An interesting (and quite long) paper. It certainly is true that you can spend a very long time reading about thyroid and hardly ever see TRH mentioned.
The forgotten effects of thyrotropin-releasing hormone: metabolic functions and medical applications
• Eleonore Fröhlicha, b,
• Richard Wahla, ,
• a Internal Medicine (Dept. of Endocrinology, Metabolism, Nephrology and Clinical Chemistry), University of Tuebingen, Otfried-Muellerstrasse 10, 72076 Tuebingen
• b Center for Medical Research, Medical University Graz, Stiftingtalstr. 24, 8010 Graz, Austria
Received 5 April 2018, Revised 7 June 2018, Accepted 20 June 2018, Available online 22 June 2018
Highlights
• Hypothalamic releasing hormone has endocrine targets and affects cognitive functions.
• TRH stimulation assay is no more widely used in the diagnosis of thyroid disorders.
• TRH analogs are approved for the treatment of spinocerebellar degenerative disease.
• A role of TRH in breast cancer has been proposed.
Abstract
Thyrotropin-releasing hormone (TRH) causes a variety of thyroidal and non-thyroidal effects, the best known being the feedback regulation of thyroid hormone levels. This was employed in the TRH stimulation test, which is currently little used. The role of TRH as a cancer biomarker is minor, but exaggerated responses to TSH and prolactin levels in breast cancer led to the hypothesis of a potential role for TRH in the pathogenesis of this disease. TRH is a rapidly degraded peptide with multiple targets, limiting its suitability as a biomarker and drug candidate. Although some studies reported efficacy in neural diseases (depression, spinal cord injury, amyotrophic lateral sclerosis, etc.), therapeutic use of TRH is presently restricted to spinocerebellar degenerative disease. Regulation of TRH production in the hypothalamus, patterns of expression of TRH and its receptor in the body, its role in energy metabolism and in prolactin secretion are addressed in this review.
Full paper freely available here: