Question

GLUT2 transporters are continuously present in high concentration in the membranes of which one below ?

Pancreatic beta cells

Pancreatic alpha cells

Muscle cells

Adipose cells

Hepatic cells

Answer 1

GLUT2 is the major glucose transporter in -cells of pancreatic islets and hepatic cells.

• In both cell types GLUT2 mediates the facilitated diffusion of glucose across cell membranes ,and then intracellular glucose metabolism is initiated by the glucose -phosphorylation enzyme,hexokinase IV or glucokinase.
• GLUT2 is a member of a family of facilitative glucose transporters (GLUT) that share a high degree of protein homology and a putative protein structure..
• In the -cell,the rate of glucose metabolism controls insulin secretion,whereas in the liver,glucose metabolism and transport are essential to subsequent glycogen synthesis and gluconeogenesis.

GLUT4 is seen in Pancreatic alpha cells, Muscle cells(skeletal and cardiac) ,Adipose cells .

• It is insulin regulated Glucose transporter.
• High glucose decreased and insulin elevated the GLUT4 expresssion in pancreatic alpha cells.
• Glucose transporter GLUT4 facilitate the transport of blood glucose into insulin-sensitive muscle and adipose tissue