Single muscle fiber contractile properties in diabetic RAT muscle

ABSTRACT Introduction: Diabetes is associated with accelerated loss of muscle mass and function. We compared the contractile properties of single muscle fibers in young rat soleus muscle of uncontrolled streptozotocin‐induced diabetic animals (n = 10) and nondiabetic controls (n = 10). Methods: Single fiber maximal force, shortening velocity, and power were assessed during maximal activation with calcium using the slack test 4 weeks after induction. Myosin heavy chain expression was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Oxidized myosin levels were detected by analyzing protein carbonyls in muscle homogenates. All fibers expressed the type I myosin heavy chain isoform. Results: Diabetic rats had higher blood glucose (537 vs. 175 mg/dl; P