Which Observation Suggested to Sutherland the Involvement of a Second

question 21

Multiple Choice

Which observation suggested to Sutherland the involvement of a second messenger in epinephrine'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 epinephrine was a ligand.
• C) Glycogen breakdown was observed only when epinephrine was administered to intact cells.
• D) Glycogen breakdown was observed when epinephrine and glycogen phosphorylase were combined.
• E) Epinephrine was known to have different effects on different types of cells.

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