Message Number: FHL2326 | New FHL Archives Search

From: "Sukie Crandall"
Date: 2007-08-28 18:41:05 UTC
Subject: [ferrethealth] Re: Room lighting and spectrum questions??
To: ferrethealth@yahoogroups.com

Well, there isn't exactly a general best light vs. worst
light and what you get for the ferrets could be very
wrong for the fish and herps.

Blue is the light colors which most disrupts melatonin
production. Green is second most disruptive. Amber
is the color which least impacts melatonin production.

In ferrets there is a documented cascade:
With adrenal growths the direct cause of the tumors
is the constant irritation of trying to respond to high
LH (luteinizing hormone) levels.

In a healthy whole ferret what happens is this: In times
when the light exposure levels are low their bodies
produce a lot of melatonin.

For ferret ancestors and wild relatives there was not a
lot of light exposure. Remember that we are talking of
burrow dwellers whose main time of activity have been
in what are called the crepuscular times (dawn and dusk
low light times which are usually clumped with the nocturnal
grouping perhaps because when low light activity is not
possible many such species opt for night activity when possible
rather than day activity -- though crepuscular animals can
comfortably do either day or night activity as needed).

Still, their sensitivity to light is good enough that when Spring
rolls around their bodies respond to increased light levels by
reducing the amount of melatonin produced.

Now, melatonin is a very old and very important hormone. It
has a lot of functions in the body, performing functions that
help fight tumors, affect marrow, affect multiple organs, and
even how much of some other hormones are made.

When the levels of melatonin decrease because of the increased
amounts of light the result is that higher amounts of some other
hormones are made, hormones the melatonin levels would
otherwise suppress. One of these is FSH (follicle stimulating
hormone) which can cause bone loss when it is produced in too
high amounts for too long and might have its own affect of the
adrenals, and another is the previously mentioned LH which is
incredibly well researched in relation to adrenal growths,
including some of about 40 LH studies involving ferrets and
some of about 70 adrenal studies involving ferrets. (Not all
veterinary since ferrets are a common animal model.)

What normally happens then is that the whole (able to breed)
ferret's body responds to the increase in LH by preparing to
reproduce. Then success causes the reproductive organs to
send a signal that ***turns off*** the high levels of LH.

Okay, a ferret who has been spayed or altered does NOT have
reproductive organs so that ferret ***can not turn off*** the
high levels of LH which begin when melatonin levels drop too
low.

So, what happens then? Well, there are NON-reproductive
organs which also produce the estrogens and androgens
which ALL bodies use, no matter what the gender. Among
those organs which can produce estrogens and androgens
are the adrenal glands. BUT those organs do not have the
ability to produce the chemical signals that reduce LH
production, so they can't shut off the irritation.

That is why chemicals which can shut off or reduce the LH
production or effects on the adrenals are important. It is
why deslorelin/Suprelorin depot, Lupron depot, and
melatonin have been or are being studied are possible
preventatives of adrenal disease, and also in one case as a
possible chemical sterilization approach (work by Dr. Nico
Schoemaker of the Netherlands, on-going, on deslorelin
depot).

So, as you see, perhaps another approach would be to
avoid the increased amount of light that decreases the
natural melatonin production. The question is how long
that would last because some animals do respond after
a while in prolonged decreased lighting by cycling into
preparation for reproduction, anyway, as and when their
bodies "choose" and that "wrench in the works" needs
further study.

The color of light that least disrupts natural melatonin
production is amber. I cite some studies below.

The color of light that most decreases melatonin production
is blue. Again, I cite some studies below.

Those who don't want to get into nerd mode may want to
stop reading here.

Something new, BTW, is that a hormone released by the
osteoblasts (osteocalcin) in bone increases both the
production of insulin and the sensitivity to insulin.
Reduced melatonin also increases FSH levels. High
FSH levels increase bone loss. The body continually tries
to replace bone that is lost when it gets neurological
feedback that those bones are used a lot. The upshot
might be that the combo perhaps may cause an increase
in circulating osteocalcin. *IF* so, that may indicate a way
beyond the adrenal disease and insulinoma being common
endocrinological diseases for high blood glucose to
happen in conjunction with adrenal disease due to a shared
primary origin (decrease in naturally produced melatonin
levels).

BEGIN QUOTE
Cell. 2007 Aug 10;130(3):456-69. Links
Endocrine regulation of energy metabolism by the skeleton.

Lee NK, Sowa H, Hinoi E, Ferron M, Ahn JD, Confavreux C,
Dacquin R, Mee PJ, McKee MD, Jung DY, Zhang Z, Kim JK,
Mauvais-Jarvis F, Ducy P, Karsenty G.
Department of Genetics & Development, College of
Physicians and Surgeons, Columbia University, New York,
NY 10032, USA.
The regulation of bone remodeling by an adipocyte-derived
hormone implies that bone may exert a feedback control of
energy homeostasis. To test this hypothesis we looked for
genes expressed in osteoblasts, encoding signaling molecules
and affecting energy metabolism. We show here that mice
lacking the protein tyrosine phosphatase OST-PTP are
hypoglycemic and are protected from obesity and glucose
intolerance because of an increase in beta-cell proliferation,
insulin secretion, and insulin sensitivity. In contrast, mice
lacking the osteoblast-secreted molecule osteocalcin display
decreased beta-cell proliferation, glucose intolerance, and
insulin resistance. Removing one Osteocalcin allele from
OST-PTP-deficient mice corrects their metabolic phenotype.
Ex vivo, osteocalcin can stimulate CyclinD1 and Insulin
expression in beta-cells and Adiponectin, an insulin-
sensitizing adipokine, in adipocytes; in vivo osteocalcin can
improve glucose tolerance. By revealing that the skeleton
exerts an endocrine regulation of sugar homeostasis this study
expands the biological importance of this organ and our
understanding of energy metabolism.
END QUOTE

That blue and green most reduce the natural melatonin
production in the body has been known for a very long
time.

As far as I know, the first hint I can find that pointed
people toward amber as the one that least disrupts
melatonin production was

>From the Science News magazine archives for members
BEGIN QUOTE
The researchers suggest that body temperature and heart
rate may be regulated by retinal cells that contain a
light-sensitive protein called melanopsin. That protein
registers only light of relatively short wavelengths, which
includes blue light, and is known to influence some
aspects of the sleep-wake cycle.

...

Cajochen, C., et al. 2005. High sensitivity of human melatonin,
alertness, thermoregulation, and heart rate to short wavelength
light.
Journal of Clinical Endocrinology & Metabolism 90(March):
1311-1316. Abstract available at
http://jcem.endojournals.org/cgi/content/abstract/90/3/1311.
Full article available at
http://www.chronobiology.ch/pdf/CC_lightpaper.pdf.
END QUOTE

and there was a larger study which pinpointed it, I think
last year, but will have to look if i can find it. That one used
goggles and measured actual circulating blood levels of
melatonin. Okay, it was in Dec. 1, 2005 Cancer Research;
I found a reference to it. One of the authors has the last
name Blask. Those who are SN subscribers will find other
intriguing studies referred to in
http://www.sciencenews.org/articles/20060107/bob9.asp

Ah, here you are. Part of the study also looked at what
effect the melatonin levels (light dependent) had on rat
tumors:
BEGIN QUOTE FROM SN
Blask, D.E., G.C. Brainard, et al. 2005. Melatonin-depleted
blood from premenopausal women exposed to light at night
stimulates growth of human breast cancer xenografts in nude
rats. Cancer Research 65(Dec. 1):11174-11184. Abstract available at
http://cancerres.aacrjournals.org/cgi/content/abstract/65/23/11174.
END QUOTE

Related:
Acta Neurobiol Exp (Wars). 2007;67(2):171-8.Links
On light as an alerting stimulus at night.

Figueiro MG, Bullough JD, Bierman A, Fay CR, Rea MS.
Lighting Research Center, Rensselaer Polytechnic Institute
21 Union Street, Troy, NY
12180, USA.

which found that blue light increased alertness (a result
which correlates with decreasing melatonin levels)

In humans shift work (more light at night -- and indoor
lights tend to be very bright, more so than many realize)
not only poses possible health burdens by decreasing
natural melatonin production but also has been linked to
increased smoking and to consumption of food, especially
fatty food, and over-weight also carried health burdens,
especially extreme over-weight which is from adipose
(fat) tissue rather than from lean tissue (muscle).

BEGIN QUOTE
Night-shift workers face fundamental challenges, Blask
says. "Melatonin works, to a large degree, by inhibiting
the cancer cells from taking up linoleic acid," he says.
Cravings for fatty foods frequently assail workers in the
middle of the night. As a result, many shift workers
consume large amounts of linoleic acid just when their
melatonin production is suppressed and unable to protect
them from the polyunsaturated fat, he says.
END QUOTE

More on blue light most decreasing melatonin production
and amber light having the least effect on melatonin
production:

BEGIN QUOTE
Med Hypotheses. 2007 Jul 14; [Epub ahead of print] Links
Dark therapy for bipolar disorder using amber lenses for
blue light blockade.

Phelps J.
Corvallis Psychiatric Clinic, 3517 Samaritan Drive,
Corvallis, OR 97330, United States.
"Dark Therapy", in which complete darkness is used as
a mood stabilizer in bipolar disorder, roughly the converse of
light therapy for depression, has support in several
preliminary studies. Although data are limited, darkness itself
appears to organize and stabilize circadian rhythms. Yet insuring
complete darkness from 6 p.m. to 8 a.m. the following morning,
as used in several studies thus far, is highly impractical and not
accepted by patients. However, recent data on the physiology of
human circadian rhythm suggests that "virtual darkness" may be
achievable by blocking blue wavelengths of light.
A recently discovered retinal photoreceptor, whose fibers
connect only to the biological clock region of the hypothalamus,
has been shown to respond only to a narrow band of
wavelengths around 450nm. Amber-tinted safety glasses, which
block transmission of these wavelengths, have already been
shown to preserve normal nocturnal melatonin levels in a light
environment which otherwise completely suppresses melatonin
production. Therefore it may be possible to influence human
circadian rhythms by using these lenses at night to blunt the
impact of electrical light, particularly the blue light of ubiquitous
television screens, by creating a "virtual darkness". One way to
investigate this would be to provide the lenses to patients with
severe sleep disturbance of probable circadian origin. A preliminary
case series herein demonstrates that some patients with bipolar
disorder experience reduced sleep-onset latency with this
approach, suggesting a circadian effect. If amber lenses can
effectively simulate darkness, a broad range of conditions might
respond to this inexpensive therapeutic tool: common forms of
insomnia; sleep deprivation in nursing mothers; circadian rhythm
disruption in shift workers; and perhaps even rapid cycling
bipolar disorder, a difficult- to -treat variation of a common illness.
END QUOTE

So, I think that the conclusion is that equipment lights should
never be blue or green when people or critters sleep in the same
room (a hard goal to achieve unless we can get manufacturers to
listen), and we should request manufacturers to go to amber ones,
ALSO that if darkness can't be otherwise provided, or perhaps even
if it can, that after a certain hour of night amber lights would be
the safest to have in ferret rooms.

BTW, possibly somewhat related to the original question:
This article, which is available to non-members has an attached
letter indicating that reduced calorie diets might help with
longevity due to increased GI levels of melatonin.
http://www.sciencenews.org/articles/20020511/fob2.asp
(A study
either this year or late last year found marked life lengthening
(I forget in what test subject species.) from lowering core body
temperature which is one of the natural consequences of
caloric restriction, and another in the same time frame or
shortly before found that in flat worms that effect could be
gotten from protein restriction but not carbohydrate reduction
so extreme caloric reduction is a very complicated subject. Also
interesting re those physiological effects may be a 4 protein
complex announced last year, hibernation-protein complex (HPc)
which is a seasonal hormone and may have a restricted number
of animals if exists in, but which is involved with some similar
effects -- which may only indicate that the cascade of its actions
might contain hints of where to look for overlaps.)






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