The solution to obesity: make muscles gluttonous
Today, in order to save their own finances and earthly resources, many people are changing old voracious cars for small cars with new economical engines, and also prefer energy-saving electrical appliances and light bulbs. However, according to data published by scientists at the Mayo Clinic (Rochester, Minnesota) and the University of Iowa in the January issue of the journal Cell Metabolism in the article "Sarcolemmal ATP-Sensitive K+ Channels Control Energy Expenditure Determining Body Weight", reducing the energy efficiency of our muscles in some cases may be a solution to the problem of obesity.
In their work, the authors deciphered the operation of the mechanism that acts as a "fuel flow meter" in the muscles. In experiments on mice, they demonstrated that disruption of the so-called ATP-sensitive to + (CATF) channels of the sarcolemma (the shell covering muscle fibers) allows you to reduce body weight by increasing the number of calories consumed by muscles during normal physical activity or during training.
These channels respond to even the slightest decrease in the concentration of ATP in the cell by shortening the duration of the action potential and limiting energy-consuming muscle contractions and maintaining ion balance. This system allows you to save energy, but with a sedentary lifestyle and overeating, it contributes to the development of obesity.
The results of earlier work showed that CATF channels identified on the surface of cells of cardiac and skeletal muscle tissue, under conditions of severe stress, for example, in coronary heart disease, play the role of a kind of safety valve. However, their functions in the daily life of the body remained a mystery, since ischemic disease is a problem of our time, from which active organisms living in natural conditions do not suffer.
In their latest work, the authors found that CATF channels ensure the effective functioning of the cardiac and skeletal muscles without unnecessary energy costs. Genetically modified mice whose skeletal muscles lack these channels as a result of knockout of the KCNJ11 gene store less glucose in the form of glycogen and deposit less fat. The reduction of fat deposits persists even when keeping such animals on a fat-rich diet. However, the price for being slim in this case is a decrease in physical endurance.
In the figure: A – wild-type mice (black) and deprived of CATF channels (albinos) at a young and mature age;
C – the change in their weight during the year; C – Body mass index (BMI) in control and genetically modified mice.
The researchers concluded that the CATF channels of the sarcolemma control muscle energy expenditure, and selective suppression of their activity in skeletal muscles is a promising strategy for the treatment of obesity by increasing the thermogenicity of muscles at rest and reducing their energy efficiency during exercise.
Evgenia Ryabtseva, Alexander Chubenko
Portal "Eternal youth" http://vechnayamolodost.ru based on ScienceDaily: A Solution to Obesity? Muscles That Act as an Energy Drain.
13.01.2010