RESUMO
The objective of this study was to examine the effects of short-term exercise training, myostatin inhibition (PF-354), and exercise+PF-354, all relative to a vehicle control, on performance and metabolic measures in 24-month-old mice. At study termination, PF-354-treated mice exhibited significantly greater muscle weights. Performance measures revealed that exercise+PF-354 increased treadmill running time and distance to exhaustion (more than twofold) and increased habitual activity. Measures of strength were not different; however, all treatment groups demonstrated more than 30% reductions in muscle fatigue. Metabolic measures showed that basal metabolic rates were higher in PF-354- and exercise+PF-354-treated mice, and exercise and exercise+PF-354 groups exhibited significantly greater insulin sensitivity. PF-354 was associated with decreased Smad3 phosphorylation and increased peroxisome proliferator-activated receptor gamma coactivator-1alpha expression and, similar to exercise, decreased MuRF-1. The data suggest that the combination of exercise training and myostatin blockade may significantly improve physical function and whole-body metabolism in older individuals.
Assuntos
Envelhecimento/metabolismo , Miostatina/antagonistas & inibidores , Condicionamento Físico Animal , Envelhecimento/patologia , Animais , Metabolismo Energético , Resistência à Insulina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Força Muscular , Músculo Esquelético/metabolismo , Fosforilação , Proteína Smad3/metabolismoRESUMO
The synthesis, in vitro, and in vivo biological characterization of a series of achiral 5-chloroindoloyl glycine amide inhibitors of human liver glycogen phosphorylase A are described. Improved potency over previously reported compounds in cellular and in vivo assays was observed. The allosteric binding site of these compounds was shown by X-ray crystallography to be the same as that reported previously for 5-chloroindoloyl norstatine amides.
