Does dopamine protect against diabetes?

Dopamine, produced in the "pleasure center" of the brain, treats type 2 diabetes mellitus

Maria Perepechaeva, "First-hand Science"

Diabetes mellitus is one of the most common diseases in the world. With this disease, the concentration of glucose in the blood is steadily increased. Regulation of glucose metabolism in the body occurs at several levels, including the highest – the hypothalamus, which is the center of the autonomic nervous system and regulates many "unconscious" processes, including the release of hormones. But as recent studies have shown, the results of which were published in the prestigious journal Science Translational Medicine, in addition to the hypothalamus, another structure of the brain is involved in the regulation of glucose metabolism, in which the "happiness hormone" dopamine is produced.

As you know, diabetes mellitus can develop for two reasons. Type 1 diabetes is an autoimmune disease in which beta cells of the pancreas that produce the hormone insulin, which regulates blood glucose levels, are destroyed. But the most common is type 2 diabetes, when cells and tissues simply lose sensitivity to insulin. This disease is often preceded (and accompanied) by the so-called metabolic syndrome, characterized by overweight, arterial hypertension and impaired carbohydrate metabolism. The mechanisms of the development of metabolic syndrome are not exactly known, but most doctors recommend that such patients first of all lose weight.

There is a hypothesis about a possible connection between obesity, insulin sensitivity and the production of the neurotransmitter dopamine, which belongs to the group of so-called "happiness hormones". Dopamine-producing neurons are located in the nucleus accumbens, located in the striatum of the brain, which is part of the "pleasure center" and is associated with the work of the reward and reinforcement system. Lack of dopamine, presumably, can lead to overeating due to insufficient "reward". But can dopamine affect glucose metabolism directly, regardless of its role in the development of obesity?

A group of Dutch and American scientists conducted an experiment on patients with obsessive-compulsive disorder (obsessive-compulsive disorder), who were treated with deep brain stimulation. With this technique, the affected areas of the brain are stimulated by electrical impulses through implanted electrodes. This method, in particular, is used in the treatment of Parkinson's disease. As a result, dopamine release increases in the nucleus accumbens, which improves the condition of patients. And the experimenters wanted to find out how such an output of dopamine would affect glucose metabolism in the body.

It turned out that during the operation of the device for deep stimulation in all these patients, the sensitivity of tissues to insulin increased. Moreover, one of the patients, who simultaneously suffered from type 2 diabetes and obesity, after treatment was able to reduce the dose of insulin prescribed for this type of diabetes. However, the patient did not lose weight at the same time. In addition, he simultaneously stopped taking a neuroleptic, the side effect of which is an increased risk of diabetes. But in any case, the tests showed that the sensitivity of his tissues to insulin really became higher.

In another experiment, already on healthy volunteers, the researchers simulated the situation of general depletion of dopamine in the body by pharmacological inhibition of the enzyme tyrosine hydroxylase involved in its synthesis. The level of dopamine in the nucleus accumbens of the brain also decreased. The result of the experiment was a significant decrease in the sensitivity of tissues to insulin in the participants of the experiment.

Scientists did not stop there and using optogenetics activated dopamine neurons in the brains of genetically engineered laboratory mice, which led to an increase in insulin sensitivity of tissues in these animals.

The experimenters admit that their work had a number of drawbacks, including the small number and heterogeneity of the sample, so additional research is required. However, the data already obtained suggest that dopamine is indeed involved in the regulation of glucose metabolism. Probably, from the nucleus accumbens of the brain, nerve signals mediated by dopamine enter the hypothalamus, which already exercises direct control over metabolic processes. And although it is not yet clear how relevant the discovered phenomenon is for practical medicine, it is possible that over time it will be possible to use it to help real patients.

Portal "Eternal youth" http://vechnayamolodost.ru