Marttin E, Verhoef J C, Cullander C, Romeijn S G, Nagelkerke J F, Merkus F W
Division of Pharmaceutical Technology and Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Leiden University, The Netherlands.
Pharm Res. 1997 May;14(5):631-7. doi: 10.1023/a:1012109329631.
To visualize the transport pathway(s) of high molecular weight model compounds across rat nasal epithelium in vivo using confocal laser scanning microscopy. Furthermore, the influence of nasal absorption enhancers (randomly methylated beta-cyclodextrin and sodium taurodihydrofusidate) on this transport was studied.
Fluorescein isothiocyanate (FITC)-labelled dextrans with a molecular weight of 3,000 or 10,000 Da were administered intranasally to rats. Fifteen minutes after administration the tissue was fixed with Bouin. The nasal septum was surgically removed and stained with Evans Blue protein stain or DiIC18(5) lipid stain prior to visualization with the confocal laser scanning microscope.
Transport of FITC-dextran 3,000 across nasal epithelium occurred via the paracellular pathway. Endocytosis of FITC-dextran 3,000 was also shown. In the presence of randomly methylated beta-cyclodextrin 2% (w/v) similar transport pathways for FITC-dextran 3,000 were observed. With sodium taurodihydrofusidate 1% (w/v) the transport route was also paracellular with endocytosis, but cells were swollen and mucus was extruded into the nasal cavity. For FITC-dextran 10,000 hardly any transport was observed without enhancer, or after co-administration with randomly methylated beta-cyclodextrin 2% (w/v). Co-administration with sodium taurodihydrofusidate 1% (w/v) resulted in paracellular transport of FITC-dextran 10,000, but morphological changes, i.e. swelling of cells and mucus extrusion, were observed.
Confocal laser scanning microscopy is a suitable approach to visualize the transport pathways of high molecular weight hydrophilic compounds across nasal epithelium, and to study the effects of absorption enhancers on drug transport and cell morphology.
使用共聚焦激光扫描显微镜在体内观察高分子量模型化合物在大鼠鼻上皮的转运途径。此外，研究鼻吸收促进剂（随机甲基化β-环糊精和牛磺二氢fusidate钠）对这种转运的影响。
将分子量为3000或10000 Da的异硫氰酸荧光素（FITC）标记的葡聚糖经鼻给予大鼠。给药15分钟后，用Bouin固定组织。手术切除鼻中隔，在用共聚焦激光扫描显微镜观察之前，用伊文思蓝蛋白染色或DiIC18(5)脂质染色。
FITC-葡聚糖3000通过细胞旁途径穿过鼻上皮。还显示了FITC-葡聚糖3000的内吞作用。在存在2%（w/v）随机甲基化β-环糊精的情况下，观察到FITC-葡聚糖3000有类似的转运途径。使用1%（w/v）牛磺二氢fusidate钠时，转运途径也是细胞旁途径并伴有内吞作用，但细胞肿胀且黏液被挤出到鼻腔中。对于FITC-葡聚糖10000，在没有促进剂或与2%（w/v）随机甲基化β-环糊精共同给药后几乎未观察到转运。与1%（w/v）牛磺二氢fusidate钠共同给药导致FITC-葡聚糖10000的细胞旁转运，但观察到形态学变化，即细胞肿胀和黏液挤出。
共聚焦激光扫描显微镜是观察高分子量亲水性化合物在鼻上皮转运途径以及研究吸收促进剂对药物转运和细胞形态影响的合适方法。
