Irvine, Calif. - October 11, 2018 - In a University of California, Irvine-led study, researchers found evidence that mast cells, an important group of immune cells typically associated with allergies, actually enable the body to survive fasting or intense exercise. The study was published today in Cell Metabolism.
Typically found in the lungs and nose, mast cells are best known for their role in the body's allergic response. During an allergy attack, mast cells release a chemical called histamine into the bloodstream, which causes sneezing, runny nose, and other symptoms related to allergies. Drugs used to treat allergies block the annoying consequences of mast cell activity.
In this new study, led by Daniele Piomelli, PhD, professor of anatomy and neurobiology at UCI School of Medicine, and director of the UCI Center for the Study of Cannabis, researchers found that fasting causes the release of histamine from a select group of mast cells present in the gut, not those in the lungs or the nose. The histamine released from the gut travels to the liver where it triggers the formation of a fat-derived molecule called oleoylethanolamide (OEA).
Until now, researchers thought that OEA's main role was to block hunger. This new study indicates that histamine-triggered OEA formation in the liver stimulates ketogenesis, the conversion of fatty acids released from fat stores into chemicals called ketone bodies. Ketone bodies are vital to survival, because they keep the brain and muscles active during a prolonged fast or intense physical exercise.
"Without mast cells, histamine or OEA, we could not survive a marathon or a day-long hike without snacks, or any long period of time without food," said Piomelli. "What's fascinating to me is that a cell that was supposed to be the 'bad guy' in allergies, is the same one that allows us to survive prolonged lack of food or major physical effort."
Further research will be needed to determine if diseases that affect the ability of mast cells to release histamine and trigger OEA production could lead to disorders like liver steatosis, a precursor for liver fibrosis and cancer.
About the UCI School of Medicine
Each year, the UCI School of Medicine educates more than 400 medical students, as well as about 130 doctoral and master's students on the Irvine, California campus. More than 700 residents and fellows are trained at UC Irvine Medical Center in Orange, California and at other affiliated institutions. The highly regarded medical school is accredited by the Liaison Committee on Medical Accreditation and ranks among the U.S. News & World Report's top 50 medical schools in the nation for research. Dedicated to advancing medical knowledge and clinical practice through scholarly research, physician education, and high-quality care, the school of medicine offers MD, MS, and PhD Degrees; a Master of Science in Biomedical and Translational Science (MS-BATS), combined MD/MBA, MD/MS-BATS, and MD/MPH programs; and a distinctive combined MD/master's program called the Program in Medical Education for the Latino Community (PRIME-LC). For more information, visit: som.uci.edu.
About the University of California, Irvine
Founded in 1965, UCI is the youngest member of the prestigious Association of American Universities. The campus has produced three Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 30,000 students and offers 192 degree programs. Located in one of the world's safest and most economically vibrant communities, UCI is Orange County's second-largest employer, contributing $5 billion annually to the local economy. For more on UCI, visit http://www.