Vasoactive Intestinal
Peptide

The Discovery

A Puzzle in the Porcine Lung

In the 1960s, Swedish researcher Viktor Mutt and Iraqi-American scientist Dr.

In the 1960s, Swedish researcher Viktor Mutt and Iraqi-American scientist Dr. Sami Said were studying tissue from pig lungs. They knew something in those lungs could relax blood vessels and make them wider. They called this mystery substance the 'vasodilator peptide.' For years, they worked to purify and identify it. They ground up lung tissue, separated it into pieces, and tested each piece. It was painstaking detective work, but they were determined. In 1969-1970, they finally isolated the pure peptide and named it VIP for 'Vasoactive Intestinal Peptide.' But here was the surprise: it was also found in the intestines, where it did much more than just relax blood vessels.

The Breakthrough

The Messenger Found Everywhere

Once scientists had identified VIP, they began finding it throughout the body.

Once scientists had identified VIP, they began finding it throughout the body. It was in the lungs, the intestines, the heart, the brain, and the nerves. VIP was like a messenger that the body had placed in strategic locations. Wherever VIP was found, blood vessels would relax and dilate. Smooth muscles would calm down. Inflammation would decrease. Glands would change their output. It became clear that VIP was not just one medicine in one location but a master control system used in many places. Each day, scientists discovered new roles for VIP. It helped control blood pressure. It regulated intestinal movement. It influenced immune responses. It affected hormone production.

The Trials

The Double Role Discovery

A major breakthrough came when scientists realized VIP had two jobs at once.

A major breakthrough came when scientists realized VIP had two jobs at once. Sometimes VIP worked as a hormone, traveling through the bloodstream to reach distant tissues. Other times, VIP worked as a neurotransmitter, relaying messages between nerve cells in the brain and throughout the body. This dual role explained why VIP had so many different effects across so many tissues. It was like a radio signal that worked both as a broadcast message and as a direct phone call. The same chemical could do completely different things depending on where it was and what was needed. This made VIP incredibly interesting to medical researchers looking for new treatments.

The Crisis

From Lungs to Treatments

By the 1990s and 2000s, researchers began testing VIP as a treatment for diseases.

By the 1990s and 2000s, researchers began testing VIP as a treatment for diseases. They reasoned that if VIP relaxes blood vessels in the lungs, it might help patients whose lung blood vessels are too tight. They tested VIP in patients with pulmonary hypertension, a condition where lung vessels narrow dangerously. The results were promising. Blood vessels relaxed. Blood pressure in the lungs decreased. Patients could breathe easier and exercise longer. They tested VIP in COPD patients whose airways were inflamed and constricted. VIP reduced inflammation and helped them breathe. Doctors in Europe saw such good results that they began using VIP clinically.

The Legacy

A Global Healing Tool Emerges

Today, VIP represents a unique story in peptide medicine.

Today, VIP represents a unique story in peptide medicine. It was discovered half a century ago and is already being used to help patients in some countries. In the United States, more advanced trials are underway to expand its approved uses. Researchers continue discovering new potential applications. Some are testing VIP for systemic inflammation. Others are exploring its role in protecting nerve cells. Still others are investigating whether VIP might help heart failure patients. The peptide that was first found in pig lungs has become a symbol of how fundamental research can lead to real healing. Dr. Said's legacy is that a simple curiosity about how lungs work has become a medical tool that helps patients breathe and live better.