RAPID DECREASE IN TRANSEPITHELIAL ELECTRICAL-RESISTANCE OF HUMAN INTESTINAL CACO-2 CELL MONOLAYERS BY CYTOTOXIC MEMBRANE PERTURBENTS

The transepithelial electrical resistance (TEER) of human intestinal C aco-2 cell monolayers cultured on a permeable filter rapidly decreased on apical exposure of the monolayer cells to such cytotoxic membrane perturbents as benzalkonium chloride and saponin. This decrease in TEE R occurred at lower concentrations of these toxicants and at earlier s tages of incubation than those for the release of intracellular lactat e dehydrogenase, which is commonly used as a parameter for assessing c ell membrane damage. The TEER decrease caused by the toxicants was ass ociated with increased transepithelial permeability of the cell monola yer, as well as with subtle changes in the cytoskeletal structure, sug gesting that membrane perturbation by the toxicants induced cytoskelet al changes that resulted in disruption of the tight junction and a sub sequent increase in paracellular permeability. The rapid TEER change c aused by the cytotoxic membrane perturbents suggests that TEER measure ment would provide a simple and sensitive method for evaluating membra ne-perturbing toxicants. (C) 1997 Elsevier Science Ltd.