Definition:
The second messenger system is inside endocrine glands where the receptor
and hormone trigger cyclic AMP for starting the action within the target
cell.
Structure:
The second messenger system inside endocrine glands and tissues, in the
hypophysis, in target
glands, and in target tissues, is a
chemical system in which the receptor and hormone trigger the synthesis
of cyclic AMP from ATP.
Function:
Within a target cell, cyclic AMP diffuses, activating a variety of enzymes,
called protein kinases, which cause the synthesis of the products of that
cell. Some of the proteins synthesized are stimulatory for a function,
and others may inhibit functions.
