LA JOLLA, CA November 19, 2009 A team led by scientists at The Scripps Research Institute have discovered a direct link between insulina hormone long associated with metabolism and metabolic disorders such as diabetesand core body temperature. While much research has been conducted on insulin since its discovery in the 1920s, this is the first time the hormone has been connected to the fundamental process of temperature regulation.
The paper was published recently in an advance, online issue of the journal Diabetes, a journal of the American Diabetes Association, and will appear in the January print edition of the publication.
The scientists found that when insulin was injected directly into a specific area of the brain in rodents, core body temperature rose, metabolism increased, and brown adipose (fat) tissue was activated to release heat. The research team also found that these effects were dose-dependentup to a point, the more insulin, the more these metabolic measures rose.
"Scientists have known for many years that insulin is involved in glucose regulation in tissues outside the brain," said Scripps Research neurobiologist Manuel Sanchez-Alavez, who was first author of the new paper with Bartfai lab colleagues Iustin V. Tabarean and Olivia Osborn (now at the University of California, San Diego). "The connection to temperature regulation in the brain is new."
In addition to suggesting a fresh perspective on diseases such as diabetes that involve the disruption of insulin pathways, the study adds to our understanding of core body temperaturethe temperature of those parts of the body containing vital organs, namely the trunk and the head. Normally, core body temperature stays within a narrow range so that key enzymatic reactions can occur. When core body temperature goes outside this range for prolonged periodshigher as in fever, or lower as in hypothermiathe result is harm to the body.
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Scripps Research Institute