Lysosomal Activation in Relation to Connective Tissue Disease

Abstract

Some effects are described of exposing rat liver lysosomes in suspension, rat liver slices, and cultures of rat "fibroblasts" to an antiserum prepared by injecting rabbits with partially purified rat liver lysosome preparations. The loss of (lysosomally) bound acid phosphatase after exposure to anti-serum was demonstrated in both the liver slices and cell cultures, but not in the lysosome suspension. From this it was concluded that the antiserum was not acting directly on the lysosomes to effect enzyme release. Under the described experimental conditions the release of acid phosphatase is inhibited by 25 [mu]g/ml hydrocortisone, and by heat inactivation of the antiserum. It is suggested that the experiments give general support to the hypothesis that the histological picture seen in a variety of rheumatic diseases could be produced by enzymes released from cells as part of a response to antibodies.