Where are ATP-sensitive potassium channels located?
ATP-sensitive potassium channels (KATP) are widely distributed and present in a number of tissues including muscle, pancreatic beta cells and the brain. Their activity is regulated by adenine nucleotides, characteristically being activated by falling ATP and rising ADP levels.
What causes the potassium channels in the pancreatic beta cell membrane to open?
The ATP generated by glucose metabolism in B cells blocks the K+(ATP) channels controlling resting membrane potential. Thus, glucose metabolism leads to closure of the ATP-dependent potassium channels; the resulting decrease in K+ permeability induces depolarization and opening of voltage-activated Ca-channels.
Does inhibition of potassium channels by ATP in pancreatic beta cells release insulin?
ATP-sensitive potassium (KATP) channels, so named because they are inhibited by intracellular ATP, play key physiological roles in many tissues. In pancreatic β cells, these channels regulate glucose-dependent insulin secretion and serve as the target for sulfonylurea drugs used to treat type 2 diabetes.
Does ATP inhibit potassium channels?
The ATP-sensitive potassium channels contain four pore-lining α subunits (Kir6) and four regulatory β subunits (SUR). SUR is a member of the ATP-binding cassette (ABC) family and contains two nucleotide binding (NB) domains. ATP acts on Kir6 to inhibit the channel whereas Mg-ADP acts on SUR to activate the channel.
Which potassium channel family do ATP sensitive potassium channels belong to?
family C
ATP-sensitive potassium channel
| ATP-binding cassette, sub-family C (CFTR/MRP), member 8 | |
|---|---|
| Identifiers | |
| Locus | Chr. 11 p15.1 |
| showSearch for |
What does KATP channel do?
KATP channels play important roles in controlling and regulating cellular functions in response to metabolic state, which are inhibited by ATP and activated by Mg-ADP, allowing the cell to couple cellular metabolic state (ATP/ADP ratio) to electrical activity of the cell membrane.
What does potassium do to insulin?
If your potassium levels are too low, your body may make less insulin. That could lead to high blood sugar. Studies show that people with low potassium levels release less insulin, have higher blood sugar levels, and are more likely to get type 2 diabetes than those with normal potassium levels.
How does potassium increase insulin?
Insulin-induced hypokalaemia increases plasma renin and angiotensin II levels while decreasing the serum aldosterone concentration. In turn, the renin-angiotensin-aldosterone system affects glucose tolerance by modulating plasma potassium levels, which act as a stimulus for glucose-induced insulin release.
Which drug inhibits ATP sensitive K channels?
Repaglinide, nateglinide and sulfonylurea are agents used for treatment of type II diabetes. They lower blood glucose levels by blocking ATP-dependent potassium channels in pancreatic beta cells to stimulate insulin secretion.
Is potassium used for ATP?
For each ATP that is broken down, it moves 3 sodium ions out and 2 potassium ions in. As the cell is depleted of sodium, this creates an electrical gradient and a concentration gradient, both of which are put to use for many tasks.
What is ATP-dependent potassium channel?
An ATP-sensitive potassium channel (or KATP channel) is a type of potassium channel that is gated by intracellular nucleotides, ATP and ADP. ATP-sensitive potassium channels are composed of Kir6. x-type subunits and sulfonylurea receptor (SUR) subunits, along with additional components.
Which drug inhibits ATP-sensitive K channels?