Nonshivering thermogenesis induced by repetitive cooling of spinal cord in the rat

1976 ◽  
Vol 230 (3) ◽  
pp. 720-723 ◽  
Author(s):  
M Banet ◽  
H Hensel
Keyword(s):  
Spinal Cord ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Rectal Temperature ◽  
Cold Adaptation ◽  
White Male ◽  
Metabolic Effect ◽  
Male Rat ◽  
Nonshivering Thermogenesis ◽  
Experimental Animals

The effect of prolonged and repetitive cooling of the spinal cord on the sensitivity to the metabolic effect of exogenous noradrenaline and on the resistance to cold exposure was studied in the white male rat. The spinal cord of 10 animals was cooled for an average of 90 h-9 h/day 5 days/wk - to a level that induced an increase in oxygen uptake of almost 70%. Oxygen consumption was then measured at 30 degrees C before and 1 h after a subcutaneous injection of noradrenaline (0.4 mg/kg). Following the noradrenaline injection, the experimental animals increased oxygen uptake by 71%, while the control ones increased it by only 33% (P less than 0.01). During exposure to -20 degrees C, the experimental animals, despite their increased capacity for nonshivering thermogenesis, did not maintain rectal temperature longer than the control ones, thus showing that other factors also play a significant role in cold adaptation in the rat.

Nonshivering thermogenesis induced by repetitive hypothalamic cooling in the rat

1976 ◽  
Vol 230 (2) ◽  
pp. 522-526 ◽  
Author(s):  
M Banet ◽  
H Hensel
Keyword(s):  
Oxygen Uptake ◽  
Cold Exposure ◽  
Preoptic Area ◽  
Temperature Sensitive ◽  
Nonshivering Thermogenesis ◽  
Hypothalamic Area ◽  
Hypothalamic Temperature ◽  
Experimental Animals ◽  
Unanesthetized Animals ◽  
Better Than

The effect of prolonged and repetitive cooling of the preoptic/anterior hypothalamic area on the sensitivity to the metabolic effect of noradrenaline and on the resistance to cold exposure was studied in the white rat. The preoptic area of 18 unanesthetized animals was cooled 9 h/day 5 days/wk, for a total of 80-150 h. One hour after a noradrenaline test injection (0.4 mg/kg), the experimental animals in which the preoptic area had been cooled to about 24 degrees C increased oxygen uptake by 81%, whereas those in which the preoptic area had been cooled to about 28 degrees C increased oxygen uptake by 48% (the control animals by only 37%). Despite their increased capacity for nonshivering thermogenesis, the experimental animals did not tolerate cold exposure (-10 degrees C) better than the controls. This development of nonshivering thermogenesis is thought to have been mediated by the hypothalamic temperature-sensitive neurons, and the possibility that it could explain the shift from shivering to nonshivering thermogenesis seen during adaptation to cold is discussed.

Role of Bradycardia and Cold per se in Increasing Mechanical Efficiency of Hypothermic Heart

1958 ◽  
Vol 192 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Henry Badeer ◽  
Avedis Khachadurian
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Arterial Pressure ◽  
Mechanical Efficiency ◽  
Metabolic Effect ◽  
Stroke Work ◽  
Per Se ◽  
Lung Preparation

The relative influence of bradycardia and of cold per se on the oxygen consumption and mechanical efficiency of the dog heart was investigated in the modified heart-lung preparation (11 experiments). Myocardial oxygen uptake was determined under constant arterial pressure and cardiac output in a) normothermia, b) normothermia with bradycardia induced by a cold thermode on the pacemaker, and c) hypothermia producing the same bradycardia as in ( b). At 36.8°C with a rate of 153 beats/min. the efficiency was 8.5% ± 0.3(S.E.), whereas with a rate of 110/min. efficiency was 9.1% ± 0.4(S.E.), a change that is statistically not significant. In hypothermia of 31.5°C with a rate of 110/min. the efficiency was 10.8% ± 0.3(S.E.), an increase that is statistically significant. Performing the same stroke work the hypothermic myocardium consumed less oxygen than the normothermic. It is concluded that the metabolic effect of cold per se is the chief factor responsible for increasing the mechanical efficiency of the hypothermic heart when pressure-volume work is kept constant.

Spinal cord thermosensitivity and sorting of neural signals in cold-exposed rats

1977 ◽  
Vol 42 (2) ◽  
pp. 154-158 ◽  
Author(s):  
C. A. Fuller ◽  
J. M. Horowitz ◽  
B. A. Horwitz
Keyword(s):  
Spinal Cord ◽  
Oxygen Consumption ◽  
Study Data ◽  
Direct Influence ◽  
Nonshivering Thermogenesis ◽  
Neural Signals ◽  
Spinal Cord Temperature ◽  
Identical Manner ◽  
Rate Of Oxygen Consumption ◽  
Spinal Cord Thermosensitivity

In the present study, data relevant to the presence or absence of sorting of neural signals were obtained by evaluating the thermal responses to spinal warming in the chronically prepared rat. Specifically, shivering activity and the rate of oxygen consumption (VO2) were measured in unanesthetized rats during cold exposure (10–16 degrees C). Warming the spinal cord at the level of T2 resulted in a significant decrease in shivering (P less than 0.001), without a significant change in VO2. The shivering response was reversed upon cessation of heating. These results are interpreted as indicating a direct influence of spinal cord temperature on shivering but not nonshivering thermogenesis in the rat. Similarly, in previous work with the rat, we have obtained data supporting hypothalamic receptor control of nonshivering but not shivering heat production. These findings are thus consistent with the suggestion that in the rat there occurs a sorting of neural signals. That is, impulses from the three thermoreceptor locations are not integrated in an identical manner for the control of shivering and nonshivering thermogenesis.

Respiration of Arctic Char (Salvelinus alpinus) From a High Arctic Lake

1973 ◽  
Vol 30 (6) ◽  
pp. 717-723 ◽  
Author(s):  
G. F. Holeton
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Cold Adaptation ◽  
Metabolic Response ◽  
Salvelinus Alpinus ◽  
High Arctic ◽  
Arctic Char ◽  
Short Term ◽  
Arctic Lake ◽  
Wet Weight

The routine of resting oxygen consumption of Arctic char (Salvelinus alpinus) from a high arctic lake (74°42′N) was measured at 2 (acclimated) and 6 C (unacclimated). The oxygen uptake versus wet weight relation at 2 C was: Log O2 uptake = 0.7316 Log weight – 1.0944. Oxygen uptake was low, not showing any evidence of "cold adaptation," and was comparable to projections of oxygen uptake versus temperature relations of other salmonid fish from lower latitudes.The short term metabolic response to a rise in temperature of 4 C was independent of body size except with fish with yolk sacs and weighing less than 0.125 g.

Chamber cold acclimatization in man

1961 ◽  
Vol 16 (6) ◽  
pp. 1011-1015 ◽  
Author(s):  
Thomas R. A. Davis
Keyword(s):  
Oxygen Consumption ◽  
Air Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Technical Assistance ◽  
Exposure Period ◽  
Seasonal Difference ◽  
Nonshivering Thermogenesis ◽  
Cold Acclimatization

In March, ten nude subjects were exposed 8 hr daily for 31 days to an air temperature of 11.8 C. In September, another six subjects were similarly acclimatized to an air temperature of 13.5 C. Measurements were made of the responses of shivering, oxygen consumption, rectal temperature, and skin temperature to a standard cold exposure. By the 14th day, shivering in both groups decreased significantly. Heat production remained unchanged in the winter group but decreased in the summer group. Basal metabolism did not change in either group. In both groups, rectal temperatures were maintained at lower values after the exposure period. In the winter group extremity temperatures were unchanged; those in the summer group were lowered by a small amount. The decrease in heat production and mean surface temperature in the summer group is related to the seasonal difference in cold acclimatization. Failure of cold-elevated metabolism to decrease despite a highly significant decrease in shivering indicates the presence of nonshivering thermogenesis in man. It is concluded that man can be artificially cold acclimatized. Note: With the Technical Assistance of D. R. Johnston, F. C. Bell, W. Rawlings, and L. Lee Submitted on May 8, 1961

Catecholamines in dogs during cold adaptation by repeated immersions

1979 ◽  
Vol 46 (4) ◽  
pp. 662-668 ◽  
Author(s):  
A. Therminarias ◽  
M. F. Chirpaz ◽  
A. Lucas ◽  
M. Tanche
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Cold Adaptation ◽  
Cold Water ◽  
Nonshivering Thermogenesis ◽  
Plasma Epinephrine ◽  
Temperature Plasma ◽  
Enhanced Sensitivity ◽  
Norepinephrine Infusion ◽  
Colonic Temperature

Dogs were immersed in cold water 1 h/day for 30 consecutive days. During the first immersion, oxygen uptake increased approximately sevenfold and colonic temperature decreased; a large increase in plasma epinephrine and norepinephrine concentrations was found; plasma glucose, lactic acid, and free fatty acid (FFA) concentrations were also increased. An adaptative response to cold was evidenced during the 10th immersion by a further increase in oxygen uptake and a reduction in the fall of colonic temperature; plasma epinephrine, glucose, and lactic acid were diminished whereas FFA were higher. Consequently 10 h spent in cold are sufficient to induce an improved capacity for heat production. An enhanced ability to produce nonshivering thermogenesis mediated by epinephrine or norepinephrine is not obvious because after the 30th immersion no enhanced calorigenic response to epinephrine or norepinephrine infusion was found. In dogs mechanisms other than norepinephrine-enhanced sensitivity might be involved in this kind of cold adaptation.

1643: Neuroanatomical Study of the Ejaculation Generator in the Spinal Cord in Male Rat

2004 ◽  
Vol 171 (4S) ◽  
pp. 434-434
Author(s):  
E.D. Yaici ◽  
M. Conrath ◽  
D. Verge ◽  
A. Jestin ◽  
Gérard Benoit ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Male Rat

scholarly journals Cardiorespiratory Responses to 10 Weeks of Exoskeleton-Assisted Overground Walking Training inChronic Nonambulatory Patients with Spinal Cord Injury

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5022
Author(s):  
Jae Hyeon Park ◽  
Hyeon Seong Kim ◽  
Seong Ho Jang ◽  
Dong Jin Hyun ◽  
Sang In Park ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Oxygen Consumption ◽  
Exercise Intensity ◽  
Moderate Physical Activity ◽  
Intensity Level ◽  
Cardiorespiratory System ◽  
Cardiorespiratory Responses ◽  
Cord Injury ◽  
Walking Efficiency

Exercise intensity of exoskeleton-assisted walking in patients with spinal cord injury (SCI) has been reported as moderate. However, the cardiorespiratory responses to long-term exoskeleton-assisted walking have not been sufficiently investigated. We investigated the cardiorespiratory responses to 10 weeks of exoskeleton-assisted walking training in patients with SCI. Chronic nonambulatory patients with SCI were recruited from an outpatient clinic. Walking training with an exoskeleton was conducted three times per week for 10 weeks. Oxygen consumption and heart rate (HR) were measured during a 6-min walking test at pre-, mid-, and post-training. Exercise intensity was determined according to the metabolic equivalent of tasks (METs) for SCI and HR relative to the HR reserve (%HRR). Walking efficiency was calculated as oxygen consumption divided by walking speed. The exercise intensity according to the METs (both peak and average) corresponded to moderate physical activity and did not change after training. The %HRR demonstrated a moderate (peak %HRR) and light (average %HRR) exercise intensity level, and the average %HRR significantly decreased at post-training compared with mid-training (31.6 ± 8.9% to 24.3 ± 7.3%, p = 0.013). Walking efficiency progressively improved after training. Walking with an exoskeleton for 10 weeks may affect the cardiorespiratory system in chronic patients with SCI.

scholarly journals No major thermogenic role for (Na+ + K+)-dependent adenosine triphosphatase apparent in hepatocytes from hyperthyroid rats

1982 ◽  
Vol 202 (3) ◽  
pp. 661-665 ◽  
Author(s):  
D G Clark ◽  
M Brinkman ◽  
O H Filsell ◽  
S J Lewis ◽  
M N Berry
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Atpase Activity ◽  
Heat Production ◽  
Adenosine Triphosphatase ◽  
Heat Output ◽  
Liver Parenchymal ◽  
Dependent Atpase ◽  
Parenchymal Cells ◽  
Isolated Liver

(Na+ + K+)-dependent ATPase activity, heat production and oxygen consumption were increased by 59%, 62% and 75% respectively in hepatocytes from tri-iodothyronine-treated rats. Ouabain at concentrations of 1 and 10 mM decreased oxygen uptake by 2-8% in hepatocytes from euthyroid rats and by 5-15% in hepatocytes from hyperthyroid animals. Heat output was decreased by 4-9% with the glycoside in isolated liver parenchymal cells from the control animals and by 11% in the cells from the tri-iodothyronine-treated animals. These results do not support the hypothesis that hepatic (Na+ + K+)-ATPase plays a major role in increased heat production in hepatocytes from hyperthyroid rats.

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