[Concentration of lysozyme during mineralization in callous tissue of healing fractures (author's transl)]

Investigations have suggested that lysozyme (E.C. 3.2.1.17) is involved in bone mineralization. High concentrations of lysozyme is found in the growth plate near cartilage bone junction, where it is located at the collagen fibrils and in the ground substance. Quantitative studies of lysozyme levels were made in ossifying tissue of healing fractures, to confirm the existence of this relationship on bone repair. Callous tissue, serum samples and normal bone was collected from 42 rats at 15 intervalls during a 50 day healing period. Agar gel diffusion test was used for quantitation of lysozyme. Electrophoresis of tissue extract and standard henn egg white lysozyme served as control. Lysozyme levels in callous tissue increased significantly (4--5-fold) from 4.--21. day p. trauma and subsequently decreased. The concentration in serum samples did not change significantly. Changes in Ca concentration and histological studies during tests confirm a direct relationship between bone mineralization and lysozyme level changes.