Figure 3: Effects of probenecid or U73122 on the GLP-1 secretion stimulated by WE or BGP-Pi in STC-1. After a 3 hr starvation in 10% FBS DMEM (low glucose), cells were treated with 0.2 % BSA DMEM (low glucose) containing (a) WE (water extract) or (b) BGP-bi in the absence or presence of probenecid or U73122 for 1 hr. All data were calculated as GLP-1 secretion per cell, and the secretion of vehicle-treated cells was taken as 1. Data are mean ± SD of 1~3 batches of experiments, with 1~3 for each treatment. * , ** , and *** denote significant difference compared to vehicle-treated cells analyzed by Student’s test with RCBD to adjust for the differences between separate experiments.