Which observation suggested to Sutherland the involvement of a second messenger in adrenalineadrenaline's effect on liver cells?
A) Enzymatic activity was proportional to the amount of calcium added to a cell-free extract.
B) Receptor studies indicated that adrenaline adrenalinewas a ligand.
C) Glycogen breakdown was observed only when adrenaline adrenalinewas administered to intact cells.
D) Glycogen breakdown was observed only when adrenaline adrenalineand glycogen phosphorylase were mixed.

Question

Quizplus · Accepted Answer

The observation that glycogen breakdown was only observed when adrenaline was administered to intact cells suggests that there is a second messenger involved in adrenaline's effect on liver cells. If there was no second messenger, glycogen breakdown would be observed in a cell-free extract as well.

Which Observation Suggested to Sutherland the Involvement of a Second