Studies of some inflammatory and immunological responses of different strains of rat.

Differences were observed in the severity of AA in four inbred strains of rats. The interindividual correlation of the primary and secondary lesions showed an inverse relationship between the gravity of the primary and secondary lesions in the LEW and LE strains. WAG strain appeared to be the lowest responder in the intensity of the primary and secondary oedema in AA and in carrageenan oedema. This is in agreement with the low vascular permeability of this strain after PGE2 injection. When the values of the immunological tests in the individual strains (LE, WAG, LEW) were compared it was found that there is a reciprocal inverse relationship between them and the intensity of the secondary lesion. It follows from our results that the induction of AA requires very precise conditions, indicating that they might depend both on a critical state of immune reactivity and on the action of the pharmacologic mediators.