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AMPK‐induced adaptive changes in carbohydrate and fat metabolism in muscle and liver
Author(s) -
Lee Abraham D.,
Nickey Jon O.,
Tscherne Todd J.,
Dobre Mihail,
Lowery Lindsay M.,
Ghosh Sumona,
Cicila George T.
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.114
Subject(s) - glycogen , medicine , endocrinology , ampk , phosphofructokinase , pyruvate kinase , chemistry , glycogen synthase , amp activated protein kinase , glycolysis , carbohydrate metabolism , glycogenesis , metabolism , protein kinase a , enzyme , biology , biochemistry
The purpose of this study was to determine if there were differences in AMPK‐induced adaptive changes in substrate contents and key enzymes involved in glucose metabolism between muscle and the liver. Two groups of inbred DA rats (5/group) were treated with either AMPK activator, AICAR (i.p. 0.8 mg/g BW), or saline solution for 9–10 days. Glycogen and triglyceride (TG) and key enzyme activities were assayed enzymatically. In white gastrocnemius AICAR‐treatment caused an increase in hexokinas (2 fold; P<0.05) and pyruvate kinase (PK; 5 fold; P<0.001) and a decrease in phosphofructokinase (PFK; 56%; P<0.05). In the liver AICAR‐treatment caused a decrease in fructose‐1,6‐diphosphatase (21%; P<0.05) and PK (34%; P<0.05) without a significant change in glucose‐6‐phosphatase and PFK. AICAR‐treatment caused an increase in liver glycogen (143%;P<0.05), and glycogen in muscles (41%–76%; P<0.05), and a decrease in liver TG (35%; P<0.05) without a significant change in muscle TG. These results suggest that in the liver substrates (glycogen and TG) and its‐associated enzymes are readily regulated by AMPK while in muscle only glycogen and its‐associated enzymes but not TG are readily altered by AMPK. AMPK‐induced increase in glycogen in muscle and the liver is due to an increase in glucose supply and/or a decrease in glycolytic capacity mediated by a decrease in PFK in muscle and PK in the liver. Supported by Ohio Challenge Fund