Early morphological changes in the connective tissue of rats around an implanted cellophane disk

Summary

Cellophane films (1×3 cm in size) and small pieces of cellophane were implanted subcutaneously to rats. These animals were sacrificed at different intervals ranging from 7 days to 7 months. Connective tissue changes occurring around the films after the implantation were studied with the aid of various morphological and histochemical methods. In 3–4 months 3 zones could be distinguished in the capsule around the films: 1) pericapsular layer, 2) capsula proper, and 3) internal layer containing proliferating cells.

Chromotrophic acid mucopolysaccharides were present in the collagenous capsule up to the end of 7 months; the presence of such mucopolysaccharides may be regarded as an indication of an incomplete process of collagen formation. Foci of cellular proliferation were present in the “capsula proper” and in the internal proliferative layer. The author briefly discusses the role of prolonged collagen formation and of the focal cell proliferation in the mechanism of plastic cancerogenesis.