Narrator: This is Science Today. A heart attack
has two phases of injury. The first is when a blood
clot forms in a coronary artery, blocking blood flow.
But there's a second, less well appreciated phase
called reperfusion injury. Dr. Marcus Horwitz, of
UCLA, says reperfusion injury actually causes about
sixty percent of the total damage to the heart after
Horwitz: It would occur with any heart attack
victim or stroke. Wherever you have a situation where
blood supply is cut off from an organ, such as the
heart and then that blood supply is restored, reperfusion
injury will take place.
Narrator: In this phase, white blood cells
flow to the oxygen deprived heart tissue, releasing
toxic molecules which damage the heart. This can't
happen without iron, so Horwitz is working with an
iron-binding tuberculosis molecule to prevent this
Horwitz: The molecule that we have prevents
iron from participating in that chemical reaction
so that the toxic oxygen molecule is now produced
and reperfusion injury does not take place.
Narrator: For Science Today, I'm Larissa Branin.