Androstenedione ELISA

Androstenedione (also known as Δ4-
androstenedione) is a steroid hormone produced in
the adrenal glands and the gonads as an intermediate
step in the biochemical pathway that produces the
androgen testosterone and the estrogens estrone and
estradiol. It is the common precursor of male and
female sex hormones. Some androstenedione is also
secreted into the plasma, and may be converted in
peripheral tissues to testosterone and estrogens.
Androstenedione has relatively weak androgenic
activity, estimated at ~ 20% of testosterone. However,
serum androstenedione levels often exceed
testosterone in both normal and disease states.
Secretion and production rates also exceed those of
testosterone in women in whom significant extraadrenal
conversion of androstenedione to
testosterone occurs.
In premenopausal women the adrenal glands and
ovaries each produce about half of the total
androstendione (about 3 mg/day). After menopause
androstenedione production is about halved, primarily
due to the reduction of steroid secreted by the ovary.
Nevertheless, androstenedione is the principal steroid
produced by the postmenopausal ovary.
Measurement of serum androstenedione provides a
useful marker of androgen biosynthesis. Elevated
androstenedione levels have been demonstrated in
virilizing congenital adrenal hyperplasia. Serum
androstenedione levels are also increased in
polycystic ovary syndrome, and in case of hirsutism in
women. Elevated serum androstenedione levels may
also occur in adrenal and ovarian virilizing tumors.