Shaw, C. S, Shepherd, S. O, Wagenmakers, A. J, Hansen, D., Dendale, P. & Van Loon, LJ. (2012). Prolonged exercise training increases intramuscular lipid content and perilipin 2 expression in type I muscle fibers of patients with type 2 diabetes. American Journal of Physiology - Endocrinology and Metabolism,303(9), 1158-1165. United States: American Physiological Society. Retrieved from https://doi.org/10.1152/ajpendo.00272.2012
The aim of the present study was to investigate changes in intramuscular triglyceride ( IMTG ) content and perilipin 2 expression in skeletal muscle tissue following 6 mo of endurance-type exercise training in type 2 diabetes patients. Ten obese male type 2 diabetes patients ( age 62 ± 1 yr, body mass index BMI 31 ± 1 kg/m2 ) completed three exercise sessions/week consisting of 40 min of continuous endurance-type exercise at 75% V̇o2 peak for a period of 6 mo. Muscle biopsies collected at baseline and after 2 and 6 mo of intervention were analyzed for IMTG content and perilipin 2 expression using fiber type-specific immunofluorescence microscopy. Endurance-type exercise training reduced trunk body fat by 6 ± 2% and increased whole body oxygen uptake capacity by 13 ± 7% ( P < 0.05 ). IMTG content increased twofold in response to the 6 mo of exercise training in both type I and type II muscle fibers ( P < 0.05 ). A threefold increase in perilipin 2 expression was observed from baseline to 2 and 6 mo of intervention in the type I muscle fibers only ( 1.1 ± 0.3, 3.4 ± 0.6, and 3.6 ± 0.6% of fibers stained, respectively, P < 0.05 ). Exercise training induced a 1.6-fold increase in mitochondrial content after 6 mo of training in both type I and type II muscle fibers ( P < 0.05 ). In conclusion, this is the first study to report that prolonged endurance-type exercise training increases the expression of perilipin 2 alongside increases in IMTG content in a type I muscle fiber-type specific manner in type 2 diabetes patients.
Mary MacKillop Institute for Health Research
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