Prolactin is a 23 kDa protein hormone secreted by the anterior pituitary gland in many species. Although it has many reported biological activities, prolactin’s most noted effects pertain to mammary gland differentiation and promotion of lactation.
Pituitary Prolactin Secretion and Its Regulation
The pituitary gland is located at the base of the brain and is composed of two parts – anterior and posterior. The posterior pituitary is an extension of brain tissue from the hypothalamus and secretes hormones such as vasopressin, which are synthesized in the hypothalamus. The anterior pituitary arises from nonneural tissue and during embryology migrates to a position anterior to the posterior pituitary. The anterior pituitary is connected to the hypothalamus by a network of blood vessels that run with the neural “stalk” connecting the posterior pituitary to the hypothalamus. This...