Effect of chronic antigen exposure on growth and intestinal histamine content of sensitized rats

The effects of chronic antigen feeding on systemically sensitized rats were investigated. Findings include a reduction of water and antigen intake in egg albumin (EA), sensitized rats receiving EA in their drinking water for an 8 day period, compared to that of sensitized rats fed bovine serum albumin and of naive rats. Feeding EA to sensitized animals also induced a decrease in daily weight gain. This decline did not seem to be a consequence of a decreased food intake, but might rather reflect a decreased water consumption and an alteration of nutrient absorption in the gut. Indeed, sensitized rats fed EA exhibited a significant increase in jejunal and ileal histamine content compared to control rats, which may indicate the development of an inflammatory reaction in the small intestinal mucosa. Intestinal troubles experienced because of this inflammatory reaction might explain the reduction of antigen and water intake observed in sensitized rats.