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High Glucose Tubular Perfusion Increased Mitochondrial Oxidative Stress in the Epithelial Cells of Renal Medullary Thick Ascending Limb
Author(s) -
Lu Yi,
Mori Takefumi,
Hu Chunyan,
Dickinson Bryan C,
Chang Christopher J,
Cowley Allen W,
Ito Sadayoshi
Publication year - 2011
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.25.1_supplement.822.7
The present study was designed to determine the effect of high glucose tubular perfusion on mitochondrial (MT) oxidative stress in medullary thick ascending limb (mTAL). Superoxide (O 2 ·− ) and hydrogen peroxide (H 2 O 2 ) responses to changes in glucose tubular perfusion (from 5.5 to 25.5 mM) at a constant perfusion rate (5 nL/min) were determined in isolated perfused mTAL from male Sprague‐Dawley rats, using MT specific O 2 ·− indicator MitoSOX and novel H 2 O 2 indicator MitoPY1, respectively. O 2 ·− and H 2 O 2 responses to SOD inhibitor DETC with MT superoxide stimulator menadione or H 2 O 2 were determined at the end of the experiment, respectively, as a positive control to confirm the cell viability. MT O 2 ·− signals were significantly increased over 390 seconds stimulated by 25.5 mM glucose perfusion (98±57 units), which were significantly inhibited by ouabain (Na‐K‐ATPase inhibitor, 4 mM, minus 20±51 units) and rotenone (MT complex I inhibitor, 10 μM, minus 17±31 units). A similar pattern was found in H 2 O 2 fluorescent signals during 25.5 mM glucose perfusion (637±157 units), which were also inhibited by ouabain (114±30 units) and rotenone (227±141units). We conclude that high glucose tubular perfusion induced MT oxidative stress in the epithelial cells of mTAL, which might be responsible for the MT dysfunction, hypertension and renal damage during diabetes. (Support: KAKENHI20590970, HL‐29587)