Irisin, the “exercise hormone,” either exists or it doesn’t, depending on one’s personal beliefs. In a recent study, the researchers who first discovered irisin suggest that it circulates in the blood at nanogram levels and increases during exercise.
In their study appearing in the August 13 issue of Cell Metabolism, according to a media release from Cell Press, senior author Bruce Speigelman of Dana-Farber Cancer Institute and Harvard Medical School, and co-author Steven Gygi used quantitative mass spectrometry techniques to suggest that irisin uses ATA (start codon) to initiate its production rather than the usual ATG.
The authors note also that although irisin circulates at low nanogram levels, its range is comparable to that observed for other hormones such as insulin. Furthermore, the release explains, the investigators developed a protocol that does not rely on antibodies to precisely measure how much irisin increases in people after exercise.
In the release, the study authors point out, however, that some irisin is lost during sample preparation, and therefore the amount of irisin detected is, if anything, a slight underestimation. The technology is also expensive and requires specific mass spectrometry instruments. However, future refinement of this work should lead to more scalable protocols.
[Source(s): Cell Press, Science Daily]