Vanadate inhibition of hyaluronic acid synthesis in Swiss 3T3 fibroblasts.

Vanadate (50 microM) increases the incorporation of 3H from D-[1,6-3H]glucosamine into hyaluronic acid (HA) in serum stimulated Swiss 3T3 fibroblasts. This increase is not a result of increased HA synthesis, but is due to a significant increase in the specific activity of the cellular UDP-N-acetyl-glucosamine. When the 3H incorporation is corrected for the change in precursor specific activity, vanadate is shown to inhibit the synthesis of HA, a result that is confirmed by measuring the HA with a competitive binding assay. The inhibition of HA synthesis by vanadate is also shown to be dependent on the media used in the experiment, with a substantial increase in the inhibition seen when the media contains the pH indicator, phenol red. The HA synthetase activity of isolated membranes is not inhibited by vanadate at concentrations up to 500 microM.