Proposed mechanism of action of thyrotropin releasing hormone (TRH). The TRH molecule binds to its receptor in lactotrophic cells of the pituitary gland and stimulates Ca2+/CaM release, which induces the PRL gene expression. Furthermore, the increase in intracellular CA2+/CaM stimulates the release of PRL stored in vesicles. This will increase PRL blood levels and promotes more milk synthesis.
