SuppVersity - Nutrition and Exercise Science for Everyone

Not the mice from this study, but still a nice example of the effects of dexamethasone on skeletal muscle (right; Quin. 2012) "Leucine-laced water + stress = insulin resistance" - This simple equation is the net result of a recent study by Nelo Eidy Zanchi and his colleagues from the Laboratory of Applied Nutrition and Metabolism at the School of Physical Education and Sports of the University of Sao Paulo in Brazil. Inspired by previous research which clearly indicated that leucine does not only have pro-anabolic, but also insulin sensitizing effects, Zanchi et al. speculated that the provision of adequate amounts of leucine would blunt the catabolic and pro-diabetic effects of 7 days of intraperitoneally injections of  dexamethasone, an artificial corticosteroid that's used to treat all sorts of inflammatory diseases. Remember SuppVersity Rule of Smart Supplementation No. 2? Right. Specificity! In order to test their hypothesis that leucine supplementati...

L-Carnitine has long been among my favorites of expensive supplements with ostensibly conclusive scientific background which are pretty worthless in practice. Now, a new study by Keller et al. ( Keller. 2010 ) found that L-Carnitine supplementation in piglets had a distinct effect on gene expression in skeletal muscle: Transcript profiling revealed 211 genes to be differentially expressed in muscle by carnitine supplementation. The identified genes were mainly involved in molecular processes such as cytoskeletal protein binding, insulin-like growth factor (IGF) binding, transcription factor activity, and insulin receptor binding. Identified genes with the molecular function transcription factor activity encoded primarily transcription factors, most of which were down-regulated by carnitine, including pro-apoptotic transcription factors such as proto-oncogene c-fos, proto-oncogene c-jun and activating transcription factor 3. Furthermore, atrophy-related genes such as atrogin-1, MuRF1...