By isolating the pancreas and using bioluminescence imaging (which relies on a protein found in the firefly), the researchers determined that a circadian clock is expressed autonomously in the pancreas. The visual proof is shown in a short video they produced of the beating clock in live insulin-producing cells of the pancreas. The cells emitted light once every 24 hours over a sustained period of time. [Video available upon request.]

"It's important to remember that body clocks are ancient mechanisms that regulate fundamental biological systems important to health, such as insulin secretion, the time we go to bed, the time we get up and the time we get hungry," Bass said.

The body's primary circadian clock resides deep in the brain, in the suprachiasmatic nuclei, but local biological clocks also are found in tissues throughout the body, including the pancreas, lungs, liver, heart and skeletal muscles. The clocks operate on a 24-hour, circadian (Latin for "about a day") cycle that governs functions such as sleeping and waking, rest and activity, fluid balance, body temperature, cardiac output, oxygen consumption, metabolism and endocrine gland secretion.

The impact of diabetes on health and economics is sobering. According to the American Diabetes Association, more than 23 million adults and children in the United States have a form of diabetes, and at least 57 million have prediabetes; the total cost of diagnosed diabetes (medical costs as well as disability, work loss and early death) is at least $174 billion; and diabetes is the seventh-leading cause of death in the country.

Source: Northwestern University