Brown fat transplantation will protect against obesity and diabetes
Brown fat transplantation contributed to weight loss in mice
The study was conducted by a group of biochemists from the Joslin Diabetes Center in Boston, led by Laurie Goodyear. The results of the experiments are published in the Journal of Clinical Investigation (Stanford et al., Brown adipose tissue regulates glucose homeostasis and insulin sensitivity – VM).
Brown fat, unlike white fat, which stores energy, consumes it with the formation of heat. In humans, its reserves are small compared to deposits of white fat between the shoulder blades, along the spine, in the heart area, around the neck and at the collarbones. Scientists have suggested that transplanting brown fat, that is, adding an additional amount of "calorie-burning" substance, can speed up the body's metabolism.
To test this assumption, the researchers injected one tenth of a gram of brown fat removed from the back of a male mouse into the body of another mouse of the same sex and age. Attempts to transplant brown fat have been made before, but they did not give any effect. According to Laurie Goodyear, the result may depend on the place of transplantation and the time elapsed after the procedure.
In the described experiments, the researchers transplanted brown fat into the abdominal cavity, that is, where it usually does not exist. In the abdominal cavity, especially in the liver area, transplanted brown fat is exposed to insulin and fats and triglycerides secreted from the blood.
Eight weeks after the brown fat injections, the mice showed normalization of glucose uptake from the blood, a decrease in insulin resistance and a decrease in body fat compared to the control group that underwent the placebo injection procedure.
Inspired by these results, the scientists continued the experiments by transferring mice to a high-fat diet. Usually, such a diet, both in mice and in humans, leads to an increase in weight and blood sugar, which creates prerequisites for the development of type II diabetes.
Brown fat smoothed out some of the effects of a high-fat diet. The mice that received the transplant maintained a constant weight and blood sugar level better than those who did not have brown fat transplanted. Moreover, the effect was more significant the more brown fat was transplanted.
The mechanism providing these effects of brown fat is currently unclear, but observations of mice with transplantation of this tissue have shown that they have elevated levels of proteins and molecules that control blood sugar levels.
Previously, activation of brown fat by the hormone fibroblast growth factor 21 (FGF21) was shown, and injections of this substance led to significant weight loss and normalization of blood sugar in mice with diabetes.
Scientists hope that an approach similar to brown fat transplantation to mice is promising for developing a treatment for obesity and diabetes in humans.
Portal "Eternal youth" http://vechnayamolodost.ru12.12.2012