Sunday , January 17 2021

Are there any allergies to the mechanisms that are useful for survival?

Mast cells are immune cells found in the nose or lungs that play an important role in allergies. In the presence of an allergen, these cells secrete histamine, a chemical mediator that once entered the bloodstream, will cause many more or less inconvenient reactions – and eye sneezing, rash to anaphylactic shock in the most severe cases. As their name implies, some anti-allergic drugs – antihistamines – block the harmful effects of mast cells.

Except that according to a study published in the journal Cell Metabolism, and led by researchers from the University of California Irvine, led by Daniel Piomelli, these same cells seem to allow our body to survive food deprivation and / or significant energy demand associated with intense physical activity.

In this case, this work shows that histamine released by mast cells in the liver causes the formation of oleoylethanolamine (OEA), a lipid derivative already known for blocking the feeling of hunger. According to a study of cellular metabolism, oleoylethanolamine is also involved in ketogenesis, in which our brain and muscles continue to function for a certain period of time in the case of fasting and / or high physical effort. The mechanism that would be most significant during our evolution, when our ancestors did not always have a full refrigerator on hand to eat.

"Without mast cells, histamine or AEO, we could not survive in a marathon or on a day of hiking without crackers in our backpack"– explains Piomelli. “What fascinates me is that these cells, which were supposed to be the“ bad guys ”of allergy, are the same ones that allow us to withstand long-term hunger or physical stress.”,

The team is currently exploring whether diseases affecting the ability of mast cells to secrete histamine, and thus stimulate AEO production, can also cause diseases such as steatosis. Foie gras are often precursors to liver fibrosis and liver cancer.

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