causes that surge of energy you get when you are frightened?
Before the work of Earl
W. Sutherland, scientists knew that the adrenal
produces a hormone
which travels to the body's cells and causes an increase in
blood sugar. The sugar gives your body energy to react to stressful
situations. But no one understood exactly how this hormone produced
such an effect.
the late 1950s, Sutherland investigated the effect of epinephrine
on liver tissue. He and T.W. Rall discovered that the hormone—the
"first" messenger—stimulates formation of a "second messenger"
within cells. It is this second substance, cyclic adenosine
monophosphate (cAMP), that stimulates the breakdown of stored
into sugar. Sutherland suggested that the actions of many other
hormones could be explained in the same way.
In 1965, Martin Rodbell was inspired when Sutherland spoke at
the NIH. Rodbell realized that his isolated fat cells were the
perfect medium for further investigation of the mechanism of
model of hormone action A
receptor accepts a hormone and stimulates adenylyl cyclase
(AC) to convert adenosine triphosphate (ATP) inside the
cell to cyclic adenosine monophosphate (cAMP). The hormone
is the first messenger; cAMP is the second. Sutherland
won a Nobel Prize for this work in 1971