Glycogen breakdown in the liver is triggered by a camp cascade upon the binding of to its receptor.

Glycogen breakdown in the liver is triggered by a cAMP cascade upon the binding of EPINEPHRINE HORMONE to its receptor.
The breaking down of glycogen inside the cell is partly controlled by hormones. The principal hormone that regulates glycogen breakdown is epinephrine. When the need for glycogen breakdown arises in the cell, epinephrine hormone will be released and it will binds to a receptor on the liver cell surface and this triggers the production of a second messenger, cAMP within the liver cell.The receptor for epinephrine is a G protein coupled receptor.

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