LH surge

黄体化ホルモンサージ

WordNet

1. see ones performance improve; "He levelled the score and then surged ahead"
2. a sudden or abrupt strong increase; "stimulated a surge of speculation"; "an upsurge of emotion"; "an upsurge in violent crime" (同)upsurge
3. the 12th letter of the Roman alphabet (同)l

PrepTutorEJDIC

1. 波のように押し寄せる,殺到する / 〈感情が〉こみあげる《+up》 / 急増する,〈株などが〉急騰する / (…が)押し寄せること,(…の)襲来,殺到《+of+名》 / (感情の)高まり,急増,急騰
2. lira(イタリアの貨幣単位リラ)
3. surgeon / surgery / surgical

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/10/15 15:44:19」(JST)

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Luteinizing hormone beta polypeptide
Effects of LH on the body
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 and sometimes lutrophin) is a hormone produced by gonadotroph cells in the anterior pituitary gland. In females, an acute rise of LH ("LH surge") triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone. It acts synergistically with FSH.

Structure

LH is a heterodimeric glycoprotein. Each monomeric unit is a glycoprotein molecule; one alpha and one beta subunit make the full, functional protein.

Its structure is similar to that of the other glycoprotein hormones, follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), and human chorionic gonadotropin (hCG). The protein dimer contains 2 glycopeptidic subunits, labeled alpha and beta subunits, that are non-covalently associated (i.e., without any disulfide bridge linking them):

• The alpha subunits of LH, FSH, TSH, and hCG are identical, and contain 92 amino acids in human but 96 amino acids in almost all other vertebrate species (glycoprotein hormones do not exist in invertebrates).

• The beta subunits vary. LH has a beta subunit of 120 amino acids (LHB) that confers its specific biologic action and is responsible for the specificity of the interaction with the LH receptor. This beta subunit contains an amino acid sequence that exhibits large homologies with that of the beta subunit of hCG and both stimulate the same receptor. However, the hCG beta subunit contains an additional 24 amino acids, and the two 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) and hCG (24 hours).

Reference ranges for the blood content of luteinizing hormone (LH) during the menstrual cycle. * The ranges denoted By biological stage may be used in closely monitored menstrual cycles in regard to other markers of its biological progression, with the time scale being compressed or stretched to how much faster or slower, respectively, the cycle progresses compared to an average cycle. * The ranges denoted Inter-cycle variability are more appropriate to use in non-monitored cycles with only the beginning of menstruation known, but where the woman accurately knows her average cycle lengths and time of ovulation, and that they are somewhat averagely regular, with the time scale being compressed or stretched to how much a woman's average cycle length is shorter or longer, respectively, than the average of the population. * The ranges denoted Inter-woman variability are more appropriate to use when the average cycle lengths and time of ovulation are unknown, but only the beginning of menstruation is given.

Genes

The gene for the alpha subunit is located on chromosome 6q12.21.

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.

Activity

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

• In females, LH supports theca cells in the ovaries that provide androgens and hormonal precursors for estradiol production. At the time of menstruation, FSH initiates follicular growth, specifically affecting granulosa cells. With the rise in estrogens, LH receptors are also expressed on the maturing follicle, which causes it to produce more estradiol. Eventually, when the follicle has fully matured, a spike in 17-hydroxyprogesterone production by the follicle inhibits the production of estrogen, leading to a decrease in estrogen-mediated negative feedback of GnRH in the hypothalamus, which then stimulates the release of LH from the anterior pituitary. This increase in LH production only lasts for 24 to 48 hours. This "LH surge" triggers ovulation, thereby not only releasing the egg from the follicle, 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 of the menstrual cycle. If pregnancy occurs, LH levels will decrease, and luteal function will instead be maintained by the action of hCG (human chorionic gonadotropin,a hormone very similar to LH but secreted from the new placenta).

• In males, LH acts upon the Leydig cells of the testis and is regulated by GnRH. The Leydig cells produce testosterone (T) under the control of LH, which regulates the expression of the enzyme 17-β hydroxysteroid dehydrogenase that is used to convert androstenedione, the hormone produced by the gonads, to testosterone, an androgen that exerts both endocrine activity and intratesticular activity on spermatogenesis.

LH is released from the pituitary gland, and is controlled by pulses of gonadotropin-releasing hormone (GnRH). When T levels are low, GnRH is released by the hypothalamus, stimulating the pituitary gland to release LH. As the levels of T increase, it will act on the hypothalamus and pituitary through a negative feedback loop and inhibit the release of GnRH and LH consequently. However, T must first be aromatized into Estradiol (E2) in order to inhibit LH. E2 decreases pulse amplitude and responsiveness to GnRH from the hypothalamus onto the pituitary.

Changes in LH and testosterone (T) blood levels and pulse secretions are induced by changes in sexual arousal in human males.

Normal levels

LH levels are normally low during childhood and, in women, high after menopause. As LH is secreted as pulses, it is necessary to follow its concentration over a sufficient period of time to get a proper information about its blood level.

During the reproductive years, typical levels are between 1-20 IU/L. Physiologic high LH levels are seen during the LH surge (v.s.); typically they last 48 hours.

In males over 18 years of age, reference ranges have been estimated to be 1.8-8.6 IU/L.

LH is measured in International Units (IU). For Human Urinary LH, one IU is defined as the amount of LH that has an activity corresponding to 0.13369 mg of pure Human Urinary LH.

Predicting ovulation

The detection of a surge in release of luteinizing hormone indicates impending ovulation. LH can be detected by urinary ovulation predictor kits (OPK, also LH-kit) that are performed, typically daily, around the time ovulation may be expected. A conversion from a negative to a positive reading would suggest that ovulation is about to occur within 24–48 hours, giving women two days to engage in sexual intercourse or artificial insemination with the intentions of conceiving.

Tests may be read manually using a colour-change paper strip, or digitally with the assistance of reading electronics.

Tests for luteinising hormone may be combined with testing for estradiol in tests such as the Clearblue fertility monitor.

The sensitivity of LH tests are measured in milli international unit, with tests commonly available in the range 10–40 m.i.u. (the lower the number, the higher the sensitivity)

As sperm can stay viable in the woman for several days, LH tests are not recommended for contraceptive practices, as the LH surge typically occurs after the beginning of the fertile window.

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.

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.

High LH levels

Persistently high LH levels are indicative of situations where the normal restricting feedback from the gonad is absent, leading to a 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. Polycystic ovary syndrome
6. Certain forms of congenital adrenal hyperplasia
7. Testicular failure
8. Pregnancy - BetaHCG can mimic LH so tests may show elevated LH

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:

1. Kallmann syndrome
2. Hypothalamic suppression
3. Hypopituitarism
4. Eating disorder
5. Female athlete triad
6. Hyperprolactinemia
7. Hypogonadism
8. Gonadal suppression therapy
   1. GnRH antagonist
   2. GnRH agonist (inducing an initial stimulation (flare up) followed by permanent blockage of the GnRH pituitary receptor)

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). All these medications have to be given parenterally. They are commonly used in infertility therapy to stimulate follicular development, the notable one being in IVF therapy.

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

References

External links

• Luteinizing Hormone at the US National Library of Medicine Medical Subject Headings (MeSH)
• LH at Lab Tests Online
• [1] LH Tests Instructions at Glance

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 月経周期の評価と排卵時期 evaluation of the menstrual cycle and timing of ovulation
• 2. 正常月経周期の生理学 physiology of the normal menstrual cycle
• 3. クエン酸クロミフェンによる排卵誘発 ovulation induction with clomiphene citrate
• 4. 原因不明の不妊症 unexplained infertility
• 5. 健常女性における卵巣の発達および機能不全（閉経） ovarian development and failure menopause in normal women

English Journal

• Reprint of "Role of G protein-coupled estrogen receptor (GPER/GPR30) in maintenance of meiotic arrest in fish oocytes".

• Thomas P1.
• The Journal of steroid biochemistry and molecular biology.J Steroid Biochem Mol Biol.2018 Feb;176:23-30. doi: 10.1016/j.jsbmb.2017.10.023. Epub 2017 Nov 2.
• PMID 29102625

• Egg deposition of maternal testosterone is primarily controlled by the preovulatory peak of luteinizing hormone in Japanese quail.

• Okuliarova M1, Meddle SL2, Zeman M3.
• General and comparative endocrinology.Gen Comp Endocrinol.2018 Jan 15;256:23-29. doi: 10.1016/j.ygcen.2017.05.004. Epub 2017 May 8.
• PMID 28495270

• Identifying ovarian tissue in the bitch using anti-Müllerian hormone (AMH) or luteinizing hormone (LH).

• Alm H1, Holst BS2.
• Theriogenology.Theriogenology.2018 Jan 15;106:15-20. doi: 10.1016/j.theriogenology.2017.09.028. Epub 2017 Sep 27.
• PMID 29028571

Japanese Journal

• Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F2α

• Journal of Reproduction and Development advpub(0), 2016
• NAID 130005150374

• 4) 卵巣顆粒膜細胞の黄体化に伴う性ステロイド合成関連遺伝子発現変化のエピジェネティクス制御機構(シンポジウム1(生殖) 卵巣のダイナミックな変化の神秘に迫る-臨床へのフィードバックを目指して-,第67回日本産科婦人科学会学術講演会講演要旨)

• 日本産科婦人科學會雜誌 67(10), 2177-2191, 2015-10-01
• NAID 110009989074

• 3) ゴナドトロピン受容体の機能にその構造及び生理活性物質が及ぼす影響(シンポジウム1(生殖) 卵巣のダイナミックな変化の神秘に迫る-臨床へのフィードバックを目指して-,第67回日本産科婦人科学会学術講演会講演要旨)

• 日本産科婦人科學會雜誌 67(10), 2167-2176, 2015-10-01
• NAID 110009989073

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★リンクテーブル★

国試過去問	「085A008」
リンク元	「黄体化ホルモンサージ」
関連記事	「L」「LH」

「085A008」

　　[★]

• 健常女子について正しい物。全て選べ

• (1) 9-10歳で卵巣性エストロゲンの産生増加が見られる
• (2) 10歳頃からLH分泌が亢進する
• (3) 初経前にLH surgeが見られる
• (4) 14-15歳で排卵周期が確立する

「黄体化ホルモンサージ」

　　[★]

英

luteinizing hormone surge, LH surge

関

黄体化ホルモン

「L」

　　[★]

• リシジン
• リンキング数
• ロイシン
• free ligand concentration

　 　

「LH」

　　[★] 黄体形成ホルモン luteinizing hormone