Prepro-TRH is a regulator of the biosynthesis of TSH in the anterior pituitary gland and acts as a neurotransmitter/neuromodulator in the central and peripheral nervous systems.Rat: H-Phe-Ile-Asp-Pro-Glu-Leu-Gln-Arg-Ser-Trp-Glu-Glu-Lys-Glu-Gly-Glu-Gly-Val-Leu-Met-Pro-Glu-OH or H-FIDPELQRSWEEKEGEGVLMPE-OH