Obesity, the Brain and Blood Glucose Dynamics

It has taken about 20 years for obesity to affect the western hemisphere to the effect that it is now a rampant epidemic.

Obesity, the Brain and Blood Glucose DynamicsIn a quest to find a solution to the problem, scientists are studying any and all relationships between overeating and obesity.

In the July 26 issue of PLoS Biology, Dr. Dongsheng Cai and his research team at Albert Einstein College of Medicine talk about a discovery they made between the brain’s ability to detect blood glucose dynamics and how this can affect appetite, obesity and obesity-related diseases.

The research team discovered that making adjustments to this pathway returns it to normal functioning and will ultimately help control obesity and return harmony to the body’s energy levels.

The brain is always monitoring the body’s environment for excess and deficits and this also applies to energy intake in the way of food, and energy output in the way of activity, stress and biological functions. It is the hypothalamus in the brain that regulates energy and body weight balance via hormone levels, specifically insulin and leptin.

There is much information available on the hormonal pathways in the hypothalamic regulation of feeding; however, not much is known about the the mechanisms for hypothalamic nutrient sensing. In addition, the cause for this relationship between nutrient sensing and obesity needs to be determined through further study.

This study set out to find the cause for this relationship. During this study on mice, the research team found that the protein complex known as hypoxia-inducible factor (HIF) has other responsibilities — hypothalamic glucose sensing and whole-body energy balance.

Tissues within the body use oxygen and when these levels are low, HIF is produced to stimulate cellular metabolic adaption and survival. HIF has been studied before in the metabolism of tumor cells;

“however, an intriguing but unexplored question is whether HIF can be important for the regulation of whole-organism metabolism, and if so, which tissue and cells are responsible.” says Cai, who is an expert in neuroendocrinology and metabolism.

HIF is affected by glucose and this in turn affects appetite regulation. When hypothalamic HIF was targeted via gene delivery in these study mice, a resistance to obesity occurred despite the condition of nutritional excess.

“It was an exciting discovery,” explains Cai, “Our study is the first to show that beyond its classical oxygen-sensing function in many cells, HIF in the hypothalamic neurons can sense glucose to control the whole-body balance of energy intake and expenditure which is critical for body weight homeostasis.”

These findings are an exceptional discovery and prove that HIF has an essential role in controlling obesity and obesity-related diseases.

Sources:

Hai Zhang, Guo Zhang, Frank J. Gonzalez, Sung-min Park, Dongsheng Cai. Hypoxia-Inducible Factor Directs POMC Gene to Mediate Hypothalamic Glucose Sensing and Energy Balance Regulation. PLoS Biology, 2011; 9 (7): e1001112 DOI: 10.1371/journal.pbio.1001112

Public Library of Science. “Treating obesity via brain glucose sensing.” ScienceDaily, 26 Jul. 2011. Web. 27 Jul. 2011.

Originally published @ FITLODE.COM

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