Abstract
To evaluate the effects of allergy on the liver, we administered ovalbumin (OVA) orally to rats previously sensitized by intraperitoneal OVA injection. The small intestine and liver were harvested before and 0.5, 1, 3 and 6 hours after OVA challenge. Tissue sections were stained with toluidine blue for secretory granules in mast cells, and stained mast cells were counted under a microscope. The number of intestinal mast cells positive for toluidine blue was significantly decreased 0.5 hour after challenge, was lowest 1 hour after challenge, and recovered to the baseline level by 6 hours after challenge. In liver, the mast cell counts started decreasing significantly 3 hours after challenge. Since the decrease in toluidine blue-positive mast cells is indicative of degranulation as a result of local allergic reaction, the time difference in the decrease of mast cell counts between the small intestine and liver suggests that immediate-type hypersensitivity reactions in the small intestine increased the permeability of macromolecules in the intestine. The absorbed macromolecules then triggered degranulation of mast cells in the liver. These results suggest the presence of allergic reactions in the liver of food-sensitized animals.
