HT29-18-C1 INTESTINAL-CELLS - A NEW MODEL FOR STUDYING THE EPITHELIALTRANSPORT OF DRUGS

A polarized differentiated subclone of HT29, a human colon carcinoma c ell line, was used to measure the passage of drugs across the intestin al epithelium. These cells, HT29-18-C1, when grown on permeable filter s, formed tight monolayers of high electrical resistance (> 400 OMEGA cm2). Electron micrographs revealed the presence of numerous apical mi crovilli and well developed junctional complexes. The transepithelial passage of various drugs was studied: the transepithelial permeability coefficients ranged from 0.8 . 10(-6) cm/s for fluorescein, to 4.8 . 10(-5) cm/s for the most lipophilic molecule, testosterone. For the fi ve compounds tested, there was a coarse correlation between the appare nt transepithelial permeability coefficient and the octanol/buffer dis tribution coefficient. The HT29-18-C1 subclone thus represents a new i n-vitro model for studying the intestinal absorption of drugs.