Abstract
Abstract
Objective
As human thermoregulatory responses to maintain core body temperature (Tcore) under multiple stressors such as cold, hypoxia, and dehydration (e.g., exposure to high-altitude) are varied, the combined effects of cold, hypoxia, and dehydration status on Tcore in rats were investigated. The following environmental conditions were constructed: (1) thermoneutral (24 °C) or cold (10 °C), (2) normoxia (21% O2) or hypoxia (12% O2), and (3) euhydration or dehydration (48 h water deprivation), resulted in eight environmental conditions [2 ambient temperatures (Ta) × 2 oxygen levels × 2 hydration statuses)]. Each condition lasted for 24 h.
Results
Normoxic conditions irrespective of hypoxia or dehydration did not strongly decrease the area under the curve (AUC) in Tcore during the 24 period, whereas, hypoxic conditions caused greater decreases in the AUC in Tcore, which was accentuated with cold and dehydration (Ta × O2 × hydration, P = 0.040 by three-way ANOVA). In contrast, multiple stressors (Ta × O2 × hydration or Ta × O2 or O2 × hydration or Ta × hydration) did not affect locomotor activity counts (all P > 0.05), but a significant simple main effect for O2 and Ta was observed (P < 0.001). Heat loss index was not affected by all environmental conditions (all P > 0.05). In conclusion, decreases in Tcore were most affected by multiple environmental stressors such as cold, hypoxia, and dehydration.
Funder
Japan Society for the Promotion of Science
Publisher
Springer Science and Business Media LLC
Subject
General Biochemistry, Genetics and Molecular Biology,General Medicine
Reference36 articles.
1. Charkoudian N. Skin blood flow in adult human thermoregulation: how it works, when it does not, and why. Mayo Clin Proc. 2003;78(5):603–12.
2. Frappell P, Lanthier C, Baudinette RV, Mortola JP. Metabolism and ventilation in acute hypoxia: a comparative analysis in small mammalian species. Am J Physiol. 1992;262(6 Pt 2):R1040–6.
3. Tattersall GJ, Blank JL, Wood SC. Ventilatory and metabolic responses to hypoxia in the smallest simian primate, the pygmy marmoset. J Appl Physiol. 2002;92(1):202–10.
4. Cipriano LF, Goldman RF. Thermal responses of unclothed men exposed to both cold temperatures and high altitudes. J Appl Physiol. 1975;39(5):796–800.
5. Johnston CE, White MD, Wu M, Bristow GK, Giesbrecht GG. Eucapnic hypoxia lowers human cold thermoregulatory response thresholds and accelerates core cooling. J Appl Physiol. 1996;80(2):422–9.
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