scholarly journals Heterothermy is associated with reduced fitness in wild rabbits

2017 ◽  
Vol 13 (12) ◽  
pp. 20170521 ◽  
Author(s):  
Shane K. Maloney ◽  
Maija K. Marsh ◽  
Steven R. McLeod ◽  
Andrea Fuller
Keyword(s):  
Body Temperature ◽  
Oryctolagus Cuniculus ◽  
Reproductive Output ◽  
Core Body Temperature ◽  
The Body ◽  
The Core ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Core Body ◽  
Growth And Reproduction

An increase in variation in the 24 h pattern of body temperature (heterothermy) in mammals can be induced by energy and water deficits. Since performance traits such as growth and reproduction also are impacted by energy and water balance, we investigated whether the characteristics of the body temperature rhythm provide an indication of the reproductive success of an individual. We show that the amplitude of the daily rhythm of body temperature in wild rabbits ( Oryctolagus cuniculus ) prior to breeding is inversely related to the number of pregnancies in the subsequent seven months, while the minimum daily body temperature is positively correlated to the number of pregnancies. Because reproductive output could be predicted from characteristics of the core body temperature rhythm prior to the breeding season, we propose that the pattern of the 24 h body temperature rhythm could provide an index of animal fitness in a given environment.

The core body temperature rhythm is altered in progressive supranuclear palsy

2009 ◽  
Vol 19 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Keisuke Suzuki ◽  
Tomoyuki Miyamoto ◽  
Masayuki Miyamoto ◽  
Koichi Hirata
Keyword(s):  
Body Temperature ◽  
Progressive Supranuclear Palsy ◽  
Core Body Temperature ◽  
The Core ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Core Body

Disturbed core body temperature rhythm after major surgery

2004 ◽  
Vol 2 (3) ◽  
pp. 226-228 ◽  
Author(s):  
Ismail GÖGENUR ◽  
Andreas EVERSBUSCH ◽  
Michael ACHIAM ◽  
Pernille SØLVING ◽  
Jacob ROSENBERG
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Major Surgery ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Core Body

scholarly journals Exercise activates compensatory thermoregulatory reaction in rats: a modeling study

2015 ◽  
Vol 119 (12) ◽  
pp. 1400-1410 ◽  
Author(s):  
Yeonjoo Yoo ◽  
Michelle LaPradd ◽  
Hannah Kline ◽  
Maria V. Zaretskaia ◽  
Abolhassan Behrouzvaziri ◽  
...  
Keyword(s):  
Body Temperature ◽  
Heat Generation ◽  
Heat Production ◽  
Core Body Temperature ◽  
Heat Stroke ◽  
The Body ◽  
Model Parameters ◽  
The Core ◽  
Treadmill Speed ◽  
Core Body

The importance of exercise is increasingly emphasized for maintaining health. However, exercise itself can pose threats to health such as the development of exertional heat shock in warm environments. Therefore, it is important to understand how the thermoregulation system adjusts during exercise and how alterations of this can contribute to heat stroke. To explore this we measured the core body temperature of rats ( Tc) running for 15 min on a treadmill at various speeds in two ambient temperatures ( Ta = 25°C and 32°C). We assimilated the experimental data into a mathematical model that describes temperature changes in two compartments of the body, representing the muscles and the core. In our model the core body generates heat to maintain normal body temperature, and dissipates it into the environment. The muscles produce additional heat during exercise. According to the estimation of model parameters, at Ta = 25°C, the heat generation in the core was progressively reduced with the increase of the treadmill speed to compensate for a progressive increase in heat production by the muscles. This compensation was ineffective at Ta = 32°C, which resulted in an increased rate of heat accumulation with increasing speed, as opposed to the Ta = 25°C case. Interestingly, placing an animal on a treadmill increased heat production in the muscles even when the treadmill speed was zero. Quantitatively, this “ready-to-run” phenomenon accounted for over half of the heat generation in the muscles observed at maximal treadmill speed. We speculate that this anticipatory response utilizes stress-related circuitry.

scholarly journals Circadian Rhythm of Core Body Temperature (Part II): Hyperbaric Environment Influence on Circadian Rhythm of Core Body Temperature

2016 ◽  
Vol 57 (4) ◽  
pp. 19-25
Author(s):  
Joanna Słomko ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
Małgorzata Tafil-Klawe ◽  
Piotr Siermontowsk ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Body Temperature ◽  
Core Body Temperature ◽  
The Body ◽  
Hyperbaric Chamber ◽  
The Core ◽  
Hyperbaric Environment ◽  
The Mean ◽  
Core Body ◽  
Telemetric Measurement

Abstract The aim of this study was to analyse dynamic fluctuations in the circadian rhythm of the core body temperature in healthy adults exposed to conditions in a hyperbaric chamber, using fully objective-telemetric measurement methods. The study group consisted of 13 healthy males (age 32±6.4 years, height 1.85±0.1 m, body weight 84.00±6.3 kg; BMI 24.7±1.2 kg/m2). The core body temperature (CBT) was measured with the Vital Sense telemetry system. The volunteers were placed in a hyperbaric chamber, exposed to compression of 400 kPa, with the exposure plateau of approx. 30 minutes, followed by gradual decompression. The mean core temperature was 36.71°C when registered within 10 minutes before the exposure, 37.20°C during the exposure, 37.27°C one hour after the exposure, 37.36°C 2 hours after the exposure, and 37.42°C three hours after the exposure. The conducted observations show that one-hour stay in a hyperbaric chamber at a depth of 30 m results in an increase in the body temperature, particularly significant after the exposure ends, and maintained for at least 3 hours after the exposure.

Modification of circadian body temperature rhythm during the luteal menstrual phase: role of melatonin

1996 ◽  
Vol 80 (1) ◽  
pp. 25-29 ◽  
Author(s):  
A. Cagnacci ◽  
R. Soldani ◽  
G. A. Laughlin ◽  
S. S. Yen
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Menstrual Phase ◽  
Temperature Rhythm ◽  
Melatonin Administration ◽  
Early Follicular Phase ◽  
Body Temperature Rhythm ◽  
The Mean ◽  
Core Body

In women during early follicular phase (FP), the rise of melatonin at night accounts for 40% of the nocturnal core body temperature (Tc) decline. In seven normal-cycling women, the circadian rhythms of Tc and melatonin of the FP were compared with those of the luteal phase (LP). In addition, in both phases the Tc response to daytime melatonin administration was investigated. Melatonin levels were comparable during the two menstrual phases, but the nocturnal melatonin onset was delayed by 90 min in the LP (P < 0.01). This was accompanied by a delay of the nadir of the Tc circadian rhythm (P < 0.002), a 0.3 degrees C elevation (P < 0.005) of the mean 24-h value, and a 40% blunting (P < 0.002) of the amplitude. This attenuation of circadian Tc in LP women was replicated in two estrogen-treated hypogonadal women by the administration of medroxyprogesterone acetate. The daytime administration of melatonin (2.5 mg) decreased Tc during the FP (P < 0.01) but was ineffective in the LP. Present data indicate that in LP, in association with high progesterone levels, an attenuated and phase-delayed circadian Tc rhythm may, in part, be due to a reduced effect of melatonin.

Circadian temperature rhythms in rabbit pups and in their does

2001 ◽  
Vol 35 (4) ◽  
pp. 364-373 ◽  
Author(s):  
B. Jilge ◽  
B. Kuhnt ◽  
W. Landerer ◽  
S. Rest
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Circadian Oscillator ◽  
Suprachiasmatic Nuclei ◽  
The Core ◽  
Temperature Rhythm ◽  
Pregnancy And Lactation ◽  
Temperature Rhythms ◽  
Milk Ingestion ◽  
Core Body

Circadian rhythms of mammals are generated endogenously, the master oscillator system residing in the suprachiasmatic nuclei (SCN). Previous experiments have indicated that the rabbit has a feeding entrainable circadian oscillator (FEO) which is supposed to be of greatest importance during the early infancy of the rabbit. Here we report the course of telemetrically monitored core body temperature of rabbit pups and of their does. Temperature increased from 37.6 ± 0.3 °C on day 2 to 39.5 ± 0.1 °C on day 28 of life. The pups showed a 24 h temperature rhythm even during their first days of life. Temperature increased 2&frac12;-3 h prior to nursing for 0.4-0.8 °C and rose for an additional 0.4-0.6 °C immediately after milk ingestion. The anticipatory, but not the postprandial component persisted when nursing was skipped twice. The persistence of a rhythm in the absence of any entraining agent is crucial for its endogenous generation. In the doe, the core body temperature gradually decreased during the last 2/3 of pregnancy. During parturition it steeply rose for 1.5-1.7 °C and attained a plateau of 39.7 ± 0.2 °C during lactation. The circadian rhythm persisted during the whole course of pregnancy and lactation. Thus, in the rabbit an endogenous, feeding entrainable circadian oscillator appears to operate from the first days of life. It is of functional significance in that it alerts the pup in time so that it is able to utilize the singular short presence of the doe for maximal milk intake.

scholarly journals Reliability and Validity of the CORE Sensor to Assess Core Body Temperature during Cycling Exercise

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5932
Author(s):  
Nina Verdel ◽  
Tim Podlogar ◽  
Urša Ciuha ◽  
Hans-Christer Holmberg ◽  
Tadej Debevec ◽  
...  
Keyword(s):  
Body Temperature ◽  
Relative Humidity ◽  
Heat Load ◽  
Core Body Temperature ◽  
Heat Stroke ◽  
Reliability And Validity ◽  
The Body ◽  
Validity And Reliability ◽  
The Core ◽  
Core Body

Monitoring core body temperature (Tc) during training and competitions, especially in a hot environment, can help enhance an athlete’s performance, as well as lower the risk for heat stroke. Accordingly, a noninvasive sensor that allows reliable monitoring of Tc would be highly beneficial in this context. One such novel non-invasive sensor was recently introduced onto the market (CORE, greenTEG, Rümlang, Switzerland), but, to our knowledge, a validation study of this device has not yet been reported. Therefore, the purpose of this study was to evaluate the validity and reliability of the CORE sensor. In Study I, 12 males were subjected to a low-to-moderate heat load by performing, on two separate occasions several days apart, two identical 60-min bouts of steady-state cycling in the laboratory at 19 °C and 30% relative humidity. In Study II, 13 males were subjected to moderate-to-high heat load by performing 90 min of cycling in the laboratory at 31 °C and 39% relative humidity. In both cases the core body temperatures indicated by the CORE sensor were compared to the corresponding values obtained using a rectal sensor (Trec). The first major finding was that the reliability of the CORE sensor is acceptable, since the mean bias between the two identical trials of exercise (0.02 °C) was not statistically significant. However, under both levels of heat load, the body temperature indicated by the CORE sensor did not agree well with Trec, with approximately 50% of all paired measurements differing by more than the predefined threshold for validity of ≤0.3 °C. In conclusion, the results obtained do not support the manufacturer’s claim that the CORE sensor provides a valid measure of core body temperature.

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