Intestinal injuries caused by experimental palytoxicosis in mice.

Intestinal injuries in mice caused by i.p. administration of palytoxin at 1 microgram/kg were studied microscopically. Within 1 hr, bleeding started from small intestinal villi. At 6 hr, congestion in the villi and edema in the lamina propria in the crypt layer developed prominently. Edema and necrosis of lamina propria in the villus appeared after 16 hr. At 24 hr, villi lost their epithelial cells and then their length decreased to 1/4 to 1/8 of normal. Diarrhea was seen after 16 hr, accompanying severe peritonitis. Hypersecretion of mucus from the large intestine was considered to be physically stimulated by peritonitis, which then induced diarrhea.