Effects of mellitic acid (MA) and sodium fluoride (NaF) on the histological appearance of murine fetal tibiae cultured in vitro.

The aim of this study was to develop a standardized image analysis method for localization and quantitative measurement of calcified structures of murine fetal tibiae cultured in vitro as a completion and verification of previous biochemical studies. The calcified structures of bone stained by von Kossa silver technique and the epiphyseal cartilages showing intensive metachromasia with toluidine-blue staining were converted with grey-value window programs and afterwards the areas of the selected structures were measured. The histomorphological investigations showed that the murine tibiae, incubated for a period of 6 days in a medium with addition of 5 mmol mellitic acid, showed both a significant reduction of calcium deposits and an increase of epiphyseal intercellular cartilage matrix. The tibiae incubated in a medium with addition of 0.5 mmol sodium fluoride significantly showed an increase of calcium deposits in the thickened lamellae of the compacta. These histomorphological results confirm previous biochemical studies.