[Effects of dietary fat composition on food anaphylaxis and formaldehyde sensitization in guinea pigs]

Adult guinea pigs were fed for 10-14 days with synthetic diets, fat constituting 11% of its total energy. Dietary fat was composed of coconut, corn, dairy and soybean oils mixtures with ratio of polyunsaturated fatty acids (PUFA) omega-6 to PUFA omega-3 equal to 24.2 (K1) or 5.53 (K2). The animals were sensitized orally by pasteurized cow milk (PCM) or epicutaneously by formaldehyde (F) during these diets feeding. The degree of the sensitization was assessed in the reaction of active anaphylactic shock (AAS) in PCM-sensitized animals and in the reaction of leukocytes specific lysis (LSL) in F-sensitized guinea pigs. In the latter pigs the concentration of serum antibodies (Ab) against dietary soya protein was measured by ELISA. Animals fed by K1 and K2 were also tested for histamine mean lethal dose resistance. The lowest lethality in AAS, number of convulsions, of positive LSL cases and Ab level were found in animals fed by K1 compared to both K2 and to animals fed by common animal chew. Resistance to histamine was similar in K1 and K2 groups, but was significantly higher compared to control (chew) group. In convulsion, the changes in PUFA omega-6/PUFA omega-3 ratio have marked effect on different indices of allergic sensitivity.