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 ÎçÒ¹¸£Àû1000¼¯ºÏ in Bethesda,
Maryland, found that even 15 minutes of light led to the enzyme’s destruction by
a protein-chewing complex called a proteosome.
Klein says in last week’s Science (vol 279, p 1358) that proteosomes
may also help to explain how the body responds rapidly to other environmental
changes.
