FIGURE 2.

Concentration dependence of mannose and glucosamine modulation of UDP-HexNAc contents and hyaluronan synthesis. HaCaT cells were incubated with 0–20 mm mannose (A and C) and 0–6 mm glucosamine (B and D) for 6 h and analyzed for UDP-HexNAc content (A and B). Hyaluronan secreted in the culture medium during a 24-h period is shown in C and D. The data represent means ± S.E. of three (A and B) and five (C and D) independent experiments (each experiment with one or more replicates). Statistical significance between control and mannose- or glucosamine-treated cultures is as follows: *, p < 0.05; **, p < 0.01; ***, p < 0.001 (by Dunnett's test).