Epinephrine triggers a direct signal transduction pathway.
I know this because when epinephrine binds to it's receptor example on a muscle cell,this is known as a type of G protein -coupled receptor,signal transduction cascade is triggered and this involves the production of a second messenger molecule cyclic AMP(cAMP).
Epinephrine also know as Adrenaline or sus-phrine.
It is a vasoconstrictor,broncho dilator and a sympathetic stimulant.
It constricts the peripheral abdominal organs as well as a stimulating the heart beat thereby raising the blood pressure,it also relaxes the spasms of the bronchial muscles thereby promoting ventilation of the lungs.