CHEVY CHASE, Md., Dec. 9 (UPI) -- U.S. scientists have discovered evidence that cells throughout the body, not just cells in the brain, likely have an internal circadian clock of their own.
Researchers studying fibroblast cells engineered a gene to link a luminescent protein to the clock gene Period2. They cultured the cells and discovered the luminescence waxed and waned rhythmically in periods ranging from 22 hours to 30 hours.
"A fibroblast is as close to a 'generic' mammalian cell as you're likely to find," said researcher David Welsh of the Scripps Research Institute. "So if fibroblasts have self-sustained clocks, most other cells probably do, too."
The researchers noted that the rhythms of individual cells do not appear synchronized. They also were puzzled as to why the cells did not follow the 24-hour cycle of the brain circadian clock.
Up to now, scientists thought the biological clock that regulates functions such as sleep, fluid balance and cardiac output was sited strictly in the brain. With this finding, the researchers think drug delivery techniques might be made more effective.
