Fig. 3.

Zn²⁺ prevents reduction of secretagogue-stimulated Cl⁻ and paracellular water transport in intestinal epithelial cells of Shigella (NY962/92) infection. A: summarized effects of Zn²⁺ on paracellular water transport (serosal-to-mucosal) in human colonic T84 cell monolayers infected with Shigella. Top: illustration of the cell indicates the direction of osmotic gradient and water transport. Water transport is reflected by the change in polyethylene glycol (PEG) concentration ratio indicating volume in the mucosal side relative to volume in the serosal side. During water secretion to the mucosal side, PEG_F falls and the ratio becomes greater than 1. B: representative current recording of Cl⁻ transport of the effect of calcium and cAMP in mouse intestine and T84 monolayers (C and E). FSK, forskolin; CCH, carbachol. Inset figures represent data pooled from 3 monolayers and expressed means ± SE; n = 6. D: bar graph showing quantification of basal short-circuit current (I_sc) changes elicited by Shigella infection alone and Shigella infection in presence of Zn²⁺. Data are pooled from 3 monolayers in each condition and results are expressed as means ± SE. *P < 0.05 vs. Control.