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Dietary arginine supplementation reduces fat mass in diet‐induced‐obese rats by improving glucose and fatty acid metabolism
Author(s) -
Jobgen Wenjuan S,
Meininger Cynthia J,
Smith Stephen B,
Spencer Thomas E,
Jobgen Scott C,
Lee MiJeong,
Fried Susan K,
Wu Guoyao
Publication year - 2007
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.21.5.a328-b
Subject(s) - medicine , endocrinology , arginine , ampk , chemistry , lipolysis , triglyceride , leptin , insulin , beta oxidation , adipose tissue , obesity , metabolism , amino acid , biochemistry , cholesterol , protein kinase a , enzyme
This study was conducted to test the hypothesis that dietary arginine supplementation can reduce fat mass in diet‐induced obesity. Male Sprague‐Dawley rats were fed low‐ or high‐fat diets for 15 wks. Thereafter, the resultant lean or obese rats continued their respective diets and received drinking water containing either 1.51% arginine‐HCl or 2.55% alanine (isonitrogenous control) for 12 wks. High‐fat diet increased the mass of retroperitoneal (RP), epididymal, subcutaneous and mesenteric fat by 49–96% compared to the low‐fat diet, and arginine reduced the mass of these fat pads by 20–40% (P<0.01). Arginine treatment decreased adipocyte sizes, plasma glucose, triglyceride and leptin levels, increased basal lipolysis and improved glucose tolerance (P<0.05). Arginine stimulated glucose oxidation in muscles as well as oleic acid oxidation in muscles and RP fat (P<0.05). The mRNA levels for hepatic FAS and SCD‐1 were reduced but those for AMPK and CPT‐I as well as skeletal muscle CPT‐I were increased by arginine treatment (P<0.05). Hepatic AMPK protein as well as AMPK and ACC activation were increased 2‐, 5‐ and 2.5‐fold, respectively, by arginine (P<0.01). These findings indicate that dietary arginine supplementation regulates expression of key genes/proteins involved the metabolism of energy substrates, thereby reducing excess fat and improving insulin sensitivity in rats. (Supported by NIH, AHA & TAMU)