What is
DHEA and why is there so much public interest in this
steroid which has been touted as the fountain of youth and is supposed to have all kinds of health benefits? Endocrinologists have been fascinated with
DHEA for a long time because of its high production in the fetal adrenals and its continued high levels until the 7th decade of life. Yet there is still little agreement about its physiological functions. In its simplest terms endocrinology is the communication between at least three organs: one sends a message, one releases a
hormone into the blood in response to the message and one responds to the
hormone.
DHEA is produced by a specific zone of the adrenal cortex, the zona reticularis, whose sole function is to produce this
steroid.
Glucocorticoids and
mineralocorticoids which are
C21 steroids are produced in two other zones of the adrenal cortex called the
zona fasicularis and the zona glomerulosa, respectively. Being
C21 steroids, they cannot be synthesized from
DHEA which is a C19
steroid. To date there is no known
hormone which specifically stimulates the zona reticularis and there is no known specific receptor for
DHEA. Thus
DHEA does not qualify as a
hormone.
DHEA could have autocrine or paracrine effects but, so far, there is no known effect of
DHEA on either the cells of the zona glomerulosa or the
zona fasicularis. Of course
DHEA could have functions as a local precursor of
androgens or
estrogens and many studies have reported on the beneficial effects of transdermal or transvaginal administration of
DHEA in postmenopausal women. This review will consider two of the potential functions of
DHEA as a precursor of
estrogen receptor beta (ERβ)
ligands.