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Effects of environmental temperature and humidity on a model of exertional heat stroke in mice (1104.26)
Author(s) -
King Michelle,
Leon Lisa,
Clanton Thomas
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1104.26
Subject(s) - hypothermia , stroke (engine) , core temperature , limiting , medicine , thermoregulation , environmental medicine , zoology , chemistry , anesthesia , biology , pathology , physics , mechanical engineering , engineering , thermodynamics , public health
Effects of environmental temperature and humidity on a model of exertional heat stroke in mice Michelle A. King 1 , Lisa R. Leon 2 , and Thomas L. Clanton 1 1 Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida; 2 U.S. Army Research Institute of Environmental Medicine, Thermal and Mountain Medicine Division, Natick, Massachusetts. The pathophysiology of exertional heat stroke (EHS) may differ from passive heat stroke, but limited models are available. We describe EHS in conscious C57Bl/6 mice, instrumented with telemeters and exposed to environmental temperatures (Tenv) from 37.5‐39.5C, and relative humidities (RH) from 30‐90%. Mice exercised on a forced running wheel using an incremental protocol until neurological symptoms (fainting) became limiting. All animals survived 4 d. No significant differences were seen between max core temperatures (Tmax=42.1‐42.5C) at differing Tenv, when RH=30‐50%. Paradoxically, at 90% RH, symptom‐limited Tmax averaged 41.50.1C (P<0.01). However, exercise time and peak running speed were highest at 90% RH (P<0.05). The minimum core temp reached during hypothermia was also significantly higher at 90% vs. 30% RH (P<0.025). Thermal loads were highest at Tenv=37.5C, irrespective of RH (P<0.01). However, the percent loss of body weight (3‐11.5%) was not different in any condition. The results demonstrate that similar forms of EHS can be observed in mice over a wide range of Tenv and RHs, resulting in symptoms, Tmax and other characteristics resembling human EHS. Author views not official US Army or DoD policy. Grant Funding Source : USARIEM, Natick MA