Others regulate ion channels. Cyclic AMP cascade . Cyclic AMP activates a protein kinase . Triggers a series of phosphorylations of various enzymes. Activation of some enzymes, inactivation of others.
Reaction is amplified at each level.
Results in different effects, depending on the hormone and target cell. Examples of cyclic AMP-mediated effects. Other second messengers. B. Steroid hormones . Cellular responses to steroid hormones are not apparent for hours or days.