I am currently conducting research aimed at improving our understanding of the regulation of the adenine nucleotide pool (ATP, ADP, AMP) in skeletal muscle and its effects on cellular energetics, muscle atrophy, and adaptive capacity. Publications (17) Increased Adenine Nucleotide Degradation in Skeletal Muscle Atrophy Article Full-text available Dec 2019 Spencer G. Miller Paul Hafen Jeffrey J Brault Adenine nucleotides (AdNs: ATP, ADP, AMP) are essential biological compounds that facilitate many necessary cellular processes by providing chemical energy, mediating intracellular signaling, and regulating protein metabolism and solubilization. A dramatic reduction in total AdNs is observed in atrophic skeletal muscle across numerous disease state... View Accumulation of Skeletal Muscle T Cells and the Repeated Bout Effect in Rats Article Dec 2019 Michael R. Deyhle Meghan Carlisle Jacob Sorensen[...] Robert D Hyldahl Purpose: The purpose of this investigation was to characterize skeletal muscle T-cell accumulation following contraction-induced muscle damage, and test the hypothesis that T-cells contribute to post-damage muscle protection (i.e., the repeated bout effect) in a way reminiscent of their role in adaptive immunity. Methods: In vivo lengthening con... View An altered response in macrophage phenotype following damage in aged human skeletal muscle: implications for skeletal muscle repair Article Jun 2019 Jacob Sorensen Jamie P. Kaluhiokalani Paul Hafen[...] Robert D Hyldahl The purpose of this study was to test the hypothesis that macrophage polarization is altered in old compared to young skeletal muscle, possibly contributing to the poor satellite cell response observed in older muscle tissue. Muscle biopsies were collected prior to and at 3, 24, and 72 h following a muscle-damaging exercise in young and old individ... View Daily heat treatment maintains mitochondrial function and attenuates atrophy in human skeletal muscle subjected to immobilization