Experimentell induzierte enchondrale Ossifikation in der thymusplastischen Nacktmaus nach Xenotransplantation von Epiphysenknorpel

Summary

Cartilage from the epiphyseal growth plate of the proximal ulna in piglets was implanted to athymic nude mice (nu/nu) and maintained subcutaneously up to 140 days. In defined intervals, the transplants were removed and examined by histological, chemomicroanalytical and biochemical methods. All transplants were found viable. As of week 4, the specimens showed newly formed bone tissue with progressing ossification. The well-oriented growth of bone tissue is interpreted in favor of pressure-independent, rather genetic determination. The addition of certain trace elements (e.g. Al, Pb or Se) in subtoxic concentrations to the drinking water of nu/nu mice with transplants of epiphyseal cartilage suggested a possible inductive influence of Al and Pb on the differentiation of osteo(chondro)clasts. Bone formation was accelerated and resulted in a higher grade of mineralization with thicker trabeculae. Selenium supplementation somewhat inhibited cellular activities in the transplants with subsequent poorer ossification. The presently unexplained mechanism of carcinogenesis inhibition by Se may be mentioned in this context.