Ignarro, Louis Joseph (1941-…), an American scientist, found that a gas called nitric oxide is a signal molecule that relaxes the smooth muscles that line blood vessels. This relaxation widens the vessels and increases blood flow. Understanding the signals that control the behavior of blood vessels has important applications in many areas of medicine, including treating heart disease. The work of Ignarro and others also led to development of a drug called sildenafil citrate, sold under the trade name Viagra. Viagra acts chiefly on blood vessels in the penis and enables men to maintain an erection.
Ignarro is a pharmacologist (scientist who studies drugs). His discovery built on the work of pharmacologist Robert F. Furchgott, who had shown that a chemical messenger that tells blood vessels to relax and widen must exist. Ignarro and Furchgott shared the 1998 Nobel Prize in physiology or medicine with Ferid Murad, another American pharmacologist who studied the biological effects of nitric oxide.
Ignarro was born on May 31, 1941, in the Brooklyn section of New York City. He received a bachelor’s degree from Columbia University in 1962 and a doctor’s degree in pharmacology from the University of Minnesota in 1966. He worked as a research scientist at the National Institutes of Health in Bethesda, Maryland, from 1966 to 1968 and at Ciba-Geigy Corporation, a drug company in Summit, New Jersey, from 1968 to 1972. Ignarro taught pharmacology at Tulane University Medical School from 1972 to 1986. He then became a professor of molecular biology in the School of Medicine at the University of California at Los Angeles (UCLA).
