A comparative study of the morphology of the systemic anaphylactic reaction (SAR) and the shock reaction induced by antigen-antibody complexes in rabbits.

Differences in the morphological picture of the systemic anaphylactic reaction (SAR), and of the shock reaction induced by antigen-antibody (ag-ab) complexes in rabbits, are described. In rabbits SAR is characterized by acute distension of the lungs, with oedematous swelling in the vicinity of bronchi and veins, intravascular stasis of basophils without degranulation or visible fixation of the inducing antigen, small clusters of blood platelets, leukostasis, minimal decomposition of neutrophil granulocytes and absence of circulating or fixed ag-ab complexes. The shock reaction induced by ag-ab complexes is characterized by acute distension of the lungs without bronchospasm, swelling of the vicinity of bronchi and veins, hyaline thrombi particularly in the pulmonary microcirculation, leukostasis, formation of antigen-antibody complexes and thrombocyte clusters in the microcirculation, and by phagocytosis of these complexes and thrombocytes by various cells.