A new research has found that the male impotence drug Viagra may be useful for treating jet lag.
Sildenafil, originally developed for the treatment of high blood pressure and angina, works by interfering with an enzyme that reduces levels of a naturally-occurring compound, cyclic guanine monophosphate (cGMP).
In the brain, cGMP has a vital function in a signalling pathway that regulates the circadian cycle, the body's daily clock.
Argentine researchers, Patricia Agostino and colleagues of the Universidad Nacional de Quilmes in Buenos Aires, injected hamsters with sildenafil and then exposed them to lights which were turned on and off to simulate jet lag.
The researchers then found that adult male hamsters given Viagra recovered from jet lag up to 50 per cent faster than hamsters that were not given it.
But the study found the drug only appeared to help the rodents when it was given before the equivalent of an eastbound flight, not the reverse.
The researchers said the findings suggested that Viagra could be useful to help people deal with jet lag or shift work.
Viagra was originally developed for high blood pressure before its anti-impotence qualities were discovered.