The team also found that the neurons in the ventromedial hypothalamus need PI3K in order to mediate the effects of the hormone leptin, which has been shown to activate this pathway and which is known to be a key player in regulating energy use in the body. Other hormones, including estrogen, might also be involved in regulating the system, the researchers said.

The next step, Dr. Elmquist said, is to identify more precisely the relationship between PI3 kinase-expressing neurons and fat-burning, as well as to characterize better the role of leptin and other hormones in the process.

Other UT Southwestern researchers involved in the study were Dr. Makoto Fukuda, instructor of internal medicine; Dr. Laurent Gautron, assistant instructor of internal medicine; Drs. Jong-Woo Sohn and Ki-Woo Kim, postdoctoral research fellows in internal medicine; Charlotte Lee, senior research scientist; Danielle Lauzon, research assistant; Dr. Jeffrey Zigman, assistant professor of internal medicine and psychiatry; Michele Choi, former research assistant in internal medicine; and Dr. Jennifer Hill, co-lead author and former instructor of internal medicine.

Researchers from Harvard Medical School, Beth Israel Deaconess Medical Center, the Dana-Farber Cancer Institute and the University of Toledo also contributed to the study. Dr. Jean Zhao of Harvard and the Dana-Farber Cancer Institute was co-senior author.

The study was funded by the National Institutes of Health, the Canadian Institutes of Health Research, the V Foundation for Cancer Research, the American Diabetes Association and the Richard and Susan Smith Family Foundation.

Source: utsouthwestern/nutrition