Thyroid hormone-induced changes in body temperature and metabolism during exercise in dogs

Changes in serum total thyroxine concentration (TT4) and the effects of thyroxine (T4) and 3,5,3'-triiodothyronine (T3) injection on plasma free fatty acid (FFA) level and rectal temperature (Tre) responses were measured in six dogs at rest and during 1 h of submaximal treadmill exercise. At rest there were no increases in FFA level or Tre up to 72 h after thyroid hormone treatment. During exercise, 5 h after a single T4 injection (0.1 mg/kg), there was a) a significant increase in TT4, although the resting level was markedly elevated, and b) a significant increase in FFA concentration and Tre above control values. Seventy-two hours after T4 injection there was a similar increase in TT4 during exercise and both FFA and Tre levels were greater than 5-h values. The elevated Tre was not associated with increased plasma Na+, K+, or osmotic concentrations. Compared with T4 data, T3 injection (0.1 mg/kg) resulted in greater increases in FFA level and Tre during exercise; two animals reached 43.1 degrees C. There were no significant differences in the respiratory exchange ratio (R) or O2 uptake between the control and T3 experiments. It was concluded that thyroid hormones markedly enhance FFA mobilization and elevated Tre during exercise, but not a rest. The hyperthermic response appears to be due to an increase in the level of regulated body temperature rather than to a depression of heat dissipation.

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Iron-induced changes in nitric oxide and superoxide radical generation in rat liver after lindane or thyroid hormone treatment

Toxicology Letters ◽

10.1016/s0378-4274(00)00295-2 ◽

2001 ◽

Vol 119 (2) ◽

pp. 87-93 ◽

Cited By ~ 21

Author(s):

Pamela Cornejo ◽

Gladys Tapia ◽

Susana Puntarulo ◽

Mónica Galleano ◽

Luis A. Videla ◽

...

Keyword(s):

Nitric Oxide ◽

Thyroid Hormone ◽

Rat Liver ◽

Superoxide Radical ◽

Hormone Treatment ◽

Radical Generation ◽

Induced Changes

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Cardiovascular phenotype and temperature control in mice lacking thyroid hormone receptor-β or both α1 and β

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1999.276.6.h2006 ◽

1999 ◽

Vol 276 (6) ◽

pp. H2006-H2012 ◽

Cited By ~ 22

Author(s):

Catarina Johansson ◽

Sten Göthe ◽

Douglas Forrest ◽

Björn Vennström ◽

Peter Thorén

Keyword(s):

Heart Rate ◽

Locomotor Activity ◽

Thyroid Hormone ◽

Body Temperature ◽

Hormone Receptor ◽

Thyroid Hormone Receptor ◽

Serum Levels ◽

Hormone Treatment ◽

Different Strains ◽

Deficient Mice

We have used a telemetry system to record heart rate, body temperature, electrocardiogram (ECG), and locomotor activity in awake, freely moving mice lacking thyroid hormone receptor (TR)-β or TR-α1 and -β (TR-α1/β). The TR-α1/β-deficient mice had a reduced heart rate compared with wild-type controls. The TR-β-deficient mice showed an elevated heart rate, which, however, was unresponsive to thyroid hormone treatment regardless of hormonal serum levels. ECG revealed that the TR-β-deficient mice had a shortened Q-Tend time in contrast to the TR-α1/β-deficient mice, which exhibited prolonged P-Q and Q-Tend times. Mental or pharmacological stimulation of the sympathetic nervous system resulted in a parallel increase in heart rate in all animals. A single injection of a nonselective β-adrenergic-receptor blocker resulted in a parallel decrease in all mice. The TR-α1/β-deficient mice also had a 0.4°C lower body temperature than controls, whereas no difference was observed in locomotor activity between the different strains of mice. Our present and previous results support the hypothesis that TR-α1 has a major role in determining heart rate under baseline conditions and body temperature and that TR-β mediates a hormone-induced increase in heart rate.

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Dickkopf-1 is dispensable for thyroid hormone-induced changes in bone remodeling

10.1055/s-0039-1680014 ◽

2019 ◽

Author(s):

E Tsourdi ◽

J Colditz ◽

F Lademann ◽

E Rijntjes ◽

J Köhrle ◽

...

Keyword(s):

Thyroid Hormone ◽

Bone Remodeling ◽

Induced Changes ◽

Dickkopf 1

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A Comparison of Physiological Demand between Self-Propelled and Motorized Treadmill Exercise

International Journal of Physical Education Fitness and Sports ◽

10.26524/ijpefs1842 ◽

2018 ◽

Vol 7 (4) ◽

pp. 13-21

Author(s):

Todd Backes ◽

Charlene Takacs

Keyword(s):

Respiratory Exchange Ratio ◽

Treadmill Exercise ◽

Cardiopulmonary Exercise Testing ◽

Mean Value ◽

The Self ◽

Mixing Chamber ◽

Wide Range ◽

The Subject ◽

The Mean ◽

Computer Controlled

There are a wide range of options for individuals to choose from in order to engage in aerobic exercise; from outdoor running to computer controlled and self-propelled treadmills. Recently, self-propelled treadmills have increased in popularity and provide an alternative to a motorized treadmill. Twenty subjects (10 men, 10 women) ranging in age from 19-23 with a mean of 20.4 ± 0.8 SD were participants in this study. The subjects visited the laboratory on three occasions. The purpose of the first visit was to familiarize the subject with the self-propelled treadmill (Woodway Curve 3.0). The second visit, subjects were instructed to run on the self-propelled treadmill for 3km at a self-determined pace. Speed data were collected directly from the self-propelled treadmill. The third visit used speed data collected during the self-propelled treadmill run to create an identically paced 3km run for the subjects to perform on a motorized treadmill (COSMED T150). During both the second and third visit, oxygen consumption (VO2) and respiratory exchange ratio (R) data were collected with COSMED’s Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system. The VO2 mean value for the self-propelled treadmill (44.90 ± 1.65 SE ml/kg/min) was significantly greater than the motorized treadmill (34.38 ± 1.39 SE ml/kg/min). The mean R value for the self-propelled treadmill (0.91 ± 0.01 SE) was significantly greater than the motorized treadmill (0.86 ± 0.01 SE). Our study demonstrated that a 3km run on a self-propelled treadmill does elicit a greater physiological response than a 3km run at on a standard motorized treadmill. Self-propelled treadmills provide a mode of exercise that offers increased training loads and should be considered as an alternative to motorized treadmills.

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Faculty Opinions recommendation of Thyroid hormone treatment among pregnant women with subclinical hypothyroidism: US national assessment.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727247808.793529058 ◽

2017 ◽

Author(s):

John Walsh

Keyword(s):

Thyroid Hormone ◽

Pregnant Women ◽

Subclinical Hypothyroidism ◽

Hormone Treatment ◽

National Assessment

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Linear modulation of serum thyrotrophin by thyroid hormone treatment in hypothyroidism

Acta Endocrinologica ◽

10.1530/acta.0.0950472 ◽

1980 ◽

Vol 95 (4) ◽

pp. 472-478 ◽

Cited By ~ 6

Author(s):

A. Eugene Pekary ◽

Jerome M. Hershman ◽

Clark T. Sawin

Keyword(s):

Thyroid Hormone ◽

Hormone Replacement ◽

Hormone Treatment ◽

Significant Negative Correlation ◽

Thyroid Hormone Replacement ◽

Basal Serum ◽

Thyroid Hormone Levels ◽

Peak Versus ◽

Hypothyroid Patients ◽

Serum Tsh

Abstract. Basal serum TSH and the peak TSH response to a 500 μg TRH bolus were measured in 57 euthyroid and in 29 hypothyroid subjects either receiving graded thyroid hormone replacement or acutely removed from full replacement therapy. Serum TSH, total T4 and T3 were determined by sensitive radioimmunoassay methods. The peak versus basal TSH data for hypothyroid patients were linear within individuals. The regression slope of the peak versus basal TSH data for all hypothyroid subjects did not differ significantly from the corresponding slope for all euthyroid subjects. Basal and peak TSH versus T3 and T4 data for hypothyroid patients were also linear within each individual. Moreover, the regression of the basal TSH values averaged over the non-replacement to full replacement state against the TSH versus T3 slope had a significant negative correlation. This trend leads to an array of regression lines which average to the familiar hyperbolic relationship between thyrotrophin and thyroid hormone levels in man.

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Growth Hormone-Induced Changes in Myofibrillar Protein Breakdown in Hypopituitary Children

Clinical Science ◽

10.1042/cs0640315 ◽

1983 ◽

Vol 64 (3) ◽

pp. 315-320 ◽

Cited By ~ 4

Author(s):

F. J. Ballard ◽

J. L. Burgoyne ◽

F. M. Tomas ◽

J. L. Penfold

Keyword(s):

Growth Hormone ◽

Hormone Treatment ◽

Myofibrillar Protein ◽

The Body ◽

Protein Breakdown ◽

Older Children ◽

Breakdown Rate ◽

Fractional Rate ◽

Excretion Rates ◽

Induced Changes

1. Creatinine and Nτ-methylhistidine excretion rates have been measured in 13 hypopituitary children to calculate the body muscle contents and rates of myofibrillar protein breakdown. Analyses have been made during periods of growth hormone withdrawal and subsequent administration. 2. The creatinine excretion rate was lower in the hypopituitary children, indicating a lower muscle content per kg body weight. This difference persisted even in children who had received growth hormone for several years. 3. Excretion of Nτ-methylhistidine was reduced by the administration of growth hormone. 4. The fractional breakdown rate of myofibrillar protein, as calculated from the Nτ-methylhistidine to creatinine molar excretion ratio, averaged 1.76%/day in the four youngest children during growth hormone withdrawal. This was significantly higher than for control children of a similar age (P < 0.02) and was reduced to the normal rate of 1.47%/day by growth hormone administration. 5. in older children the fractional rate of myofibrillar protein degradation remained in the normal range irrespective of growth hormone treatment. 6. These results are discussed in the context of the anabolic effects of growth hormone on muscle being partly explained by its action to decrease rates of protein breakdown.

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