Protein released from fat after exercise improves glucose -- ScienceDaily"In contrast to the negative effects of many adipokines, our study identified transforming growth factor beta 2 (TGF-beta 2) as an adipokine released from adipose tissue (fat) in response to exercise that actually improves glucose tolerance," says Laurie J. Goodyear, PhD, Head of Joslin's Section on Integrative Physiology and Metabolism and study co-author. Not only did exercise-stimulated TGF-beta 2 improve glucose tolerance, treating obese mice with TGF beta 2 lowered blood lipid levels and improved many other aspects of metabolism. "The fact that a single protein has such important and dramatic effects was quite impressive," says Goodyear, Professor of Medicine at Harvard Medical School. Two years ago, the international research team first demonstrated that adipose tissue offers beneficial metabolic effects in response to exercise. "Our hypothesis was that exercise is changing the fat, and as a result of that change, the fat releases these beneficial proteins into the bloodstream," says Goodyear. "Before this discovery, we always just focused on the positive effects of muscle."