Physical education will not help with obesity?
Obesity prevents muscles from growingKirill Stasevich, Compulenta
A sedentary lifestyle is not so much a cause as a consequence of obesity.
The appearance of excess weight is accompanied by the silencing of the gene of one of the skeletal muscle proteins.
The problem of obesity is not overweight at all, but that skeletal muscles cannot adapt to it, says a group of scientists from the University of Pennsylvania (USA). Usually, when the body builds up mass, not only does the proportion of stored adipose tissue increase, but the muscles that help us cope with the growing weight also strengthen. At the same time, it is believed that one of the main causes of obesity is a sedentary lifestyle. They say, move more, and excess weight will "burn" by itself.
A team of researchers led by Rudolf Schilder showed that, alas, this is not quite true. In a series of experiments on mice, scientists tested how mammalian skeletal muscles respond to changes in body weight; it was assumed that there were some molecular defects that cause low mobility in obesity. It turned out that the troponin T protein gene works differently in normal mice and obese mice.
Troponin in chicken heart muscle cells.
Troponin filaments are colored red, cell nuclei are blue.
(Photo: arboreus.)
Troponin is one of the main proteins involved in the process of contraction of striated (skeletal) and cardiac muscles. In obese animals, the regulation of the synthesis of this protein is disrupted. Normally, weight gain also stimulates the synthesis of troponin, which increases muscle strength and helps maintain body mobility. In obesity, the troponin gene does not respond to weight gain.
In one experiment, researchers artificially increased the mass of mice by 30% by putting special heavy "vests" on them. For five days of wearing them, rodents had a sharp increase in troponin synthesis. If a similar experiment was carried out with mice that were genetically predisposed to obesity (but whose weight was normal due to diet), there was no increase in muscle protein synthesis.
The full results of the research are published in the Journal of Experimental Biology (Schilder et al., Body weight-dependent troponin T alternative splicing is evolutionarily conserved from insects to mammals and is partially impacted in skeletal muscle of obese rats).
Thus, it turns out that low mobility and weak muscles are not the cause of obesity at all, but a concomitant symptom. Even if an overweight person begins to exercise intensively, he is more likely to get heart problems than to gain muscle mass, the increase of which is restrained by a molecular genetic defect. Of course, it cannot be said that obesity occurs due to flaws in the regulation of muscle proteins. But if you learn to correct these defects, then the predisposition to overweight can be compensated and restrained by the growth of muscle mass.
Prepared based on the materials of the University of Pennsylvania: Obesity impairs muscle function in rats, Penn State researchers find.
Portal "Eternal youth" http://vechnayamolodost.ru11.05.2011