Figure 5.
Effects of the concentration of FBS or rabbit serum on the prevention of calcification in cell culture. Confluent cells were exposed to various concentrations of FBS or rabbit sera for 2 hrs. Concentrations of the sera ranging from 0.004 to 1% were used. The initial Ca × P ion product in culture media was 9.37 mM2. Each data point for Ca and P determinations represents the average of duplicate data. The C1/2 values in these experiments were about 0.07 % for Ca and P deposition. The serum levels are expressed as a negative log scale of the percentage of the serum, i.e., the higher the scale to the right of the X axis, the more the serum was diluted as indicated. The deposition of Ca and P was determined by colorimetric procedures and expressed as μmol Ca or P per mg of cell proteins. At 0.004% serum, the amounts of mineral Ca and P were nearly equal to those without serum. (A) FBS. (B) Normal rabbit serum.