BACKGROUND: Interleukin (IL)-6 is locally produced in skeletal muscles and shows a remarkable increase in plasma after eccentric exercises. OBJECTIVE: To elucidate the cell types in the muscles responsible for IL-6 production after eccentric exercises. STUDY DESIGN: Controlled laboratory study. METHODS: An eccentric contraction model was made using electrical stimulation. The authors investigated the muscle damage and regeneration processes after eccentric exercises histologically, and the cell types expressing IL-6 and its subcellular compartimentalization with time immunohistochemically after eccentric exercises. RESULTS: Swollen myofibers were detected from 8 hours to 3 days after exercises. Disrupted myofibers were detected from 24 hours to 7 days, with a peak of 3 days. IL-6 was detected only in the cytoplasm of myofibers until 12 hours; thereafter, it was found in the inflammatory cells and proliferating satellite cells as well. The swollen myofibers were negatively stained for IL-6. The positive ratios of IL-6 in myofibers immediately increased after exercises, peaked in 12 hours, and then decreased. CONCLUSIONS: After eccentric exercises, IL-6 expression increased in myofibers preceding the disruption of myofibers. IL-6 might be closely related to muscle damage caused by strenuous exercises.
BACKGROUND: Interleukin (IL)-6 is locally produced in skeletal muscles and shows a remarkable increase in plasma after eccentric exercises. OBJECTIVE: To elucidate the cell types in the muscles responsible for IL-6 production after eccentric exercises. STUDY DESIGN: Controlled laboratory study. METHODS: An eccentric contraction model was made using electrical stimulation. The authors investigated the muscle damage and regeneration processes after eccentric exercises histologically, and the cell types expressing IL-6 and its subcellular compartimentalization with time immunohistochemically after eccentric exercises. RESULTS: Swollen myofibers were detected from 8 hours to 3 days after exercises. Disrupted myofibers were detected from 24 hours to 7 days, with a peak of 3 days. IL-6 was detected only in the cytoplasm of myofibers until 12 hours; thereafter, it was found in the inflammatory cells and proliferating satellite cells as well. The swollen myofibers were negatively stained for IL-6. The positive ratios of IL-6 in myofibers immediately increased after exercises, peaked in 12 hours, and then decreased. CONCLUSIONS: After eccentric exercises, IL-6 expression increased in myofibers preceding the disruption of myofibers. IL-6 might be closely related to muscle damage caused by strenuous exercises.
Authors: Jun F Tong; Xu Yan; Mei J Zhu; Stephen P Ford; Peter W Nathanielsz; Min Du Journal: Am J Physiol Endocrinol Metab Date: 2009-01-27 Impact factor: 4.310
Authors: Anna E Thalacker-Mercer; Louis J Dell'Italia; Xiangqin Cui; James M Cross; Marcas M Bamman Journal: Physiol Genomics Date: 2009-11-10 Impact factor: 3.107
Authors: Bryon R McKay; Michael De Lisio; Adam P W Johnston; Ciara E O'Reilly; Stuart M Phillips; Mark A Tarnopolsky; Gianni Parise Journal: PLoS One Date: 2009-06-24 Impact factor: 3.240