This will be more about the role and effects of endogenously produced insulin
Insulin production
In pancreatic beta cells insulin independant glucose channels allow glucose to enter the cell.
When glucose enters the cell,
Mitochondrial ATP generation blocks ATP sensitive K+ channels in the plasma membrane which leads to influx of calcium and release of insulin. This means when Blood sugar is high insulin will be released, which is how it is supposed to work
Production regards to cAMP signaling
As previously mentioned ATP blocks the K+ channel. Another pathway to block the K channel is through cAMP, which acts on PKA to close the channel.
Increasing cAMP increases K+ channel blockage and therefore increases insulin production. 3 salient factors influence this:
- α-Adrenergic stimulation will decrease cAMP
- ß-Adrenergic stimulation will increase cAMP
- Incretins (through the GLP-1 receptor) will increase cAMP
Physiological effects of insulin
Insulin acts on the insulin receptors (TKR) to induce GLUT transporters to begin taking glucose into the cell. The effect of insulin can last for several hours