AUGUSTA, Ga. Health care providers assess blood and tissue type as well as organ size and health to enhance transplant success. New research indicates that checklist might also need to include the circadian clock.
While some human studies have shown the time of day transplant surgery is performed can influence the outcome, this study of mice with dysfunctional internal clocks is the first correlating circadian clocks with transplant success, said Dr. Daniel Rudic, vascular biologist at Georgia Health Sciences University and corresponding author of the study published in Proceedings of the National Academy of Sciences.
The GHSU researchers found that arteries of mice with circadian clock dysfunction became thick and diseased within a few weeks of being transplanted to healthy mice. Arteries transplanted from healthy mice to the mutant mice remained healthy.
Blood vessel disease, and resulting blood loss to donated organs, is a key pitfall for transplant patients, potentially leading to organ failure and rejection.
"You take an organ out of a human, you don't think about it having a bad clock," Rudic said. "But the fact is the time at which you do the organ transplant may influence overall success and, if you have a donor who has a sleep disorder or is a night shift worker, it may affect it as well."
Since even healthy clocks produce variability in tissue function across the span of a day, transplantation might be best performed during optimal organ function, he said.
In addition to enabling sleep/wake cycles, circadian clocks are found throughout the body and involved in a lot more than sleep. "The clock is expressed not only in the brain but everywhere in the body and can function autonomously in different areas," Rudic said.
"Our research shows it's the clock within the blood vessel that is key to conferring the disease response in this case," said Dr. Bo Cheng, GHSU postdoctoral fello
|Contact: Toni Baker|
Georgia Health Sciences University