[Glucose transporters. Physiology and physiopathology].
Glucose transport is an important step in the regulation of glucose homeostasis. Two types of transport systems are described: active transport accumulates glucose in specific cells, whereas facilitative transport equilibrates blood glucose and intracellular glucose inside all mammalian cells. At the present time, different levels of facilitative transport regulation are known. Facilitative transport is achieved by 5 different isoforms; each isoform has its own characteristics and is subjected to tissue-specific regulation. Alteration of glucose transporters expression may be involved in a physiopathological situation such as diabetes which is characterized by insulin resistance of peripheral tissues and impaired insulin secretion by beta pancreatic cells. Thus, Glut 2 expression is reduced in the beta cells of diabetic rats. The reduction of Glut 2 expression correlates with, and may contribute to the loss of glucose-stimulated insulin secretion. However, Glut 2 expression in liver remains unaltered. The insulin resistance of peripheral tissues may be explained in adipose tissue by a decrease in Glut 4 expression. In skeletal muscle, Glut 4 expression remains constant whatever the physiological or physiopathological situation.
Girard
J
J
Centre de Recherche sur l'Endocrinologie moléculaire et le Développement, CNRS, Meudon.
Postic
C
C
Burcelin
R
R
Guillet
I
I
Leturque
A
A
D001693:Biological Transport, Active / Q000502:physiology*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D008099:Liver / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009119:Muscle Contraction / Q000502:physiology; D010179:Pancreas / Q000378:metabolism
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D005947:Glucose
Transporteurs de glucose. Physiologie et physiopathologie.