Fractional rates of protein synthesis in longissimus dorsi (LD) muscle of 6- and 26-day-old pigs in response to euinsulinemic-euglycemic-euaminoacidemic conditions (C), euinsulinemic-euglycemic-hyperaminoacidemic clamps (AA), and hyperinsulinemic-euglycemic-euaminoacidemic clamps (INS) (panel A). Fractional rates of protein synthesis in LD muscle of 6-day-old pigs in response to individual infusion of the branched-chain amino acids, leucine (Leu), isoleucine (Iso) and valine (Val), in comparison with saline (sal)/control (panel B). Values are means ± SEM, means with different letters differ at P < 0.05.