New Haven, Conn. -- Researchers at Yale University School of Medicine and the Institutes for Pharmaceutical Discovery in Branford, Conn., have discovered a possible new mechanism for the body to control its fat stores by inducing the growth of new blood vessels, which suggests a new avenue for weight regulation.

The mechanism involves the action of leptin, a naturally occurring hormone known for its hunger-blocking effect on the hypothalamus, a region in the brain. According to a study published in the Sept. 11 issue of the journal Science, leptin also triggers the formation of new vessels in fat tissue, which may be a crucial adaptive response that provides more efficient release of metabolic energy and, thereby, weight loss.

The discovery was made by M. Rocio Sierra-Honigmann, M.D., Ph.D., associate research scientist in the Yale pathology department, and her husband Jaime Flores-Riveros, Ph.D, of the Institutes for Pharmaceutical Discovery (IPD), along with their colleagues.

"Now we have strong evidence for the existence of functional leptin receptors outside the brain, which could give us new insights into how leptin controls body fat besides blocking hunger," Sierra-Honigmann said.

"We were certainly puzzled by our initial observation that leptin receptors were present in endothelial cells lining blood vessels, a location never suspected to be a site of leptin action," said Flores-Riveros, a research director at IPD and previously a scientist in the Bayer Research Center in West Haven, Conn.

Other members of the research team were Anjali K. Nath, Chiaki Murakami, Guillermo Garcia-Cardena, Andreas Papapetropoulos, William C. Sessa, Lisa A. Madge, Jeffrey S. Schechner and Michael B. Schwabb of the Boyer Center for Molecular Medicine, Yale School of Medicine; and Peter J. Polvernini of the University of Michigan School of Dentistry.

According to Sierra-Honigmann, the growth of ne
'"/>

Contact: Cynthia Atwood
cynthia.atwood@yale.edu
203-432-1345
Yale University
10-Sep-1998