In article <1994Jan6.163745.13692 at midway.uchicago.edu> bmdelane at midway.uchicago.edu writes:
>>I know melatonin secretion is governed largely by light and possibly
>magnetic fields; I'm just wondering if negative feedback may also play
>a role. This could be relevant to attempts to use melatonin
>supplements therapeutically for sleep disorders, circadian
>re-synchronization (for international flight crews), etc.
>
Exogenous melatonin is capable of phase shifting the endogenous melatonin
rhythm in some instances. However, I can't think of a study off of the
top of my head that shows that melatonin inhibits its own production. I
would guess from what I know as well as my current work, that negative
feedback does not play a significant role in melatonin secretion, although
it may play a small role. More pronounced would be it's phase shifting
effects. These effects probably very widely between different species.
Eric Mintz
mintz at orchid.ucsc.edu
