U.S. research team uncovers the production process of the previously unknown yellow color pigment
The mystery of why urine turns yellow, which had remained unsolved for over 100 years, has finally been solved.
According to CBS on the 3rd (local time), a research team from the University of Maryland published the results of their research in the scientific journal ‘Nature’ that they discovered an enzyme that determines the color of urine.
“It is surprising that such an everyday biological phenomenon has remained unexplained for so long,” Brantley Hall, professor of cell biology and molecular genetics at the University of Maryland, said in a statement. “I am thrilled that our research team has figured it out.”
Urine consists of water, electrolytes, and waste that the kidneys filter from the blood. About 125 years ago, scientists discovered urobilin, the pigment that makes urine appear yellow, but they could not determine what produces urobilin.
The research team explained that the color of urine is related to the red blood cells in the body. Red blood cells are produced, active for about 6 months, and then decomposed at the end of their lifespan. During this process, a bright orange pigment called bilirubin is produced.
Bilirubin is usually secreted and excreted in the intestines, or some of it is reabsorbed by the body. The research team discovered ‘bilirubin reductase’, which converts bilirubin into a colorless by-product called urobilinogen in an enzyme secreted by intestinal microorganisms when bilirubin reaches the intestines.
Professor Hall said, “Urobilinogen converted by bilirubin reductase is naturally decomposed into a molecule called urobilin, which has a yellow color that we are all familiar with. This is why urine has a yellow color.”
In addition to uncovering the reason why urine is yellow, the research team said that this could also help determine health status.
“The discovered enzyme allows us to study how intestinal bilirubin levels affect health conditions such as jaundice,” said Xiaofang Zhang, co-author of the study. “This discovery provides an opportunity to understand the interrelationship between the intestines and the liver.” “The foundation has been laid,” he said.
Source: Donga
Mark Jones is a world traveler and journalist for News Rebeat. With a curious mind and a love of adventure, Mark brings a unique perspective to the latest global events and provides in-depth and thought-provoking coverage of the world at large.