Luteinizing Hormone

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luteinizing hormone

[′lüd·ē·ə‚nīz·iŋ ′hȯr‚mōn]
(biochemistry)
A glycoprotein hormone secreted by the adenohypophysis of vertebrates which stimulates hormone production by interstitial cells of gonads. Abbreviated LH. Also known as interstitial-cell-stimulating hormone (ICSH).

Luteinizing Hormone

 

(LH; also, interstitial cell-stimulating hormone, or ICSH), one of the gonadotropic hormones secreted by the anterior pituitary.

Chemically, LH is a glycoprotein whose physical and chemical properties differ from species to species (in sheep, the molecular weight of LH is 40,000; in swine, 100,000). In females, LH stimulates the growth of the follicles in the stages preceding estrus and ovulation, in ovulation, and during the formation of the corpus luteum. A deficiency of LH in rats and guinea pigs leads to continuous estrus, a result of the abnormal enlargement of the follicles that did not undergo ovulation. The action of follicle-stimulating hormone (FSH) on the follicle is necessary before LH can exert its influence on the ovary. Ovulation, which is induced by LH, depends on the stage of follicular development, for which both the action time of LH and an optimal ratio of LH to FSH are important. For example, in cats and rabbits, the most effective ratio is 1:100. In males, LH stimulates interstitial testicular tissue and the secretion of the male sex hormone testosterone.

V. M. SAMSONOVA

References in periodicals archive ?
The oocytes that are aspirated from over stimulated follicles prior to the LH surge show changes in their nuclear and cytoplasmic morphology, which is recommended as a necessary condition to complete the entire competence.
On the contrary, FEFS after GnRHa trigger occurs following a failure of induction of optimal endogenous LH surge and/or progesterone rise.
When the secondary follicle cohort following stimulation reaches 12 mm, pituitary suppression with GnRH antagonist is initiated to prevent premature secondary LH surge and continued until the trigger (9).
Successful treatment of empty follicle syndrome by triggering endogenous LH surge using GnRH agonist in an antagonist down-regulated IVF cycle.
Ovulation predictor kits are more than 90% successful, if used properly, in identifying the LH surge 5 to 12 days after CC is finished (usually around cycle day 16 or 17).
Other researchers also showed that LPS affects LH secretion and even disturbs the preovulatory LH surge in ewes [29, 30].
LH surge is started by a remarkable rise of estradiol produced by the preovula-
One of the protocols is by Progesterone (P4) block on LH surge through Control Internal Drug Release (CIDR) application (Cerri et al., 2009; Dias, 2008).
This is known as the "LH surge." Typically on CD 13, the LH surge rises to a peak, causing resumption of meiosis and ovulation of the Graafian follicle.
The patients were all given the GnRH antagonist cetrorelix (Cetrotide; Serono International, Geneva, Switzerland) for the purposes of LH surge inhibition.
The LH surge occurs 24 to 36 hours before ovulation, signaling the optimal time to try to conceive.