Insulin hormone

[vergil5203]

How Insulin can reduce blood sugar level?...When insulin attach on membrane then what occur inside the cell?

[Dr.Stein]

Insulin facilitates cell membrane for glucose absorption to convert into glycogen. More glucose absorbed, then less amount locates in the blood.

[vergil5203]

thank you...but the realy i wan to know..its when insulin bind to liver cell membrane.What occuring inside the cell.

[sachin]

When sugar concentration of blood is high or when there is need of braking sugar for energy.... the insulin is secreated by Ilets of L.H. in pancreas and it binds to cells and sugar transport is activated..

[Dr.Stein]

So you want to know what happens inside the target cell?
Take this

[MrMistery]

GLUT4? I thought the only ones are GLUT1 and GLUT2. SO how many are there? And where are the others except 1 and 2 located?

[sdekivit]

GLUT4? I thought the only ones are GLUT1 and GLUT2. SO how many are there? And where are the others except 1 and 2 located?

you also have GLUT 3 and GLUT 5 with known functions. GLUT4 is the only insulin-dependant glucose transporter (although contraction in the muscle is the main trigger for GLUT4-expression)

They all belong to the same family, but all have different kinetic properties and thus are distributed in different tissues.

GLUT2: high Km --> thus never saturated under physiological conditions (that's why it's expressed in the liver and pancreas cells for glucose sensing and acting like a glucose sink in the liver and transport over the basolateral cell membrane in the small intestine)

GLUT3: low Km and thus very high affinity for glucose --> expressed in the brain, because it's saturated and thus keeps glucose transport into the brains constant till glucoseconcentration to 2 mM

--> the mechanism of how insulin triggers effects in the target cell is not yet completely understood. Probably it acts through the insulin recepotor phosporylating the insulin receptor substrates and then act via the PI3K-pathway.

[MrMistery]

i'm confused, i though glut 1 was in the brain? are they both in the brain? and where is glut 4 located?

[Dr.Stein]

Ask google

[MrMistery]

yeah, i've looked it up on wikipedia. but it's easier to ask someone else...
Anyway thank you for taking the time to explain it for me sdekivit

[sdekivit]

i have a very good book about the metabolic regulation:

metabolic regulation: a human perspective by Frayn.

GLUT4 is located in the adipose tissue and the striated muscle --> thus these tissues will take up glucose under influence of insulin

[vergil5203]

However,wat is GLUT?? n the type of it n the function related to it...i wan to know more bout the mechanism of insulin.