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Full-Text Articles in Life Sciences
High-Frequency Electrically Stimulated Skeletal Muscle Contractions Increase P70S6k Phosphorylation Independent Of Known Igf-I Sensitive Signaling Pathways, Sarah Witkowski, Richard M. Lovering, Espen E. Spangenburg
High-Frequency Electrically Stimulated Skeletal Muscle Contractions Increase P70S6k Phosphorylation Independent Of Known Igf-I Sensitive Signaling Pathways, Sarah Witkowski, Richard M. Lovering, Espen E. Spangenburg
Exercise and Sport Studies: Faculty Publications
Insulin-like growth factor (IGF-I) is hypothesized to be a critical upstream regulator of mammalian target of rapamycin (mTOR)-regulated protein synthesis with muscle contraction. We utilized a mouse model that expresses a skeletal muscle specific dominant-negative IGF-I receptor to investigate the role of IGF-I signaling of protein synthesis in response to unilateral lengthening contractions (10 sets, 6 repetitions, 100. Hz) at 0 and 3. h following the stimulus. Our results indicate that one session of high frequency muscle contractions can activate mTOR signaling independent of signaling components directly downstream of the receptor.
Thrombin And Exercise Similarly Influence Expression Of Cell Cycle Genes In Cultured Putative Endothelial Progenitor Cells, Michael M. Lockard, Sarah Witkowski, Nathan T. Jenkins, Espen E. Spangenburg, Thomas O. Obisesan, James M. Hagberg
Thrombin And Exercise Similarly Influence Expression Of Cell Cycle Genes In Cultured Putative Endothelial Progenitor Cells, Michael M. Lockard, Sarah Witkowski, Nathan T. Jenkins, Espen E. Spangenburg, Thomas O. Obisesan, James M. Hagberg
Exercise and Sport Studies: Faculty Publications
Acute exercise and exercise training may influence putative endothelial progenitor cell (EPC) number and colony forming units (CFU-ECs), although the mechanisms remain unclear. This study examined the effects of in vitro thrombin supplementation and acute exercise on CFU-EC gene expression, associated with cellular proliferation and differentiation. The effect of habitual physical activity was evaluated through analysis of EPCs from chronically high- and low-active men. Participants were healthy high- and low-active men (n = 23), aged 55-80 yr. Circulating CD34+/VEGFR2+ number, CFU-ECs, plasma prothrombin fragment (F1+2), and thrombin-antithrombin III were measured at rest and after 30 min of exercise. Gene expression …
Endurance Exercise Training Effects On Body Fatness, Vo2max Hdl-C Subfractions, And Glucose Tolerance Are Influenced By A Plin Haplotype In Older Caucasians, Nathan T. Jenkins, Jennifer A. Mckenzie, Coleen M. Damcott, Sarah Witkowski, James M. Hagberg
Endurance Exercise Training Effects On Body Fatness, Vo2max Hdl-C Subfractions, And Glucose Tolerance Are Influenced By A Plin Haplotype In Older Caucasians, Nathan T. Jenkins, Jennifer A. Mckenzie, Coleen M. Damcott, Sarah Witkowski, James M. Hagberg
Exercise and Sport Studies: Faculty Publications
Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with …
Relationship Between Circulating Progenitor Cells, Vascular Function And Oxidative Stress With Long-Term Training And Short-Term Detraining In Older Men, Sarah Witkowski, Michael M. Lockard, Nathan T. Jenkins, Thomas O. Obisesan, Espen E. Spangenburg, James M. Hagberg
Relationship Between Circulating Progenitor Cells, Vascular Function And Oxidative Stress With Long-Term Training And Short-Term Detraining In Older Men, Sarah Witkowski, Michael M. Lockard, Nathan T. Jenkins, Thomas O. Obisesan, Espen E. Spangenburg, James M. Hagberg
Exercise and Sport Studies: Faculty Publications
Exercise may contribute to the maintenance of vascular function via enhanced liberation and action of bone-marrow-derived progenitor cells. Activity related changes in oxidative stress may also influence the number and function of these cells. In the present study, we sought to determine (i) whether adaptations in reactive hyperaemic FBF (forearm blood flow) response associated with long-term endurance exercise and short-term detraining were related to resting putative progenitor cell number and function, and (ii) whether oxidative stress affected these factors. Participants included men with a history of more than 30 years of moderate-to-high-intensity exercise (HI group) and healthy low-active age- and …