Post-exercise carbohydrate plus whey protein hydrolysates supplementation increases skeletal muscle glycogen level in rats.
Recent studies showed that a combination of carbohydrate and protein was more effective than carbohydrate alone for replenishing muscle glycogen after exercise. However, it remains to be unclear whether the source or degree of hydrolysis of dietary protein influences post-exercise glycogen accumulation. The aim of this study was to compare the effect of dietary protein type on glycogen levels in the post-exercise phase, and to investigate the effects of post-exercise carbohydrate and protein supplementation on phosphorylated enzymes of Akt/PKB and atypical PKCs. Male Sprague-Dawley rats, trained for 3 days, swam with a 2% load of body weight for 4 h to deplete skeletal muscle glycogen. Immediately after the glycogen-depleting exercise, one group was killed, whereas the other groups were given either glucose or glucose plus protein (whey protein, whey protein hydrolysates (WPH), casein hydrolysates or branched-chain amino acid (BCAA) solutions. After 2 h, the rats were killed, and the triceps muscles quickly excised. WPH caused significant increases in skeletal muscle glycogen level (5.01 +/- 0.24 mg/g), compared with whey protein (4.23 +/- 0.24 mg/g), BCAA (3.92 +/- 0.18 mg/g) or casein hydrolysates (2.73 +/- 0.22 mg/g). Post-exercise ingestion of glucose plus WPH significantly increased both phosphorylated Akt/PKB (131%) and phosphorylated PKCzeta (154%) levels compared with glucose only. There was a significant positive correlation between skeletal muscle glycogen content and phosphorylated Akt/PKB (r = 0.674, P < 0.001) and PKCzeta (r = 0.481, P = 0.017). Post-exercise supplementation with carbohydrate and WPH increases skeletal muscle glycogen recovery by activating key enzymes such as Akt/PKB and atypical PKCs.
Morifuji
Masashi
M
Food and Health R&D Laboratories, Meiji Seika Kaisha Ltd., 5-3-1 Chiyoda, Sakado, Saitama, 350-0289, Japan. masashi_morifuji@fuji.waseda.jp
Kanda
Atsushi
A
Koga
Jinichiro
J
Kawanaka
Kentaro
K
Higuchi
Mitsuru
M
D000596:Amino Acids / Q000032:analysis; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage / Q000032:analysis; D000818:Animals; D045163:Antibodies, Phospho-Specific; D002364:Caseins / Q000008:administration & dosage / Q000737:chemistry; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D019587:Dietary Supplements / Q000032:analysis; D004789:Enzyme Activation; D006003:Glycogen / Q000378:metabolism*; D008297:Male; D008894:Milk Proteins / Q000008:administration & dosage* / Q000737:chemistry; D018482:Muscle, Skeletal / Q000378:metabolism*; D010766:Phosphorylation; D005082:Physical Exertion; D011492:Protein Hydrolysates / Q000008:administration & dosage* / Q000737:chemistry; D011493:Protein Kinase C / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013550:Swimming; D000067816:Whey Proteins
D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D045163:Antibodies, Phospho-Specific; D002364:Caseins; D004040:Dietary Carbohydrates; D008894:Milk Proteins; D011492:Protein Hydrolysates; D000067816:Whey Proteins; C475729:casein hydrolysate; D006003:Glycogen; D051057:Proto-Oncogene Proteins c-akt; D011493:Protein Kinase C