1 · Rest · GLUT4 sequestered
In a resting muscle cell, sits almost entirely in cytoplasmic vesicles, with little on the membrane, so a fasting muscle that is not contracting takes up little glucose.In a resting muscle cell, the glucose transporter is almost entirely sequestered in small cytoplasmic vesicles (GSV, GLUT4 storage vesicles). Very little GLUT4 sits on the membrane surface — which is why a fasting muscle that is not contracting takes up only a little glucose.Meanwhile extracellular blood glucose is normally ~5 mmol/L, so the inside-vs-outside concentration gradient is large — but the door is closed.