Figure 1.

Medium conditioned by dermal fibroblasts under hypoxic conditions increased the proliferation of human umbilical vein endothelial cells. Doubling time was calculated from growth curves determined after cell counts for unconditioned medium (DF medium, black dash line), medium conditioned by dermal fibroblasts under normoxic conditions (DF-Nx medium, solid black line) and medium conditioned by dermal fibroblasts under hypoxic conditions (DF-Hx medium, solid grey line). The periods of conditioning were 1, 2 or 3 weeks. Results are presented as average +/− standard deviation.