Figure 4. Effect of Sfrp5 on glucose uptake in primary human adipocytes.

Mature adipocytes were kept untreated, exposed to 100/ml Sfrp5 for 24 h, when indicated (+) stimulated with insulin (30 min; 100 nM), whereafter glucose uptake was determined. The incorporated amount of 2-deoxy-D-[1-³H]glucose was normalized for protein content and expressed as mean ± standard error of the mean of four independent experiments using cells from different donors. The values obtained for Sfrp5-untreated, insulin-treated cells were considered as control and set at 100%. Differences among groups were calculated by two-way ANOVA followed by Bonferroni multiple comparison analysis. #, indicates p<0.05 for the effect of insulin stimulation; *, p<0.05 for the effect of Sfrp5.