THE EFFECT OF INTERMITTENT INDOOR COLD EXPOSURE ON WHITE RATS

1960 ◽  
Vol 38 (1) ◽  
pp. 517-521 ◽  
Author(s):  
O. Héroux
Keyword(s):  
Constant Temperature ◽  
Cold Exposure ◽  
Cold Resistance ◽  
Muscle Growth ◽  
Cold Temperature ◽  
Continuous Exposure ◽  
White Rats ◽  
Winter Conditions ◽  
The One ◽  
Cellular Alterations

Recently it has been shown that when white rats are kept in individual cages and exposed indoors to constant cold temperature or when they are exposed in groups to the outdoor winter conditions, they develop similar degrees of cold resistance and similar metabolic adjustments but they differ in endocrine, insulative, and peripheral adjustments.In an attempt to determine whether variations in temperature alone could be responsible for the type of adjustments developed outdoors, white rats were kept at 30 °C for 4 weeks but exposed to 6 °C for a few hours every day. Through these intermittent cold exposures, the animals developed the same type of acclimation as the one produced indoors by continuous exposure to a constant temperature, but to a lesser degree. Adrenals tended to hypertrophy, body and muscle growth tended to decrease, and over-all insulation appeared to decrease. In contrast to continuously exposed rats, however, they showed no cold injury, no change in ear vascularization, and no thickening of the ear epidermis, probably because the skin was never cooled long enough at any given time for the cold temperature to produce cellular alterations that could not be corrected during the warm periods.

THE EFFECT OF INTERMITTENT INDOOR COLD EXPOSURE ON WHITE RATS

1960 ◽  
Vol 38 (6) ◽  
pp. 517-521 ◽  
Author(s):  
O. Héroux
Keyword(s):  
Constant Temperature ◽  
Cold Exposure ◽  
Cold Resistance ◽  
Muscle Growth ◽  
Cold Temperature ◽  
Continuous Exposure ◽  
White Rats ◽  
Winter Conditions ◽  
The One ◽  
Cellular Alterations

Recently it has been shown that when white rats are kept in individual cages and exposed indoors to constant cold temperature or when they are exposed in groups to the outdoor winter conditions, they develop similar degrees of cold resistance and similar metabolic adjustments but they differ in endocrine, insulative, and peripheral adjustments.In an attempt to determine whether variations in temperature alone could be responsible for the type of adjustments developed outdoors, white rats were kept at 30 °C for 4 weeks but exposed to 6 °C for a few hours every day. Through these intermittent cold exposures, the animals developed the same type of acclimation as the one produced indoors by continuous exposure to a constant temperature, but to a lesser degree. Adrenals tended to hypertrophy, body and muscle growth tended to decrease, and over-all insulation appeared to decrease. In contrast to continuously exposed rats, however, they showed no cold injury, no change in ear vascularization, and no thickening of the ear epidermis, probably because the skin was never cooled long enough at any given time for the cold temperature to produce cellular alterations that could not be corrected during the warm periods.

SEASONAL ADJUSTMENTS IN CAPTURED WILD NORWAY RATS: II. SURVIVAL TIME, PELT INSULATION, SHIVERING, AND METABOLIC AND PRESSOR RESPONSES TO NORADRENALINE

1962 ◽  
Vol 40 (1) ◽  
pp. 537-545 ◽  
Author(s):  
O. Héroux ◽  
Donna Wright
Keyword(s):  
Survival Time ◽  
Metabolic Response ◽  
Cold Temperature ◽  
White Rats ◽  
Winter Conditions ◽  
Pressor Responses ◽  
Wild Rats ◽  
Norway Rats ◽  
Shivering Thermogenesis

During the winter, wild rats (Rattus norwegicus) develop metabolic adjustments similar to those found in the white rats acclimated to cold in the laboratory. The rate of shivering found in the winter-captured wild rats is lower than that found in the summer-captured rats, indicating the presence of non-shivering thermogenesis. The metabolic response to noradrenaline is enhanced suggesting that non-shivering metabolism in these wild rats, as in the case of white rats, is mediated by noradrenaline. Unlike white rats acclimated to a constant cold temperature in the laboratory, but like white rats acclimatized to cold by group exposure to outdoor winter conditions, wild rats develop a greater pelt insulation in winter.

COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: I. METABOLIC AND INSULATIVE CHANGES

1959 ◽  
Vol 37 (3) ◽  
pp. 473-478 ◽  
Author(s):  
O. Héroux ◽  
F. Depocas ◽  
J. S. Hart
Keyword(s):  
Metabolic Rate ◽  
Constant Temperature ◽  
Environmental Conditions ◽  
Resting Metabolic Rate ◽  
Thermal Acclimation ◽  
Cold Temperature ◽  
Metabolic Rates ◽  
Temperature Range ◽  
White Rats ◽  
Physiological Adjustments

Physiological adjustments to cold temperature have been compared in white rats exposed either to the outdoor fluctuating environmental conditions or to the indoor constant temperature conditions. While the metabolic adjustments such as increased peak metabolism and decreased shivering were similar in outdoor and indoor rats exposed to cold, the adjustments in insulation and thermoneutral metabolic rates were quite different. The pelage insulation increased in the rats kept outside during the winter but remained unchanged in the rats kept in a constant temperature room maintained at 6 °C. The resting metabolic rate measured at 30 °C increased in the 6 °C acclimated rats but not in the winter-exposed animals. Over the temperature range +30 °C to −15 °C, while the indoor cold-acclimated rats had a higher metabolic rate than their controls acclimated to 30 °C, the winter rats had a lower metabolism than their summer controls.

SEASONAL ADJUSTMENTS IN CAPTURED WILD NORWAY RATS: II. SURVIVAL TIME, PELT INSULATION, SHIVERING, AND METABOLIC AND PRESSOR RESPONSES TO NORADRENALINE

1962 ◽  
Vol 40 (4) ◽  
pp. 537-545 ◽  
Author(s):  
O. Héroux ◽  
Donna Wright
Keyword(s):  
Survival Time ◽  
Metabolic Response ◽  
Cold Temperature ◽  
White Rats ◽  
Winter Conditions ◽  
Pressor Responses ◽  
Wild Rats ◽  
Norway Rats ◽  
Shivering Thermogenesis

During the winter, wild rats (Rattus norwegicus) develop metabolic adjustments similar to those found in the white rats acclimated to cold in the laboratory. The rate of shivering found in the winter-captured wild rats is lower than that found in the summer-captured rats, indicating the presence of non-shivering thermogenesis. The metabolic response to noradrenaline is enhanced suggesting that non-shivering metabolism in these wild rats, as in the case of white rats, is mediated by noradrenaline. Unlike white rats acclimated to a constant cold temperature in the laboratory, but like white rats acclimatized to cold by group exposure to outdoor winter conditions, wild rats develop a greater pelt insulation in winter.

COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: V. METABOLIC AND CARDIOVASCULAR RESPONSE TO NORADRENALINE

1961 ◽  
Vol 39 (12) ◽  
pp. 1829-1836 ◽  
Author(s):  
O. Héroux
Keyword(s):  
Blood Pressure ◽  
Oxygen Consumption ◽  
Intramuscular Injection ◽  
Cold Resistance ◽  
Cardiovascular Response ◽  
Great Sensitivity ◽  
Slight Degree ◽  
White Rats ◽  
Winter Conditions ◽  
Indoor And Outdoor

White rats cold-acclimated at a constant temperature in the laboratory are known to be more sensitive to noradrenaline than warm-acclimated controls. The present study reveals that this responsiveness to noradrenaline is linearly related to the temperature at which the animals are conditioned. Concomitant measurements (after intramuscular injection of noradrenaline) of oxygen consumption, blood pressure, and heart rates on white rats acclimatized to outdoor summer or winter conditions revealed a much greater metabolic and cardiovascular sensitivity to noradrenaline in winter than in summer rats. The slight degree of shivering upon exposure to 6 °C which was observed in the outdoor winter rats, as well as their great sensitivity to noradrenaline, suggests that under both indoor and outdoor environmental conditions, increased cold resistance is obtained through similar metabolic mechanisms.

Cold exposure of Southdown and Welsh Mountain sheep. 1. Effects of breed, plane of nutrition and acclimatization to cold upon resistance to body cooling

1969 ◽  
Vol 11 (1) ◽  
pp. 65-75 ◽  
Author(s):  
A. R. Sykes ◽  
J. Slee
Keyword(s):  
Cold Exposure ◽  
Cold Resistance ◽  
Temperature Treatment ◽  
Cold Temperature ◽  
Acute Exposure ◽  
Acute Cold Exposure ◽  
Similar Temperature ◽  
Body Cooling ◽  
Female Sheep

SUMMARY1. Twenty-four Southdown and 24 Welsh Mountain year-old female sheep, half on high plane and half on low plane nutrition, were closely shorn and given two short acute cold exposures (−20°C, 4 mph wind) in climate chambers. For two weeks before the first acute exposure half the sheep were kept at a moderately cold temperature (+8°C) and the remainder at a thermoneutral temperature (+30°C). During the next two weeks between acute exposures these temperatures were reversed for each group of sheep.2. Resistance to body cooling during acute cold exposure was significantly greater after exposure to + 8°C. This was attributed to acclimatization. No further acclimatization resulted from acute cold exposure in addition to chronic moderate cold exposure.3. Sheep which had been kept at +8°C cooled 33% more slowly than those which had been at + 30°C. High plane sheep cooled 34 % more slowly than low plane sheep. Southdowns cooled 32 % more slowly than Welsh sheep, but the Welsh sheep showed relatively greater acclimatization on low plane nutrition.4. Compared with Scottish Blackface sheep given similar temperature treatment in an earlier experiment, the Southdowns and Welsh showed less initial cold resistance and less capacity for acclimatization.

COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: I. METABOLIC AND INSULATIVE CHANGES

1959 ◽  
Vol 37 (1) ◽  
pp. 473-478 ◽  
Author(s):  
O. Héroux ◽  
F. Depocas ◽  
J. S. Hart
Keyword(s):  
Metabolic Rate ◽  
Constant Temperature ◽  
Environmental Conditions ◽  
Resting Metabolic Rate ◽  
Thermal Acclimation ◽  
Cold Temperature ◽  
Metabolic Rates ◽  
Temperature Range ◽  
White Rats ◽  
Physiological Adjustments

Physiological adjustments to cold temperature have been compared in white rats exposed either to the outdoor fluctuating environmental conditions or to the indoor constant temperature conditions. While the metabolic adjustments such as increased peak metabolism and decreased shivering were similar in outdoor and indoor rats exposed to cold, the adjustments in insulation and thermoneutral metabolic rates were quite different. The pelage insulation increased in the rats kept outside during the winter but remained unchanged in the rats kept in a constant temperature room maintained at 6 °C. The resting metabolic rate measured at 30 °C increased in the 6 °C acclimated rats but not in the winter-exposed animals. Over the temperature range +30 °C to −15 °C, while the indoor cold-acclimated rats had a higher metabolic rate than their controls acclimated to 30 °C, the winter rats had a lower metabolism than their summer controls.

EFFECT OF COLD EXPOSURE ON RESPIRATORY C14O2 PRODUCTION DURING INFUSION OF ALBUMIN-BOUND PALMITATE-1-C14 IN WHITE RATS

1961 ◽  
Vol 39 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Roberto Masironi ◽  
Florent Depocas
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Cold Exposure ◽  
Carbohydrate Utilization ◽  
White Rats ◽  
Constant Rate ◽  
Oxidation Of Glucose ◽  
Fasted Rats

Albumin palmitate-1-C14 complex was infused at a constant rate through a carotid cannula (inserted 5–7 days earlier) into otherwise intact non-fasted rats in environments at 30° or 6 °C, after acclimation to 30° or 6 °C. At 6 °C, both warm- and cold-acclimated rats similarly exhaled as CI4O2 a larger proportion of the injected C14 and gave lower terminal amounts of C14 in the extracted free fatty acids (F.F.A.) of plasma than at 30 °C. These results indicate that plasma F.F.A. serve as substrate for cold-thermogenesis. Also, increased turnover and oxidation of F.F.A. are not always inversely related to carbohydrate utilization but may be increased under conditions which result in concomitantly higher rates of turnover and oxidation of glucose.

scholarly journals effectiveness testing of l-carnitine on the quality of spermatozoa and testosterone hormone in white rats (Rattus norvegicus) feeding with high fat

2021 ◽  
Vol 4 (1) ◽  
pp. 102-109
Author(s):  
Ni Wayan Sukma Antari ◽  
Ida Ayu Manik Damayanti ◽  
Nadya Treesna Wulansari
Keyword(s):  
Rattus Norvegicus ◽  
Membrane Integrity ◽  
White Rats ◽  
Long Time ◽  
Statistical Program ◽  
High Doses ◽  
The One ◽  
Dose Variation ◽  
One Way Anova

This study aims to determine the increase in the quality of spermatozoa and testosterone after giving L-carnitine to white rats (Rattus norvegicus). This study was conducted by giving L-carnitine as a treatment for 42 days in white rats with a dose variation of 100 mg/kg bw, 150 mg/kg bw, and 200 mg/kg bw and user controls as a comparison. The variables observed in this study were the quality of spermatozoa, namely: morphology, motility, viability, membrane integrity, and seeing the levels of the hormone testosterone. The research data were processed using a computer statistical program (SPSS 22.0 for Windows) using the One Way Anova test. The results showed that giving high doses of L-carnitine supplements for a long time could cause decreased spermatozoa quality, namely: morphology, motility, viability, membrane integrity and decreased levels of the hormone testosterone.

COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: II. SURFACE TEMPERATURE, VASCULARIZATION, AND IN VITRO RESPIRATION OF THE SKIN

1959 ◽  
Vol 37 (1) ◽  
pp. 1247-1253 ◽  
Author(s):  
O. Héroux
Keyword(s):  
Oxygen Uptake ◽  
Surface Temperature ◽  
Respiratory Rate ◽  
Environmental Conditions ◽  
Cold Temperature ◽  
Dorsal Skin ◽  
Adult Rats ◽  
White Rats ◽  
Different Types

The effect of cold temperature on the skin was studied on white rats exposed to two different types of environmental conditions. Two groups of adult rats kept in individual cages were continuously exposed for 3 months to constant cold temperature (18° and 6 °C) in the laboratory (indoor rats) while other groups of the same colony kept in groups of 10 were exposed for the same length of time to the fluctuating environmental conditions prevailing outside (outdoor rats).Indoor rats acclimated to 18 °C and 6 °C showed the same increase in the number of opened capillaries in the ears over the number observed in controls acclimated to 30 °C. "Summer and winter" outdoor rats showed the same number of capillaries as the "18 °C or 6 °C" indoor rats. Signs of injury healing such as thicker epidermis and larger nuclei were found in the ears of all the "6 °C" rats but in none of the "winter" rats. While the skin temperature measured at + 6 °C was slightly higher (0.4 to 1.0 °C) in rats acclimated at 6 °C than in those at 30 °C, it was lower (1.3 to 2.9 °C) in "winter" than in "summer" rats. After 28 days of acclimation, the rate of oxygen uptake of the dorsal skin of the foot was lower in "6 °C" than in "30 °C" rats but after 84 days it was significantly higher in the cold-acclimated rats. Similarly, after 3 months, the respiratory rate of the dorsal skin of the foot was higher in "winter" rats than in "summer" rats.

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