Drinking-induced thermoregulatory panting in rehydrated sheep: influences of oropharyngeal/esophageal signals, core temperature, and thirst satiety

2009 ◽  
Vol 296 (6) ◽  
pp. R1881-R1888 ◽  
Author(s):  
M. J. McKinley ◽  
F. Weissenborn ◽  
M. L. Mathai
Keyword(s):  
Drinking Water ◽  
Body Temperature ◽  
Core Temperature ◽  
Heat Load ◽  
Water Deprivation ◽  
Saline Solution ◽  
Isotonic Saline ◽  
Cool Water ◽  
Rapid Fall

Dehydrated mammals conserve body water by reducing thermoregulatory evaporative cooling responses e.g., panting and sweating. Increased core temperature (Tc) may result. Following rehydration and correction of fluid deficits, panting and sweating commence. We investigated the role of oropharyngeal/esophageal, postabsorptive and thermal signals in the panting response, and reduced Tc that occurs when unshorn sheep drink water following water deprivation for 2 days (ambient temperature 20°C). Ingestion of water (at body temperature) resulted in increased respiratory rate (panting) and reduced Tc within 4 min that persisted for at least 90 min. Initially, a similar panting response and reduced Tc occurred following rehydration by drinking isotonic saline solution, but panting was not sustained after 20 min, and Tc began to rise again. Rehydration by intraruminal administration of water, without any drinking, resulted in delayed panting and fall in Tc. Intraruminal infusion of saline was ineffective. Rehydration by drinking cool water (20°C) resulted in a rapid fall in Tc without increased panting. Shorn sheep had lower basal Tc that did not increase during 2 days of water deprivation, and they did not pant on rehydration by drinking water. Our results indicate that signals from the oropharyngeal and/or esophageal region associated with the act of drinking play a crucial role in the initial 20–30 min of the panting response to rehydration. Postabsorptive factors most likely reduced plasma tonicity and cause continued panting and further reduction in Tc. Tc also influences rehydration-induced panting. It occurs only if sheep incur a heat load during bodily dehydration.

Role of interleukin 6 in fever in rats

1990 ◽  
Vol 258 (3) ◽  
pp. R798-R803 ◽  
Author(s):  
L. G. LeMay ◽  
A. J. Vander ◽  
M. J. Kluger
Keyword(s):  
Cerebrospinal Fluid ◽  
Body Temperature ◽  
Core Temperature ◽  
Interleukin 6 ◽  
Endogenous Pyrogen ◽  
The Core

The purpose of these studies was to assess whether interleukin 6 (IL-6) is an endogenous pyrogen, responsible for all or part of the fever caused by lipopolysaccharide (LPS) in rats. We have found that the core temperature (as measured by biotelemetry) rose significantly after intracerebroventricular (icv) injection of recombinant human IL-6. The same doses of IL-6, when administered intravenously or intraperitoneally, had no effect on body temperature. The fever caused by icv administration of IL-6 was completely blocked by indomethacin. After injection of fever-inducing doses of LPS, the plasma and cerebrospinal fluid (CSF) IL-6 activities rose, the former much more than the latter. The correlation between fever and plasma IL-6 activity was r = 0.84 (P less than 0.0025); the correlation between fever and CSF IL-6 activity was r = 0.77 (P less than 0.015). The results of this study are consistent with the hypothesis that IL-6 is a mediator of LPS-induced fever in the rat.

Role of the sweating from the tail in the thermal balance of the rat-kangaroo Potorous tridactylus

1975 ◽  
Vol 23 (4) ◽  
pp. 453 ◽  
Author(s):  
JW Hudson ◽  
TJ Dawson
Keyword(s):  
Body Temperature ◽  
Heat Balance ◽  
Heat Load ◽  
Thermal Balance ◽  
The Body ◽  
Thermoregulatory Response ◽  
Thermoregulatory Responses ◽  
Air Temperatures ◽  
Potorous Tridactylus

Among the marsupials the thermoregulatory response of sweating is uncommon and has only been described in the larger macropodids. Sweating in kangaroos is very unusual in that it only occurs in response to an exercise heat load. The thermoregulatory responses of a smaller, more generalized rat-kangaroo Potorous tridactylus were therefore examined to obtain a more general appreciation of sweating in macropodids. The pattern of heat balance at low and neutral temperatures was characteristic of that previously found for macropodids; body temperature was 35.9 � 0.52 (mean � se). Standard metabolism was only slightly higher than the predicted level for marsupials and minimal conductance was low, c. 1.3 W m-2 per degree Celsius. At moderate air temperatures heat was primarily lost by vasodilation and panting. The thermoregulatory responses at high air temperatures (near or above body temperature) also included copious sweating from the tail, but not from the body generally. Sweating rates of 600-650 g water per m2 per hour were obtained; these are about twice the generally reported rates for eutherians such as cows and horses.

Thermal dehydration-induced thirst in rats: role of body temperature

1995 ◽  
Vol 269 (3) ◽  
pp. R557-R564 ◽  
Author(s):  
C. C. Barney ◽  
M. M. Folkerts
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Water Intake ◽  
Thermal Dehydration ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Access To Water

Male Sprague-Dawley rats were used to study the possible role of hyperthermia in the thirst associated with thermal dehydration. Rats were exposed to 40 degrees C for 4 h and then allowed access to water at different times after they were transferred to 25 degrees C. Delaying the time prior to allowing the rats to drink did not significantly alter either water intake or percent rehydration even though core temperature decreased during the first 1.5 h after removal from the heat. Exposing thermally dehydrated rats to 5 degrees C for 30 min prior to allowing them access to water also failed to significantly affect water intake or percent rehydration. Thermally dehydrated rats allowed to drink while remaining in the heat did not show a significant increase in water intake during the first hour or percent rehydration over rats drinking at 25 degrees C. Nondehydrated rats did show significant increases in water intake and percent rehydration when allowed to drink in the heat. Hyperthermia does not play a role in drinking in thermally dehydrated rats but can stimulate drinking in water-replete rats.

scholarly journals Dehydration followed by sham rehydration contributes to reduced neuronal activation in vasopressinergic supraoptic neurons after water deprivation

2010 ◽  
Vol 299 (5) ◽  
pp. R1232-R1240 ◽  
Author(s):  
W. David Knight ◽  
Lisa L. Ji ◽  
Joel T. Little ◽  
J. Thomas Cunningham
Keyword(s):  
Supraoptic Nucleus ◽  
Water Deprivation ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Inhibitory Interneurons ◽  
Lamina Terminalis ◽  
Fos Expression ◽  
Supraoptic Neurons ◽  
Hypothalamic Activation

This experiment tested the role of oropharyngeal and gastric afferents on hypothalamic activation in dehydrated rats instrumented with gastric fistulas and allowed to drink water or isotonic saline compared with euhydrated controls (CON). Rats were water-deprived for 48 h (48 WD) or 46 h WD with 2 h rehydration with water (46+W) or isotonic saline (46+S). 46+W and 46+S rats were given water with fistulas open (46+WO/46+SO, sham) or closed (46+WC/46+SC). Compared with CON, water deprivation increased and water rehydration decreased plasma osmolality, while sham rehydration had no effect. Water deprivation increased c-Fos staining in the lamina terminalis. However, none of the sham or rehydration treatments normalized c-Fos staining in the lamina terminalis. Analysis of AVP and c-Fos-positive neurons in the supraoptic nucleus (SON) revealed reduced colocalization in 46+WO and 46+SC rats compared with 48 WD and 46+SO rats. However, 46+WO and 46+SC rats had higher c-Fos staining in the SON than 46+WC or CON rats. Examination of c-Fos in the perinuclear zone (PNZ) revealed that sham and rehydrated rats had increased c-Fos staining to CON, while 48 WD and 46+SO rats had little or no c-Fos staining in this region. Thus, preabsorptive reflexes contribute to the regulation of AVP neurons in a manner independent of c-Fos expression in the lamina terminalis. Further, this reflex pathway may include inhibitory interneurons in the PNZ region surrounding the SON.

Exercise-induced hyperthermia and hormonal responses to exercise

1998 ◽  
Vol 76 (5) ◽  
pp. 547-552 ◽  
Author(s):  
M W Radomski ◽  
M Cross ◽  
A Buguet
Keyword(s):  
Growth Hormone ◽  
Body Temperature ◽  
Core Temperature ◽  
Acid Base Balance ◽  
Thermal Threshold ◽  
Hormonal Responses ◽  
Induced Hyperthermia ◽  
Series Of Experiments ◽  
Exercise Induced

Changes in plasma hormonal concentrations during exercise have been ascribed to the type, duration, and intensity of exercise, physical fitness of subjects, oxygen availability and debt, and acid-base balance. However, relatively few studies have examined the possible role of exercise-induced hyperthermia. This paper reviews previous studies on this subject and describes a series of experiments carried out in our laboratories to define the role of changes in body temperature in the release of hormones during exercise. In a first series of experiments, we studied the relationship between thermoregulatory and growth hormone responses to severe exercise at 23°C for 2 h in fit euhydrated subjects, controlling the core temperature increase to a maximum of 40°C by varying wind speed. Exponential relationships were found between increases in core temperature and plasma growth hormone, prolactin, and catecholamines during exercise, suggesting the existence of a thermal threshold for stimulation of hormonal release during exercise. The effect of endurance exercise with and without a thermal clamp (immersion in cold and warm water) on hormonal and leukocyte responses was examined. Again, a significant exponential relationship was found between increases in core temperature and hormonal responses. Thermal clamping significantly diminished the hormonal and the leukocytic responses to exercise, suggesting that an exercise-induced thermal threshold of ~38°C exists where hormonal responses are observed. Therefore, core temperature increases may be integrated in the controlling system of hormonal and leukocytic responses to exercise.Key words: exercise, hyperthermia, body temperature, growth hormone, catecholamines, hormones.

Contactless Core-Temperature Monitoring by Infrared Thermal Sensor using Mean Absolute Error Analysis

2020 ◽  
Vol 15 ◽  
Author(s):  
Fahad Layth Malallah ◽  
Baraa T. Shareef ◽  
Mustafah Ghanem Saeed ◽  
Khaled N. Yasen
Keyword(s):  
Body Temperature ◽  
Embedded System ◽  
Core Temperature ◽  
Integrated Circuit ◽  
Mean Absolute Error ◽  
Absolute Error ◽  
Thermal Sensor ◽  
Human Face ◽  
Body Contact ◽  
Arduino Microcontroller

Aims: Normally, the temperature increase of individuals leads to the possibility of getting a type of disease, which might be risky to other people such as coronavirus. Traditional techniques for tracking core-temperature require body contact either by oral, rectum, axillary, or tympanic, which are unfortunately considered intrusive in nature as well as causes of contagion. Therefore, sensing human core-temperature non-intrusively and remotely is the objective of this research. Background: Nowadays, increasing level of medical sectors is a necessary targets for the research operations, especially with the development of the integrated circuit, sensors and cameras that made the normal life easier. Methods: The solution is by proposing an embedded system consisting of the Arduino microcontroller, which is trained with a model of Mean Absolute Error (MAE) analysis for predicting Contactless Core-Temperature (CCT), which is the real body temperature. Results: The Arduino is connected to an Infrared-Thermal sensor named MLX90614 as input signal, and connected to the LCD to display the CCT. To evaluate the proposed system, experiments are conducted by participating 31-subject sensing contactless temperature from the three face sub-regions: forehead, nose, and cheek. Conclusion: Experimental results approved that CCT can be measured remotely depending on the human face, in which the forehead region is better to be dependent, rather than nose and cheek regions for CCT measurement due to the smallest

ROLE OF SCIENCE IN POLICY, SYSTEMS STRENGTHENING AND SUSTAINABLE SERVICE DELIVERY OF ARSENIC SAFE DRINKING WATER

2019 ◽  
Author(s):  
Prosun Bhattacharya ◽  
◽  
Md. Tahmidul Islam ◽  
Dara Johnston ◽  
Nargis Akter ◽  
...  
Keyword(s):  
Drinking Water ◽  
Service Delivery ◽  
Safe Drinking Water ◽  
Policy Systems

Desaturation of exhaled air in camels

1981 ◽  
Vol 211 (1184) ◽  
pp. 305-319 ◽  
Keyword(s):  
Drinking Water ◽  
Heat Exchange ◽  
Body Temperature ◽  
Water Vapour ◽  
Mechanical Model ◽  
Ambient Air ◽  
Body Core Temperature ◽  
Hygroscopic Properties ◽  
Exhaled Air ◽  
Body Core

We have found that camels can reduce the water loss due to evaporation from the respiratory tract in two ways: (1) by decreasing the temperature of the exhaled air and (2) by removal of water vapour from this air, resulting in the exhalation of air at less than 100% relative humidity (r. h.). Camels were kept under desert conditions and deprived of drinking water. In the daytime the exhaled air was at or near body core temperature, while in the cooler night exhaled air was at or near ambient air temperature. In the daytime the exhaled air was fully saturated, but at night its humidity might fall to approximately 75% r. h. The combination of cooling and desaturation can provide a saving of water of 60% relative to exhalation of saturated air at body temperature. The mechanism responsible for cooling of the exhaled air is a simple heat exchange between the respiratory air and the surfaces of the nasal passageways. On inhalation these surfaces are cooled by the air passing over them, and on exhalation heat from the exhaled air is given off to these cooler surfaces. The mechanism responsible for desaturation of the air appears to depend on the hygroscopic properties of the nasal surfaces when the camel is dehydrated. The surfaces give off water vapour during inhalation and take up water from the respiratory air during exhalation. We have used a simple mechanical model to demonstrate the effectiveness of this mechanism.

Sign in / Sign up

Export Citation Format

Share Document