Affiliation:
1. College of Nursing and Health Innovation University of Texas at Arlington Arlington Texas USA
2. Frances Payne Bolton School of Nursing Case Western Reserve University Cleveland Ohio USA
3. Department of Population Health Sciences, College of Medicine University of Central Florida Orlando Florida USA
Abstract
AbstractIntroduction/AimsBecause wounded warfighters or trauma victims may receive en route care to the closest medical facility via airplane transport, we investigated the effects of extended mild hypobaric hypoxia (HB), the environmental milieu of most airplanes, on inflammation and regeneration after muscle trauma or monotrauma (MT) and muscle trauma‐hemorrhagic shock or polytrauma (PT).MethodsMale C57BL/6N mice were assigned to one of six groups pertaining to injury (control/uninjured, MT, and PT) and atmospheric pressure exposure (HB and normobaric normoxia, NB). Body mass, blood and muscle leukocyte number by flow cytometry, immunohistochemistry, or both, and the muscle relative mRNA level of selected genes involved in inflammation and muscle regeneration were examined at ~1.7, 4, 8, and 14 days post trauma (dpt). At 14 dpt, the proportion of smaller‐ and larger‐sized myofibers at the regenerating site of MT mice was determined.ResultsGreater body mass loss, an increased number of blood and muscle leukocytes, and differential muscle relative mRNA levels were observed in MT and PT groups compared to controls. The MT+HB or PT+HB mice demonstrated more body mass loss and altered relative mRNA level than the corresponding NB mice. Additionally, a subgroup of MT+HB mice demonstrated a greater proportion of smaller myofibers (250 to 500 μm2) than MT+NB mice at 14 dpt.DiscussionHB exposure after muscle trauma alone may prolong regeneration. Following HB exposure, therapies that promote oxygenation may be needed during this muscle recovery.
Funder
U.S. Department of Defense
Subject
Physiology (medical),Cellular and Molecular Neuroscience,Neurology (clinical),Physiology