Intermittent vibration protects aged muscle from mechanical and oxidative damage under prolonged compression.
Deep tissue pressure ulcers, a serious clinical challenge originating in the muscle layer, are hardly detectable at the beginning. The challenge apparently occurs in aged subjects more frequently. As the ulcer propagates to the skin surface, it becomes very difficult to manage and can lead to fatal complications. Preventive measures are thus highly desirable. Although the complex pathological mechanisms have not been fully understood, prolonged and excessive physical challenges and oxidative stress are believed to be involved in the ulcer development. Previous reports have demonstrated that oxidative stress could compromise the mechanical properties of muscle cells, making them easier to be damaged when physical challenges are introduced. In this study, we used senescence accelerated (SAMP8) mice and its control breed (SAMR1) to examine the protective effects of intermittent vibration on aged and control muscle tissues during prolonged epidermal compression under 100mmHg for 6h. Results showed that an application of 35Hz, 0.25g intermittent vibration during compression decreased the compression-induced muscle breakdown in SAMP8 mice, as indicated histologically in terms of number of interstitial nuclei. The fact that no significant difference in muscle damage could be established in the corresponding groups in SAMR1 mice suggests that SAMR1 mice could better accommodate the compression insult than SAMP8 mice. Compression-induced oxidative damage was successfully curbed using intermittent vibration in SAMP8 mice, as indicated by 8-OHdG. A possible explanation is that the anti-oxidative defense could be maintained with intermittent vibration during compression. This was supported by the expression level of PGC-1-alpha, catalase, Gpx-1 and SOD1. Our data suggested intermittent vibration could serve as a preventive measure for deep tissue ulcer, particularly in aged subjects.
Division of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong.
Sing Wan
SW
Wong
Division of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong.
Brian Chun Ho
BCH
Cheung
Division of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong.
Bruce Tak Keung
BTK
Pang
Division of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong.
Ateline
A
Kwong
Division of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong.
Anna
A
Chung
School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong.
Kenneth Ka Ho
KKH
Lee
Division of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong. Electronic address: arthurmak@cuhk.edu.hk.
Arthur Fut Tak
AFT
Mak
D000375:Aging / Q000378:metabolism*; D000818:Animals; D051379:Mice; D009132:Muscles / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D018384:Oxidative Stress; D011312:Pressure; D013314:Stress, Mechanical; D014732:Vibration
Deep tissue injury; Intermittent vibration; Oxidative stress; Skeletal muscle; Tissue mechanics