Molecular mechanisms of glucose uptake in skeletal muscle at rest and in response to exercise

Abstract

Glucose uptake is an important phenomenon for cell homeostasis and for organism health. Under resting conditions, skeletal muscle is dependent on insulin to promote glucose uptake. Insulin, after binding to its membrane receptor, triggers a cascade of intracellular reactions culminating in activation of the glucose transporter 4, GLUT4, among other outcomes. This transporter migrates to the plasma membrane and assists in glucose internalization. However, under special conditions such as physical exercise, alterations in the levels of intracellular molecules such as ATP and calcium act to regulate GLUT4 translocation and glucose uptake in skeletal muscle, regardless of insulin levels. Regular physical exercise, due to stimulating pathways related to glucose uptake, is an important non-pharmacological intervention for improving glycemic control in obese and diabetic patients. In this mini-review the main mechanisms involved in glucose uptake in skeletal muscle in response to muscle contraction will be investigated.