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Skeletal Muscle Mitochondrial Subpopulation Response in a Type 2 Diabetic Mouse Model
Author(s) -
Baseler Walter Allen,
Dabkowski Erinne R.,
Willamson Courtney L.,
Frisbee Jefferson C.,
Brock Robert W.,
Hollander John M.
Publication year - 2009
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.23.1_supplement.lb93
Subject(s) - sarcolemma , skeletal muscle , mitochondrion , endocrinology , medicine , diabetes mellitus , gastrocnemius muscle , type 2 diabetes , type 2 diabetes mellitus , pathogenesis , myofibril , biology , chemistry , microbiology and biotechnology
Dysfunctional mitochondria are central to the pathogenesis of type 2 diabetes mellitus. In skeletal muscle, two spatially distinct mitochondrial subpopulations exist. The interfibrillar mitochondria (IFM) which are situated between myofibrils and the subsarcolemmal mitochondria (SSM) which reside directly below the sarcolemma. The objective of this study was to determine how type 2 diabetes mellitus differentially affects distinct mitochondrial subpopulations in skeletal muscle. Db/db mice and littermate controls were sacrificed at 20 weeks of age and mitochondrial subpopulations were isolated from the gastrocnemius muscle. State 3 respiration in db/db mice was significantly lower in both IFM and SSM populations compared to respective controls leading to a decrease in RCR ratios (P<0.05). Electron transport chain complex I and IV activities were significantly decreased in the diabetic IFM with no change in the SSM (P<0.05 for both). Superoxide production was increased in the diabetic IFM and SSM, although to a greater extent in the IFM. These findings indicate that both mitochondrial subpopulations in mouse gastrocnemius muscle are affected during type 2 diabetes mellitus, however, the IFM exhibit a greater dysfunctional profile.