THURSDAY, May 24 (HealthDay News) -- Sildenafil (Viagra) appears to help hamsters adjust more quickly to a six-hour shift in their daily circadian cycle, suggesting that the drug might also help frequent flyers and shift workers, according to a report in the May 22 Proceedings of the National Academy of Sciences Early Edition.
Diego A. Golombek, Ph.D., from the Universidad Nacional de Quilmes in Buenos Aires, Argentina, and colleagues injected hamsters with sildenafil at night and then turned on bright lights six hours before their usual time to measure how long it took the rodents to adjust to the change.
The investigators found that sildenafil-treated hamsters adjusted to the new light/dark cycle about 20 to 25 percent earlier than vehicle-treated hamsters, as measured by activity on an exercise wheel. The drug only worked when it was given in advance of the daily cycle shift, however. The researchers further show that the target of sildenafil, cGMP-specific phosphodiesterase 5, is present in the hamster suprachiasmatic nuclei and was inhibited by sildenafil treatment.
"Our results indicate that interference with the cGMP-related pathway might be a useful [therapeutic] tool, especially for jet-lag symptoms due to eastbound flights," the authors write. "Sildenafil could also be useful in other circadian disorders that involve poor synchronization with the environment, including delayed sleep-phase syndrome and adaptation to changing light schedules."
Abstract
Full Text (subscription or payment may be required)
