LH (green line) surges at ovulation
Luteinizing hormone beta polypeptide
Identifiers
Symbol	LHB
Entrez	3972
HUGO	6584
OMIM	152780
RefSeq	NM_000894
UniProt	P01229
Other data
Locus	Chr. 19 q13.3

Luteinizing hormone (LH, also known as lutropin^[1]) is a hormone synthesized and secreted by gonadotropes in the anterior lobe of the pituitary gland.^[2] In concert with the other pituitary gonadotropin follicle stimulating hormone (FSH) it is necessary for proper reproductive function: Image File history File links Estradiol. ... The Entrez logo The Entrez Global Query Cross-Database Search System allows access to databases at the National Center for Biotechnology Information (NCBI) website. ... Hugo is a masculine name. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The National Center for Biotechnology Information (NCBI) is part of the US National Library of Medicine (NLM), which is a branch of the US National Institutes of Health. ... Swiss-Prot is a curated biological database of protein sequences created in 1986 by Amos Bairoch during his PhD and developed by the Swiss Institute of Bioinformatics and the European Bioinformatics Institute. ... Short and long arms Chromosome. ... Chromosome 19 is one of the 23 pairs of chromosomes in humans. ... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Gonadotropes are cells in the anterior pituitary which produce the gonadotropins luteinizing hormone or follicle-stimulating hormone. ... The anterior pituitary (also called the adenohypophysis, from Greek adeno, gland; hypo, under; physis, growth; hence, glandular undergrowth) comprises the anterior lobe of the pituitary gland and is part of the endocrine system. ... The pituitary gland, or hypophysis, is an endocrine gland about the size of a pea that sits in a small, bony cavity (sella turcica) covered by a dural fold (sellar diaphragm) at the base of the brain. ... Follicle stimulating hormone (FSH) is a hormone produced by gonadotropes in the anterior pituitary gland. ... Follicle stimulating hormone (FSH) is a hormone produced by gonadotropes in the anterior pituitary gland. ... For other uses, see Reproduction (disambiguation) Reproduction is the biological process by which new individual organisms are produced. ...

• In the female, an acute rise of LH – the LH surge – triggers ovulation. ^[3]

• In the male, where LH had also been called Interstitial Cell Stimulating Hormone (ICSH)^[4], it stimulates Leydig cell production of testosterone. ^[5]

Ovulation is the process in the menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (also known as an oocyte, female gamete, or casually, an egg) that participates in reproduction. ... Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testes. ... Testosterone is a steroid hormone from the androgen group. ...

Structure

LH is a glycoprotein. Each monomeric unit is a protein molecule with a sugar attached to it; two of these make the full, functional protein. A glycoprotein is a macromolecule composed of a protein and a carbohydrate (an oligosaccharide). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...

Its structure is similar to the other glycoproteins, FSH, TSH, and hCG. The protein dimer contains 2 polypeptide units, labeled alpha and beta subunits that are connected by two disulfide bridges: Follicle stimulating hormone (FSH) is a hormone produced by gonadotropes in the anterior pituitary gland. ... Thyroid-stimulating hormone (also known as TSH or thyrotropin) is a hormone produced by thyrotrope cells in the anterior pituitary gland which regulates the endocrine function of the thyroid gland. ... Human chorionic gonadotropin (hCG) is a peptide hormone produced in pregnancy, that is made by the embryo soon after conception and later by the syncytiotrophoblast (part of the placenta). ... Peptides are the family of molecules formed from the linking, in a defined order, of various amino acids. ... A disulfide bond (SS-bond), also called a disulfide bridge, is a strong covalent bond between two sulfhydryl groups. ...

• The alpha subunits of LH, FSH, TSH, and hCG are identical, and contain 92 amino acids.

• The beta subunits vary. LH has a beta subunit of 121 amino acids (LHB) that confers its specific biologic action and is responsible for interaction with the LH receptor. This beta subunit contains the same amino acids in sequence as the beta sub unit of hCG and both stimulate the same receptor, however, the hCG beta subunit contains an additional 24 amino acids, and both hormones differ in the composition of their sugar moieties.

The different composition of these oligosaccharides affects bioactivity and speed of degradation. The biologic half-life of LH is 20 minutes, shorter than that of FSH (3-4 hours) or hCG (24 hours).^{[citation needed]} The Alpha subunit of glycoprotein hormones is a peptide formed by gene found on chromosome 6. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... The luteinizing hormone/choriogonadotropin receptor (LHCGR), also lutropin/choriogonadotropin receptor (LCGR) is a transmembrane receptor that interacts with both luteinizing hormone (LH) and chorionic gonadotropins (such as hCG in humans) and represents a G protein-coupled receptor (GPCR). ... Human chorionic gonadotropin (hCG) is a peptide hormone produced in pregnancy, that is made by the embryo soon after conception and later by the syncytiotrophoblast (part of the placenta). ... An oligosaccharide is a saccharide polymer containing a small number (typically three to six) of component sugars, also known as simple sugars. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ...

Genes

The gene for the alpha subunit is located on chromosome 6q12.21. For a non-technical introduction to the topic, see Introduction to Genetics. ... Chromosome 6 is one of the 23 pairs of chromosomes in humans. ...

The luteinizing hormone beta subunit gene is localized in the LHB/CGB gene cluster on chromosome 19q13.32. In contrast to the alpha gene activity, beta LH subunit gene activity is restricted to the pituitary gonadotropic cells. It is regulated by the gonadotropin releasing hormone from the hypothalamus. Inhibin, activin, and sex hormones do not affect genetic activity for the beta subunit production of LH. Chromosome 19 is one of the 23 pairs of chromosomes in humans. ... Gonadotropin Releasing Hormone (GnRH) is a peptide hormone responsible for the release of FSH and LH from the anterior pituitary. ... The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). ... Inhibin is a peptide that is an inhibitor of FSH synthesis and secretion and participates in the regulation of the menstrual cycle. ... Activin is a peptide that enhances FSH synthesis and secretion and participates in the regulation of the menstrual cycle. ... Sex hormones are hormones that affect the reproductive system. ...

Activity

In both males and females, LH is essential for reproduction.

• In females, at the time of menstruation, FSH initiates follicular growth, specifically affecting granulosa cells.^[2] With the rise in estrogens, LH receptors are also expressed on the maturing follicle that produces an increasing amount of estradiol. Eventually at the time of the maturation of the follicle, the estrogen rise leads via the hypothalamic interface to the “positive feed-back” effect, a release of LH over a 24-48 hour period. This 'LH surge' triggers ovulation hereby not only releasing the egg, but also initiating the conversion of the residual follicle into a corpus luteum that, in turn, produces progesterone to prepare the endometrium for a possible implantation. LH is necessary to maintain luteal function for the first two weeks. In case of a pregnancy luteal function will be further maintained by the action of hCG from the newly established pregnancy. LH supports thecal cells in the ovary that provide androgens and hormonal precursors for estradiol production.

• In the male, LH acts upon the Leydig cell of the testis and is responsible for the production of testosterone, the “male hormone” that exerts both endocrine activity and intratesticular activity such as spermatogenesis.

The release of LH at the pituitary gland is controlled by pulses of gonadotropin-releasing hormone (GnRH) from the hypothalamus. Those pulses, in turn, are subject to the estrogen feedback from the gonads. A granulosa cell is a supporting cell for the developing female gamete in the ovary of mammals. ... Estradiol (17β-estradiol) (also oestradiol) is a sex hormone. ... Ovulation is the process in the menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (also known as an oocyte, female gamete, or casually, an egg) that participates in reproduction. ... The corpus luteum (Latin for yellow body) is a small, temporary endocrine structure in animals. ... Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. ... The endometrium is the inner membrane of the mammalian uterus. ... Implantation is a phenomenon in prenatal development, i. ... A pregnant woman near the end of her term Pregnancy is the carrying of one or more offspring in an embryonal or fetal stage of development by female mammals, including humans, inside their bodies, between the stages of conception and birth. ... Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to androgen receptors. ... Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ... Testosterone is a steroid hormone from the androgen group. ... This article or section is in need of attention from an expert on the subject. ... Gonadotropin-releasing hormone 1 (GNRH1 also called LHRH) is a peptide hormone responsible for the release of FSH and LH from the anterior pituitary. ...

Normal levels

LH levels are normally low during childhood and, in women, high after menopause. Childhood (song) Childhood is a broad term usually applied to the phase of development in humans between infancy and adulthood. ... Menopause is the physiological cessation of menstrual cycles associated with advancing age in women. ...

During the reproductive years typical levels are between 5-20 mIU/ml.

Physiologic high LH levels are seen during the LH surge (v.s.); typically they last 48 hours.

Ovulation predictor kit (LH kit)

The detection of the LH surge has become useful for people who want to know when ovulation occurs. LH can be detected by urinary ovulation predictor kits (OPK, also LH-kit) that are performed daily around the time ovulation may be expected.^[6] The conversion from a negative to a positive reading would suggest that ovulation is about to occur within 24-48 hours. Couples who plan to conceive would time intercourse accordingly.^[7] The term conception can refer to more than one meaning: Concept Fertilisation Embryonic implantation Conception is also the name of a progressive metal band from Norway. ...

As sperm can stay viable in the woman for several days, such tests are not recommended for contraceptive practices.

Disease states

Relative elevations

In children with precocious puberty of pituitary or central origin, LH and FSH levels may be in the reproductive range instead of the low levels typical for their age. Precocious puberty means early puberty. ...

During the reproductive years, relatively elevated LH is frequently seen in patients with the polycystic ovary syndrome; however it would be unusual for them to have LH levels outside of the normal reproductive range. Polycystic ovary syndrome (PCOS, also known clinically as Stein-Leventhal syndrome), is an endocrine disorder that affects approximately one in ten women. ...

High LH levels

Persistently high LH levels are indicative of situations where the normal restricting feedback from the gonad is absent, leading to an unrestricted pituitary production of both LH and FSH. While this is typical in the menopause, it is abnormal in the reproductive years. There it may be a sign of:

1. Premature menopause
2. Gonadal dysgenesis, Turner syndrome
3. Castration
4. Swyer syndrome
5. Certain forms of CAH
6. Testicular failure

Menopause (also known as the Change of life or climacteric) is a stage of the human female reproductive cycle that occurs as the ovaries stop producing estrogen, causing the reproductive system to gradually shut down. ... Gonadal dysgenesis generally refers to a condition where gonadal development is abnormal, often only presenting streaks of connective tissue. ... Castration (also referred as: gelding, neutering, orchiectomy, orchidectomy, and oophorectomy) is any action, surgical, chemical, or otherwise, by which a male loses the functions of the testes or a female loses the functions of the ovaries. ... Swyer syndrome, or XY gonadal dysgenesis, is a type of female hypogonadism in which no functional gonads are present to induce puberty in an otherwise normal girl whose karyotype is then found to be XY. Her gonads are found to be nonfunctional streaks. ... Congenital adrenal hyperplasia (CAH) refers to any of several autosomal recessive diseases resulting from defects in steps of the synthesis of cortisol from cholesterol by the adrenal glands. ...

Deficient LH activity

Diminished secretion of LH can result in failure of gonadal function (hypogonadism). This condition is typically manifest in males as failure in production of normal numbers of sperm. In females, amenorrhea is commonly observed. Conditions with very low LH secretions are: Amenorrhoea (BE) or amenorrhea (AmE) is the absence of a menstrual period in a woman of reproductive age. ...

1. Kallmann syndrome
2. Hypothalamic suppression
3. Hypopituitarism
4. Eating disorder
5. Hyperprolactinemia
6. Gonadotropin deficiency
7. Gonadal suppression therapy
   1. GnRH antagonist
   2. GnRH agonist (downregulation)

Kallmann syndrome is an example of hypogonadism (decreased functioning of the sex hormone-producing glands) caused by a deficiency of gonadotropin-releasing hormone (GnRH), which is created by the hypothalamus. ... Hypothalamic-pituitary dysfunction is a term to describe a nonorganic relative inactivity of the gonadotropin-releasing hormone (GnRH) system of the hypothalamus and its dependent pituitary gonadotrophs that normally produce follicle stimulating hormone, FSH, and luteinizing hormone, LH. The condition occurs during the reproductive years and leads to hypogonadotropic hypogonadism. ... Hypopituitarism is a medical term describing deficiency (hypo) of one or more hormones of the pituitary gland. ... Prolactin is a hormone secreted by lactotropes in the adenohypophysis (anterior pituitary gland) which is made up of 199 amino acids with a molecular weight of about 23,000 daltons. ... Hypogonadism is a medical term for a defect of the reproductive system which results in lack of function of the gonads (ovaries or testes). ... A GnRH antagonist is a synthetic peptide that competes with the gonadotropin releasing hormone (GnRH) for its receptor thus decreasing or blocking GnRH action. ... A GnRH agonist is a synthetic peptide that acts like the gonadotropin-releasing hormone (GnRH) but has a much longer biological half life. ... Down regulation is the process by which a cell decreases the number of receptors to a given hormone or neurotransmitter to reduce its sensitivity to this molecule. ...

Availability

LH is available mixed with FSH in the form of Pergonal, and other forms of urinary gonadotropins . More purified forms of urinary gonadotropins may reduce the LH portion in relation to FSH. Recombinant LH is available as lutropin alfa (Luveris®)^[8]. All these medications have to be given parenterally. They are commonly in infertility therapy to stimulate follicular development, notably in IVF therapy. Pergonal® is a infertility medicine used to stimulate ovarian follicles in infertility treatments, i. ... Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates. ... In vitro fertilization (IVF) is a technique in which egg cells are fertilized outside the mothers body in cases where conception is difficult or impossible through normal intercourse. ...

Often, hCG medication is used as an LH substitute as it activates the same receptor. Medically used hCG is derived from urine of pregnant women, less costly, and has a longer half-life than LH.

References

eMedicine is an online clinical medical knowledge base that was founded in 1996. ... In 1828 the Medical Academy of Georgia was chartered by the state of Georgia with plans to offer a single course of lectures leading to a bachelors degree. ... In 1828 the Medical Academy of Georgia was chartered by the state of Georgia with plans to offer a single course of lectures leading to a bachelors degree. ...

External links

• MeSH Luteinizing+Hormone