Kunes Martin, Kvetina Jaroslav, Malakova Jana, Bures Jan, Kopacova Marcela, Rejchrt Stanislav
Institute of Experimental Biopharmaceutics, Joint Research Centre of PRO.MED.CS Praha a.s. and the Czech Academy of Sciences, Czech Republic.
Neuro Endocrinol Lett. 2010;31 Suppl 2:57-61.
Confocal laser scanning endomicroscopy (CLSE) is a diagnostic technology that produces virtual histology of the mucosal layer using fluorescence technique. Fluorescein (FSC) is the most commonly used fluorescence agent. Fluorescence light coming from a horizontal special focal plane is detected during confocal laser endomicroscopy of the gastrointestinal tract. FSC causes intensive yellowish discoloration of tissues, including skin and mucous membranes. This pre-clinical study was aimed to evaluate the tissue distribution and pharmacokinetics of FSC after its intravenous administration.
The study was performed in an adult experimental pig. A reversed-phase high-performance liquid chromatographic method with fluorescence detection was used for the determination of fluorescein in blood plasma and tissue samples.
The pharmacokinetic study of fluorescein determined the optimum time interval for diagnostic scanning (5-10 min.) The biodistribution study of fluorescein (aimed on the potential organ accumulation) proved the high concentration in the renal system followed by levels in bile > lung > adipose tissue > all other organs (including gastrointestinal wall) and these were relatively similar to each other. Fluorescein has a significantly low distribution in the brain (contrast with the level in adipose tissue indicates the low ability to penetrate the blood-brain barrier).
共聚焦激光扫描内镜显微镜检查（CLSE）是一种利用荧光技术生成黏膜层虚拟组织学图像的诊断技术。荧光素（FSC）是最常用的荧光剂。在胃肠道共聚焦激光内镜显微镜检查过程中，检测来自水平特殊焦平面的荧光。FSC会使包括皮肤和黏膜在内的组织出现强烈的淡黄色变色。这项临床前研究旨在评估静脉注射FSC后其在组织中的分布和药代动力学。
该研究在成年实验猪身上进行。采用反相高效液相色谱荧光检测法测定血浆和组织样本中的荧光素。
荧光素的药代动力学研究确定了诊断扫描的最佳时间间隔（5 - 10分钟）。荧光素的生物分布研究（针对潜在的器官蓄积）证明，其在肾脏系统中的浓度较高，其次是胆汁＞肺＞脂肪组织＞所有其他器官（包括胃肠道壁），且这些器官中的浓度相对彼此较为相似。荧光素在大脑中的分布显著较低（与脂肪组织中的水平形成对比，表明其穿透血脑屏障的能力较低）。
