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Effects of an L‐Arginine Infusion on Postprandial Fat Metabolism in Healthy Young Subjects
Author(s) -
Katsanos Christos S,
Meyer Christian,
Puga Guilherme
Publication year - 2012
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.26.1_supplement.254.4
Subject(s) - postprandial , medicine , endocrinology , ingestion , arginine , morning , insulin , triglyceride , chemistry , metabolism , dyslipidemia , cholesterol , obesity , biochemistry , amino acid
Activation of the L‐arginine‐nitric oxide pathway is linked to improved lipid metabolism, information largely obtained in animal studies. We sought to determine the effects of an acute increase in plasma L‐arginine concentration on lipid metabolism after fat ingestion in young (age, 23±2 yrs), lean subjects, free of dyslipidemia (N=7). Subjects ingested whipping cream (0.7 g fat/kg body weight) supplemented with [ 13 C]‐triolein in the morning after a 12‐h fast on two separate occasions: 300 ml of 10% L‐arginine (ARG) or saline (SAL) were infused during the first hour after the fat ingestion. Blood samples and expired CO2 were collected before and for eight hours after the fat ingestion. Although plasma insulin concentrations were increased at 1 hour in the ARG trial (42±13 vs 10±2 μIU/ml, P = 0.03), the incremental area under the curve during the entire 8‐hour postprandial period (AUCi 0−8h ) of insulin did not differ between ARG and SAL trials (3±9 vs 4±4 μIU/ml/hr, P = 0.92). ARG reduced the AUCi 0−8h of plasma free fatty acid (FFA) concentrations ~70% (0.45±0.55 vs 1.53±0.35 mmol/l/hr; P < 0.05) but did not significantly alter the AUCi 0−8h of plasma triglyceride (TG) concentrations (37±30 vs 91±34 mg/dl/hr; P = 0.37). Further, ARG increased plasma 3 ‐ hydroxybutyrate concentrations ~80% during the last four hours (AUCi 4−8h ) of the postprandial period (1050±162 vs 574±109 μmol/l/hr; P = 0.06), but did not alter whole‐body oxidation of the ingested fat (246±32 vs 235±18 mg/kg/hr; P = 0.62). We conclude that acute activation of the nitric oxide pathway by L‐arginine infusion, despite only transiently increasing plasma insulin levels, drastically reduces plasma FFA concentrations but not TG concentrations, and increases hepatic but not systemic lipid oxidation after fat ingestion in healthy young subjects.