Sports
The newly discovered protein seems to provide humans and mice with the benefits that physical activity usually provides, but now it will not be necessary to sweat too much.
Most of us, as we know, don't particularly like to work out physically, and those who go to the gym or go jogging regularly are likely to sometimes ask the question: when is finally Will they invent a pill to replace all this?
As it turned out, such a tool that will replace sports has already been found. Scientists from the Dana-Farber Cancer Institute and Harvard Medical School have discovered a key protein in muscles that provides the benefits of exercise: it normalizes levels blood sugar, gets rid of extra pounds. The problem is that this tool works only on mice so far.
A membrane protein in muscle cells found in both mice and humans that is destroyed during exercise and secreted as a hormone. Researchers named this new hormone “irisin” after Iris, the goddess of the rainbow, the courier of the gods in Greek mythology.
Irisin acts as a chemical messenger in the body, having a serious effect on fat cells, according to Boston scientists. Irisin defeats ordinary “white” fat cells and turns them into “brown fat”, a type of adipose tissue that helps regulate body temperature while burning large amounts of energy. In humans, the largest stores of brown fat are found in newborns, who require more heat produced by burning fat cells to maintain a body temperature close to the one that was in the womb until they could survive in a new, colder environment.
Adults have few stores of brown fat, mostly in the back of the neck. For a long time, scientists have been striving to find ways to activate or increase this scarce supply. In humans and mice, brown fat stores increase, and white fat stores decrease after physical activity, so our body begins to expend significantly more energy, reported researchers.
Further studies in mice suggest that metabolic changes may improve the body's ability to break down glucose, reducing the risk of diabetes and accelerating weight loss. Scientists believe that the therapeutic potential of irisin is obvious.
Researchers at the Dana-Farber Cancer Institute announced that they have already received approval to use irisin for pharmaceutical development.
The head of the laboratory that studied the properties of irisin, Bruce Spiegelman, and his colleagues identified the role of the new hormone. They began looking for an answer at the molecular level, looking for genes and proteins that could be regulated by a substance called PGC1-alpha, which is responsible for many of the effects of physical activity in muscles. Once they isolated the hormone irisin, they tested it and found that it could help fat cells turn brown: both cultured cells and live mouse cells.
They then confirmed that in mice and humans, irisin levels in the blood increase after physical activity. Participants who followed a 10-week endurance sports program doubled their irisin levels in their blood.
Finally, Spiegelman and his colleagues showed that irisin can alleviate existing health problems in mice that were obese or diabetic due to fatty foods. Scientists injected mice with irisin. On average, after 10 days, the mice lost weight, although slightly, and had improved glucose tolerance and were better able to cope with diabetes. In mice that were not given irisin, no changes were observed. The results of the experiments made it clear that irisin can be used as a therapeutic agent — it is an “exercise” in the form of a pill.
However, one more mystery remains: why does physical activity contribute to the formation of brown fat? Brown fat helps the body regulate temperature, but it burns a lot of extra calories during the process, so we didn't have to store those extra calories.
In cold weather, muscles begin to work harder due to the fact that we shiver. Shivering, in turn, sends signals to the body to produce more brown fat, which would help regulate temperature. While scientists still have a lot to learn about how brown fat works, irisin will be tested in humans. Even if the beneficial properties of irisin are proven, it is possible that it will not be able to provide everything that physical activity provides. It will not be able to strengthen and build muscle mass, for example.
“We should not expect that irisin will help us forget about physical activity and proper nutrition forever, and we will be able to replace these things with it,” Spiegelman said in conclusion.