Figure 5.

Bar graphs depict the concentration‐dependent effects of SDF‐1α (stromal cell‐derived factor 1α; 1, 3, and 10 nmol/L) on cell number (A and B), ³H‐leucine incorporation (C and D), and ³H‐proline incorporation (E and F) in glomerular mesangial cells (GMCs) from spontaneously hypertensive rats (SHR; A, C, and E) and normotensive Wistar–Kyoto rats (WKY; B, D, and F) in the absence and the presence of sitagliptin (1 μmol/L). The P values at the top of the main panels for ³H‐leucine incorporation (C and D) and ³H‐proline incorporation (E and F) are the 3‐way interaction P values from a 3‐factor ANOVA. These P values demonstrate that the strain from which the cells were derived (SHR vs WKY) interacts with sitagliptin to determine the overall effects of SDF‐1α on ³H‐leucine incorporation and ³H‐proline incorporation. For cell number, however, the strain×sitagliptin×SDF‐1α interaction was not significant. The P values at the top of subpanels (A, B, C, E, and F) are the 2‐way interaction P values from a 2‐factor ANOVA. These P values demonstrate that sitagliptin augmented responses to SDF‐1α. In WKY GMCs, SDF‐1α and sitagliptin modestly enhanced ³H‐leucine incorporation, but the interaction was not significant. *Significant difference (P<0.05; Fisher least significant difference test) between the indicated concentration of SDF‐1α and the basal values (ie, values in the absence of SDF‐1α) for the indicated variable. ^†Significant difference (P<0.05; Fisher least significant difference test) between sitgliptin‐treated and non‐sitagliptin‐treated cells at indicated concentration of SDF‐1α. Values are means and SEM.