Yoshioka M, Kikuchi A, Matsumoto M, Ushiki T, Minami M, Saito H
First Department of Pharmacology, Hokkaido University School of Medicine, Sapporo, Japan.
Res Commun Chem Pathol Pharmacol. 1993 Mar;79(3):370-6.
Free 5-hydroxytryptamine (5-HT) concentration in the portal vein was monitored in anesthetized rats using microdialysis. The 5-hydroxytryptamine metabolite 5-hydroxyindoleacetic acid (5-HIAA) was also measured. Concentration of 5-HT in the portal vein decreased gradually after insertion of a microdialysis probe but fluctuated markedly throughout the entire perfusion, whereas 5-HIAA values did not fluctuated in the same manner. An electron microscopic study of the probe membrane after dialysis showed platelet adhesion and aggregation on part of the membrane. In contrast, 5-HT concentration measured by puncture and direct blood sampling of the portal vein did not fluctuate in the same way as that determined by microdialysis. These results suggest that measurement of free 5-HT concentration in the blood by microdialysis might be inaccurate due to contamination of 5-HT from adhesion and aggregation of platelets on the probe membrane.
采用微透析技术监测麻醉大鼠门静脉中游离5-羟色胺（5-HT）的浓度。同时还检测了5-羟色胺代谢产物5-羟吲哚乙酸（5-HIAA）。插入微透析探针后门静脉中5-HT的浓度逐渐降低，但在整个灌流过程中波动明显，而5-HIAA值并未以相同方式波动。透析后对探针膜进行的电子显微镜研究显示，膜的部分区域有血小板黏附和聚集。相比之下，通过门静脉穿刺和直接采血测定的5-HT浓度与微透析测定的结果波动方式不同。这些结果表明，由于血小板在探针膜上的黏附和聚集导致5-HT污染，通过微透析测量血液中游离5-HT浓度可能不准确。
