Louis Ignarro

Louis Joseph Ignarro
Ignarro in 2013
Louis Joseph Ignarro
Born	Louis Joseph Ignarro 31 5, 1941
Birthplace	Brooklyn, New York, U.S.
Nationality	American
Occupation	Pharmacologist, academic
Title	Professor Emeritus of Pharmacology
Employer	UCLA School of Medicine
Known for	Discovery of the signaling properties of nitric oxide
Education	Ph.D. in Pharmacology, University of Minnesota (1966)
Awards	Nobel Prize in Physiology or Medicine (1998), Basic Research Prize of the American Heart Association (1998)
Website	[http://www.healthiswealth.net/ Official site]

Louis Joseph Ignarro (born May 31, 1941) is an American pharmacologist and Nobel laureate whose groundbreaking research into the signaling properties of nitric oxide in the cardiovascular system transformed the understanding of how blood vessels dilate and how the heart and circulatory system function. Born in Brooklyn, New York, to Italian immigrant parents, Ignarro's curiosity about science was sparked as a child when his parents gave him a chemistry set at the age of ten — a gift that set him on a path from modest beginnings to the highest echelons of scientific achievement. In 1998, Ignarro was awarded the Nobel Prize in Physiology or Medicine, jointly with Robert F. Furchgott and Ferid Murad, "for their discoveries concerning nitric oxide as a signalling molecule in the cardiovascular system." His work elucidated a previously unknown biological mechanism by which a simple gas — nitric oxide — serves as a critical messenger molecule in the body, with profound implications for the treatment of heart disease, hypertension, and erectile dysfunction. Because nitric oxide is indirectly involved in the pharmacological action of sildenafil (marketed as Viagra), Ignarro has sometimes been referred to as the "Father of Viagra." He serves as professor emeritus of pharmacology at the UCLA School of Medicine's Department of Molecular and Medical Pharmacology, a position he has held since joining the university in 1985.

Early Life

Louis Joseph Ignarro was born on May 31, 1941, in Brooklyn, New York, the son of Italian immigrants. His father, Giacomo Ignarro, had emigrated from the town of Torre del Greco, near Naples, Italy, and worked as a carpenter in New York City. His mother, Frances, was also of Italian descent. The family lived in modest circumstances in the Long Beach area of Long Island, New York.

Ignarro's interest in science began at an early age. According to his own account, his parents purchased a chemistry set for him when he was approximately ten years old, and the experience of performing simple chemical experiments at home profoundly influenced his intellectual development. He has described the chemistry set as a formative gift that ignited a lifelong devotion to scientific inquiry. Growing up in a working-class Italian-American family, Ignarro did not have scientists or academics as role models within his immediate household, but his natural curiosity and the encouragement he received from his parents propelled him toward academic achievement.

As a young man, Ignarro attended local schools in the Long Beach area. He has spoken publicly about the importance of his upbringing and cultural heritage in shaping his work ethic and determination. In a 2017 address at The Catholic University of America, Ignarro discussed his early life and the values instilled by his immigrant parents, emphasizing that his path to scientific achievement began with the simple act of experimentation as a child.

Education

Ignarro pursued his undergraduate education at Columbia University in New York City, where he earned a Bachelor of Science degree in pharmacy in 1962. He then enrolled at the University of Minnesota School of Medicine, where he undertook doctoral studies in pharmacology. He completed his Ph.D. in pharmacology in 1966.

Following the completion of his doctorate, Ignarro pursued postdoctoral training through a fellowship in chemical pharmacology at the National Institutes of Health (NIH), which he completed in 1968. This postdoctoral experience at the NIH provided him with advanced training in the biochemical and pharmacological methods that would underpin his later research into nitric oxide and its role in the cardiovascular system. The combination of his pharmaceutical training at Columbia and his pharmacological research training at Minnesota and the NIH equipped Ignarro with a multidisciplinary perspective that proved essential to his subsequent discoveries.

Career

Early Career at CIBA-GEIGY

After completing his postdoctoral fellowship at the National Institutes of Health in 1968, Ignarro entered the pharmaceutical industry. He worked as a staff scientist in the research department of the pharmaceutical division of CIBA-GEIGY Corporation (now Novartis) in New York. During his time at CIBA-GEIGY, Ignarro gained experience in drug development and pharmacological research within a corporate setting. This period provided him with practical knowledge of how basic scientific research translates into pharmaceutical applications, an understanding that would later inform his academic career and his investigations into the mechanisms by which drugs affect the cardiovascular system.

Tulane University

Ignarro left the pharmaceutical industry to pursue an academic career. He joined the faculty of Tulane University School of Medicine in New Orleans, Louisiana, where he served as a professor of pharmacology for twelve years. During his tenure at Tulane, Ignarro began the research program that would ultimately lead to his Nobel Prize-winning discoveries. He investigated the biochemical mechanisms underlying the relaxation of smooth muscle in blood vessels, a line of inquiry that gradually directed his attention toward the role of nitric oxide as a signaling molecule.

At Tulane, Ignarro built a productive research laboratory and mentored numerous graduate students and postdoctoral fellows. His work during this period laid the foundation for understanding how the endothelium — the thin layer of cells lining blood vessels — communicates with the underlying smooth muscle to regulate vascular tone and blood pressure. The questions he pursued at Tulane were part of a broader scientific effort during the 1970s and 1980s to identify the endothelium-derived relaxing factor (EDRF), a substance that had been shown to cause blood vessels to relax but whose chemical identity remained unknown.

UCLA and Nitric Oxide Research

In 1985, Ignarro joined the faculty of the UCLA School of Medicine in Los Angeles, California, as a professor in the Department of Molecular and Medical Pharmacology. It was at UCLA that his most celebrated research achievements took place.

The central question that drove Ignarro's research was the identity of the endothelium-derived relaxing factor (EDRF). In the early 1980s, Robert F. Furchgott had demonstrated that the endothelium released a substance that caused relaxation of vascular smooth muscle, but the chemical nature of this substance was not known. Working independently, Ignarro and Furchgott each concluded that EDRF was in fact nitric oxide (NO), a simple gaseous molecule previously known primarily as an atmospheric pollutant and a component of automobile exhaust.

Ignarro's experiments at UCLA demonstrated that nitric oxide is produced by endothelial cells and acts on adjacent smooth muscle cells to cause vasodilation — the widening of blood vessels. He showed that nitric oxide activates the enzyme guanylate cyclase, leading to an increase in cyclic guanosine monophosphate (cGMP), which in turn triggers smooth muscle relaxation. This cascade of molecular events explained, at a fundamental level, how the body regulates blood flow and blood pressure.

The identification of nitric oxide as EDRF was a paradigm-shifting discovery in biomedical science. Prior to this work, it was not appreciated that a gas could serve as a signaling molecule in biological systems. The discovery opened entirely new fields of research and had immediate implications for understanding and treating a wide range of diseases, including hypertension, atherosclerosis, and other cardiovascular conditions.

Ferid Murad, working separately, had earlier demonstrated that nitroglycerin and related vasodilator drugs act by releasing nitric oxide, which then activates guanylate cyclase. Together, the work of Ignarro, Furchgott, and Murad established that nitric oxide is a fundamental signaling molecule in the cardiovascular system.

Ignarro's research also contributed to the understanding of the mechanism of action of sildenafil (Viagra), a drug used to treat erectile dysfunction. Sildenafil works by inhibiting phosphodiesterase type 5 (PDE5), an enzyme that breaks down cGMP. Because nitric oxide triggers the production of cGMP in the smooth muscle of the penis, leading to vasodilation and erection, the nitric oxide pathway is integral to the drug's effect. This connection earned Ignarro the informal title "Father of Viagra," although the drug was developed by Pfizer scientists independently of Ignarro's laboratory.

In 2025, UCLA highlighted Ignarro's Nobel Prize-winning research in a report on the role of federal university funding in pharmaceutical development, noting the impact of his discoveries on the development of vital drugs.

Ignarro has published numerous research articles throughout his career and is recognized as one of the most prolific contributors to the scientific literature on nitric oxide biology. He holds the title of professor emeritus at the UCLA School of Medicine.

Nitric Oxide Society and Scientific Publishing

In addition to his laboratory research, Ignarro played a central role in building the institutional infrastructure for the field of nitric oxide biology. He founded the Nitric Oxide Society, an organization dedicated to promoting research and collaboration among scientists studying nitric oxide. He also founded the journal Nitric Oxide Biology and Chemistry, for which he served as editor-in-chief. The journal became a primary outlet for publishing research on the biological and chemical properties of nitric oxide, and its establishment reflected the rapid growth of the field following the discoveries of the late 1980s and 1990s.

Corporate and Advisory Roles

Beyond his academic work, Ignarro has been involved in a number of corporate and advisory capacities. He served as a member of the scientific committee of Nicox, a French pharmaceutical company engaged in the development of nitric oxide-donating drugs. He also served as a member of the Board of Directors of Antibe Therapeutics, a Canadian drug discovery company focused on the development of hydrogen sulfide-releasing anti-inflammatory drugs.

Ignarro was a past member of the Nutritional Advisory Board for Herbalife, a multi-level marketing company that sells nutritional supplements. His association with Herbalife drew scrutiny, as some commentators questioned the appropriateness of a Nobel laureate lending his name and reputation to a company in the nutritional supplement industry.

He also served as a member of the Board of Directors of Operation USA, a non-profit organization providing disaster relief and development assistance.

Public Speaking and Science Advocacy

Ignarro has been active as a public speaker, delivering lectures at universities, medical conferences, and public events. In September 2017, he delivered an address at a biology symposium at The Catholic University of America, where he discussed his scientific career and the significance of nitric oxide research. In February 2019, he was invited to deliver a keynote address at a conference hosted by Oregon State University's Linus Pauling Institute, where he spoke about advances in the treatment of heart disease and impotence stemming from his discoveries.

In an extended interview conducted by Adam Smith, editor-in-chief of Nobelprize.org, Ignarro discussed his personal motivations, the trajectory of his career, and his reflections on the significance of the Nobel Prize for his research and for the broader field of nitric oxide biology.

Personal Life

Ignarro is of Italian-American descent, the son of immigrants from southern Italy. He has spoken publicly about the influence of his cultural heritage on his character and work ethic. In interviews, he has described his upbringing in a close-knit Italian-American family as a source of motivation and resilience throughout his career.

Ignarro has been an advocate for physical fitness and healthy living. He has participated in marathon running, reflecting his interest in cardiovascular health outside the laboratory setting.

He has maintained ties to his Italian heritage and has been recognized by Italian-American cultural organizations for his achievements. His story — from the son of an immigrant carpenter in Brooklyn to a Nobel laureate — has been cited in Italian-American media as an example of the opportunities afforded by education and scientific pursuit in the United States.

Recognition

Ignarro's most prominent recognition is the 1998 Nobel Prize in Physiology or Medicine, which he shared with Robert F. Furchgott and Ferid Murad for their discoveries concerning nitric oxide as a signaling molecule in the cardiovascular system.

In 1998, Ignarro also received the Basic Research Prize of the American Heart Association, in recognition of his outstanding contributions to the advancement of cardiovascular science.

That same year, Ignarro was elected to the National Academy of Sciences, one of the highest honors bestowed upon scientists in the United States. In 1999, he was inducted into the American Academy of Arts and Sciences.

In 2020, Ignarro was among faculty members recognized by the National Academy of Inventors, further acknowledging his contributions to scientific innovation.

Ignarro has received honorary degrees and awards from numerous institutions worldwide. He has been invited to deliver named lectures and keynote addresses at major scientific meetings, and his work has been profiled in publications including the European Heart Journal and Circulation Research.

Legacy

The discovery that nitric oxide functions as a signaling molecule in the cardiovascular system is considered one of the most significant advances in biomedical science in the late twentieth century. Prior to the work of Ignarro, Furchgott, and Murad, the idea that a simple gas — a molecule consisting of only one nitrogen atom and one oxygen atom — could play a central role in cellular communication was unknown. Their findings opened a new chapter in physiology and pharmacology, with implications that extended far beyond the cardiovascular system to include neuroscience, immunology, and other fields.

Ignarro's identification of nitric oxide as the endothelium-derived relaxing factor provided a molecular explanation for how blood vessels regulate their own diameter, and thus how blood flow and blood pressure are controlled at the cellular level. This understanding has had direct clinical consequences, informing the development and use of drugs that target the nitric oxide pathway, including nitroglycerin for angina, inhaled nitric oxide for pulmonary hypertension in newborns, and phosphodiesterase inhibitors such as sildenafil for erectile dysfunction.

The institutional contributions Ignarro made to the field — including the founding of the Nitric Oxide Society and the journal Nitric Oxide Biology and Chemistry — helped to establish nitric oxide research as a recognized discipline within the biomedical sciences. These organizations provided a platform for researchers worldwide to share findings and advance understanding of nitric oxide biology.

In the broader context of science history, the nitric oxide story illustrates how basic, curiosity-driven research can lead to transformative clinical applications. Ignarro himself has emphasized in public lectures and interviews the importance of fundamental research and the role of federal funding in enabling scientific discoveries that ultimately benefit public health. His career trajectory — from a childhood chemistry set in Brooklyn to a Nobel Prize — has been cited as an exemplary case of how investment in education and basic science can yield profound societal returns.