Thyrotropin-releasing hormone (TRH), is a hormone, produced by neurons in the hypothalamus, that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary.
It has been used for the treatment of spinocerebellar degeneration and disturbance of consciousness in humans.
It is synthesized within parvocellular neurons of the paraventricular nucleus of the hypothalamus.
Multiple steps produce 6 copies of the mature TRH molecule per precursor molecule for human TRH.
The synthesizing neurons located in the
paraventricular nucleus project to the medial portion of the external layer of the median eminence.
From the median eminence, TRH secretions travels to the anterior pituitary via the hypophyseal portal system where it binds to the TRH receptor that stimulates the release of thyroid-stimulating hormone from thyrotropes and prolactin from lactotropes.
TRH half life in blood is approximately 6 minutes.
A TRH intravenous injection can test the response of the anterior pituitary gland in thyroid disorders such as secondary hypothyroidism and in acromegaly.
TRH has anti-depressant and anti-suicidal properties.
It is suggested that TRH has a fundamental role in the regulation of metabolic and hormonal functions.
Side effects after intravenous TRH administration:minimal, nausea, flushing, urinary urgency, and mild rise in blood pressure have been reported.