine were studied after simultaneous i.v. injection in anesthetized dogs. The distribution of both compounds in extracellular fluid space was characterized by a three-compartment model in which the mean central compartment blood volume of 1.37 liters was identical with the expected value. The two peripheral compartments of the model appear to represent rapid and slow equilibrating interstitial fluid compartments. A mammillary model structure was selected in which intercompartmental clearance corresponds to transcapillary exchange. Previous studies indicate that inulin and smaller hydrophyllic molecules diffuse across capillary walls at rates proportional to their respective free water diffusion coefficients. For the ratio of the transcapillary permeability coefficients of inulin and gallamine to equal their free water diffusion coefficient ratio of 5.34 +/- 0.02 (+/- S.D)., it appears that the sum of blood flow to the fast and slow interstitial fluid compartments is less than cardiac output. When this assumption is made, blood flow to fast equilibrating interstitial fluid is estimated to be 39% of cardiac output, in agreement with previous measurements of splanchnic blood flow. This supports the hypothesis that the fast equilibrating interstitial fluid space is supplied by porous splanchnic capillaries that lack a continuous investment of basement membrane.
在麻醉犬身上同时静脉注射后，研究了菊粉和加拉明的动力学。两种化合物在细胞外液空间的分布用三室模型进行表征，其中平均中央室血容量为1.37升，与预期值相同。该模型的两个外周室似乎代表快速和缓慢平衡的间质液室。选择了一种乳头模型结构，其中室间清除率对应于跨毛细血管交换。先前的研究表明，菊粉和较小的亲水性分子以与其各自的自由水扩散系数成比例的速率扩散穿过毛细血管壁。为了使菊粉和加拉明的跨毛细血管渗透系数之比等于其自由水扩散系数之比5.34±0.02（±标准差），快速和缓慢间质液室的血流总和似乎小于心输出量。当做出这一假设时，快速平衡间质液的血流估计为心输出量的39%，这与先前对内脏血流量的测量结果一致。这支持了这样一种假设，即快速平衡的间质液空间由缺乏连续基底膜覆盖的多孔内脏毛细血管供应。
