Figure 4. β-hydroxybutyrate (HB) decreases the expression of insulin signaling in aged rats. (A) Western blotting was performed to examine the protein levels of p-IRS-1 (Ser307), p-IRS-1 (Tyr632), IRS, p-Akt, and Akt as well as (B) p-IKK, IKK p-JNK, and JNK in the kidney of aged rats treated with HB. Three independent experiments were performed, and similar results were obtained. Western blot results from 3 independent experiments were quantified by densitometry. ###p < 0.001 vs. Young; *p < 0.05, **p < 0.01, ***p < 0.001 vs. Old.