The uptake of 45Cacalcium ions by matrix vesicles isolated from calcifying cartilage (Short Communication)

Extracellular membranous matrix vesicles, which contain various phosphatases and appear to initiate hydroxyapatite formation in growth cartilage, were isolated and incubated with (45)Ca(2+) and shown to form mineral in the presence of ATP. There is enhanced calcification in the presence of serum and under alkaline conditions.