Mucosal damage during intestinal anaphylaxis in the rat. Effect of betamethasone and disodium cromoglycate.

In this study, two antiallergic compounds, betamethasone and disodium cromoglycate were tested in an animal model of intestinal anaphylaxis. Rats, immunized with Nippostrongylus brasiliensis, were challenged intravenously with whole worm antigen or saline. Antigen challenge resulted in significant abnormalities: epithelial damage with shorter villi, decreased activity of digestive enzymes, decreased levels of mucosal histamine, a mast cell mediator, and increased blood uptake of [51Cr]EDTA from the lumen. Low-dose betamethasone, 24 and 48 hr before antigen, was not effective in preventing the effects: villus damage and increased [51Cr]EDTA uptake were seen, although mucosal mast cell numbers were significantly reduced by the drug. High-dose betamethasone completely prevented intestinal anaphylaxis: villus height, digestive function, and [51Cr]EDTA recovery in antigen-challenged animals were not significantly different from controls. Mucosal histamine levels and mast cells were significantly reduced in the high dose betamethasone group. Oral disodium cromoglycate did not prevent the abnormalities but provided a slight beneficial effect.