|Products||LH IRMA Test|
|Company||Diagnostic Systems Laboratories, Inc.|
|Item||LH IRMA Test|
|Description|| Luteinizing hormone (LH) is a glycoprotein secreted by the anterior pituitary gland. Like the FSH, hCG and TSH, the intact LH molecule is a noncovalently-linked dimer containing alpha- and beta-subunits. These glycoproteins all have homologous alpha-subunits, however each hormone has a unique beta-subunit. Both LH and FSH production and secretion are stimulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus. LH binds to specific cell membrane receptors on ovarian theca cells and testicular Leydig cells. In women, LH is responsible for ovulation, stimulation of corpus luteum formation and stimulation of ovarian progesterone synthesis. During ovarian follicular growth, LH acts to stimulate theca cell production of androgens which are aromatized to estrogens in the granulosa cells. In the late follicular phase, the increased amounts of estrogen exert positive feedback on the hypothalamus and pituitary resulting in a GnRH surge and a peak of LH and FSH release [1,2]. The LH surge is followed by rupture of the graafian follicle and ovulation [1,2,3]. During the luteal phase, estrogens and progesterone exert negative feedback on the pituitary, resulting in low levels of LH secretion. In men, LH stimulates production of testosterone by the Leydig cells and acts with FSH and testosterone to stimulate spermatogenesis. The measurement of LH in serum is useful in the diagnosis and treatment of gonadal dysfunction.
|Info|| Diagnostic Systems Laboratories, Inc.|
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