By Merritt McKinney

NEW YORK, Apr 11 (Reuters Health) - Scientists in Massachusetts have discovered that the sugar-regulating hormone insulin plays a crucial role in moving fatty acids from the blood to fat-storage cells after a meal.

Although the research was conducted on the cellular level, eventually it may lead to a better understanding of how fat is metabolized in the body, the study's lead author told Reuters Health.

After a meal, levels of both sugar, or glucose, and fatty acids rise in the blood. Scientists knew already that insulin reduces glucose in the blood in two ways. First, the hormone signals the liver to slow its production of glucose. Second, insulin increases the uptake of sugar into tissues by causing glucose transporters within each cell to move to the surface where they draw sugar into the cell.

How the body lowers levels of fatty acids in the blood has been uncertain, however.

Now Dr. Harvey F. Lodish and colleagues at the Whitehead Institute for Biomedical Research at the Massachusetts Institute of Technology in Cambridge report that insulin is also involved in regulating levels of fatty acids in the blood. A report on the findings appears in the April issue of the journal Developmental Cell.

"Insulin causes cells to take up fatty acids from the blood," Lodish said in an interview. "It does so by a fundamentally similar mechanism" to how it handles sugar, he explained.

When the researchers added insulin to cells called adipocytes--which store most of the body's fat--fatty acid transporters moved to the surface of the cells from other parts of the cells. These transporters, FATP1 and FATP4, seem to promote the uptake of fatty acids into cells, because as the transporters congregated at the cell membrane, levels of fatty acids in the blood dropped.

Now that researchers understand how fatty acid transporters affect the uptake of fat on the cellular level, the next step, according to Lodish, is to measure the impact the transporters have on overall levels of fat in the body.

Genetically altering mice to have more or fewer fatty acid transporters may reveal the role these transporters have in the metabolism of fat by the whole body, he said. Such research could also lead to a better understanding of diseases that affect metabolism, including type 2 diabetes, Lodish and his colleagues note in their report.

SOURCE: Developmental Cell 2002;2:477-488.

http://health.yahoo.com/search/heal...=s&p=id%3A18240

YIKES!

It is shocking that these guys are just figuring out the role of insulin in fat storage. I would expect Dr. Robert C. Atkins has know this for at least 40 years.

The link below is the transcript of an interesting speech given by Dr. Ron Rosedale about insulin and its metabolic effects. One must excuse the typos because the transcript was never edited. Dr. Rosedale was a partner with Drs. Michael and Mary Dan Eades, authors of Protein Power, at their Boulder, Colorado office until recently.

http://www.dfhi.com/interviews/rosedale.html

Thing is, Even though I went to a low-carb diet, nearly tripled my caloric intake, and dropped 100+ lbs, I can't say for sure insulin was the culprit or how it was the culprit. I can say something is funny. All theories include Insulin as part of the equation, but exactly how has not been identified. Now if in rats, we see rats gain massive amounts of weight.... and the study is reproduced with similar... or better yet... identical results.......

We will see.

When I first read this article, I had the same thought as Kent .. Good Grief! This is not news! But then I read it again, and what I see is that the researchers have identified the actual means by which insulin causes fatty acids to be stored in the fat cells. It was not known before exactly how this worked .. Now it appears that insulin regulates FATP1 and FATP4 within the fat cell, and these "transporters" are what carry the fatty acids across the cell membrane for storage .. ie, it's NOT insulin itself that moves the fatty acids into the fat cells.

I looked up Dr. Harvey F. Lodish, who headed up the research team of the above study. Great website for cellular biology buffs The Lodish Lab. His team has been busy, and a lot of interesting research ongoing in the area of insulin and fatty acid transport and metabolism.

For example, they've cloned a hormone that exists only in fat cells, ACRP30, which induces fat and glucose catabolism by muscle, enhances glycogen accumulation in muscle, and inhibits gluconeogenesis in liver. Importantly, it induces prolonged weight loss in obese mice. You can read more about it here. And, more research on how insulin signals fat cells.

I think the research is promising, but I have no doubt that any discoveries will translate into some expensive new drug to deal with it, rather than simple lifestyle changes like carb-restriction and exercise.

Doreen