title: Exercise training increases the activity of pyruvate dehydrogenase complex in skeletal muscle of diabetic rats.
abstract: The effects of diabetes and exercise training on the activity of pyruvate dehydrogenase (PDH) complex in skeletal muscle were examined in rats. Male Sprague-Dawley rats were divided into four groups as follows: non-diabetic sedentary, non-diabetic trained, diabetic sedentary, and diabetic trained groups. Diabetic rats were prepared by a bolus injection of intravenous streptozotocin (50 mg/kg body weight). Exercise training was performed by having rats run on a treadmill at a speed of 25 m/min for 45 min/day, 6 days/wk for 4 wks. Exercise training decreased serum concentrations of glucose and non-esterified fatty acid in diabetic rats. GLUT4 content in skeletal muscle in sedentary rats was significantly decreased by diabetes; however, exercise training significantly increased the GLUT4 content in diabetic rats. The total and actual activities and the proportion of actual activity of the PDH complex were decreased in diabetic sedentary rats. Exercise training did not affect the total activity of the PDH complex in non-diabetic rats, whereas it increased the total activity in diabetic rats to the same level as that in non-diabetic rats. In diabetic rats, exercise training tended to increase the proportion of actual activity of the PDH complex from 2.7 +/- 0.4% to 4.7 +/- 0.8%, although the proportion of actual activity in non-diabetic rats was decreased by exercise training. The present study suggests that exercise training may improve glucose metabolism in the skeletal muscle of streptozotocin-induced diabetic rats probably through the mechanisms of increasing both GLUT4 content and the activity of the PDH complex.
authors.affiliation: Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Nakai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Sato
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Oshida
authors.forename: Masaru
authors.initials: M
authors.lastname: Nagasaki
authors.forename: Minoru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kunio
authors.initials: K
authors.lastname: Nakashima
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Shimomura
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology* / Q000628:therapy; D004558:Electric Stimulation; D005230:Fatty Acids, Nonesterified / Q000097:blood; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000097:blood; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000032:analysis; D009119:Muscle Contraction; D009124:Muscle Proteins; D018482:Muscle, Skeletal / Q000201:enzymology*; D005082:Physical Exertion / Q000502:physiology*; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D011768:Pyruvate Dehydrogenase Complex; C495694:Slc2a4 protein, rat