Modulation of hypersensitivity reaction by lipids given orally.

The effect of lipids administration by gavage (0.4% body weight) given daily during four weeks on the hypersensitivity reaction in trachea, upper and lower bronchi, liver, kidney, mesentery, and pancreas was investigated in male rats. The plasma exudation was assessed by using Evans blue (EB) dye extravasation method. There was a significant difference in the permeability of the organs in nonimmunized rats. The immunization increased the vascular permeability and the response with the organs varied greatly. The effect of lipids on anaphylactic reaction was compared to those of untreated rats (control group). The EB extravasation was significantly increased in the trachea obtained from rats treated with cocoa butter and soybean oil. In the upper bronchi of rats treated with soybean oil, the EB extravasation was increased. However, in the lower bronchi, none of the treatments with lipids changed the extravasation of EB. The same was observed in the liver and kidney. The animals treated with lipids by gavage did not present differences in EB extravasation in the mesentery. However, in the pancreas and duodenum, the treatment with fish and soybean oils and cocoa butter markedly lowered EB extravasation.