Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2549685 | Journal of Pharmacological and Toxicological Methods | 2007 | 8 Pages |
Introduction: The rat small intestinal cell line, IEC-18, was used as an in vitro model to differentiate between acute cytotoxicity (AC) and paracellular permeability (PP) of selected chemicals. Methods: This study compares the low resistance rat intestinal mortal cell line, IEC-18 (transepithelial electrical resistance, TEER = 160 ± 10 Ω cm2) with the high resistance human intestinal cell line, Caco-2 (TEER = 900 ± 100 Ω cm2). The two cell lines differ in state of differentiation, TEER and paracellular permeability characteristics. The IEC-18 cell line is originated from the ileum and resembles more closely the small intestine than the Caco-2. Cytotoxicity was carried out using MTT cell viability assay in 96-well plates for 24-h exposure time. PP was measured using TEER (membrane integrity indicator) and PP markers such as [3H]-d-mannitol, lucifer yellow (LY) and FITC-dextran (fluorescein-dextran) on cells grown on inserts. Results: The data showed that there is a high correlation (R2 = 0.99) between MTT and TEER using IEC-18 cell for 24-h exposure time. IEC-18 is as sensitive as Caco-2 for both MTT and TEER measurements. Decrease in TEER is inversely proportional with increase in PP of tight junction indicators. There is a good correlation between IC50's MTT, TEER and Registry of Cytotoxicity (RC) data. Discussion: Based on the results from the experiments, IEC-18 can be used as an in vitro model to differentiate between concentrations needed for AC and those required for PP.