Detection And Quantitation Of Circulating Human Irisin By Tandem Mass Spectrometry

[Hugh Johnson]

http://www.cell.com/cell-metabolism/pdfExtended/S1550-4131(15)00392-7
Detection and Quantitation of Circulating
Human Irisin by Tandem Mass Spectrometry

SUMMARY
Exercise provides many health benefits, including
improved metabolism, cardiovascular health, and
cognition. We have shown previously that FNDC5, a
type I transmembrane protein, and its circulating
form, irisin, convey some of these benefits in mice.
However, recent reports questioned the existence
of circulating human irisin both because human
FNDC5 has a non-canonical ATA translation start
and because of claims that many human irisin antibodies
used in commercial ELISA kits lack required
specificity. In this paper we have identified and
quantitated human irisin in plasma using mass spectrometry
with control peptides enriched with heavy
stable isotopes as internal standards. This precise
state-of-the-art method shows that human irisin is
and circulates at
3.6 ng/ml in sedentary individuals;
this level is increased to
4.3 ng/ml in individuals
undergoing aerobic interval training. These data
unequivocally demonstrate that human irisin exists,
circulates, and is regulated by exercise.

http://www.the-scientist.com/?articles.view/articleNo/43738/title/Irisin-Redeemed/
Here is an article introducing this study. In it they also mention a genetic and in vitro study that suggests Irisin is not relevant to humans, found here

http://journals.plos.org/plosone/articl ... ne.0073680

A lot of people have experienced dramatic weight loss from minor exercise.

 

[Mauritio]

Great reviews on irisin!

Irisin: A Hope in Understanding and Managing Obesity and Metabolic Syndrome


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