Thyroid Hormone Deiodination and Action in the Gonads.

Arturo Hernandez1

  • 1Maine Medical Center Research Institute, Center for Molecular Medicine, Scarborough, Maine, USA.

Summary

Thyroid hormone (TH) disruptions impact male reproductive development and function. Key factors like TH receptor alpha regulate TH action in the developing testis, influencing fertility.

Related Concept Videos

Gonadal and Placental Hormones01:24

Gonadal and Placental Hormones

The gonads, namely the testes in males and the ovaries in females, are pivotal in producing gonadal hormones that orchestrate the intricate processes of sexual development and reproduction.
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair...
3.1K
Functions of Thyroid Hormones01:18

Functions 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...
5.6K
Synthesis and Regulation of Thyroid Hormones01:20

Synthesis 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...
7.8K
Secondary Messengers in Hormone Action01:26

Secondary Messengers in Hormone Action

Water-soluble hormones cannot cross the plasma membrane, so they rely on protein receptors that span the membrane to trigger intracellular signaling pathways. These pathways then activate second messengers inside the cell, including cAMP or calcium ions.
Many hormones bind to transmembrane G protein-coupled receptors that connect to regulatory G proteins. These G proteins can then activate enzymes such as adenylyl cyclase or phospholipase C. Adenylyl cyclase converts ATP to cAMP, activating...
5.5K
Types of Hormones02:13

Types of Hormones

Hormones can be classified into three main types based on their chemical structures: steroids, peptides, and amines. Their actions are mediated by the specific receptors they bind to on target cells.
83.5K