Arthus tonsillitis in the rabbit. Histological findings and fibrinolytic activity in the blood.

Arthus-type hypersensitivity was induced experimentally in the tonsils of rabbits. Histopathological studies were performed on the Arthus tonsillitis so produced, and estimations of the plasma fibrinolytic activity were made on the blood of these rabbits. The findings obtained by macroscopic inspection of the tonsil revealed significant bleeding and swelling. Furthermore, the histopathological studies demonstrated bleed and infiltration of leukocytes into various parts of the parenchyma and connective tissue surrounding the tonsil during the early stages of tonsillitis. From the results concerning certain parameters of the fibrinolytic system in the blood, it was demonstrated that, during the early stage of tonsillitis, the fibrinolytic activity increased and whole plasmin was consumed. Based on the above findings, it seems that the change in fibrinolytic activity found in rabbits affected by Arthus tonsillitis closely resembles that in patients suffering from acute tonsillitis.