Chronic kidney disease (CKD) results in the accumulation of metabolic waste products that are normally cleared by the kidney, known as uremia. Many of these waste products are from bacteria metabolites in the gut. Accumulation of uremic toxins in plasma and tissue, as well as the gut-plasma-tissue metabolic axis are important for understanding pathophysiological mechanisms of comorbidities in CKD. In this study, an untargeted metabolomics approach was used to determine uremic toxin accumulation in plasma, liver, heart and kidney tissue in rats with adenine-induced CKD. Rats with CKD were also given AST-120, a spherical carbon adsorbent, to assess metabolic changes in plasma and tissues with the removal of gut-derived uremic toxins. AST-120 decreased >55% of metabolites that were increased in plasma, liver and heart tissue of rats with CKD. CKD was primarily defined by 8 gut-derived uremic toxins, which were significantly increased in plasma and all tissues. These metabolites were derived from aromatic amino acids and soy protein including: indoxyl sulfate, p-cresyl sulfate, hippuric acid, phenyl sulfate, pyrocatechol sulfate, 4-ethylphenyl sulfate, p-cresol glucuronide and equol 7-glucuronide. Our results highlight the importance of diet and gut-derived metabolites in the accumulation of uremic toxins and define the gut-plasma-tissue metabolic axis in CKD.

CitationNevison SE, Jun Y, Dickey JP. The gluteus medius activation in female indoor track runners is asymmetrical and may be related to injury risk. ResearchPage 27 ABSTRACTTrack runners train and compete solely in the counter clockwise direction around the track. These repetitive motions place track runners at risk of "over-use" injury, but strength differences place females at greater risk than males. This study was conducted to evaluate the asymmetry of gluteus medius muscle activation patterns in female runners as they run around the curves of an unbanked 200 m track. Wireless surface electromyography (EMG) sensors were adhered to the skin overlaying the gluteus medius. Participants' muscle activation was recorded as they ran two 200 m trials at a pace of 5±0.5 m/s and walked 200 m at a chosen pace. Each participant's EMG for the running strides was normalized to the average amplitude of their walking trials. There were significant increases in muscle activation of the outside (right) gluteus medius when athletes ran on the curves compared to the straightaways (359.1 percent of walking ±132.8 and 324.7±102.6 respectively, p=0.015). There was a trend for decreases in muscle activation of the inside (left) gluteus medius when athletes ran on the curves compared to the straightaways (449.2 percent of walking ±136.1 and 469.4±132.6 and respectively, p=0.065). These data suggest that the gluteus medius abducted the outside (right) leg to contribute to the lateral forces necessary to run around the curve. The muscular demands for the two legs are different, and are consistent with observed injury patterns. This loading pattern and mechanism of injury may be useful for guiding training and rehabilitation strategies.