Effects of adrenaline and noradrenaline on the heat production of warm- and cold-acclimated sheep

1981 ◽  
Vol 59 (9) ◽  
pp. 985-993 ◽  
Author(s):  
A. D. Graham ◽  
R. J. Christopherson
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Dose Rate ◽  
Respiration Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Gas Analysis ◽  
Dose Rates ◽  
Temperature Responses

The heat production (HP), heart rate (HR), respiration rate, rumen motility, and body temperature responses to 2.5-h adrenaline (A) and noradrenaline (NA) intrajugular infusions at 0.00, 0.15, 0.30, 0.60, and 0.90 μg∙kg−1∙min−1 were studied in 10 shorn wethers which had been chronically (3–8 weeks) exposed to warm (19–24 °C) or moderately cold (8–13 °C) temperatures. Heat production, as estimated from respired gas analysis, increased 40–45% with all doses of A and the effect was potentiated by chronic cold exposure. Only the higher dose rates of NA induced an increase in HP. The maximum HP increase due to NA was 30% and the effect was not influenced by chronic cold exposure. Thermoneutral HP was greater by 16–19% in cold-acclimated as compared with warm-acclimated sheep. Corresponding to the HP effects of A and NA, all doses of A and the highest dose of NA resulted in slight increases in rectal temperature. Respiration rate increased with increased dose rate of NA but only the highest dose of A resulted in an increase in respiration rate. HR, rectal temperature, and respiration rate responses to A and NA were not influenced by cold acclimation.

Effect of continuous cold exposure on nocturnal body temperatures of man

1959 ◽  
Vol 14 (1) ◽  
pp. 43-45 ◽  
Author(s):  
M. B. Kreider ◽  
P. F. Iampietro ◽  
E. R. Buskirk ◽  
David E. Bass
Keyword(s):  
Body Temperature ◽  
Cold Stress ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Control Period ◽  
Cold Period ◽  
Body Temperatures ◽  
Temperature Responses

Effects of continuous cold stress on 24-hour patterns of body temperature were studied in five men. Cold stress consisted in living at 15.6℃ (60℉) for 14 days wearing only shorts. The cold period was preceded and followed by 2 weeks at 26.7℃ (80℉). Activity (minimal) and diet were the same for all periods. One blanket was used at night. Rectal temperature (Tr) and skin temperature (Ts) were measured. Tr during sleep fell more rapidly and to lower values during cold exposure (35.6℃) than during the control period (36.1℃). Ts during sleep was slightly lower in the cold than in the control period; also, Ts did not exhibit the gradual drop characteristic of sleep in the control period. Comparison of Tr and Ts between early and later cold days revealed the following differences: a) nocturnal Tr fell to lower levels on the later cold days; b) nocturnal toe temperatures were 15℃ (27℉) higher on the later cold days. The arch temperatures followed the same pattern as the toes. No significant differences were found in daytime temperatures between early and later cold days. The data suggest that evidence for acclimatization to cold in terms of altered body temperature responses may be fruitfully sought in responses during rewarming and/or sleep. Submitted on September 19, 1958

Acclimatization of calves to a hot humid environment

1959 ◽  
Vol 52 (3) ◽  
pp. 305-312 ◽  
Author(s):  
W. Bianca
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Metabolic Heat ◽  
Hot Environment ◽  
Humid Environment ◽  
Physiological Reactions

1. Three calves were exposed in a climatic room to an environment of 40° C. dry-bulb and 38° C. wet-bulb temperature for up to 110 min. each day for 1-2 weeks.2. These exposures produced progressive changes in the physiological reactions of the animals to heat:(a) Rectal temperature and skin temperature (for a given time of exposure) declined. In consequence there was a marked increase in the tolerance time, i.e. in the time for which the animals could withstand the hot environment before reaching a rectal temperature of 42° C.(b) Respiratory rate rose earlier and assumed higher levels (for given levels of body temperature).(c) Heart rate decreased markedly.3. These changes are discussed in relation to heat loss and heat production and have been interpreted as reflecting chiefly a reduction in the metabolic heat production of the animals.

Effect of aminophylline on metabolic and thermoregulatory responses during hypothermia associated with cold exposure in lambs

2003 ◽  
Vol 83 (4) ◽  
pp. 739-748 ◽  
Author(s):  
B. Zimmermann ◽  
G. Diebold ◽  
J. Galbraith ◽  
W. Whitmore ◽  
M. Okamoto ◽  
...  
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Phosphodiesterase Inhibitor ◽  
Rate Of Development ◽  
Dose Rates ◽  
Maximum Metabolic Rate ◽  
Response Trial

Three experiments were conducted with lambs to test the hypothesis that the phosphodiesterase inhibitor/adenosine blocker, aminophylline would enhance metabolic rate and delay the development of hypothermia. In exp. 1, eight lambs were treated either with aminophylline or control (0.9% saline) injections. During hypothermia, metabolic rate was increased from a resting value of 4.8 W kg-1 to maximum values of 15–16 W kg-1. The rate of development of hypothermia and recovery there from were inversely related to age and body weight. Aminophylline (8 mg kg-1) did not affect resting or maximum metabolic rate, but after a second injection, aminophylline increased metabolic rate after warming (P < 0.05) and tended to shorten the absolute period of time to restore normal rectal temperature (P < 0.10). In exp. 2, a dose-response trial with six lambs each receiving 0, 2, 16 or 32 mg aminophylline indicated that dose rates of 16 and 32 mg kg-1 increased (P < 0.05) metabolic rate of lambs. In exp. 3, 21 lambs received either 0.9% saline or aminophylline (24 mg kg-1) injections. Mean heat production ranged from 13 to 15 W kg-1 and was increased approximately 7% (P < 0.01) by aminophylline. Aminophylline, therefore, has some potential as a treatment for hypothermia or to improve recovery from hypothermia in lambs by increasing metabolic rate during cold stress. Key words: Lamb, metabolic rate, hypothermia, thermoregulation, Aminophylline®, phosphodiesterase inhibitor

scholarly journals 18 Comparing stress indicators of horses used for therapy in riding activities and groundwork activities

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 83-83
Author(s):  
Gabrielle Abbott ◽  
Kathi Jogan ◽  
Erin L Oberhaus ◽  
Jason Apple ◽  
Charles Rosenkrans
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Respiration Rate ◽  
Rectal Temperature ◽  
Latin Square ◽  
Serum Cortisol ◽  
Well Being ◽  
Experimental Unit ◽  
Activity Type ◽  
Experimental Time

Abstract Equine therapy is used to assist people suffering from various physical and mental disabilities. Equine-assisted activities and therapies (EAAT) include therapeutic riding and hippotherapy. Our objective was to determine the effects of EAAT on horse heart rate, respiration rate, temperature, and serum cortisol. Horses (n = 7) were assigned to activity type (groundwork or riding) in a Latin square design in which all horses performed both activities twice. Heart rate, respiration rate, rectal temperature, and serum cortisol concentrations were determined at 15 minutes before, and 15, 45, and 75 minutes after activity was initiated. Pearson correlations revealed that cortisol was not correlated (r &lt; 0.12; P &gt; 0.22) with heart rate, respiration rate, or rectal temperature. Heart rate was correlated (P &lt; 0.05) with respiration rate (r = 0.77) and body temperature (r = 0.2); and body temperature was correlated with respiration rate (r = 0.21; P &lt; 0.05). Analysis of variance was performed with horse within date as the experimental unit, main effects of activity type, horse, date, experimental time, and interactions. Serum concentrations of cortisol (varied from 2.8 to 89.7 ng/mL) and body temperature (37.4 ± 0.06) were affected (P &lt; 0.01) by an interaction between experimental time and horse. Heart rate (61 ± 2.1) and respiration rate (30 ± 1.4) were affected (P &lt; 0.01) by interactions between experimental time and horse; and experimental time and activity type. Our results demonstrate that equine athletes serving in EAAT programs have altered physiological responses depending on the horse, type of activity, and length of time performing the task. Based on our results, cortisol concentrations are not the best indicator of a horse’s response to EAAT work, and we recommend that trainers monitor horses’ heart and respiration rates as an indicator of horse well-being while working with patients.

Cold-induced inhibition of thermal panting in shorn sheep. 2. Effect of previous acclimatization to cold

1973 ◽  
Vol 17 (1) ◽  
pp. 9-19 ◽  
Author(s):  
J. Slee
Keyword(s):  
Heart Rate ◽  
Heat Stress ◽  
Body Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Heat Dissipation ◽  
Heat Storage ◽  
Metabolic Rates ◽  
Respiratory Centre ◽  
Reduction Effect

SUMMARY1. Short cold exposures (2 hr at 18° or 8°C) were used to delay or block panting during subsequent heat stress in shorn Merino and Scottish Blackface sheep. The effect of previous acclimatization to cold upon the block to thermal panting was studied.2. After acclimatization the block was reduced, but less in Merinos than in Blackfaces. In Blackfaces, the reduction effect was inconsistent after short periods of acclimatization, but became significant after prolonged (3 weeks) acclimatization.3. Acclimatization produced elevations in heart rate and body temperature implying increased heat production. Variation in block reduction between breeds and between individuals was related to these presumed changes in heat production. Sheep with highly elevated metabolic rates showed complete block prevention. 4. After cold exposure ceased, elevated heat production disappeared within 8 days and the block returned.5. It was concluded that elevated heat production resulting from acclimatization caused block prevention partly because increased heat storage cancelled the heat debt otherwise incurred during blocking treatment and partly because the increased requirement for heat dissipation overruled the respiratory centre block.

scholarly journals 19 Comparing stress indicators of horses used for therapy in riding activities and groundwork activities

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 36-37
Author(s):  
Gabrielle Abbott ◽  
Kathi Jogan ◽  
Erin L Oberhaus ◽  
Jason Apple ◽  
Charles Rosenkrans
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Respiration Rate ◽  
Rectal Temperature ◽  
Latin Square ◽  
Serum Cortisol ◽  
Well Being ◽  
Experimental Unit ◽  
Activity Type ◽  
Experimental Time

Abstract Equine therapy is used to assist people suffering from various physical and mental disabilities. Equine-assisted activities and therapies (EAAT) include therapeutic riding and hippotherapy. Our objective was to determine the effects of EAAT on horse heart rate, respiration rate, temperature, and serum cortisol. Horses (n = 7) were assigned to activity type (groundwork or riding) in a Latin square design in which all horses performed both activities twice. Heart rate, respiration rate, rectal temperature, and serum cortisol concentrations were determined at 15 minutes before, and 15, 45, and 75 minutes after activity was initiated. Pearson correlations revealed that cortisol was not correlated (r &lt; 0.12; P &gt; 0.22) with heart rate, respiration rate, or rectal temperature. Heart rate was correlated (P &lt; 0.05) with respiration rate (r = 0.77) and body temperature (r = 0.2); and body temperature was correlated with respiration rate (r = 0.21; P &lt; 0.05). Analysis of variance was performed with horse within date as the experimental unit, main effects of activity type, horse, date, experimental time, and interactions. Serum concentrations of cortisol (varied from 2.8 to 89.7 ng/mL) and body temperature (37.4 ± 0.06) were affected (P &lt; 0.01) by an interaction between experimental time and horse. Heart rate (61 ± 2.1) and respiration rate (30 ± 1.4) were affected (P &lt; 0.01) by interactions between experimental time and horse; and experimental time and activity type. Our results demonstrate that equine athletes serving in EAAT programs have altered physiological responses depending on the horse, type of activity, and length of time performing the task. Based on our results, cortisol concentrations are not the best indicator of a horse’s response to EAAT work, and we recommend that trainers monitor horses’ heart and respiration rates as an indicator of horse well-being while working with patients.

ADAPTATION OF WHITE MICE (MUS MUSCULUS) TO REPEATED COOLING

1967 ◽  
Vol 45 (3) ◽  
pp. 321-327 ◽  
Author(s):  
David M. Ogilvie
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Mus Musculus ◽  
Room Temperature ◽  
The Body ◽  
Progressive Decrease

The effects, on the body temperature of white mice, of repeated short exposures to cold were investigated using two methods of restraint. Animals held in a flattened posture became hypothermic at room temperature, cooled more than five times as fast at −10 °C as mice that could adopt a heat-conserving posture, and continued to cool for some time after they were removed from the cold. With repeated tests, cooling at room temperature decreased, and an improvement in re warming ability was observed. In addition, with lightly restrained mice, the fall in rectal temperature during cold exposure showed a progressive decrease, a phenomenon not observed with severely restrained animals.

scholarly journals Human thermoregulatory responses during serial cold-water immersions

1998 ◽  
Vol 85 (1) ◽  
pp. 204-209 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
Michael N. Sawka ◽  
Kent B. Pandolf
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Alternative Explanation ◽  
Cold Water ◽  
Metabolic Heat Production ◽  
Normal Body Temperature ◽  
Repeat Trial ◽  
Metabolic Heat ◽  
Made In

This study examined whether serial cold-water immersions over a 10-h period would lead to fatigue of shivering and vasoconstriction. Eight men were immersed (2 h) in 20°C water three times (0700, 1100, and 1500) in 1 day (Repeat). This trial was compared with single immersions (Control) conducted at the same times of day. Before Repeat exposures at 1100 and 1500, rewarming was employed to standardize initial rectal temperature. The following observations were made in the Repeat relative to the Control trial: 1) rectal temperature was lower and heat debt was higher ( P < 0.05) at 1100; 2) metabolic heat production was lower ( P < 0.05) at 1100 and 1500; 3) subjects perceived the Repeat trial as warmer at 1100. These data suggest that repeated cold exposures may impair the ability to maintain normal body temperature because of a blunting of metabolic heat production, perhaps reflecting a fatigue mechanism. An alternative explanation is that shivering habituation develops rapidly during serially repeated cold exposures.

Acclimatization of calves to a hot dry environment

1959 ◽  
Vol 52 (3) ◽  
pp. 296-304 ◽  
Author(s):  
W. Bianca
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Metabolic Heat Production ◽  
Metabolic Heat ◽  
Physiological Reactions

1. Three calves were individually exposed in a climatic room to an environment of 45° C. dry-bulb and 28° C. wet-bulb temperature for 21 successive days up to 5 hr. each day.2. In the 21-day period, mostly during the first half of it, the following changes in the physiological reactions of the animals were observed: progressive reductions in rectal temperature, in heart rate and in respiratory rate with a change of breathing from a laboured to a less laboured type.3. It was suggested that a decrease in metabolic heat production might play a part in the observed acclimatization.

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