Dietary Alaska Pollack Protein Induces Acute Skeletal Muscle Hypertrophy in Rats, Regardless of Specific Amino Acid and Amino Acid Balance of Diet

Abstract

In previous studies, Alaska pollack protein intake induced acute and sustainable skeletal muscle hypertrophy in rats. The present study used 5-week-old male Sprague–Dawley rats to investigate whether a specific amino acid or amino acid composition is related to Alaska pollack protein-induced skeletal muscle hypertrophy. The results suggest that dietary Alaska pollack protein increases the gastrocnemius muscle mass, regardless of specific amino acids including arginine and leucine, which are suggested to increase skeletal muscle mass and amino acid balance in the diet. The oral administration of 333 mg/kg/day Alaska pollack protein significantly increased gastrocnemius muscle weight compared with the oral administration of casein. In this case, the amino acid intake was expected to be almost the same as in the casein group because Alaska pollack protein made up approximately 1/60 of the protein consumed per day. The specific protein or the specific hydrolyzed peptides from Alaska pollack protein or other minor components in Alaska pollack protein may be responsible for gastrocnemius muscle weight hypertrophy.