Luteinizing hormone

(noun)

A hormone produced by gonadotropic cells of the anterior pituitary gland. It triggers ovulation and development of the corpus luteum in females and stimulates Leydig cell production of testosterone in males.

Related Terms

Examples of Luteinizing hormone in the following topics:

  • Hormonal Regulation of the Male Reproductive System

    • Hormonal control of spermatogenesis varies among species.
    • They are capable of producing the hormones estradiol and inhibin.
    • There it stimulates the synthesis and secretion of the gonadotropins, FSH and luteinizing hormone (LH).
    • Follicle-stimulating hormone (FSH)  is released by the anterior pituitary gland.
    • Luteinizing hormone (LH) is released by the anterior pituitary gland.

  • Onset, Duration, and Half-Life of Hormone Activity

    • A hormone's half-life and duration of activity are limited and vary from hormone to hormone.
    • A hormone's half-life and duration of activity are limited and vary from hormone to hormone.
    • For instance, the biological half-life of luteinizing hormone is 20 minutes, which is shorter than that of a follicle-stimulating hormone (three to four hours), and of human chorionic gonadotropin (24 hours).
    • Follicle-stimulating hormone 2.
    • Luteinizing hormone 4.

  • The Anterior Pituitary

    • Thyroid-stimulating hormone is a glycoprotein hormone that affects the thyroid gland and the secretion of thyroid hormones.
    • Follicle-stimulating hormone is a glycoprotein hormone that targets the gonads and effects the growth of the reproductive system.
    • Luteinizing hormone is a glycoprotein hormone that targets the gonads to effect sex-hormone production.
    • Growth hormone is a polypeptide hormone that targets the liver and adipose tissue and promotes growth through lipid and carbohydrate metabolism.
    • Hormone secretion from the anterior pituitary gland is regulated by hormones secreted by the hypothalamus.

  • Hormone Receptors

    • A hormone receptor is a molecule that binds to a specific hormone.
    • Receptors for peptide hormones tend to be found on the plasma membrane of cells, whereas receptors for lipid-soluble hormones are usually found within the cytoplasm.
    • The hormone activity within a target cell is dependent on the effective concentration of hormone-receptor complexes that are formed.
    • Many hormones are composed of polypeptides—such as thyroid-stimulating hormones, follicle-stimulating hormones, luteinizing hormones, and insulin.
    • Lipophilic hormones—such as steroid or thyroid hormones—are able to pass through the cell and nuclear membrane; therefore receptors for these hormones do not need to be, although they sometimes are, located in the cell membrane.

  • Male Hormones

    • The onset of puberty is controlled by two major hormones: FSH initiates spermatogenesis and LH signals the release of testosterone.
    • These changes are largely influenced by hormonal activity.
    • Hormones play an organizational role, priming the body to behave in a certain way once puberty begins, and an activational role, referring to changes in hormones during adolescence that trigger behavioral and physical changes.
    • At the onset of puberty, the hypothalamus begins secreting high pulses of GnRH, or gonadotropin-releasing hormone.
    • In response, the pituitary gland releases follicle stimulating hormone (FSH) and luteinizing hormone (LH) into the male system for the first time.

  • Hypothalamic-Pituitary Axis

    • The anterior pituitary produces seven hormones: growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH), melanin-stimulating hormone (MSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
    • Anterior pituitary hormones are sometimes referred to as tropic hormones because they control the functioning of other organs.
    • While these hormones are produced by the anterior pituitary, their production is controlled by regulatory hormones produced by the hypothalamus.
    • These regulatory hormones can be releasing hormones or inhibiting hormones, causing more or less of the anterior pituitary hormones to be secreted.
    • Negative feedback then regulates how much of these regulatory hormones are released and how much anterior pituitary hormone is secreted.

  • Hormonal Regulation of the Reproductive System

    • During puberty, in both males and females, the hypothalamus produces gonadotropin-releasing hormone (GnRH), which stimulates the production and release of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland.
    • FSH production is inhibited by the hormone inhibin, which is released by the testes.
    • It is also called interstitial-cell-stimulating hormone.
    • Prolactin levels are regulated by the hypothalamic hormones, prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH) (which is now known to be dopamine).
    • Hormonal regulation of the female reproductive system involves hormones from the hypothalamus, pituitary, and ovaries.

  • Hormonal Methods

    • Hormonal birth control contains steroid hormones that alter female fertility.
    • Altogether, 18% of the world's contraceptive users rely on hormonal methods.
    • Hormonal contraception is highly effective: when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1% per year.
    • The effect of hormonal agents on the reproductive system is complex.
    • 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.

  • Hormonal Regulation of the Female Reproductive Cycle

    • The menstrual cycle is controlled by a series of changes in hormone levels, primarily estrogen and progesterone.
    • Follicle-stimulating hormone induces the proliferation of granulosa cells in the developing follicles and the expression of luteinizing hormone (LH) receptors on these cells.
    • The surge also initiates luteinization of theca and granulosa cells.
    • The hormones produced by the corpus luteum suppress production of the FSH and LH, which leads to its atrophy.
    • Because the hormone is unique to the embryo, most pregnancy tests look for the presence of hCG.

  • Female Hormones

    • The stages of the ovarian cycle in the female are regulated by hormones secreted by the hypothalamus, pituitary, and the ovaries.
    • As with the male, the hypothalamic hormone GnRH (gonadotropin-releasing hormone) causes the release of the hormones FSH (follicle stimulating hormone) and LH (luteinizing hormone) from the anterior pituitary.
    • Follicle cells produce the hormone inhibin, which inhibits FSH production.
    • Estradiol and progesterone are steroid hormones that prepare the body for pregnancy.
    • Rising and falling hormone levels result in progression of the ovarian and menstrual cycles.