Epithelial response to intestinal anaphylaxis in rats: goblet cell secretion and enterocyte damage

Abstract
The effects of IgE-mediated reactions on the intestinal epithelium were examined during intestinal anaphylaxis in the rat. Rats sensitized by i.p. injection of egg albumin (EA) plus Al developed high serum titers of IgE anti-EA antibodies after 14 days; shamtreated littermate controls had no anti-EA antibodies. Two isolated loops of jejunum were prepared in vivo in anesthetized rats. The loops were injected with EA in saline or saline alone, and intraluminal contents of each loop were examined after 4 h. Mucosal histamine decreased in sensitized rat intestine exposed to EA. Luminal mucin, measured by radioimmunoassay, was not increased by antigen challenge. In contrast, DNA, protein and sucrase activities were elevated in contents from the isolated segments exposed to EA in sensitized rats. Histology revealed that periodic acid-Schiff-stained material was contained in goblet cells in sections prepared from these segments after antigen exposure. Cellular debris was present over the tips of the villi. IgE-mediated reactions in the intestine evidently cause epithelial damage and loss of material from cells other than goblet cells. Release of goblet cell mucus is not a feature of intestinal anaphylaxis.