Glycogen synthesis and lysis

[garytse86]

How are signals form insulin integrated with those from adrealine and contraction to regulate the breakdown or synthesis of glycogen in muscle?

I know that adrenaline stimulates the conversion of ATP to cyclic AMP by activating adenyl cyclase, and I think insulin does the opposite. But how are the signals combined before having a net effect? It would be easier if they were both hormones. Is adrenaline a hormone? Because it is a neurotransmitter specifically acting on target tissues (though Wikipedia says it's a hormone as well). Is the integration of signals just a simple "summation" of the effects? But that would mean there is no integration...

 

[garytse86]

anyone please?

 

[ravenprp]

The regulation of glycogen synthesis and lysis in muscle is a complex process that involves the integration of signals from multiple hormones and neurotransmitters, including insulin, adrenaline, and contraction. These signals work together to ensure that the breakdown or synthesis of glycogen is tightly regulated and meets the energy demands of the body.

Insulin is a hormone produced by the pancreas that plays a key role in promoting glycogen synthesis. When insulin levels are high, it signals to muscle cells to take up glucose from the blood and convert it into glycogen for storage. This process is important for maintaining blood glucose levels and providing a readily available source of energy for the body.

On the other hand, adrenaline (also known as epinephrine) is a hormone and neurotransmitter that is released by the adrenal glands in response to stress or exercise. Adrenaline stimulates the conversion of ATP to cyclic AMP, which activates an enzyme called protein kinase A (PKA). PKA then phosphorylates and activates enzymes involved in glycogen breakdown, leading to the release of glucose from glycogen stores.

The integration of signals from insulin and adrenaline is crucial for regulating glycogen breakdown and synthesis in muscle. When both hormones are present, their effects are combined to achieve a net effect on glycogen metabolism. This is achieved through a process called crosstalk, where signals from different hormones converge and interact with each other to produce a coordinated response.

Additionally, the effects of adrenaline on glycogen metabolism are also influenced by muscle contraction. During exercise, muscle contraction leads to an increase in calcium levels, which activates a signaling pathway that works in parallel with adrenaline to promote glycogen breakdown. This ensures that the body has enough energy to meet the demands of physical activity.

In summary, the integration of signals from insulin, adrenaline, and muscle contraction is a complex and coordinated process that regulates glycogen synthesis and lysis in muscle. These signals work together to ensure that the body has a steady supply of glucose for energy production and maintain homeostasis.