Kathy's two sentences:
>I believe that when a ferret is still intact, they mask the symptoms of
>the disease, i.e., hair loss, aggression, etc.  It may be rarer in
>intact animals, but it definitely can develop.
 
Sum up Randy's more detailed description of how and why adrenal disease
may be hidden in intact ferrets, and brings up the important point of
the rates being unknown.
 
Part of the (largely but not completely proven) hypothesis that a
combination of too much light exposure and being neutered promoting or
triggering adrenal disease would suggest that the rate would be lower
in whole animals.  Ditto, work done both in the Netherlands and the U.S.
Yet, actual rates are still lacking.  (That is also a problem when
dealing with insulinoma hypotheses, BTW: lack of rate numbers.)
 
Now there is some new information on how melatonin (which the body
produces in response to darkness -- with the degree of darkness important
since dimness just doesn't cut it.  There is a very large human breast
cancer study and some smaller new studies, one downright elegant which
echo findings of a number of other smaller studies on a range of
malignancies, and some researchers took it one giant step further.  THEY
FOUND ONE OF THE WAYS THAT MELATONIN SLOWS MALIGNANCY GROWTH in the type
of tumor they were studying (so now other types need to be studied).  No
joke.  Apparently when there is sufficient melatonin in the body the
growths sort of "go to sleep".
 
>In further experiments, Blask's team determined that melatonin blocks
>cancer cells' metabolism of linoleic acid, a polyunsaturated fat
>that's abundant in food.  The same team had previously shown that
>13-hydroxyoctadecadienoic acid, the product of linoleic acid metabolism,
>spurs cancer cells to divide.
>
> The team reports its results in the Dec. 1, 2005 Cancer Research.
 
To cover their bases they did the reverse experiment where they took
human blood with enough melatonin in it -- which suppressed tumor growth,
and then they added a compound that suppresses melatonin but itself has
no effect on tumors and, yep, when you suppress the melatonin the growth
starts up again.
 
You can find an excellent Science News article, complete with
references here:
http://www.sciencenews.org/articles/20060107/bob9.asp
 
Here is a small segment:
>A woman's blood provides better sustenance for breast cancer just
>after she's been exposed to bright light than when she's been in
>steady darkness, researchers led by David E. Blask of the Bassett
>Research Institute in Cooperstown, N.Y., report.
>
>"Light at night is now clearly a risk factor for breast cancer,"
>Blask says. "Breast tumors are awake during the day, and melatonin
>puts them to sleep at night." Add artificial light to the night
>environment, and "cancer cells become insomniacs," he says.
>
>"Sleep per se is not important for melatonin," says Russel J. Reiter,
>a neuroendocrinologist at the University of Texas Health Science Center
>in San Antonio.  "But darkness is."
>
>The new study has far-reaching implications, says Reiter.  First, it
>could spawn trials that test whether malignancies can be slowed down
>by altering a person's light environment or by using melatonin
>supplements.  Second, he says, similar studies could show whether
>exposure to nocturnal light poses a prostate cancer risk to men, as
>some researchers suspect, or promotes other cancers previously linked
>to light at night (SN: 8/28/04, p. 141: Available to subscribers at
>http://www.sciencenews.org/articles/20040828/note11.asp).
 
THERE ARE CAUTIONS, of course, and certainly grogginess and the risk to
human children with seizure disorders (See _PDF for Herbal Medicines_.)
are both serious ones.  Everything has its cautions, and if someone
pretends that something doesn't them run as fast as you can away from
them.  You can find one of them in that SN article and some others in
<http://www.smartgroups.com/message/viewdiscussion.cfm?
gid=1423922&messageid=16351>
 
So, providing enough darkness (not just dimness) could have a benefit
beyond reducing or preventing the trigger hormones (LH to irritate
the adrenals, FSH to increase bone loss) that the pituitary releases
when melatonin levels in the body go too low.
 
Getting the concept that actual darkness is the trigger for the pineal
gland to create such a very important body product as melatonin seems
foreign to many humans, who have long been raised to fear predators in
the shadows of the night, but it is concept people need to get used to
because the level of research supporting benefits of melatonin is large
and growing, as is the list of useful functions it performs in the body.
[Posted in FML issue 5118]