Enzyme Sets Internal Clock

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Enzyme Sets Internal Clock

THURSDAY, Aug. 19 (HealthDayNews) -- The activation of an enzyme called

PKG-II triggers biochemical reactions that may be critical in helping our

biological clock tell the difference between night and day.

That's what researchers at the University of Illinois at Urbana-Champaign

found.

In experiments with rats, the scientists blocked the action of PKG-II and noted

the impact on the rats' internal clocks.

Without PKG-II, the rats' circadian rhythms seemed stuck in the " late night "

phase, suggesting the enzyme helps regulate the transition from night to day.

" Activation of PKG-II may serve as a critical checkpoint, " the authors wrote,

allowing our internal clocks to " align with dawn in the solar cycle. "

The study appears in the Aug. 19 issue of Neuron.

More information

The U.S. National Institute of Neurological Disorders and Stroke has

information about sleep at

http://www.ninds.nih.gov/health_and_medical/pubs/

understanding_sleep_brain_basic_.htm

(SOURCE: University of Illinois at Urbana-Champaign, news release, Aug.

18, 2004)