Seasonal changes in serum thyroid hormone levels in ruffed grouse maintained under natural conditions of temperature and photoperiod

1979 ◽  
Vol 57 (10) ◽  
pp. 2022-2027 ◽  
Author(s):  
A. Garbutt ◽  
J. F. Leatherland ◽  
A. L. A. Middleton
Keyword(s):  
Thyroid Hormone ◽  
Seasonal Changes ◽  
Gonadal Development ◽  
Early Spring ◽  
Light Period ◽  
Ruffed Grouse ◽  
Natural Conditions ◽  
Blood Samples ◽  
Serum Thyroid Hormone ◽  
Thyroid Hormone Levels

Serum triiodothyronine (T3) and thyroxine (T4) concentrations were measured in a population of ruffed grouse, held outdoors under natural conditions of photoperiod and temperature. Blood samples were collected at monthly intervals, and at the solstices and equinoxes to test for variation through the light period. No changes in T4 or T3 levels were found during the light period but levels of T3 and T4 showed marked seasonal changes. Lowest T4 and T3 levels were found in birds during the winter months, with an increase in the concentration of both hormones in early spring concomitant with gonadal development in the adults. A lowering of serum T4 and T3 values was associated with the period of molt.

scholarly journals Effects of Daily Kelp (Laminaria japonica) Intake on Body Composition, Serum Lipid Levels, and Thyroid Hormone Levels in Healthy Japanese Adults: A Randomized, Double-Blind Study

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 352
Author(s):  
Seiichiro Aoe ◽  
Chiemi Yamanaka ◽  
Hirofumi Ohtoshi ◽  
Fumiko Nakamura ◽  
Suguru Fujiwara
Keyword(s):  
Thyroid Hormone ◽  
Body Fat ◽  
Laminaria Japonica ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Double Blind ◽  
Serum Thyroid Hormone ◽  
Thyroid Hormone Levels ◽  
Male Subjects ◽  
Japanese Subjects

To investigate whether supplementation with iodine-reduced kelp (Laminaria japonica) powder decreases body fat composition in overweight Japanese subjects, a randomized, double-blind, placebo-controlled intervention study was conducted in 50 Japanese subjects with body mass index (BMI) ≥25 and <30 kg/m2. Subjects were randomly assigned to consume thirty tablets/d (10 tablets orally, 3 times/d) containing either iodine-reduced kelp powder (test, 6 g kelp powder corresponding to 3 g alginate/d) or kelp-free powder (placebo) for 8 weeks. Anthropometric measurements, blood lipids, and serum thyroid hormone levels were obtained before and after the trial. Body fat percentage was significantly decreased in male subjects from the test group compared with the placebo group. The same tendency was observed for body weight (p = 0.065) and BMI (p = 0.072) in male subjects. No significant changes in anthropometric measurements or visceral fat area were observed in female subjects. Serum thyroid hormone concentrations did not increase after 1.03 mg/d of iodine supplementation through kelp intake. The intake of iodine-reduced kelp powder led to significant and safe reductions in body fat percentage in overweight male subjects. The consumption of kelp high in alginate may contribute to preventing obesity without influencing thyroid function in Japanese subjects with a relatively high intake of iodine from seaweed.

scholarly journals Serum Thyroid Hormone Levels in Healthy Children from Birth to Adulthood and in Short Children Born Small for Gestational Age

2012 ◽  
Vol 97 (9) ◽  
pp. 3170-3178 ◽  
Author(s):  
Annemieke J. Lem ◽  
Yolanda B. de Rijke ◽  
Hans van Toor ◽  
Maria A. J. de Ridder ◽  
Theo J. Visser ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Healthy Children ◽  
Hormone Levels ◽  
Short Children ◽  
Serum Thyroid Hormone ◽  
Thyroid Hormone Levels

Pathophysiology and management of functional endocrine tumours in the critically ill

2016 ◽  
Author(s):  
Sara Nikravan ◽  
Frederick Mihm
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Diagnostic Tests ◽  
Concurrent Treatment ◽  
Peripheral Tissues ◽  
Endocrine Tumours ◽  
Optimal Dosing ◽  
Serum Thyroid Hormone ◽  
Thyroid Hormone Levels ◽  
T3 Receptors

Thyroid hormones act on most tissues via nuclear T3 receptors. Thyroid hormones stimulate oxygen consumption and heat production, influence cell growth and maturation (central nervous system, bone), and modulate metabolism (carbohydrates, lipids, proteins, drugs). Treatment for presumed thyroid disease frequently has to be initiated before the results of diagnostic tests are available. Treatment of hyperthyroidism should result in the reduction of serum thyroid hormone levels and their action on peripheral tissues with concurrent treatment of the precipitating event. In severe hypothyroidism the choice of thyroid hormone (thyroxine or tri-iodothyronine), optimal dosing, and the route of administration remain controversial

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