From:
Sukie Crandall
Date: 2009-06-21 18:00:33 UTC
Subject: [ferrethealth] abstract: brown fat
To: fhl <ferrethealth@yahoogroups.com>
Abstract after subject introduction comments and a general URL for the=20
subject matter.
As we all know, obesity and inactivity (which tend to often -- though=20
not always -- go together) contributor or cause multiple serious=20
health problems in a number of species. An example which came up here=20
last year or the year before is how they play into the development of=20
diabetes in cats. (It came up because those studies showed that a=20
hypothesis about carbohydrates causing diabetes in cats and another in=20
humans did not fit study results, and that hypothesis was part of the=20
reason people first wondered about that factor with ferret insulinoma=20
(which is a different pancreatic disorder). BTW, has anyone ever=20
looked closely at BMI (body mass index) and activity levels in ferrets=20
who get insulinoma vs. those who don't for a rates study to add to the=20
knowledge base?)
Okay, there are multiple factors which play into weight from amounts=20
and types of foods eaten to exercise amounts and types, to epigenetics=20
(Thinking of the fetal genistein studies on that regard), and more,=20
including brown fat amounts which may be part of the answer why=20
individuals can vary in the maintenance calories they burn.
Brown fat is not derived from the same origin cells as white fat. (I=20
don't know if anyone has looked to see if creates any endocrinological=20
products like white fat does.) Brown fat comes from the same=20
undifferentiated cells as make muscle.
Here is a study proposing that ferrets may be good human-model animals=20
in which to study brown fat. (If they differ substantially among=20
individuals this may be useful for knowledge that could improve ferret=20
health care, so may study results help with ferret health care as more=20
is learned about brown fat since there may wind up being answers for=20
some ferrets who have obesity problems and related health woes.) It=20
is a highly technical paper, so those who just want basics on the=20
topic can use this human health resource:
http://www.webmd.com/diet/news/20080820/brown-fat-new-key-to-weight-loss
Comp Biochem Physiol A Mol Integr Physiol. 2009 Jan 19. [Epub ahead of=20
print]
UCP1 and oxidative capacity of adipose tissue in adult ferrets=20
(Mustela putorius furo).
Fuster A, Oliver P, S=E1nchez J, Pic=F3 C, Palou A.
Laboratory of Molecular Biology, Nutrition and Biotechnology,=20
Universitat de les Illes Balears, and CIBER de Fisiopatolog=EDa de la=20
Obesidad y Nutrici=F3n (CIBEROBN), Palma de Mallorca, Spain.
The main mass of brown adipose tissue is located in the interscapular=20
region in rodents, while certain species, such as humans, have a=20
tissue that resembles the brown depot, but in different locations.=20
Ferrets have been described as a useful model in different studies=20
because of their similarity with humans. Here we have characterised=20
the oxidative capacity (cytochrome c oxidase activity) and the pattern=20
of UCP1 production in different adipose tissue depots=20
(retroperitoneal, inguinal and interscapular) in ferrets housed at=20
different temperatures. For this purpose adult female ferrets were=20
divided into two groups, one housed at 22 degrees C and the other=20
acclimated to 4 degrees C for one week. Our data show that, in 22=20
degrees C-acclimated ferrets, and unlike rodents, UCP1 is present at=20
low levels in the different adipose tissue depots studied, with higher=20
specific levels in the retroperitoneal than in the interscapular=20
depot, whereas the inguinal depot has intermediate levels. Cold-
exposure produces a transformation in the adipose tissue, increasing=20
the number of brown adipocytes and UCP1 levels in the retroperitoneal=20
and in the interscapular depots. Cytochrome c oxidase activity is also=20
higher in the retroperitoneal depot but is not affected by cold. Due=20
to its higher oxidative capacity and UCP1 content, the retroperitoneal=20
adipose depot in ferrets seems to be the most important when=20
considering a potential thermogenic role. In conclusion, in adult=20
ferrets, UCP1 is expressed in different adipose depots and the=20
expression of this protein is responsive to a cold-stimulus. These=20
results suggest that ferrets could be considered as a useful animal=20
model to approach studies of adipose tissue thermogenesis.
PMID: 19535042
For those who want a bit of an overview of the endocrinological=20
properties of white fat (which also produces estrogens):
Dig Dis Sci. 2008 Dec 4. [Epub ahead of print]
Adipose Tissue: The New Endocrine Organ? A Review Article.
Wozniak SE, Gee LL, Wachtel MS, Frezza EE.
Department of Surgery, Texas Tech University Health Sciences Center,=20
Lubbock, TX, USA.
Fat is either white or brown, the latter being found principally in=20
neonates. White fat, which comprises adipocytes, pre-adipocytes,=20
macrophages, endothelial cells, fibroblasts, and leukocytes, actively=20
participates in hormonal and inflammatory systems. Adipokines include=20
hormones such as leptin, adiponectin, visfatin, apelin, vaspin,=20
hepcidine, chemerin, omentin, and inflammatory cytokines, including=20
tumor necrosis factor alpha (TNF), monocyte chemoattractant protein-1=20
(MCP-1), and plasminogen activator protein (PAI). Multiple roles in=20
metabolic and inflammatory responses have been assigned to adipokines;=20
this review describes the molecular actions and clinical significance=20
of the more important adipokines. The array of adipokines evidences=20
diverse roles for adipose tissue, which looms large in the mediators=20
of inflammation and metabolism. For this reason, treating obesity is=20
more than a reduction of excess fat; it is also the treatment of=20
obesity's comorbidities, many of which will some day be treated by=20
drugs that counteract derangements induced by adipokine excesses.
PMID: 19052866
Sukie (not a vet)
Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/
http://www.ferrethealth.msu.edu/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
all ferret topics:
http://listserv.ferretmailinglist.org/archives/ferret-search.html
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