11 research outputs found
Copeptin reflects physiological strain during thermal stress.
PURPOSE: To prevent heat-related illnesses, guidelines recommend limiting core body temperature (T c) ≤ 38 °C during thermal stress. Copeptin, a surrogate for arginine vasopressin secretion, could provide useful information about fluid balance, thermal strain and health risks. It was hypothesised that plasma copeptin would rise with dehydration from occupational heat stress, concurrent with sympathoadrenal activation and reduced glomerular filtration, and that these changes would reflect T c responses. METHODS: Volunteers (n = 15) were recruited from a British Army unit deployed to East Africa. During a simulated combat assault (3.5 h, final ambient temperature 27 °C), T c was recorded by radiotelemetry to differentiate volunteers with maximum T c > 38 °C versus ≤ 38 °C. Blood was sampled beforehand and afterwards, for measurement of copeptin, cortisol, free normetanephrine, osmolality and creatinine. RESULTS: There was a significant (P  38 °C (n = 8) vs ≤ 38 °C (n = 7) there were significantly greater elevations in copeptin (10.4 vs. 2.4 pmol L(-1)) and creatinine (10 vs. 2 μmol L(-1)), but no differences in cortisol, free normetanephrine or osmolality. CONCLUSIONS: Changes in copeptin reflected T c response more closely than sympathoadrenal markers or osmolality. Dynamic relationships with tonicity and kidney function may help to explain this finding. As a surrogate for integrated physiological strain during work in a field environment, copeptin assay could inform future measures to prevent heat-related illnesses
Long-term HIF-1α transcriptional activation is essential for heat-acclimation-mediated cross tolerance: mitochondrial target genes
Comment on: Thompson H.J. & Kagan S.H. (2011) Clinical management of fever by nurses: doing what works. Journal of Advanced Nursing 67(2), 359-370
Selected Contribution: Ambient temperature for experiments in rats: a new method for determining the zone of thermal neutrality
Control of insensible evaporate water loss by two species of mesic parrot suggests a thermoregulatory role
Modelled performance of energy saving air treatment devices to mitigate heat stress for confined livestock buildings in Central Europe
Stress-induced rise in body temperature is repeatable in free-ranging Eastern chipmunks (Tamias striatus)
In response to handling or other acute stressors, most mammals, including humans, experience a temporary rise in body temperature (T b). Although this stress-induced rise in T b has been extensively studied on model organisms under controlled environments, individual variation in this interesting phenomenon has not been examined in the field. We investigated the stress-induced rise in T b in free-ranging eastern chipmunks (Tamias striatus) to determine first if it is repeatable. We predicted that the stress-induced rise in T b should be positively correlated to factors affecting heat production and heat dissipation, including ambient temperature (T a), body mass (M b), and field metabolic rate (FMR). Over two summers, we recorded both T b within the first minute of handling time (T b1) and after 5 min of handling time (T b5) 294 times on 140 individuals. The mean ∆T b (T b5 – T b1) during this short interval was 0.30 ± 0.02°C, confirming that the stress-induced rise in T b occurs in chipmunks. Consistent differences among individuals accounted for 40% of the total variation in ∆T b (i.e. the stress-induced rise in T b is significantly repeatable). We also found that the stress-induced rise in T b was positively correlated to T a, M b, and mass-adjusted FMR. These results confirm that individuals consistently differ in their expression of the stress-induced rise in T b and that the extent of its expression is affected by factors related to heat production and dissipation. We highlight some research constraints and opportunities related to the integration of this laboratory paradigm into physiological and evolutionary ecology