Figure 2.

Reduced insulin sensitivity in CKD activates AMPD1 in the skeletal muscle

(A and B) Plasma insulin levels over time (minutes) and area under the curve (AUC) in wild type (black) and AMPD1 KO (red) mice undergoing sham operation (open symbols) or after polectomy and lateral nephrectomy followed by 3 weeks of high protein diet (solid symbols) after an oral glucose (1.75 g/kg) tolerance test.

(C and D) Plasma glucose levels and area under the curve (AUC) in wild type and AMPD1 KO mice undergoing CKD.

(E) Plasma phosphate levels at sacrifice in the same mice as in A).

(F) Intramuscular phosphate levels at sacrifice in the same mice as in A).

(G) Representative western blot for AMPD1 and insulin dependent phosphate uptake in C2C12 myotubes control (scr, scramble) or silenced for AMPD1 (shAMPD1).

(H) Representative western blot and densitometry for total and phosphorylated IRS1 and AKT in saline or insulin exposed control and AMPD1 deficient C2C12 myotubes.

(I) AMPD activity in control and AMPD1 deficient C2C12 myotubes under 10 mM Pi (Pi10) or phosphate deprived (Pi0) conditions in the presence or absence of insulin.

(J) Insulin-dependent phosphate uptake in control C2C12 myotubes in the presence of increasing amounts of urea. Statistical analysis: For B-D, F: One-way ANOVA followed by Tukey’s multiple comparison test. ∗∗p <0.01 versus respective strain sham. #p <0.05, ##p <0.01 n= 5 mice per group. For G, I-J, One-way ANOVA followed by Tukey’s multiple comparison test. ∗∗p <0.01 versus respective control. #p <0.05, ##p <0.01 Data graphed is the result of 5 independent replicates.