Body Weight Regulated by Newly Discovered Hormone
A protein, identified in mice and humans, reduced body weight in mice by 30 percent after two weeks of treatment, report scientists in the July 28 Science. The findings have important implications for understanding the causes of obesity, which affects one in three Americans.
New therapies for weight control in humans will require more studies and years of testing, the authors note. However, "the current results suggest the protein, leptin, is a novel hormone that regulates body weight by signaling the amount of fat stored," explains senior author Jeffrey Friedman, M.D., Ph.D., professor at The Rockefeller University and an associate investigator with the Howard Hughes Medical Institute (HHMI).
Friedman, collaborating with Stephen K. Burley, D.Phil., M.D., professor at Rockefeller and HHMI investigator, and several coinvestigators found the protein, named leptin from the Greek root leptos meaning thin, in the blood of mice and humans. Man-made versions of mouse and human leptin decreased the body weight of mice by reducing food intake and increasing energy expenditure. The instructions to make leptin are carried by a gene that is defective in the obese (ob ) mouse. The ob mouse was identified by scientists at the Jackson Laboratory in Bar Harbor, Me., in 1950. Friedman and his colleagues reported the cloning of the ob gene in December 1994.
Mouse and human leptin both reduced body weight in ob mice. "The fact that human leptin reduces weight in the mice raises the possibility that giving leptin to people might have similar effects. However, we must proceed cautiously to prove that the protein treatment is safe in animals. Studies of humans cannot begin until the protein has been confirmed to be without unwanted side effects," says Friedman.
nanoboy
A protein, identified in mice and humans, reduced body weight in mice by 30 percent after two weeks of treatment, report scientists in the July 28 Science. The findings have important implications for understanding the causes of obesity, which affects one in three Americans.
New therapies for weight control in humans will require more studies and years of testing, the authors note. However, "the current results suggest the protein, leptin, is a novel hormone that regulates body weight by signaling the amount of fat stored," explains senior author Jeffrey Friedman, M.D., Ph.D., professor at The Rockefeller University and an associate investigator with the Howard Hughes Medical Institute (HHMI).
Friedman, collaborating with Stephen K. Burley, D.Phil., M.D., professor at Rockefeller and HHMI investigator, and several coinvestigators found the protein, named leptin from the Greek root leptos meaning thin, in the blood of mice and humans. Man-made versions of mouse and human leptin decreased the body weight of mice by reducing food intake and increasing energy expenditure. The instructions to make leptin are carried by a gene that is defective in the obese (ob ) mouse. The ob mouse was identified by scientists at the Jackson Laboratory in Bar Harbor, Me., in 1950. Friedman and his colleagues reported the cloning of the ob gene in December 1994.
Mouse and human leptin both reduced body weight in ob mice. "The fact that human leptin reduces weight in the mice raises the possibility that giving leptin to people might have similar effects. However, we must proceed cautiously to prove that the protein treatment is safe in animals. Studies of humans cannot begin until the protein has been confirmed to be without unwanted side effects," says Friedman.
nanoboy
