Respiratory and limb muscle weakness induced by tumor necrosis factor-α: Involvement of muscle myofilaments

摘要: The respiratory and limb skeletal muscles become weakened in sepsis, congestive heart failure, other inflammatory diseases. A potential mediator of muscle weakness is tumor necrosis factor (TNF)-α, a cytokine that can stimulate wasting also induce contractile dysfunction without overt catabolism. This study addressed the latter process. Murine diaphragm (flexor digitorum brevis [FDB]) preparations were used to determine relative sensitivities these TNF-α. Intact fibers isolated from FDB microinjected with indo-1 measure changes sarcoplasmic calcium regulation. We found TNF-α depressed tetanic force comparable degrees across range stimulus frequencies. In fibers, decreased altering transients or resting levels. conclude (1) compromises function similarly, (2) decre...