Studies on mechanisms of diarrhea induced by fusarenon-X, a trichothecene mycotoxin from Fusarium species

Abstract

Cardinal signs of red mold toxicosis in man and farm animals are vomiting, nausea, diarrhea, and food refusal. The red mold toxicosis has been suggested to be induced by trichothecenes which are produced by Fusarium fungi. Fusarenon-X (F-X) is one of the trichothecene mycotoxins. The ip injection of F-X to rats caused watery diarrhea 36 to 60 hr after injection. Autopsy done 24 hr after an injection of F-X revealed an expansion of the small intestine but no macroscopic bleeding into the lumen of the intestine. F-X increased the absorption rate of d-xylose from the intestine in vitro, caused leakage of intravenously injected Evan's blue dye into the intestinal lumen, and decreased the serum sodium level. However, F-X did not increase leakage of erythrocytes into the intestinal lumen. In histological observations, F-X shortened intestinal villi and caused an infiltration of erythrocytes into the intestinal lamina propria. These findings suggest that F-X may increase the permeability of the blood vessel wall and intestinal mucosal epithelium and thereby cause leakage of plasma contents into the intestinal lumen which eventually leads to diarrhea.