Kwong M S, Egan E A
Microvasc Res. 1985 Mar;29(2):152-60. doi: 10.1016/0026-2862(85)90013-5.
The use of [57Co]cyanocobalamin as an extracellular marker has been validated. Its simultaneous use with 51Cr-labeled erythrocytes and 125I-human serum albumin allows quantitative measurement of tissue water and the fractional exclusion of albumin from the interstitial compartment. The extravascular extracellular spaces of rabbit tissue are lung, 32 +/- 4%; heart, 25 +/- 2%; gut, 24 +/- 4%; and muscle, 13 +/- 1%. The fractional excluded albumin spaces are lung, 0.78 +/- 0.05; heart, 0.37 +/- 0.03; gut, 0.69 +/- 0.05; and muscle 0.58 +/- 0.03. The oversimplification that the extravascular extracellular space is a homogeneous region defined by a small tracer molecule and has the composition of lymph must be reconsidered. Albumin has a vastly different distribution in the interstitial spaces of different organs. Use of the three tracers reported here allows efficient measurement of blood volume, interstitial space, and interstitial albumin exclusion in whole tissues and organs, and thus can lead to further understanding of the in vivo changes occurring in various physiologic and disease states.
[57Co]氰钴胺作为一种细胞外标志物的应用已得到验证。它与51Cr标记的红细胞和125I - 人血清白蛋白同时使用，可对组织水进行定量测量，并测定白蛋白从间质间隙的分数排除率。兔组织的血管外细胞外间隙在肺中为32±4%；心脏中为25±2%；肠道中为24±4%；肌肉中为13±1%。白蛋白的分数排除间隙在肺中为0.78±0.05；心脏中为0.37±0.03；肠道中为0.69±0.05；肌肉中为0.58±0.03。那种认为血管外细胞外间隙是由小分子示踪剂定义的均匀区域且具有淋巴成分的过度简化观点必须重新审视。白蛋白在不同器官的间质间隙中的分布差异很大。本文报道的三种示踪剂的使用能够有效地测量全组织和器官中的血容量、间质间隙以及间质白蛋白排除情况，从而有助于进一步了解各种生理和疾病状态下体内发生的变化。
