The abundance and phosphorylation of ULK1 in longissimus dorsi muscle in response to age and amino acids, insulin, and leucine infusion. (A) Muscle ULK1 abundance from experiment 1 during euinsulinemic-euglycemic-euaminoacidemic (control; C), euinsulinemic-euglycemic-hyperaminoacidemic (AA), and hyperinsulinemic-euglycemic-euaminoacidemic (INS) clamps for 2 h in 6- and 26-d-old pigs. (B) Muscle ULK1 abundance from experiment 2 during euinsulinemic-euglycemic-euaminoacidemic-euleucinemic (C), euinsulinemic-euglycemic-hypoaminoacidemic-hyperleucinemic (L), and euinsulinemic-euglycemic-euaminoacidemic-hyperleucinemic (L+AA) clamps for 24 h in 5-d-old pigs. (C) Muscle ULK1 phosphorylation from experiment 1 during C, AA, and INS clamps for 2 h in 6- and 26-d-old pigs. (D) Muscle ULK1 phosphorylation from experiment 2 during C, L, and L+AA clamps for 24 h in 5-d-old pigs. Data are expressed in arbitrary units (AU). Values are means ± SEM, n = 4–7. Values not sharing common symbols differ significantly (P < 0.05).