Cutting blood supply to kill off fat.

In a strategy dubbed molecular liposuction, researchers have created a drug that homes in on and destroys the blood vessels that sustain fat cells. Severely obese mice treated with the compound quickly shed fat until they reached normal weights, according to a report in the June Nature Medicine.

The new work follows up on similar findings reported in 2002. Then, Maria Rupnick of Brigham and Women's Hospital in Boston found that drugs designed to starve tumors by thwarting new blood vessel formation, or angiogenesis, also cause dramatic weight loss in obese mice. The drugs apparently have this effect because growing fat is particularly dependent on new blood vessels (SN: 8/3/02, p. 67).

Concerned that typical angiogenesis inhibitors might disrupt needed blood supplies elsewhere in the body, Wadih Arap of the University of Texas M.D. Anderson Cancer Center in Houston and his colleagues devised a way to selectively destroy the vascular system in fat. After identifying a small protein that travels specifically to blood vessels servicing fat tissue, the researchers affixed a cell-killing drug to the protein. In a matter of weeks, obese mice receiving the treatment had lost most of their excess fat.