ÉTUDE DE L'ACCLIMATION THERMIQUE CHEZ LA LIMACE ARION CIRCUMSCRIPTUS

1963 ◽  
Vol 41 (4) ◽  
pp. 671-698 ◽  
Author(s):  
Adolphe Roy
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Heat Production ◽  
Regression Line ◽  
Experimental Temperature ◽  
Acclimation Temperature ◽  
Direct Calorimetry

Slugs of the species Arion circumscriptus were acclimated to temperatures of 5°, 8° 10°, 20°, and 25 °C respectively. After acclimation, metabolic rate was determined, either as oxygen consumption, at 30° and 20°, or by direct calorimetry, at 25° and 12.5°, At all given exposure temperatures, the average metabolic rate was lower, by 1% to 1.5%, for each degree of increase in the acclimation temperature. When the logarithms of total O2 consumption or heat production per hour are plotted against the logarithms of body weight, the regression line obtained for slugs acclimated to heat stands below that obtained for slugs acclimated to cold; the slope is also slighter for the warm-acclimated slugs than for the cold-acclimated, so that the distance between corresponding points of two such curves is larger in the righthand side of the graph, where the large specimens are represented, than in the lefthand side where the small specimens are shown. This would imply that an increase in the acclimation temperature reduces metabolic rate to a proportionately greater extent in the larger specimens than it does in the smaller ones. The value of the slope, which is inversely correlated with acclimation temperature, is also inversely correlated with the experimental temperature at which metabolism is determined.

METABOLIC REFERENCE STANDARDS FOR THE NEONATE

PEDIATRICS ◽  
1967 ◽  
Vol 39 (5) ◽  
pp. 724-732
Author(s):  
John C. Sinclair ◽  
Jon W. Scopes ◽  
William A. Silverman
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Extracellular Fluid ◽  
Mean Value ◽  
Reference Standards ◽  
Contributory Factor ◽  
Tissue Mass ◽  
Rate Of Oxygen Consumption

Oxygen consumption of 92 normally grown newborn babies of birth weight 750 to 3,940 gm has been expressed in terms of various metabolic reference standards in order to identify any systematic variation in expression of metabolic rate that is introduced by these bases of reference in the newborn population. It is postulated that differences in body composition comprise a contributory factor to the variation among newborn babies in rate of oxygen consumption per kilogram body weight. The predictive error from a mean value is increased if surface area, body weight, or fat-free body weight is substituted for body weight as a metabolic reference standard. By taking into account known changes in body composition of the fetus with increasing maturity, a compartment representing the active tissue mass is calculated. This corresponds closely to body weight minus extracellular fluid and includes fat. Rate of oxygen consumption is proportional to the size of this compartment over the range of body weights studied. Implications are discussed as to the metabolic rate of adipose tissue in the newborn and body composition among undergrown babies.

Metabolic Factors in the Development of Homeothermy in Dogs

1958 ◽  
Vol 194 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Donald G. McIntyre ◽  
H. E. Ederstrom
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Metabolic Factors ◽  
Air Temperatures ◽  
Heat Conservation

Dogs from 1 to 25 days of age were exposed to air temperatures of 5, 23 and 30°C and their oxygen consumption measured in a closed calorimeter. Animals 1–5 days old had a rise of 20–25% in metabolic rate, but rectal temperature fell, when they were exposed to 5 or 23°C. At 11–21 days of age dogs exposed to 5°C had a rise of about 75% in metabolic rate, but rectal temperature fell several degrees in 1 hour. In dogs 21–25 days of age metabolic rate increased about 75% at air temperatures of 5°C and rectal temperature fell only about 1°C. Under the same conditions a trained adult dog had a rise of 80% in metabolic rate, and no fall in rectal temperature. Since heat production in 2- to 3-week-old dogs was increased to about the same extent as in the adult on cold exposure, it was assumed that heat conservation lagged behind heat production in the development of homeothermy.

SOME PHYSIOLOGICAL AND NUTRITIONAL ASPECTS OF THE DWARF CHICKEN

1971 ◽  
Vol 51 (1) ◽  
pp. 209-216 ◽  
Author(s):  
G. RAJARATNAM ◽  
J. D. SUMMERS ◽  
A. S. WOOD ◽  
E. T. MORAN Jr.
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Weight Gain ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Body Weight Gain ◽  
Carcass Composition ◽  
Lower Body ◽  
Brand Name ◽  
Dwarf Chicken

A study was undertaken to investigate the feasibility of hypothyroidism as an explanation for the smaller body size and lower metabolic activity of the recessive sex-linked dwarf chicken. A significant increase in body weight gain and feed intake for dwarf chicks with little change in these parameters for normal chicks receiving a diet supplemented with Protamone (brand name for iodinated casein) suggests a hypothyroidic state for the dwarfs. Similarly, a significantly lower body temperature, oxygen consumption and basal metabolic rate with a higher percentage of carcass fat in dwarf chicks as compared with normal ones supports the above hypothesis. Protamone supplementation of the diet increased body temperature and metabolic rate, and altered the carcass composition of the dwarfs to values closer to that of normal chicks, again suggesting a low thyroxine output for the dwarfs.

Energy exchanges of veal calves in relation to body weight, food intake and air temperature

1976 ◽  
Vol 23 (1) ◽  
pp. 35-42 ◽  
Author(s):  
A. J. F. Webster ◽  
J. G. Gordon ◽  
J. S. Smith
Keyword(s):  
Body Weight ◽  
Heat Loss ◽  
Heat Production ◽  
Live Weight ◽  
Milk Replacer ◽  
Total Heat Loss ◽  
Direct Calorimetry ◽  
Veal Calves ◽  
Air Temperatures ◽  
Energy Retention

SUMMARY1. Two series of energy balance trials were conducted with British Friesian veal calves. In the first, calves were given a milk replacer diet at three different planes of nutrition. In the second, calves were raised from about 80 to 180 kg at four air temperatures, 5°, 10°, 15° and 20°.2. The net efficiency of utilization of the milk replacer diet for growth was 0·72. The effect of body size on heat production in growing calves was best expressed by an exponent of body weight slightly but not significantly below W0·75.3. Measurements of heat production estimated from respiratory exchange and heat loss measured by direct calorimetry agreed exactly at all planes of nutrition. Heat production at zero energy retention was 675 kJ/kg W0·75 per 24 hr.4. Average daily live-weight gain and total heat loss were the same at all air temperatures. Changes during growth in the partition of heat loss into its sensible and evaporative components indicated that calves acclimated progressively to the air temperatures to which they were exposed.

An improved water-bath test to study effects of age and previous sucking on metabolic rate and resistance to cold in newborn lambs

1990 ◽  
Vol 50 (2) ◽  
pp. 319-331 ◽  
Author(s):  
J. Slee ◽  
S. P. Simpson ◽  
A. W. Stott ◽  
J. C. Williams ◽  
D. E. Samson
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Heat Production ◽  
Cold Resistance ◽  
Resting Metabolic Rate ◽  
Induced Hypothermia ◽  
Fast Cooling ◽  
Rate Of Cooling ◽  
Effect Of Age ◽  
Shivering Thermogenesis

ABSTRACTDifferent procedures for measuring cold resistance and metabolic rate of newborn lambs were evaluated by varying the extent of induced hypothermia, the rate of cooling and the method of rewarming. Relatively fast cooling followed by a simple self-rewarming procedure proved harmless and satisfactory.The effect of age, from birth up to 2 weeks, on thermoregulation was studied. There was no difference in cold resistance between 0·5 h and 30 h after birth, and between 1 day and 2 weeks after birth, despite a large increase in insulation, body weight and coat depth over this period. Weight-specific resting metabolic rate and cold-induced peak metabolic rate similarly did not change significantly in the first 30 h, although resting metabolic rate tended to be lower at birth than at 30 h of age. Peak metabolic rate decreased significantly between 1 day and 2 weeks of age.The effect of fasting, for 3 to 4 h after birth, on thermoregulation was also studied. Cold resistance and peak metabolic rate were not significantly affected by fasting. Recovery from hypothermia was slightly slower in fasted lambs.These results may reflect the newborn lamb's initial reliance on heat production derived from brown fat and non-shivering thermogenesis. Older lambs, which benefit from better insulation, rely more upon shivering. Fasted lambs showed a tendency to rely more on insulation and slightly less on heat production than suckled lambs.

Effect of hypothyroidism on tolerance of rats to heat

1963 ◽  
Vol 204 (6) ◽  
pp. 1039-1044 ◽  
Author(s):  
Melvin J. Fregly ◽  
Kenneth M. Cook ◽  
Arthur B. Otis
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Heat Production ◽  
Heat Exposure ◽  
Muscular Activity ◽  
Heat Conductance ◽  
Lower Heat ◽  
Do Control ◽  
Colonic Temperature ◽  
Skin Temperatures

Hypothyroid (propylthiouracil-treated) rats show slower rates of rise of both colonic and skin temperatures than do control rats when both groups are restrained and exposed to air at 40 C. The increased tolerance to heat does not appear to be associated with increased heat conductance through skin but rather with lower heat production (oxygen consumption). Metabolic rate of hypothyroid rats decreases slightly during heat exposure while that of controls increases. When both groups are compared at the same colonic temperatures during heating, the metabolic rate of hypothyroid rats is significantly less than that of controls. The lower metabolic rate may be a reflection of the lower level of spontaneous muscular activity observed in these animals during heating. The greater tolerance of hypothyroid rats to heat thus appears to be associated with an ability to resist an increase in heat production as colonic temperature rises.

Abstract 19336: Chronic Vagal Nerve Stimulation Causes Weight Loss by Reducing Food Intake and Feeding Efficiency in Mice

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Harald M Stauss ◽  
Daniel P Dias ◽  
Donald A Morgan ◽  
Kamal Rahmouni
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Weight Gain ◽  
Food Intake ◽  
Metabolic Rate ◽  
Body Weight Gain ◽  
Caloric Intake ◽  
Vagal Nerve ◽  
Feeding Efficiency

Chronic electrical vagal nerve stimulation (VNS) has emerged as a new tool to treat human diseases including obesity. Indeed, chronic VNS has been shown to cause weight loss in humans and in experimental animal models. However, the mechanisms for VNS-induced weight loss are largely unknown. We hypothesized that an increase in metabolic rate together with reduced caloric intake and reduced feeding efficiency (body weight gain per calories consumed) contribute to chronic VNS-induced weight loss or reduced weight gain. To test this hypothesis, we developed a miniaturized microprocessor-operated nerve stimulator for chronic use in conscious mice. Effectiveness of the stimulator was verified by bradycardia at stimulation frequencies above 5 Hz (3V, 1mA, 1ms pulses). Male C57Bl/6 mice (16 weeks old, standard mouse chow diet) were instrumented with nerve stimulators (3V, 1mA, 1ms pulses at 5 Hz) on the right cervical vagal nerve and body weight, food intake and metabolic rate (indirect calorimetry) were determined at baseline and weekly thereafter. After the initial post-surgical weight loss, sham animals (n=9, stimulators off) regained pre-surgical body weight within 16 days (100.0±2.7%). In contrast, mice with chronic VNS (n=12) never reestablished pre-surgical body weight (94.5±0.9% on day 16, P<0.05 vs. sham). Caloric intake was significantly reduced in mice with chronic VNS compared to sham animals (74.7±2.4 vs. 84.6±4.2 kcal/week, P<0.05). Likewise, mice with chronic VNS showed significantly reduced feeding efficiency compared to sham mice (2.6±2.0 vs. 10.6±2.4 mg body weight gain per kcal consumed). Oxygen consumption tended to be elevated (2734±152 vs. 2490±124 mL/kg/h, P=0.23) during the first week, but not thereafter. In conclusion reduced food intake and lower feeding efficiency contribute to reduced weight gain in mice with chronic VNS. We speculate that an initial increase in metabolic rate (assessed by oxygen consumption) may be antagonized by compensatory mechanisms in response to chronic VNS.

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 The influence of food intake on portal blood flow and heat production in the digestive tract of sheep

1975 ◽  
Vol 34 (1) ◽  
pp. 125-139 ◽  
Author(s):  
A. J. F. Webster ◽  
P. O. Osuji ◽  
F. White ◽  
J. F. Ingram
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Food Intake ◽  
Digestive Tract ◽  
Heat Production ◽  
Portal Blood Flow ◽  
Total Heat ◽  
Portal Blood ◽  
Heat Increment

1. Measurements were made of portal blood flow, heat production and oxygen consumption in the digestive tract of sheep either fasted or given the following diets: chopped, dried grass; pelleted, dried grass; chopped, dried lucerne; pelleted, dried lucerne; or a pelleted baley diet.2. For sheep that had been fasted for 48 h, portal blood flow was 1.84 1/min, total visceral heat production was 62.3 kJ/kg body-weight0.75 per 24 h and aerobic heat production, estimated from oxygen consumption, was 62.1 kJ/kg body-weight0.75 per 24 h.3. Portal blood flow was markedly influenced by food intake, increasing from 1.8 1/min for starved sheep to 2.4 and 4 1/min for sheep fed at maintenance and 2.5 × maintenance levels of intake respectively. Variations in the quality and physical form of the diets had no apparent effect on portal blood flow.4. There was a curvilinear relationship between total heat production in the gut and metabolizable energy (ME) intake. The increase obtained for levels of intake below maintenance was greatest with lucerne diets, and least with pelleted, dried grass or pelleted barley diets. Above maintenance levels of intake the rate of increase in heat production, with all diets, was about 150 kJ/MJ ME intake.5. The heat of fermentation, estimated from the difference between total visceral metabolism and the aerobic metabolism of the tissues of the gut wall, was 76, 60 and 22 kJ/MJ digestible energy intake for the dried grass, lucerne and barley diets respectively.6. The contribution of fermentation heat and the aerobic metabolism of the gut to the total heat increment of feeding in sheep was assessed. It was concluded that about half the heat increment must be derived from tissues outside the digestive tract.

Left ventricular heat production during induced tachycardia in the intact dog

1965 ◽  
Vol 209 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Skoda Afonso ◽  
David H. McKenna ◽  
George S. O'Brien ◽  
George G. Rowe ◽  
Charles W. Crumpton
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Coronary Blood Flow ◽  
Heat Production ◽  
Myocardial Oxygen Consumption ◽  
Left Ventricular ◽  
Metabolic Parameters ◽  
Heat Control

It is well established that heart rate is a determinant of myocardial oxygen consumption. However, it has not been demonstrated that the increase of oxygen consumption at faster rates actually represents loss of energy, degraded as heat. Control measurements of systemic and coronary hemodynamic and metabolic parameters and left ventricular heat production (measured by a recently reported method) were obtained in 10 dogs. Tachycardia was then induced electrically and the same parameters redetermined. Significant increases occurred in coronary blood flow, cardiac metabolic rate of oxygen, and left ventricular heat production. The elevated myocardial oxygen consumption at higher rates is associated with increased heat production.

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