LH

(noun)

Luteinizing hormone is produced by the anterior pituitary gland and in males causes the synthesis and secretion of testosterone and androgen.

Related Terms

Examples of LH in the following topics:

  • Hormonal Regulation of the Female Reproductive Cycle

    • LH induces androgen synthesis by theca cells, stimulates proliferation and differentiation, and increases LH receptor expression on granulosa cells.
    • Estrogen levels are highest right before the LH surge begins.
    • Ovulation normally occurs 30 (± 2) hours after the beginning of the LH surge.
    • Ovulation is triggered by a spike in the amount of FSH and LH released from the pituitary gland.
    • Human chorionic gonadotropin is structurally similar to LH and can preserve the corpus luteum.

  • Female Hormones

    • Progesterone assists in endometrial re-growth and inhibition of FSH and LH release .
    • The spike in LH causes ovulation: the most mature follicle ruptures and releases its egg .
    • The inhibition of FSH and LH prevents any further eggs and follicles from developing.
    • As women approach their mid-40s to mid-50s, their ovaries begin to lose their sensitivity to FSH and LH.
    • This mature egg follicle may rupture and release an egg in response to a surge of LH.

  • Hormonal Regulation of the Reproductive System

    • In both males and females, FSH stimulates gamete production and LH stimulates production of hormones by the gonads.
    • At the pituitary, GnRH stimulates the synthesis and secretion of the gonadotropins, FSH and LH.
    • Low-frequency GnRH pulses lead to FSH release, whereas high-frequency GnRH pulses stimulate LH release.
    • LH stimulates production of the sex hormones (androgens) by the Leydig cells of the testes.
    • GnRH, secreted by the hypothalamus, stimulates the production of FSH and LH from the pituitary gland.

  • Male Hormones

    • The onset of puberty is controlled by two major hormones: FSH initiates spermatogenesis and LH signals the release of testosterone.
    • In response, the pituitary gland releases follicle stimulating hormone (FSH) and luteinizing hormone (LH) into the male system for the first time.
    • LH also enters the testes, stimulating the interstitial cells, called Leydig cells, to make and release testosterone into the testes and the blood.
    • GnRH stimulates the production of FSH and LH, which act on the testes to begin spermatogenesis and to develop secondary sex characteristics in the male.
    • In turn, the testes production of testosterone and the hormone inhibin inhibit the release of GnRH, FSH, and LH in a negative feedback loop.

  • Hormonal Regulation of the Male Reproductive System

    • Studies from rodent models suggest that gonadotropin hormones (both LH and FSH) support the process of spermatogenesis by suppressing the proapoptotic signals and thus promoting spermatogenic cell survival.
    • There it stimulates the synthesis and secretion of the gonadotropins, FSH and luteinizing hormone (LH).
    • Luteinizing hormone (LH) is released by the anterior pituitary gland.
    • In the testes, LH binds to receptors on Leydig cells, which stimulates the synthesis and secretion of testosterone.

  • Ovarian Cycle

    • Many endocrinologists believe that estrogen secretion of the dominant follicle increases to a level that indirectly lowers the levels of LH and FSH.
    • Ovulation normally occurs 30 (± 2) hours after the beginning of the LH surge (when LH is first detectable in urine).
    • After ovulation, the pituitary hormones FSH and LH cause the remaining parts of the dominant follicle to transform into the corpus luteum.
    • The hormones produced by the corpus luteum suppress production of the FSH and LH, causing the corpus luteum will atrophy.
    • After implantation, human embryos produce human chorionic gonadotropin (hCG), which is structurally similar to LH and can preserve the corpus luteum.

  • Hormonal Methods

    • Progesterone negative feedback decreases the frequency of gonadotropin-releasing hormone (GnRH) released by the hypothalamus, which decreases the release of follicle-stimulating hormone (FSH), and greatly decreases the release of luteinizing hormone (LH) by the anterior pituitary.
    • Progesterone negative feedback and the lack of estrogen positive feedback on LH release, prevent a mid-cycle LH surge.
    • Inhibition of follicular development and the absence of a LH surge prevent ovulation.

  • Puberty

    • GnRH signals from the hypothalamus induce pulsed secretion of LH (and to a lesser degree, FSH) at roughly one to two hour intervals.
    • LH stimulates the Leydig cells of the testes to make testosterone and blood levels begin to rise.
    • For females, as the amplitude of LH pulses increases, the theca cells of the ovaries begin to produce testosterone and smaller amounts of progesterone.
    • Hormones include: 1 Follicle-stimulating hormone - FSH. 2 Luteinizing hormone - LH. 3 Progesterone. 4 Estrogen. 5 Hypothalamus. 6 Pituitary gland. 7 Ovary. 8 Pregnancy - hCG (Human chorionic gonadotropin). 9 Testosterone. 10 Testicle. 11 Incentives. 12 Prolactin - PRL.

  • Transposition Scorereading Assignment

    • Videotape yourself singing and playing the LH.
    • Videotape yourself singing the RH while playing the LH.

  • Relationship of MC and AVC to MPL and APL

    • At point H, the AP is a maximum at this level of input (LH).