투과성 Filter 에 배양한 Opossum Kidney ( OK ) 세포에서 유기물질의 이동 특성 = Characteristics of Organic Compound Transport in Opossum Kidney ( OK ) Cell Monolayer Cultured on permeable Filters

다국어 초록 (Multilingual Abstract)

Objectives: Opossum kidney cells were cultured as monolayer on permeable filters and the characteristics regarding the transepithelial resistance and polarized uptake or transepithelial transport of organic compounds were determined. So, we want to know the usefulness of OK cells as a experimental model for the study of proximal tubular transport. Methods: OK cells were grown as monolayer on permeable filters of Transwell chamber. The seeding cell density was 10(3) cell/Cm2 and OK cells were incubated in Dulbecco`s Modified Eagles medium. The used organic compounds were [14Cl labelling mannitol, β-methylglucose, cycloleucine, TEA, We measured age dependent change of cell density, transepithelial resistance, polarized uptake or transepithelial transport of organic compounds. Results: transepithelial resistance increased, whereas transepithelial mannitol flux decreased, with aging and reached the maximum level 6days after seeding, which indicate formation of functional tight junction. On polarized uptake studies for α-methylglucose, an nonmetabloized analogue of glucose, OK cell monolayer expressed a Na+-dependent, phlorizininhibitable uptake in their apical membrane and a Na+-independent, phloretin-inhibitable uptake in their basolateral membrane. Uptake studies for cycloleucine, an unmetabolized neutral amino acid analogue, from either side of monolayers indicated that OK cells accumulated cycloleucine through both sides of membranes via both Na+-dependent and -independent mechanisms but with a different Na+-dependency (44% for apical and 29% for basolateral membrane). Transepithelial transport studies for tetraethylammonium, a typical organic cation, showed a unidirectional transcellular transport from basolateral to apical side which was stimulated by acidic pH of apical medium. Conclusion . These results suggest that OK cell monolayers grown on permeable filters developed functional tight junction and membrane polarity and that OK cells might be a good experimental model for the study of proximal tubular transport.