Disturbances in epithelial ionic secretion in different experimental models of colitis.

This paper studies the disturbances in ionic secretion in the colon of rats with different models of acute and chronic colitis measured as changes in short-circuit current. The aim was to verify whether the reported inhibition of basal and stimulated secretion in the trinitrobenzene sulfonic acid and mytomicin C models are applicable to experimental colitis as such. All models showed remarkable similarity in ion transport as determined in Ussing chambers, with downregulated basal as well as carbachol evoked secretion. The EC(50) of carbachol was unchanged in all cases. Iodoacetamide and oxazolone colitis models were notable exceptions in that the dose response curves for carbachol were unaltered compared to controls. The reason is unclear but seems to be unrelated to either interferon gamma or interleukin 4 levels or to the severity of the inflammatory response.