Nitroglycerin's talent for opening blood vessels, now frequently exploited by doctors treating people with angina or heart failure, was first observed in the 1860s when physicians studied side effects experienced by workers in a dynamite factory. Scientists have now found a long-sought enzyme that may be behind nitroglycerin's dilation of blood vessels.
In work that led to a Nobel prize in 1998, investigators several decades ago learned that nitroglycerin's medicinal effects are the result of its conversion in the body into nitric oxide (SN: 10/17/98, p. 246). This gas relaxes the muscle cells that narrow and expand blood vessels.
Because it's difficult to grow blood vessels in the laboratory, investigators have struggled to identify the molecules that convert nitroglycerin into nitric oxide.