Changes produced by external radiation in parameters influencing intestinal permeability and microparticle uptake in vitro.

Purpose: To determine the interaction between X-irradiation and in vitro intestinal microparticle uptake through Caco-2 epithelial cells.

Methods: Caco-2 cells were cultured on 3 microm porous membranes for 21 days, X-irradiated with 2 Gy or sham-irradiated, then incubated for 5 or 30 min and exposed apically for 30 min to 2 microm latex microparticles. Measurements included cell dimensions, from confocal microscope 'optical slices'; transepithelial resistance (TER) for tight junction (TJ) permeability; particle aggregation; and particle numbers on (adsorbed), in (intraepithelial) and through (submembranous) the epithelium.