Type-specific collagen degradation by eosinophils.

Despite the association of eosinophils with wound-healing and fibrotic processes, their collagenolytic ability has been poorly defined. By using highly purified eosinophil preparations (greater than 95% eosinophils) obtained from guinea-pigs by peritoneal lavage, we have examined type-specific collagen degradation by eosinophils using sensitive detection methods. The results show that eosinophils contain a metalloprotein that degrades types I and III collagens. This activity was apparent only after the addition of 4-aminophenylmercuric acetate to the reaction mixture, a finding similar to that for latent collagenases described from other sources. No collagenolytic activity against types IV and V collagens could be detected. Thus eosinophils may play a role in the alterations in connective-tissue matrices seen in physiological and pathological states.