Acclimatization of Scottish Blackface sheep to cold. 2. Skin temperature, heart rate, respiration rate, shivering intensity and skinfold thickness

1968 ◽  
Vol 10 (1) ◽  
pp. 17-35 ◽  
Author(s):  
A. R. Sykes ◽  
J. Slee
Keyword(s):  
Heart Rate ◽  
Skin Temperature ◽  
Cold Exposure ◽  
Chronic Exposure ◽  
Physiological Responses ◽  
Skinfold Thickness ◽  
Acute Exposure ◽  
Heart Rates ◽  
Ambient Temperatures ◽  
Acute Cold Exposure

Closely shorn Scottish Blackface female sheep aged 9–14 months, half on high plane and half on low plane nutrition, were subjected, in climate chambers, to two short acute cold exposures down to −20°C. The acute exposures were separated by two weeks chronic exposure to a moderately subcriticai temperature (+8°C) or to a thermoneutral temperature (+30°C). Most of the sheep showed a greater resistance to body cooling at the second acute exposure (Slee and Sykes, 1967). This increased resistance to hypothermia, defined as acclimatization, was apparently influenced more by acute than by chronic cold exposure. The present paper deals with changes in skin temperature, heart rate, shivering intensity and skinfold thickness which also resulted from cold exposure, and accompanied acclimatization.After acute cold exposure followed by chronic exposure to +8°C the following changes in these parameters were observed:1. Extremity skin temperatures and heart rates were consistently increased at thermoneutral ambient temperatures.2. Vasoconstriction of the extremities and increased heart rate, both of which normally occur during the early stages of cold exposure, were delayed.3. Heart rates at sub-zero ambient temperatures were increased.4. Cold-induced vasodilatation at sub-zero ambient temperatures was increased.After acute cold treatment alone the intensity of shivering during the second acute exposure was reduced. Also the onset of foot vasoconstriction was slightly delayed.A highly significant relationship was observed between shivering intensity and heart rate during cold exposure.Plane of nutrition had less effect on the physiological responses to cooling than did previous cold experience.It was suggested in discussion that the physiological responses associated with acclimatization were: elevated basal metabolic rate, delayed onset of vasoconstriction and delayed metabolic response to cold, and consequent lowering of the critical temperature. Summit metabolism was also increased and shivering intensity reduced during acute cold exposure. Some of these responses could have resulted from either acute or chronic moderate cold exposure. However their persistence, once induced, appeared to depend upon continued exposure to moderate cold.

Changes in beta-adrenergic responsiveness of rats during chronic cold exposure

1980 ◽  
Vol 49 (6) ◽  
pp. 923-929 ◽  
Author(s):  
C. C. Barney ◽  
M. J. Katovich ◽  
M. J. Fregly ◽  
P. E. Tyler
Keyword(s):  
Heart Rate ◽  
Cold Exposure ◽  
Chronic Exposure ◽  
Cardiovascular Responses ◽  
Time Dependent ◽  
Adrenergic Stimulation ◽  
Adrenergic Agonist ◽  
Beta Adrenergic ◽  
Heart Rates ◽  
Beta Adrenergic Agonist

Administration of isoproterenol (50 micrograms/kg sc) to rats that had been exposed to cold (6 degrees C) for 10, 15, and 25 days was accompanied by a greater increase in tail skin and colonic temperatures than in controls kept at 25 degrees C. Administration of isoproterenol (8 micrograms/kg sc) to cold-treated rats (1, 3, 5, 7, 14, and 28 days) increased heart rates above that of controls. However, resting unstimulated heart rates of cold-treated rats were also increased above that of controls after 1, 3, 5, and 7 days of cold exposure but were not different from controls after 14 and 28 days. Cold exposure also led to time-dependent increases in the weights of heart, adrenals, and interscapular brown fat. Thus, chronic exposure of rats to cold is accompanied by an increase in responsiveness of both heart rate and tail skin and colonic temperatures to beta-adrenergic stimulation. The results also suggest that increases in responsiveness to a beta-adrenergic agonist may not occur at the same time for the different beta-adrenergic-mediated metabolic and cardiovascular responses in cold-treated rats.

Cold Exposure of Southdown and Welsh Mountain Sheep. 2. Effects of breed, plane of nutrition and previous acclimatization to cold upon skin temperature, heart rate, shivering and respiration rate

1969 ◽  
Vol 11 (1) ◽  
pp. 77-89 ◽  
Author(s):  
A. R. Sykes ◽  
J. Slee
Keyword(s):  
Heart Rate ◽  
Metabolic Rate ◽  
Skin Temperature ◽  
Cold Exposure ◽  
Basal Metabolic Rate ◽  
Temporary Increase ◽  
Heart Rates ◽  
Breed Differences ◽  
Body Cooling ◽  
Skin Temperatures

SUMMARYShorn Southdown and Welsh Mountain sheep on high or maintenance levels of nutrition were subjected to two acute (−20°C; 4 mph wind) cold exposures in climate chambers. Before and between exposures the sheep were kept in either a cold (+8°C) or a thermoneutral (+30°C) environment.1. At +8°C, all the sheep shivered and showed sustained vasoconstriction and elevated heart rates.2. At + 30°C, heart rates, skin temperatures on the extremities and muscular tone were all consistently higher in sheep which had previously been kept at +8°C.3. During cooling, the onset of vasoconstriction and increase in heart rate were both delayed in sheep previously kept at + 8°C.4. These effects (2, 3) were retained for at least 2 days but less than 12 days after the sheep returned to thermoneutrality. They decayed faster than the increased resistance to body cooling produced simultaneously in the same sheep (Sykes and Slee, 1969), since this was still detectable after 2 weeks.5. Breed differences were mainly small.6. It was concluded that acclimatization induced by chronic cold exposure was associated with a temporary increase in basal metabolic rate.

Responses of cold- and warm-adapted dogs to infused norepinephrine and acute body cooling

1965 ◽  
Vol 209 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Tetsuo Nagasaka ◽  
Loren D. Carlson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cold Exposure ◽  
Nonshivering Thermogenesis ◽  
Mechanically Ventilated ◽  
Cold Adapted ◽  
Pentobarbital Sodium ◽  
Acute Cold Exposure ◽  
Increased Sensitivity ◽  
Body Cooling

Oxygen consumption, heart rate, and colonic, pinna, and paw temperatures were recorded continuously in warm-adapted (W-A) and cold-adapted (C-A) dogs anesthetized with pentobarbital sodium (30 mg/kg), paralyzed with Flaxedil (5 mg/kg per hr), and mechanically ventilated. The dogs were infused with norepinephrine (1.25 µg/kg per min) for 20 min at 30 C and after 45 min of acute cold exposure to 5 C. Oxygen consumption of C-A dogs increased with a slight increase in the heart rate during the initial 18–20 min of body cooling. O2 consumption decreased continuously during cold exposure in W-A dogs. Calorigenic effects of infused noradrenaline were similar in C-A and W-A dogs at 30 C and 5 C. Heart rate increased in W-A dogs at 30 and 5 C. These results show that nonshivering thermogenesis is well developed by cold acclimation in dogs, and suggest that the increase may be due to an increase in noradrenaline in blood rather than to increased sensitivity of the animals to the calorigenic effects of noradrenaline.

Physiological reactions to heat of Bushmen and of unacclimatized and acclimatized Bantu

1964 ◽  
Vol 19 (5) ◽  
pp. 885-888 ◽  
Author(s):  
C. H. Wyndham ◽  
N. B. Strydom ◽  
J. S. Ward ◽  
J. F. Morrison ◽  
C. G. Williams ◽  
...  
Keyword(s):  
Physical Fitness ◽  
Ethnic Groups ◽  
Cold Exposure ◽  
Skinfold Thickness ◽  
Good Evidence ◽  
Heat Conductance ◽  
Heart Rates ◽  
Kalahari Desert ◽  
Cold Responses ◽  
Physiological Reactions

Bushmen in the Kalahari desert fulfill two criteria for acclimatization to heat. They exercise actively, in hunting, in relatively severe heat in midsummer. Compared with unacclimatized Bantu they have higher sweat rates per square meter and lower heart rates. However, rectal temperatures are not much lower than those of unacclimatized Bantu. River Bushmen present a paradoxical picture. In summer sweat rates are higher than in winter, but are not as high as desert Bushmen. Summer heart rates are, however, higher than in winter. Rectal temperatures in the two seasons are similar. The higher sweat rates in summer are good evidence of better acclimatization than in winter; the higher heart rates may be a reflection of differences in physical fitness in the two seasons. association of morphology and metabolism on cold exposure; cold responses of Bantu, Bushmen, and Caucasians; heat conductance and skinfold thickness in cold; metabolisms of Bantu, Bushmen, and Caucasians in cold; toe, finger, and rectal temperatures of different ethnic groups in cold Submitted on February 4, 1964

Threshold temperatures for shivering in acute and chronic hypercapnia

1976 ◽  
Vol 41 (1) ◽  
pp. 67-70 ◽  
Author(s):  
K. E. Schaefer ◽  
W. Wunnenberg
Keyword(s):  
Oxygen Consumption ◽  
Cold Exposure ◽  
Muscle Activity ◽  
Chronic Exposure ◽  
Time Course ◽  
Acute Exposure ◽  
Metabolic Adaptation ◽  
Cervical Cord ◽  
Threshold Temperatures ◽  
Electrical Muscle

Threshold temperatures for shivering in acute and chronic hypercapnia were determined in guinea pigs by measuring the time course of cervical cord temperature, skin temperature, oxygen consumption (Vo2), and electrical muscle activity during cold exposure (15 degrees C). Prior to acute exposure to CO2, the shivering threshold was determined in each animal during controlconditions breathing air. With increasing CO2 concentrations (5,7.5, and 15% CO2) the shivering thresholds fell to lower temperatures, decreasing by approximately 40 degrees C at 15% CO2. The shift of the shivering threshold to lower values found during acute exposure to 15% CO2 was reversed after chronic exposure to 15% CO2 for 3 days, which marks the time of metabolic adaptation to CO2.

Cold exposure of Southdown and Welsh Mountain sheep. 4. Changes in concentrations of free fatty acids, glucose, acetone, protein-bound iodine, protein and antibody in the blood

1969 ◽  
Vol 11 (4) ◽  
pp. 479-491 ◽  
Author(s):  
R. Halliday ◽  
A. R. Sykes ◽  
J. Slee ◽  
A. C. Field ◽  
A. J. F. Russel
Keyword(s):  
Serum Protein ◽  
Cold Exposure ◽  
Temperature Treatment ◽  
Acute Exposure ◽  
Protein Levels ◽  
Glucose Levels ◽  
Acute Cold Exposure ◽  
Effects Of Temperature ◽  
Antibody Levels ◽  
Female Sheep

SUMMARYTwenty-four Southdown and 24 Welsh Mountain year-old female sheep, half on high-plane and half on low-plane nutrition, were shorn and given two acute cold exposures in climate chambers. For 2 weeks before and 2 weeks between exposures the sheep were kept in a subcritical (+ 8°C) or a thermoneutral (+30°C) environment. Before the temperature treatment each sheep received an injection of Brucella abortus vaccine. Blood samples were taken during exposure to + 8°C and + 30°C and during the acute cold exposures for estimation of free fatty acid (FFA), protein-bound iodine (PBI), glucose, acetone, serum protein and antibody levels. FFA and glucose levels alone were measured in 32 similarly treated Scottish Blackface sheep.1. Low plane sheep had higher PBI levels at all temperatures, and higher glucose levels during acute cold exposure than high plane sheep. Otherwise most major effects were attributable to ambient temperature.2. At +8°C the PBI, FFA, glucose, serum protein and acetone levels were higher than at + 30°C.3. Blackface sheep had lower FFA and glucose levels than Southdown and Welsh sheep at both temperatures.4. During acute cold exposure, PBI, acetone and FFA levels increased further. PBI levels were highest in sheep previously at + 30°C, and acetone highest in sheep previously at + 8°C. Very high FFA levels were recorded, especially in sheep not previously cold-acclimatized.5. Glucose levels increased initially, but fell towards the end of acute exposure, suggesting that relatively less carbohydrate and more fat was utilized for energy metabolism during this period.6. Serum protein levels fell during acute exposure, possibly because protein catabolism increased. The proportions of albumin and γ-globulin increased and decreased respectively.7. No effects of temperature on antibody levels were detected.

Assessment of Autonomic Responses to Different Driving and Road Conditions

2000 ◽  
Vol 44 (37) ◽  
pp. 679-679
Author(s):  
Byung-Chan Min ◽  
Soon-Cheol Chung ◽  
Sang-Gyun Kim ◽  
Byung-Woon Min ◽  
Chul-Jung Kim ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Skin Temperature ◽  
Galvanic Skin Response ◽  
Physiological Responses ◽  
Mean Value ◽  
Autonomic Responses ◽  
Skin Response ◽  
Curved Road

The purpose of this study was to compare changes in autonomic responses due to different driving and road conditions. We measured physiological responses of the 10 health subjects such as Heart Rate Variability (HRV), Galvanic Skin Response (GSR) and skin temperature in rest and stimulation conditions. The ratio of LF/HF significantly increased and averaged R-R interval decreased on the abrupt stopping and starting and abruptly curved road conditions, compared to other conditions. Mean value of GSR increased and mean value of skin temperature decreased in the abrupt stopping and starting and abruptly curved road conditions, compared to other conditions.

SEASONAL ENERGY EXPENDITURES AND THERMOREGULATORY RESPONSES OF BISON AND CATTLE

1979 ◽  
Vol 59 (3) ◽  
pp. 611-617 ◽  
Author(s):  
R. J. CHRISTOPHERSON ◽  
R. J. HUDSON ◽  
M. K. CHRISTOPHERSEN
Keyword(s):  
Cold Exposure ◽  
Low Temperatures ◽  
Metabolic Rates ◽  
Heart Rates ◽  
Ambient Temperatures ◽  
Energy Expenditures ◽  
Thermoregulatory Responses ◽  
Air Temperatures ◽  
Wind Velocities

The metabolic rates of two bison and four Hereford spring-born calves were measured at monthly intervals from December until the following November. Following adaptation at seasonal ambient temperatures, metabolic measurements were made while calves were exposed to controlled temperatures of +10, 0 and −30 °C. Exposure of the Hereford calves to −30 °C resulted in increased metabolic rates during the first 6 mo of the study but the magnitude of the response was greatly attenuated as the calves grew larger. At −30 °C, bison calves either maintained or reduced metabolic rates compared to expenditures at +10 °C. When the calves were about 17 mo of age, they were exposed to a combination of low temperatures and wind. Wind velocities of 4.7 km∙h−1 did not influence metabolic rates of either bison or Herefords at air temperatures of 0 °C. However, at −30 °C, metabolic rates increased from 650 and 700 KJ∙kg−.75∙d−1 to 835 and 950 KJ∙kg−.75∙d−1 in Hereford and bison calves, respectively. Neither respiratory frequencies nor heart rates were influenced significantly during cold exposure, but heart rates increased in response to wind. In general, metabolic rates and heart rates were lower in bison calves.

scholarly journals Correction: Physiological responses to acute cold exposure in young lean men

PLoS ONE ◽  
2018 ◽  
Vol 13 (7) ◽  
pp. e0200865 ◽  
Author(s):  
Francisco M. Acosta ◽  
Borja Martinez-Tellez ◽  
Guillermo Sanchez-Delgado ◽  
Juan M. A. Alcantara ◽  
Pedro Acosta-Manzano ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Physiological Responses ◽  
Acute Cold Exposure

Use of Individualized Versus Standard Criteria to Identify Abnormal Levels of Heart Rate or Oxygen Saturation in Preterm Infants

2001 ◽  
Vol 9 (2) ◽  
pp. 181-200 ◽  
Author(s):  
Lynda Harrison ◽  
Michael L. Berbaum ◽  
John T. Stem ◽  
Katherine Peters
Keyword(s):  
Heart Rate ◽  
Oxygen Saturation ◽  
Preterm Infants ◽  
Neonatal Intensive Care ◽  
Physiological Responses ◽  
Clinical Effectiveness ◽  
Low Oxygen ◽  
Heart Rates ◽  
Developmental Care ◽  
Physiological Indicators

Preterm infants’ physiological indicators, such as heart rate, respiratory rate, and oxygen saturation levels, are routinely monitored by devices that can alert nurses to threatening changes in condition. Most Neonatal Intensive Care Units use standard criteria as alerting algorithms to determine when an alert should be issued, and these standard criteria have been adopted uncritically in studies of preterm infants. This article presents results from a study examining preterm infants’ physiological responses to a gentle human touch (GHT) intervention in which we compared the use of standard and individualized criteria to define the percentages of abnormally low and high heart rates (HRs) and abnormally low oxygen saturation (O2 sat) levels before, during, and after periods of GHT. Results indicated that there were no differences in the percentages of abnormal HRs or O2 sat values between periods using standard criteria. However, using individualized criteria, there were significantly greater percentages of abnormally low heart rates and O2 sat levels during and after GHT periods as compared to baseline periods. The findings suggest that standard criteria may not be sensitive enough to detect subtle physiological responses to environmental stimuli such as touch. Moreover, consistent with the recognition of the value of individualized developmental care, these results suggest that the clinical effectiveness of individualized criteria for setting monitor alert limits merits further investigation.

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