DECREASE IN PASSIVE CUTANEOUS ANAPHYLAXIS REACTIONS IN RATS SECONDARYTO STRESS

Anaphylaxis was assayed by the passive cutaneous anaphylaxis (PCA) tes t in male Wistar rats (250 g body weight). Three experimental groups w ere used: animals restrained in an electric chamber and submitted to e lectric shock immediately after sensitization and 24 h before anaphyla xis (31 animals), animals restrained in the electric chamber for the s ame time but receiving no electric shock (23 animals), and, non-manipu lated, home-cage control animals (24 animals). The frequency of PCA re actions was decreased in the group of animals submitted to restraint w hen compared with the home-cage control group. However, the group of a nimals submitted to both restraint and electric shock showed no decrea se in the frequency of PCA reactions. It is suggested that, in rats, s tress induced by restraint decreases PCA reactions and that this decre ase is counteracted by a simultaneous strew induced by electric shock.