Skeletal Muscle Energetics are Compromised Only During High Intensity Contractions in the Goto-Kakizaki Rat Model of Type 2 Diabetes.

Skeletal Muscle Energetics are Compromised Only During High Intensity Contractions in the Goto-Kakizaki Rat Model of Type 2 Diabetes. Am J Physiol Regul Integr Comp Physiol. 2019 Jun 12;: Authors: Lewis MT, Kasper JD, Bazil JN, Frisbee JC, Wiseman RW Abstract Type 2 diabetes (T2D) presents with hyperglycemia and insulin resistance affecting over 30 million people in the US alone. Previous work has hypothesized that mitochondria are dysfunctional in T2D and results in both reduced ATP production and glucose disposal. However, a direct link between mitochondrial function and T2D has not been determined. In the current study, the Goto-Kakizaki (GK) rat model of T2D was used to quantify mitochondrial function in vitro and in vivo over a broad range of contraction-induced metabolic workloads. During high frequency sciatic nerve stimulation hindlimb muscle contractions at 2 and 4 Hz intensities the GK rat failed to maintain similar bioenergetic steady-states to Wistar controls (WC) measured by phosphorus magnetic resonance spectroscopy despite similar force production. Differences were not due to changes in mitochondrial content in red (RG) or white gastrocnemius (WG) muscles (cytochrome c oxidase, RG: 22.2 ± 1.6 versus 23.3 ± 1.7 U/gWW, WG: 10.8 ± 1.1 versus 12.1 ± 0.9 U/gWW;GK versus WC, respectively). Mitochondria isolated from muscles of GK and WC rats also showed no difference in mitochondrial ATP production capacity in vitro meas...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research