Related Experiment Video
Updated: Jul 12, 2026
08:33
An Ex vivo Culture System to Study Thyroid Development
Published on: June 6, 2014
Evolving concepts of thyroid hormone action
1Department of Medicine, University of Minnesota, Minneapolis 55466, USA.
Biochimie
|July 14, 1999
Summary
Thyroid hormone action is now understood to be mediated by triiodothyronine binding to nuclear receptors. Advances in cloning these receptors allow detailed analysis of thyroid hormone's physiological and pathological effects.
Area of Science:
- Endocrinology
- Molecular Biology
Background:
- Thyroid hormone action concepts have evolved significantly over 25 years.
- The role of triiodothyronine (T3) as the primary mediator is now established.
Purpose of the Study:
- To review advances in understanding thyroid hormone action.
- To highlight the impact of nuclear receptor identification and cloning.
Main Methods:
- Review of scientific literature over the past 25 years.
- Discussion of displacement studies identifying nuclear receptors.
- Analysis of receptor cloning techniques.
Main Results:
- Recognition of triiodothyronine as the key active thyroid hormone.
- Identification and characterization of specific nuclear receptors for thyroid hormone.
- Cloning of thyroid hormone receptor variants.
Conclusions:
- Nuclear receptors are central to thyroid hormone action.
- Cloned receptors facilitate detailed biochemical analysis of hormone effects.
- This progress deepens understanding of thyroid hormone's physiological and pathological roles.
Related Concept Videos
01:22Target Cell Response to Hormones
Hormones intricately bind to receptors on the surface or within target cells, initiating a cascade of cellular responses.
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
01:23The Thyroid Gland
The thyroid gland is a small, butterfly-shaped gland located in the neck and covers the anterior surface of the trachea. The gland has two lateral lobes connected by a thin tissue mass called the isthmus. Internally, each lobe comprises many small spherical structures known as thyroid follicles, surrounded by a network of blood vessels.
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...
01:20Synthesis and Regulation of Thyroid Hormones
Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the thyrotropin-releasing hormone (TRH). TRH then reaches the pituitary gland and stimulates the release of thyroid-stimulating hormone(TSH) into the bloodstream.
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
01:18Functions of Thyroid Hormones
The thyroid hormone (TH) plays a pivotal role in the intricate orchestration of physiological processes, exerting profound effects on development, metabolism, and homeostasis throughout different life stages.
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:27Hyperthyroidism II: Pathophysiology
Hyperthyroidism is a hypermetabolic state caused by elevated levels of thyroid hormones, triiodothyronine (T3) and thyroxine (T4). It results from dysregulation at the thyroid, pituitary, or immune system level and affects multiple organ systems.PathophysiologyThe most common cause of hyperthyroidism is Graves’ disease, an autoimmune disorder in which antibodies, specifically thyroid-stimulating antibodies (TSAb), a subtype of TSH receptor antibodies (TRAb), bind to and activate TSH receptors...
01:23Hypothyroidism II: Pathophysiology
Hypothyroidism is a disorder characterized by insufficient production of thyroid hormones, which regulate metabolism, energy balance, and multiple organ systems.TypesHypothyroidism is classified based on the level of dysfunction. Primary hypothyroidism results from intrinsic thyroid gland dysfunction, causing reduced hormone production despite normal or increased stimulation. Secondary hypothyroidism arises from inadequate thyroid-stimulating hormone (TSH) secretion by the pituitary. Tertiary...