INTERLEUKIN-10 MODULATES ION-TRANSPORT IN RAT SMALL-INTESTINE

Background & Aims: It has been proposed that the anti-inflammatory cyt okine interleukin (IL)-10 might be an effective therapeutic agent in t he treatment of inflammatory bowel disease, This study examined the ef fects of human recombinant IL-10 on ileal sodium and chloride transpor t in Sprague-Dawley rats, Methods: Unidirectional fluxes of sodium and chloride and tissue electrical parameters were measured under voltage -clamped conditions in Ussing chambers. Intracellular levels of adenos ine 3',5'-cyclic monophosphate (cAMP) were measured in isolated entero cytes, Results: Jejunal and ileal tissue responded to serosal addition of IL-10 with a transient decrease in short-circuit current reflectin g an IL-10-induced increase in net sodium and chloride absorption beca use of an increase in mucosal to serosal ion movement. The IL-10-induc ed absorption was not prevented by tetrodotoxin but did show tachyphyl axis. IL-10 reversed, or markedly attenuated, forskolin- and carbachol -induced net chloride secretion, The effects of IL-10 on net secretion were accompanied by a reduction in forskolin-stimulate cAMP levels an d a decrease in basal cAMP levels, An additional effect of IL-10 was i ts induction of bicarbonate secretion only in the presence of secretag ogues. Conclusions: This study shows that IL-10 enhances intestinal el ectroneutral sodium and chloride absorption, inhibits stimulated chlor ide secretion, and under some secretory conditions stimulates bicarbon ate secretion.