Source and Entry of Glucose into Cells

The properties of glucose transporter proteins (GLUT) consist of tissue specificity and differences in functional properties reflected in their glucose metabolism. Five transporter proteins. Glut 1-5, have been identified 

GLUT 1 Brain, microvessels, red blood cells, placenta, kidney, and many other cells Low (about ImM), ubiquitous basal transporter 

GLUT 2 Liver, pancreatic j3-cell, small intestine High (15-20mM) 

GLUT 3 Brain, placenta, fetal muscle Low provide glucose for tissue cells metabolically dependent on glucose 

GLUT 4 Skeletal and heart muscle, fat tissue (adipocytes) (5mM), insulin responsive transporter 

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