Date: 2011-05-08 23:44:44 UTC
Subject: [ferrethealth] Re: My ferrets lack of energy; now Vitamins
This may be of interest in addition to the others:
Br J Nutr. 2009 Dec;102(11):1686-94. Epub 2009 Jul 27.
Effects of beta-carotene supplementation on adipose tissue thermogenic capacity in ferrets (Mustela putorius furo).
Sánchez J, Fuster A, Oliver P, Palou A, Picó C.
Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears, and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Edificio Mateu Orfila, Cra. Valldemossa Km 7.5, Palma de Mallorca 07122, Spain.
We previously described that the intake of pharmacological doses of beta-carotene (BC) resulted in higher body weight gain in the ferret (Mustela putorius furo), an animal model that resembles human subjects in terms of intestinal BC absorption and metabolism. These results were some way unexpected considering the condition of BC as a vitamin A precursor and the previous data in rodents showing these compounds as thermogenic activators. Here, we aimed to characterise in the ferret whether the mentioned changes in body weight could be explained by changes in adipose tissue thermogenic capacity. We studied the effects of 6-month supplementation with BC (0.8 and 3.2 mg/kg per d) on adipose tissue morphology and uncoupling protein-1 (UCP1) content. BC supplementation resulted in higher body weight (the high dose), induced depot- and dose-dependent hypertrophy of white adipocytes, decreased the amount of brown-like multilocular adipocytes in the retroperitoneal depot and decreased UCP1 content in different fat depots. To ascertain whether BC effects could be mediated by retinoic acid (RA), 1 week supplementation with RA (0.25 and 25 mg/kg per d) was also studied. RA treatment resulted in a slight decrease in adiposity, decreased cell lipid accumulation and increased UCP1 content, suggesting that the effects of BC on thermogenic capacity are not through RA. In conclusion, RA, but not BC, may have in the ferret comparable effects with those described in rodents, whereas differences concerning BC and RA treatments may be attributable to the different BC metabolism in the present animal model with a lower conversion of BC to RA compared with rodents.
PMID: 19631020 [PubMed - indexed for MEDLINE]
Here is when it goes very wrong with a lot of tobacco smoke exposure or asbestos exposure:
J Nutr. 2004 Jan;134(1):262S-268S.
The enigma of beta-carotene in carcinogenesis: what can be learned from animal
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging,
Tufts University, Boston, MA 02111, USA.
Beta-carotene and other carotenoids have been thought to have anti-cancer
activity, either because of antioxidant activity or because of their ability to
be converted to vitamin A. Nevertheless, two large scale intervention studies in
humans using high doses of beta-carotene found that beta-carotene supplementation
resulted in more lung cancer rather than less lung cancer among smoking and
asbestos exposed populations. Studies conducted in the ferret have elucidated
molecular mechanisms behind this observation, in that high-dose beta-carotene and
smoke exposure in these animals leads to squamous metaplasia, a pre-cancerous
lesion in the lung. High dose beta-carotene in the smoke exposed animals was
found to give rise to a number of transient oxidative metabolites, which include
P450 enzymes that result in the destruction of retinoic acid, and diminished
retinoid signaling, and enhanced cell proliferation. In addition, eccentric
cleavage beta-carotene metabolites facilitate the binding of smoke derived
carcinogens to DNA. In other ferret studies low dose beta-carotene smoke exposure
provided mild protection against squamous metaplasia. Thus, it appears that the
explanation of the apparent paradoxical effects of beta-carotene on lung cancer
is related to dose. The metabolism and breakdown of natural products should be
thoroughly investigated in animal models before embarking on large scale
intervention trials, particularly when using unusually high doses that greatly
exceed normal dietary levels.
PMID: 14704331 [PubMed - indexed for MEDLINE]
with more in:
may be useful; it looks potentially interesting.
Sukie (not a vet)
Recommended ferret health links:
all ferret topics:
"All hail the procrastinators for they shall rule the world tomorrow."
(2010, Steve Crandall)
On change for its own sake: "You can go really fast if you just jump off the cliff."
(2010, Steve Crandall)
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