What is "releasing factor"

n. a substance produced by the hypothalamus that is capable of accelerating the secretion of a given hormone by the anterior pituitary gland [syn: releasing hormone, RF]

any of several hormones produced in the hypothalamus and carried by a vein to the anterior pituitary gland where they stimulate the release of anterior pituitary hormones; each releasing hormone causes the anterior pituitary to secrete a specific hormone [syn: releasing hormone, RH, hypothalamic releasing hormone, hypothalamic releasing factor]