Calories and appetite
2000/11/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
Obesity is due to eating habits, but it is evident that there are other factors that influence the body. A few years ago leptin was identified. This hormone controls the processing of food according to the amount of fat contained in the body. Increasing adipocytes also increases the number of leptin, decreasing appetite and increasing energy expenditure. In this way, the amount of body fat is stable despite the significant changes in the daily intake or expenditure of energy. Leptin fulfills this function by binding the superficial receptors of the neurons of the central nervous system. However, in most cases of obesity, the number of leptin is high. This is due to the resistance to leptin, that is, to the lack of physiological response to the increase of leptin. For this reason, the researchers have tried to detect errors in the leptin receptors. Now, however, anti-obesity drugs have the feeling of being neurons. In some of these neurons, leptin releases neuropeptides from the melanotin family that will adhere to receptors of other neurons. Currently, two melanocortina receptors are known in the central nervous system: Mc3r and Mc4r. It has been proven that both give different response to leptin. Mute mice that do not produce Mc4r were known as fat, especially because they ate more than conventional mice and spent less energy. Even those who do not have Mc3r accumulate more fat with the same meal. Mice with both mutations at the same time fattens much more than those with a single one. And they eat more because they don't have Mc4r and accumulate more calories because they don't have Mc3r. Therefore, the team that has carried out the research considers that Mc3r and Mc4r can serve to create very specific drugs against obesity.
