Exercising is good. It helps control weight and can prolong life. Unfortunately, we don’t know how muscle activity generates these benefits. Now scientists are beginning to understand the molecular mechanism that turns muscle activity into longevity. A molecule responsible for this process has been discovered.
Scientists compared the blood of mice and horses after strenuous training with the blood of these same animals immediately before training. We know that a huge number of components change their concentrations in the blood after exercise, but with the new mass spectrometers (a type of equipment) molecules that exist in small amounts, such as new hormones, can be identified.
In both horses and humans and mice, scientists have discovered a new molecule whose concentration increases after exercise. It is a dimer: a lactate molecule bound to a phenylalanine (Lac-Phe) molecule. Lactate is produced by the muscles when we exercise. Phenylalanine is one of the 20 amino acids that make up our proteins.
By analyzing how Lac-Phe is produced, the scientists discovered the enzyme that links lactate to phenylalanine. And based on that information they produced large amounts of Lac-Phe and also a genetically modified mouse that does not have the enzyme.
In a first experiment, they injected Lac-Phe into mice that had not exercised. They observed that these mice had their appetite reduced in the same way as the mice that exercised. If the substance was injected for many days in a row, the mouse lost weight and fat tissue in the same way as an exercised mouse.
This experiment demonstrates that the Lac-Phe causes loss of appetite and weight even in the absence of muscle activity. Then the scientists exercised the mice that were unable to produce Lac-Phe. These animals, despite doing a lot of exercise, did not lose weight or appetite. But when these same animals were given Lac-Phe injections, they lost their appetite and weight again. These experiments demonstrate that Lac-Phe is one of the molecules that control appetite and weight loss after exercise.
It is likely that new drugs based on this discovery will help us get the benefits of exercise without doing activities.
More information: An exercise-inducible metabolite that suppresses feeding and obesity. Nature.
* IS A BIOLOGIST, PHD IN CELLULAR AND MOLECULAR BIOLOGY AT CORNELL UNIVERSITY AND AUTHOR OF THE ARRIVAL OF THE NEW CORONAVIRUS IN BRAZIL; LOTUS LEAF, MOSQUITO SLIDE; AND THE LONG MARCH OF THE CANNIBAL CRICKETS