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Protein Dynamics across splanchnic and skeletal muscle beds following co‐ingestion of whey protein and casein in humans
Author(s) -
Soop Mattias,
Nehra Vandana,
Bigelow Maureen L,
Boirie Yves,
Ford G. Charles,
Nair K. Sreekumaran
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.693
Subject(s) - ingestion , splanchnic , lactose , chemistry , casein , medicine , endocrinology , meal , carbohydrate , biochemistry , food science , hemodynamics
It has been shown ingestion of whey protein (WP) results in rapid systemic appearance rates of amino acids (AA) but in higher amino acid (AA) oxidation and whole body protein synthesis than in with casein (cas) ingestion which inhibits protein breakdown. To determine whether combined ingestion of both cas and WP in a meal containing carbohydrate has any disparate effects on protein economy in splanchnic and muscle beds we studied 12 healthy volunteers who ingested intrinsically labeled WP and Cas protein fractions. Following ingestion of 0.625 g·kg FFM −1 each of [ 15 N]WP and [ 13 C]Cas and 0.9 g·kg FFM −1 of lactose; or 0.625 g·kg FFM −1 each of [ 13 C]WP and [ 15 N]CAS and 0.9 g·kg FFM −1 of lactose blood samples were collected from femoral artery and vein and hepatic vein at frequent intervals. At 80–120 min, the rate of appearance (PheRa) of Phe at hepatic vein from WP and Cas were similar (5.5 (0.9) vs 5.2 (0.7) μmol, min −1 , but at 220–260 min, PheRa from WP was slower than PheRa from Cas (2.4 (0.5) vs 5.3 (1.2) μmol, min −1 , P<0.05). Retention rates of Phe in muscle (PheRd) absorbed from WP and Cas were similar at 80–120 min (0.8 (0.1) vs 0.9 (0.2) μmol, min −1 , ns) but was significantly lower for WP than Cas at 220–260 min (0.5 (0.1) vs 1.1 (0.3) μmol, min −1 , P<0.05). In conclusion Cas has more sustained systemic effects and muscle protein accretion than WP. The different metabolic effects of co‐ingested protein fractions have potential implications in designing appropriate nutritional support.