Journal of Burn Care And Research (formerly Journal of Burn Care & Rehabilitation)
Year, Volume, Issue, Page(s):, 37, 1, 53-63
Study examined skeletal muscle mitochondrial respiratory capacity and function in healthy individuals and in burn victims for up to 2 years postinjury. Muscle biopsies were collected from 16 healthy men and from 69 children with burns encompassing at least 30 percent of their total body surface area. Seventy-nine biopsies were collected from cohorts of burn victims at 2 weeks, 6 months, 12 months, and 24 months postburn. Hypermetabolism was determined by the difference in predicted and measured metabolic rate. Mitochondrial respiration was determined in saponin-permeabilized myofiber bundles. Outcomes were modeled by analysis of variance, with differences in groups assessed by Tukey-adjusted contrasts. Results showed that burn patients were hypermetabolic for up to 2 years postinjury. Coupled mitochondrial respiration was lower at 2 weeks, 6 months, and 12 months postburn compared with healthy controls. Coupled respiration was greater at 6, 12, and 24 months postburn versus 2 weeks postburn. Mitochondrial adenosine diphosphate and oligomycin sensitivity (measures of coupling control) were lower at all time-points postburn vs control, but greater at 6, 12, and 24 months postburn versus 2 weeks postburn. The findings suggest that muscle mitochondrial respiratory capacity remains significantly lower in burn victims for 1-year postinjury. Mitochondrial coupling control is diminished for up to 2 years postinjury in burn victims, resulting in greater mitochondrial thermogenesis. These quantitative and qualitative derangements in skeletal muscle bioenergetics likely contribute to the long-term pathophysiological stress response to burn trauma.
Porter, Craig, Herndon, David N., Borsheim, Elisabet, Bhattarai, Nisha, Chao, Tony, Reidy, Paul T., Rasmussen, Blake B., Andersen, Clark R., Suman, Oscar E., Sidossis, Labros S>