Yu H.,Sun Yat Sen University |
Chen S.,Sun Yat Sen University |
Yang Z.,Sun Yat Sen University |
Pan A.,Sun Yat Sen University |
And 4 more authors.
Cell Biology International | Year: 2010
TMT (trimethyltin chloride), an organotin, is ubiquitous in the environment. The consumption of contaminated food may cause exposure of the human diet to this toxic compound. The present study was to investigate the effects of TMT on the regulation of ion transport across the rat distal colon. The rat colonic mucosa was mounted in Ussing chambers. The effects of TMT were assessed using the /sc (short-circuit current). Both apical and basolateral TMT induced, dose-dependently, an increase in /sc, which was due to a stimulation of CI- secretion as measured using ion substitution experiments and pharmacological manoeuvres. The secretion was also inhibited by several K+ channel blockers administrated at the basolateral side. When the apical side was permeabilized by nystatin, the TMT-induced K+ conductance was effectively blocked by tetrapentylammonium, a Ca2+-sensitive K+ channel blocker. The response of TMT was sensitive to the basolateral Ca2+ and the intracellular Ca2+ store, which could be dlosed by applying the inhibitors of ryanodine receptors and inositol 1,4,5-trisphosphate receptors. In conclusion, TMT led to CI- secretion, which was essentially regulated by basolateral Ca2+-sensitive K+ channels. These results suggest the importance of K+ channels in the toxicity hazard of TMT. © The Author(s) Journal compilation. © 2010 Portland Press Ltd.