Effect of enterotoxin on glutathione status in the intestinal mucosa.
The effect of luminal exposure of enterotoxins on the intestinal mucosal glutathione (GSH) was studied in rat. Cholera toxin induced fluid secretion and decreased mucosal GSH by 35% without altering oxidized glutathione (GSSG) level. Toxin induced fluid secretion was tested after mucosal GSH depletion by compounds such as diethyl maleate (DEM) and buthionine sulfoximine (BSO) and thiol supplementation with N-Acetyl cysteine (NAC). Fluid secretion was not altered by prior thiol depletion or supplementation. Exposure of intestinal lumen to bacterial endotoxin resulted in 25% decrease in mucosal GSH with two fold increase in GSSG. Luminal exposure of Shiga toxin did not alter the mucosal thiol. The level of other low molecular weight thiols, cysteine and cystine was not altered by luminal exposure of any of these toxins. These results show that although cholera toxin decreased the mucosal GSH level, prior modulation of thiol status of the mucosa may not have any effect on toxin-induced fluid secretion.