Cyclic AMP was the first chemical to be isolated and identified as a second messenger--a substance produced by a cell when a hormone or other chemical (the first messenger) binds to specific receptor sites on the cell surface. The second messenger, in turn, influences the cell's processes. The discovery was a major step toward understanding how both hormones and cells function.

Until 1956, scientists thought that hormones performed their action on cells directly. Then the American physician and pharmacologist Earl Sutherland showed that hormones stimulate production by the cell of cyclic AMP (adenosine-3',5' -phosphoric acid), which effects the cell's activity. He received the 1971 Nobel Prize in physiology or medicine for his work.

Sutherland was born and raised in Burlingame, Kansas. He graduated from Washburn University in Topeka and received his M.D. from Washington University in St. Louis, Missouri...