Saturday, December 01, 2007

Fat Cells Help Pancreas To Secrete Insulin

According to researchers from Washington University in St. Louis, fat cells - at least those in mice - release a protein, called Nampt, that helps the beta cells of the pancreas secrete insulin.
"In the face of increasing insulin resistance," says lead author Shin-ichiro Imai, "this process could be critical for compensating pancreatic beta cell function."
So why do people who are overweight have difficulty metabolizing glucose? Dr. Imai says,
"It may be that in some obese individuals a threshold has been reached so that this mechanism no longer provides adequate compensation. But there may be ways to overcome this threshold."
Those ways involve a compound produced by Nampt, called NMN. NMN circulates in the bloodstream. When it reaches the pancreas in high enough amounts, it stimulates insulin secretion. Mice that were short on Nampt had impaired glucose metabolism, a condition that improved when they were given NMN.

This discovery could lead to new ways of treating insulin resistance and diabetes.

The study was reported in the November 7 issue of Cell Metabolism:
Nampt/PBEF/Visfatin Regulates Insulin Secretion in β Cells as a Systemic NAD Biosynthetic Enzyme

Washington University news brief:
Fat Cells Send Message That Aids Insulin Secretion

Photo of four fat cells, from immaturity to full maturity, via University of Medicine and Dentistry of New Jersey: UMDNJ Magazine