Fig. 2.

Effects of EX4 and ALG on phosphorylated Na⁺/H⁺ exchanger (NHE3) in renal membranes and plasma dipeptidyl peptidase-4 (DPP-4) activity. Kidneys and plasma were harvested 1 h after application of EX4 (10 μg/kg body wt ip), ALG (10 mg/kg body wt ip), or vehicle (0.85% NaCl, 2 μl/g body wt). A–C: natriuretic response to EX4, but not ALG, was associated with increased NHE3 phosphorylated at S552 (pS552) and S605 (pS605) in renal membranes. This effect of EX4 was absent in Glp1r^−/− mice. Values are means ± SE; n = 5 per group. *P < 0.05 vs. vehicle. D: ALG inhibited DPP-4 activity in WT and Glp1r^−/− mice. Data are expressed relative to the mean of the vehicle-treated WT group, which was set as 100%. EX4 was without effect. Values are means ± SE; n = 5 per group. *P < 0.05 vs. vehicle.