Effects of orally administered glycine on myofibrillar proteolysis and expression of proteolytic-related genes of skeletal muscle in chicks.
We examined the effects of orally administered glycine on myofibrillar proteolysis in food-deprived chicks. Food-deprived (24 h) chicks were orally administered 57, 113, and 225 mg glycine/100 g body weight and killed after 2 h. The plasma N(tau)-methylhistidine concentration, used as myofibrillar proteolysis, was decreased by glycine. We also examined the expression of proteolytic-related genes by real-time PCR of cDNA from chick skeletal muscles. The mRNA expression of atrogin-1/MAFbx, proteasome C2 subunit, m-calpain large subunit, and cathepsin B was decreased by glycine in a dose-dependent manner. The plasma corticosterone concentration was also decreased by glycine, but the plasma insulin concentration was unaffected. These results indicate that orally administered glycine suppresses myofibrillar proteolysis and expression of proteolytic-related genes of skeletal muscle by decreasing the plasma corticosterone concentration in chicks.
Nakashima
K
K
Molecular Nutrition Research Team, National Institute of Livestock and Grassland Science, Tsukuba, Japan. kaznaka@affrc.go.jp
Yakabe
Y
Y
Ishida
A
A
Katsumata
M
M
D000284:Administration, Oral; D000818:Animals; D002154:Calpain / Q000187:drug effects / Q000235:genetics; D002401:Cathepsin B / Q000187:drug effects / Q000235:genetics; D002645:Chickens; D003345:Corticosterone / Q000097:blood; D005508:Food Deprivation; D015870:Gene Expression / Q000187:drug effects; D005998:Glycine / Q000008:administration & dosage*; D008762:Methylhistidines / Q000097:blood; D009124:Muscle Proteins / Q000235:genetics; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics
D008762:Methylhistidines; D009124:Muscle Proteins; D012333:RNA, Messenger; D044843:SKP Cullin F-Box Protein Ligases; D002154:Calpain; D002401:Cathepsin B; D046988:Proteasome Endopeptidase Complex; D005998:Glycine; D003345:Corticosterone