Studies on the biology of fish bone-II bone matrix changes during resorption

1. 1. The present investigation describes changes in the water-soluble organic matrix during bone resorption in the acellular-boned fish Tilapia macrocephala. Bone resorption was induced after scale removal. 2. 2. Bone carbohydrate concentration decreased 49.2% in 2 days and 93.7% 6 days after scale removal. 3. 3. Bone calcium concentration remained the same at 2 and 4 days but decreased by 63% 6 days after scale removal. 4. 4. The soluble organic matrix was found to be altered prior to mineral removal. 5. 5. In normal bone matrix, two heat-labile, calcium-binding components were identified: One (molecular weight 15,000), not sensitive to beta-glucuronidase, and the other (molecular weight 6000), which was sensitive to beta-glucuronidase. Uronic acid was found to be associated with these components. 6. 6. In resorbing bone matrix only one calcium binding component (molecular weight 15,000) was identified.