IF you get up in the middle of the night, better leave the light off.
Researchers have learnt how even a short period of light shuts down the
production of melatonin, a sleep-regulating hormone.
The enzyme that makes melatonin in the pineal gland reaches a peak of
activity in the middle of the night. By monitoring the enzyme in rats, David
Klein and his colleagues at the National Institutes of 91色情片 in Bethesda,
Maryland, found that even 15 minutes of light led to the enzyme鈥檚 destruction by
a protein-chewing complex called a proteosome.
Klein says in last week鈥檚 Science (vol 279, p 1358) that proteosomes
may also help to explain how the body responds rapidly to other environmental
changes.
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