Regulated Secretion

NDSU Virtual Cell Animations Project animation 'Regulated Secretion'. For more information please see http://vcell.ndsu.edu/animations.

Proteins can be secreted, or transferred out of a cell, by multiple pathways. Regulated secretion is one of these processes. In regulated secretion proteins are secreted from a cell in large amounts when a specific signal is detected by the cell. The example used in this animation is the release of insulin after a glucose signal enters a pancreatic beta cell.

Category:

Education

Tags:

• regulated
• secretion
• eukaryotic
• biology
• golgi

[AaranTL]

When blood glucose rises, GLUT2

transporters carry glucose into the β cells

It is converted to glucose-6-P and

enters glycolysis, the citric acid cycle

and oxidative phosphorylation causing the concentration of ATP inside the cell to rise. This rise in ATP closes ATP-gated K+ channelsand the membrane depolarizes; this opens voltage sensitive Ca channels and Ca++ floods in. It's this influx of Ca that triggers fusion of

the secretory granules with the

plasma membrane, and insulin release.

[ChinixzA]

this video is much better than my teacher's explanation!!! lol

[collieh1]

"its a complicated process"

not near as complicated as cholesterol formation. believe that

[nhieny]

Perfect, couldn't have said it better myself.

[enderfield]

It's probably something about a mid-transmitter between the glucose and the interior of a cell. It means that glucose itself doesn't enter the cell, but it activates certain receptors on the cell's surface. The activated receptors produce transmitters that cause the secretion of insulin. I'm not sure about the details, but it's probably similar to the mechanism of cells' reaction to certain hormones whose molecules are to big to pass through the cell membrane.

[Jorfapigo]

It says that glucose triggers a complicated process to release insulin... which goes like this.

Glucose concentration inside the cell builds up.

Ergo, ATP conc. also raises.

ATP blocks a certain K+ channel, this results in accumulation of + charges (mainly Ca+), also known as depolarization.

Ca+ inside the cell promotes the vesicles to release insulin into the blood stream... and there you have it, glucose starts the insulin release process, but it's not the only trigger that acts this way.

[BGSoccerMagic]

Diabetes is caused by the inability of the body to utilise the glucose that is in the curculation. This could be the result of: 1, The pancreas doesn't secrete any insulin, and the insulin is the hormone that triggers the utilization of glucose by the certain cells, like muscle, fat; or 2. The said cells do not respond to insulin, due to malfunction of the insulin cell-signaling pathway.

[Daud2008]

Practically what I don't understand, and maybe you could make another video to explain it, is in the video when the speaker says: "glucose itself doesn't cause the release" when what does cause the release? Because I always thought that if the pancreas works then insulin is released when someone ingest food to bring glucose inside the cells, but then they say people with diabetes don't produce enough insulin and they need to inject it to absorb the glucose.

[Daud2008]

Thanks for the video, however it seems extremely complicated, and in reality the mechanism is not explained.

[bornagain7777777]

Thanks for this video