Whole-body cryostimulation increases parasympathetic outflow and decreases core body temperature

The purpose of this study was to develop a method to clean and rehabilitate sea otters (Enhydra lutris) that might become contaminated during an oil spill and to determine which physiological and behavioral factors were important in restoring the insulation provided by the fur. Tests were conducted on 12 sea otters captured in Alaska and brought to the Sea World Research Institute in San Diego. Measurements of average metabolic rate, core body temperature, behavior, and squalene (the major lipid of sebum) concentration on the fur were made under three conditions: (i) before oiling (base line), (ii) 1–3 days after 20% of the body surface area was covered with fresh crude oil, and (iii) after cleaning. Under base-line conditions in water at 13 °C, average metabolic rate was 8.0 W/kg, core body temperature was 38.9 °C, and whole body thermal conductance was 10.7 W/(m2∙ °C). Otters spent 35% of their time grooming, 45% resting, 10% swimming, and 10% feeding. The squalene concentration on the fur averaged 3.7 mg/g fur. Oiling increased thermal conductance 1.8 times. To compensate for the loss of insulation and maintain a normal core body temperature (39 °C), the otters increased average metabolic rate (1.9 times) through voluntary activity and shivering; the time spent grooming and swimming increased 1.7 times. Using Dawn detergent, we were able to clean the oiled fur during 40 min of washing and rinsing. Grooming activity by the otters was essential for restoring the water-repellent quality of the fur. Core body temperature, average metabolic rate, and thermal conductance returned to base-line levels 3–6 days after cleaning. Squalene was removed by cleaning and did not return to normal levels in the oiled area after 7 days. Veterinary care was important to keep the otters healthy. At least 1–2 weeks should be allowed for otters to restore the insulation of their fur and for recovery from the stress of oiling and cleaning.

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Influence of Cold-TRP Receptors on Cold-Influenced Behaviour

Pharmaceuticals ◽

10.3390/ph15010042 ◽

2021 ◽

Vol 15 (1) ◽

pp. 42

Author(s):

Dibesh Thapa ◽

Brentton Barrett ◽

Fulye Argunhan ◽

Susan D. Brain

Keyword(s):

Body Temperature ◽

Cold Exposure ◽

Transient Receptor Potential ◽

Trp Channels ◽

Core Body Temperature ◽

Physical Restraint ◽

Receptor Potential ◽

Whole Body ◽

Direct Role ◽

Core Body

The transient receptor potential (TRP) channels, TRPA1 and TRPM8, are thermo-receptors that detect cold and cool temperatures and play pivotal roles in mediating the cold-induced vascular response. In this study, we investigated the role of TRPA1 and TRPM8 in the thermoregulatory behavioural responses to environmental cold exposure by measuring core body temperature and locomotor activity using a telemetry device that was surgically implanted in mice. The core body temperature of mice that were cooled at 4 °C over 3 h was increased and this was accompanied by an increase in UCP-1 and TRPM8 level as detected by Western blot. We then established an effective route, by which the TRP antagonists could be administered orally with palatable food. This avoids the physical restraint of mice, which is crucial as that could influence the behavioural results. Using selective pharmacological antagonists A967079 and AMTB for TRPA1 and TRPM8 receptors, respectively, we show that TRPM8, but not TRPA1, plays a direct role in thermoregulation response to whole body cold exposure in the mouse. Additionally, we provide evidence of increased TRPM8 levels after cold exposure which could be a protective response to increase core body temperature to counter cold.

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Uncertainty Analysis of the Core Body Temperature Under Thermal and Physical Stress Using a Three-Dimensional Whole Body Model

Journal of Heat Transfer ◽

10.1115/1.4034962 ◽

2016 ◽

Vol 139 (3) ◽

Cited By ~ 2

Author(s):

Robins T. Kalathil ◽

Gavin A. D'Souza ◽

Amit Bhattacharya ◽

Rupak K. Banerjee

Keyword(s):

Thermal Conductivity ◽

Heat Stress ◽

Body Temperature ◽

Metabolic Rate ◽

Core Body Temperature ◽

Thermal Response ◽

Whole Body ◽

Tissue Properties ◽

The Core ◽

Core Body

Heat stress experienced by firefighters is a common consequence of extreme firefighting activity. In order to avoid the adverse health conditions due to uncompensable heat stress, the prediction and monitoring of the thermal response of firefighters is critical. Tissue properties, among other parameters, are known to vary between individuals and influence the prediction of thermal response. Further, measurement of tissue properties of each firefighter is not practical. Therefore, in this study, we developed a whole body computational model to evaluate the effect of variability (uncertainty) in tissue parameters on the thermal response of a firefighter during firefighting. Modifications were made to an existing human whole body computational model, developed in our lab, for conducting transient thermal analysis for a firefighting scenario. In conjunction with nominal (baseline) tissue parameters obtained from literature, and physiologic conditions from a firefighting drill, the Pennes' bioheat and energy balance equations were solved to obtain the core body temperature of a firefighter. Subsequently, the uncertainty in core body temperature due to variability in the tissue parameters (input parameters), metabolic rate, specific heat, density, and thermal conductivity was computed using the sensitivity coefficient method. On comparing the individual effect of tissue parameters on the uncertainty in core body temperature, the metabolic rate had the highest contribution (within ±0.20 °C) followed by specific heat (within ±0.10 °C), density (within ±0.07 °C), and finally thermal conductivity (within ±0.01 °C). A maximum overall uncertainty of ±0.23 °C in the core body temperature was observed due to the combined uncertainty in the tissue parameters. Thus, the model results can be used to effectively predict a realistic range of thermal response of the firefighters during firefighting or similar activities.

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