[Enzymehistochemical and immunopathological findings in the guinea pig lung after repeated doses of Freund's adjuvant (author's transl)].

An interstitial cell reaction was produced in guinea pigs by repeated doses of complete Freund's adjuvant. The resulting changes were investigated with enzymehistochemical and immunopathological methods. Histologically there were diffuse or focal interstitial infiltrations of histiocytes, lymphocytes, plasma cells, polymorphonuclear leucocytes and some eosinophils. Enzymehistochemically a strong activity of acid phosphatase and beta-glucuronidase is found in an increased number of alveolar macrophages, in contrast to the poor enzyme content of the interstitial cell infiltrations. Only some granulomas with starting fibrosis, visible after 6 weeks, exhibit an activity of leucine aminopeptidase and alkaline phosphatase. Immunopathologically, with the aid of anti-guinea pig-globulin, no immunoglobulins could be detected in the lungs of all animals.