Why Men Will Want to Travel East

Sildenafil might be a treatment for jet lag, according to this preliminary animal study.

Travel or change in work schedules can disrupt circadian rhythms. The master biological clock in the suprachiasmatic nuclei is dependent upon light-activated pathways. The mechanism for light-induced phase advances (e.g., on eastbound flights) is activated by guanylyl cyclase (cGMP) and protein kinase. Circadian changes in cGMP-phosphodiesterase (PDE) activity appear to cause daily variations of cGMP. Because sildenafil is a cGMP-specific PDE inhibitor, researchers examined the effects of sildenafil on circadian behavior, entrainment to new cycles, and photic stimulation in hamsters.

The investigators abruptly advanced the hamsters’ light-dark cycle by 6 hours; the hamsters subsequently resynchronized their motor activity. Sildenafil injecte…

Reviewing Author

Jonathan Silver, MD

Disclosures

RoyaltiesTextbook of Traumatic Brain Injury, 2nd and 3rd editions

Editorial BoardsUpToDate; Journal of Neuropsychiatry and Clinical Neuroscience

Leadership Positions in Professional SocietiesNorth American Brain Injury Association (Board Member); National Institute on Disability, Independent Living, and Rehabilitation Research (Chair of Data Monitoring Safety Board for study of donepezil on cognition after traumatic brain injury)

Jonathan Silver, MD

Disclosures

RoyaltiesTextbook of Traumatic Brain Injury, 2nd and 3rd editions

Editorial BoardsUpToDate; Journal of Neuropsychiatry and Clinical Neuroscience