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70-494: Follicle-stimulating hormone ( FSH ) is a gonadotropin , a glycoprotein polypeptide hormone . FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, pubertal maturation , and reproductive processes of the body. FSH and luteinizing hormone (LH) work together in the reproductive system . FSH is a 35.5 kDa glycoprotein heterodimer , consisting of two polypeptide units, alpha and beta. Its structure

140-420: A pulsatile manner (as a result of pulsatile GnRH release), unlike the case of GnRH and GnRH agonists , constant/non-pulsatile activation of the gonadotropin receptors by the gonadotropins does not produce functional inhibition. This can be seen during the first 7–10 weeks of pregnancy, where constantly high and progressively-increasing levels of hCG circulate and mediate production of estrogen and progesterone by

210-558: A "fill-by-mass" product. The mean values for women before ovulation are around (3.8-8.8) IU/L. After ovulation these levels drop to between (1.8-5.1) IU/L. At the mid of the menstrual cycle it reaches its highest value, between (4.5-22.5) IU/L. During menopause , the values goes up even more, between (16.74-113.59) IU/L. For men, the mean values are around (16.74-113.59) IU/L. FSH levels are normally low during childhood and, in females, high after menopause . The most common reason for high serum FSH concentration

280-447: A 70-year-old woman, levels are approximately 2- to 4-fold higher in the man. In women, serum estradiol is measured in a clinical laboratory and reflects primarily the activity of the ovaries. The Estradiol blood test measures the amount of estradiol in the blood. It is used to check the function of the ovaries, placenta, adrenal glands. This can detect baseline estrogen in women with amenorrhea or menstrual dysfunction, and to detect

350-714: A heart attack or long periods of hypertension, E2 inhibits the adverse effects of pathologic remodeling of the heart. During pregnancy , high levels of estrogens, namely estradiol, increase coagulation and the risk of venous thromboembolism . Estradiol has complex effects on the liver . It affects the production of multiple proteins , including lipoproteins , binding proteins, and proteins responsible for blood clotting . In high amounts, estradiol can lead to cholestasis , for instance cholestasis of pregnancy . Certain gynecological conditions are dependent on estrogen, such as endometriosis , leiomyomata uteri, and uterine bleeding . Estradiol acts primarily as an agonist of

420-548: A more favorable environment for follicle growth and preventing premature luteinization. As a woman nears perimenopause, the number of small antral follicles recruited in each cycle diminishes and consequently insufficient Inhibin B is produced to fully lower FSH and the serum level of FSH begins to rise. Eventually, the FSH level becomes so high that downregulation of FSH receptors occurs and by postmenopause any remaining small secondary follicles no longer have FSH nor LH receptors. When

490-433: A positive effect on the hypothalamus and pituitary and rapid GnRH pulses occur and an LH surge results. The increase in serum estradiol levels causes a decrease in FSH production by inhibiting GnRH production in the hypothalamus. The decrease in serum FSH level causes the smaller follicles in the current cohort to undergo atresia as they lack sufficient sensitivity to FSH to survive. Occasionally two follicles reach

560-507: A recently discovered non-nuclear receptor for estradiol, via which it can mediate a variety of rapid, non- genomic effects. Unlike the case of the ER, GPER appears to be selective for estradiol, and shows very low affinities for other endogenous estrogens, such as estrone and estriol . Additional mERs besides GPER include ER-X , ERx , and G q -mER . ERα/ERβ are in inactive state trapped in multimolecular chaperone complexes organized around

630-471: A result, cellular transformation and cancer cell proliferation occurs. Estrogen affects certain blood vessels . Improvement in arterial blood flow has been demonstrated in coronary arteries . 17-beta-estradiol (E2) is considered the most potent estrogen found in humans. E2 influences vascular function, apoptosis, and damage during cardiac ischemia and reperfusion. E2 can protect the heart and individual cardiac myocytes from injuries related to ischemia. After

700-495: A role in the maintenance of pregnancy. Research is investigating the role of estrogens in the process of initiation of labor . Actions of estradiol are required before the exposure of progesterone in the luteal phase. The effect of estradiol (and estrogens in general) upon male reproduction is complex. Estradiol is produced by action of aromatase mainly in the Leydig cells of the mammalian testis , but also by some germ cells and

770-481: A third gonadotropin called chorionic gonadotropin (CG). LH and FSH are heterodimers consisting of two peptide chains, an alpha chain and a beta chain. LH and FSH share nearly identical alpha chains (about 100 amino acids long), whereas the beta chain provides specificity for receptor interactions. These subunits are heavily modified by glycosylation . The alpha subunit is common to each protein dimer (well conserved within species, but differing between them), and

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840-443: A unique beta subunit confers biological specificity. The alpha chains are highly conserved proteins of about 100 amino acid residues which contain ten conserved cysteines all involved in disulfide bonds, as shown in the following schematic representation. 'C': conserved cysteine involved in a disulphide bond. Intracellular levels of free alpha subunits are greater than those of the mature glycoprotein, implying that hormone assembly

910-551: A very wide range of solid tumors. FSH binding is thought to upregulate neovascularization via at least two mechanisms – one in the VEGF pathway, and the other VEGF independent – related to the development of umbilical vasculature when physiological. This presents possible use of FSH and FSH-receptor antagonists as an anti-tumor angiogenesis therapy (cf. avastin for current anti-VEGF approaches). Gonadotropin Gonadotropin

980-425: Is about 10-fold more potent than estrone and about 100-fold more potent than estriol. As such, estradiol is the main estrogen in the body, although the roles of estrone and estriol as estrogens are said not to be negligible. Estradiol, like other steroid hormones , is derived from cholesterol . After side chain cleavage and using the Δ or the Δ - pathway, androstenedione is the key intermediary. A portion of

1050-438: Is additionally conjugated with an ester into lipoidal estradiol forms like estradiol palmitate and estradiol stearate to a certain extent; these esters are stored in adipose tissue and may act as a very long-lasting reservoir of estradiol. Estradiol is excreted in the form of glucuronide and sulfate estrogen conjugates in urine . Following an intravenous injection of labeled estradiol in women, almost 90%

1120-407: Is also metabolized via hydroxylation into catechol estrogens . In the liver, it is non-specifically metabolized by CYP1A2 , CYP3A4 , and CYP2C9 via 2-hydroxylation into 2-hydroxyestradiol , and by CYP2C9 , CYP2C19 , and CYP2C8 via 17β-hydroxy dehydrogenation into estrone , with various other cytochrome P450 (CYP) enzymes and metabolic transformations also being involved. Estradiol

1190-456: Is an estrogen steroid hormone and the major female sex hormone . It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles . Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts , widening of the hips and a female pattern of fat distribution . It is also important in the development and maintenance of female reproductive tissues such as

1260-445: Is driven by estrogens, to be specific, estradiol. These changes are initiated at the time of puberty , most are enhanced during the reproductive years, and become less pronounced with declining estradiol support after menopause . Thus, estradiol produces breast development , and is responsible for changes in the body shape , affecting bones, joints, and fat deposition . In females, estradiol induces breast development, widening of

1330-414: Is due to reduced skin hydration and surface lipids (sebum production). Along with chronological aging and photoaging, estrogen deficiency in menopause is one of the three main factors that predominantly influences skin aging. Hormone replacement therapy consisting of systemic treatment with estrogen alone or in combination with a progestogen, has well-documented and considerable beneficial effects on

1400-425: Is excreted in urine and feces within 4 to 5 days. Enterohepatic recirculation causes a delay in excretion of estradiol. Levels of estradiol in premenopausal women are highly variable throughout the menstrual cycle and reference ranges widely vary from source to source. Estradiol levels are minimal and according to most laboratories range from 20 to 80 pg/mL during the early to mid follicular phase (or

1470-664: Is in a female who is undergoing or has recently undergone menopause . High levels of FSH indicate that the normal restricting feedback from the gonad is absent, leading to an unrestricted pituitary FSH production. FSH may contribute to postmenopausal osteoporosis and cardiovascular disease. If high FSH levels occur during the reproductive years, it is abnormal. Conditions with high FSH levels include: Most of these conditions are associated with subfertility or infertility. Therefore, high FSH levels are an indication of subfertility or infertility. Diminished secretion of FSH can result in failure of gonadal function (hypogonadism). This condition

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1540-456: Is limited by the appearance of the specific beta subunits, and hence that synthesis of alpha and beta is independently regulated. Another human gonadotropin is human chorionic gonadotropin (hCG), produced by the placenta during pregnancy . Gonadotropin receptors are embedded in the surface of the target cell membranes and coupled to the G-protein system. Signals triggered by binding to

1610-416: Is produced in the testicles . The rest is synthesized via peripheral aromatization of testosterone into estradiol and of androstenedione into estrone (which is then transformed into estradiol via peripheral 17β-HSD). This peripheral aromatization occurs predominantly in adipose tissue , but also occurs in other tissues such as bone , liver , and the brain . Approximately 40 to 50 μg of estradiol

1680-401: Is produced per day in men. In plasma, estradiol is largely bound to SHBG and albumin . Only about 2.21% (± 0.04%) of estradiol is free and biologically active. The percentage remains constant throughout the menstrual cycle . Inactivation of estradiol includes conversion to less-active estrogens, such as estrone and estriol. Estriol

1750-606: Is produced within the follicles of the ovaries and in other tissues including the testicles , the adrenal glands , fat, liver , the breasts, and the brain. Estradiol is produced in the body from cholesterol through a series of reactions and intermediates . The major pathway involves the formation of androstenedione , which is then converted by aromatase into estrone and is subsequently converted into estradiol. Alternatively, androstenedione can be converted into testosterone , which can then be converted into estradiol. Upon menopause in females, production of estrogens by

1820-415: Is responsible for interaction with the follicle-stimulating hormone receptor . The sugar portion of the hormone is covalently bonded to asparagine , and is composed of N-acetylgalactosamine , mannose , N-acetylglucosamine , galactose , and sialic acid . In humans, the gene for the alpha subunit is located at cytogenetic location 6q14.3. It is expressed in two cell types, most notably the basophils of

1890-421: Is similar to those of luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and human chorionic gonadotropin (hCG). The alpha subunits of the glycoproteins LH, FSH, TSH, and hCG are identical and consist of 96 amino acids , while the beta subunits vary. Both subunits are required for biological activity. FSH has a beta subunit of 111 amino acids (FSH β), which confers its specific biologic action, and

1960-484: Is sometimes abbreviated Gn . The alternative spelling gonadotrophin which inaccurately implies a nourishing mechanism is also used. There are various preparations of gonadotropins for therapeutic use, mainly as fertility medication . There are also fad diet or quack preparations, which are illegal in various countries. The two principal gonadotropins in vertebrates are luteinizing hormone (LH) and follicle-stimulating hormone (FSH), although primates produce

2030-420: Is the first day of menstrual flow). The cohort of small antral follicles is normally sufficient in number to produce enough Inhibin B to lower FSH serum levels. In addition, there is evidence that gonadotropin surge-attenuating factor produced by small follicles during the first half of the follicle phase also exerts a negative feedback on pulsatile luteinizing hormone (LH) secretion amplitude, thus allowing

2100-429: Is the major urinary metabolite . Estradiol is conjugated in the liver to form estrogen conjugates like estradiol sulfate , estradiol glucuronide and, as such, excreted via the kidneys . Some of the water-soluble conjugates are excreted via the bile duct , and partly reabsorbed after hydrolysis from the intestinal tract . This enterohepatic circulation contributes to maintaining estradiol levels. Estradiol

2170-421: Is the only time at which estetrol occurs in the body, while during menopause, estrone predominates (both based on serum levels). The estradiol produced by male humans, from testosterone, is present at serum levels roughly comparable to those of postmenopausal women (14–55 versus <35 pg/mL, respectively). It has also been reported that if concentrations of estradiol in a 70-year-old man are compared to those of

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2240-455: Is typically manifested in males as failure in production of normal numbers of sperm. In females, cessation of reproductive cycles is commonly observed. Conditions with very low FSH secretions are: Isolated FSH deficiency due to mutations in the gene for β-subunit of FSH is rare with 13 cases reported in the literature up to 2019. FSH is used commonly in infertility therapy, mainly for ovarian hyperstimulation as part of IVF . In some cases, it

2310-407: Is used in ovulation induction for reversal of anovulation as well. FSH is available mixed with LH activity in various menotropins including more purified forms of urinary gonadotropins such as Menopur , as well as without LH activity as recombinant FSH (Gonapure, Gonal F, Follistim, Follitropin alpha). Elevated FSH receptor levels have been detected in the endothelia of tumor vasculature in

2380-487: The Sertoli cells of immature mammals. It functions ( in vitro ) to prevent apoptosis of male sperm cells. While some studies in the early 1990s claimed a connection between globally declining sperm counts and estrogen exposure in the environment, later studies found no such connection, nor evidence of a general decline in sperm counts. Suppression of estradiol production in a subpopulation of subfertile men may improve

2450-413: The Sertoli cells of the testes by binding to FSH receptors on their basolateral membranes, and is critical for the initiation of spermatogenesis . Follicle-stimulating hormone is typically measured in the early follicular phase of the menstrual cycle, typically day three to five, counted from last menstruation. At this time, the levels of estradiol (E2) and progesterone are at the lowest point of

2520-424: The corpus luteum until the placenta takes over the production of these hormones. Gonadotropin deficiency due to pituitary disease results in hypogonadism , which can lead to infertility . Treatment includes administered gonadotropins, which, therefore, work as fertility medication . Such can either be produced by extraction and purification from urine or be produced by recombinant DNA . Failure or loss of

2590-556: The estrogen receptor (ER), a nuclear steroid hormone receptor . There are two subtypes of the ER, ERα and ERβ , and estradiol potently binds to and activates both of these receptors. The result of ER activation is a modulation of gene transcription and expression in ER-expressing cells , which is the predominant mechanism by which estradiol mediates its biological effects in the body. Estradiol also acts as an agonist of membrane estrogen receptors (mERs), such as GPER (GPR30),

2660-596: The luteinizing hormone surge, inducing ovulation. In the luteal phase, estradiol, in conjunction with progesterone , prepares the endometrium for implantation . During pregnancy , estradiol increases due to placental production. The effect of estradiol, together with estrone and estriol , in pregnancy is less clear. They may promote uterine blood flow, myometrial growth, stimulate breast growth and at term, promote cervical softening and expression of myometrial oxytocin receptors. In baboons, blocking of estrogen production leads to pregnancy loss, suggesting estradiol has

2730-486: The mammary glands , uterus and vagina during puberty , adulthood and pregnancy . It also has important effects in many other tissues including bone , fat , skin , liver , and the brain . Though estradiol levels in males are much lower than in females, estradiol has important roles in males as well. Apart from humans and other mammals , estradiol is also found in most vertebrates and crustaceans , insects , fish , and other animal species . Estradiol

2800-487: The menstrual cycle involve ovarian estradiol as the link to the hypothalamic-pituitary system to regulate gonadotropins . Estrogen is considered to play a significant role in women's mental health, with links suggested between the hormone level, mood and well-being. Sudden drops or fluctuations in, or long periods of sustained low levels of estrogen may be correlated with significant mood-lowering. Clinical recovery from depression postpartum, perimenopause, and postmenopause

2870-438: The menstrual cycle . FSH levels in this time is often called basal FSH levels, to distinguish from the increased levels when approaching ovulation. FSH is measured in international units (IU). For Human Urinary FSH, one IU is defined as the amount of FSH that has an activity corresponding to 0.11388 mg of pure Human Urinary FSH. For recombinant FSH, one IU corresponds to approximately 0.065 to 0.075  μg of

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2940-462: The ovary . In early (small) antral follicles, FSH is the major survival factor that rescues the small antral follicles (2–5 mm in diameter for humans) from apoptosis (programmed death of the somatic cells of the follicle and oocyte). In the luteal-follicle phase transition period the serum levels of progesterone and estrogen (primarily estradiol) decrease and no longer suppress the release of FSH, consequently FSH peaks at about day three (day one

3010-535: The secretion of oxytocin and to increase the expression of its receptor , the oxytocin receptor , in the brain . In women, a single dose of estradiol has been found to be sufficient to increase circulating oxytocin concentrations. Estradiol has been tied to the development and progression of cancers such as breast cancer, ovarian cancer and endometrial cancer. Estradiol affects target tissues mainly by interacting with two nuclear receptors called estrogen receptor α (ERα) and estrogen receptor β (ERβ). One of

3080-508: The semen analysis. Males with certain sex chromosome genetic conditions , such as Klinefelter's syndrome , will have a higher level of estradiol. Estradiol has a profound effect on bone. Individuals without it (or other estrogens) will become tall and eunuchoid , as epiphyseal closure is delayed or may not take place. Bone density is also affected, resulting in early osteopenia and osteoporosis . Low levels of estradiol may also predict fractures, with post-menopausal women having

3150-420: The 10 mm stage at the same time by chance and as both are equally sensitive to FSH both survive and grow in the low FSH environment and thus two ovulations can occur in one cycle possibly leading to non-identical ( dizygotic ) twins. FSH stimulates primary spermatocytes to undergo the first division of meiosis , to form secondary spermatocytes. FSH enhances the production of androgen-binding protein by

3220-442: The androstenedione is converted to testosterone, which in turn undergoes conversion to estradiol by aromatase. In an alternative pathway, androstenedione is aromatized to estrone , which is subsequently converted to estradiol via 17β-hydroxysteroid dehydrogenase (17β-HSD). During the reproductive years, most estradiol in women is produced by the granulosa cells of the ovaries by the aromatization of androstenedione (produced in

3290-477: The anterior pituitary. The gene for the FSH beta subunit is located on chromosome 11p13, and is expressed in gonadotropes of the pituitary cells, controlled by GnRH , inhibited by inhibin , and enhanced by activin . FSH regulates the development, growth, pubertal maturation and reproductive processes of the human body. Control of FSH release from the pituitary gland is unknown. Low frequency gonadotropin-releasing hormone (GnRH) pulses increase FSH mRNA levels in

3360-422: The brain, both prenatally and later in life. There is also evidence the programming of adult male sexual behavior in many vertebrates is largely dependent on estradiol produced during prenatal life and early infancy. It is not yet known whether this process plays a significant role in human sexual behavior, although evidence from other mammals tends to indicate a connection. Estrogen has been found to increase

3430-514: The early and mid luteal phase, and at the time of the late luteal phase, or a few days before menstruation, reach a low of around 40 pg/mL. The mean integrated levels of estradiol during a full menstrual cycle have variously been reported by different sources as 80, 120, and 150 pg/mL. Although contradictory reports exist, one study found mean integrated estradiol levels of 150 pg/mL in younger women whereas mean integrated levels ranged from 50 to 120 pg/mL in older women. During

3500-406: The first week of the menstrual cycle, also known as menses). Levels of estradiol gradually increase during this time and through the mid to late follicular phase (or the second week of the menstrual cycle) until the pre-ovulatory phase. At the time of pre-ovulation (a period of about 24 to 48 hours), estradiol levels briefly surge and reach their highest concentrations of any other time during

3570-437: The follicle matures and reaches 8–10 mm in diameter it starts to secrete significant amounts of estradiol . Normally in humans only one follicle becomes dominant and survives to grow to 18–30 mm in size and ovulate, the remaining follicles in the cohort undergo atresia . The sharp increase in estradiol production by the dominant follicle (possibly along with a decrease in gonadotrophin surge-attenuating factor) cause

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3640-496: The functions of these estrogen receptors is the modulation of gene expression . Once estradiol binds to the ERs, the receptor complexes then bind to specific DNA sequences , possibly causing damage to the DNA and an increase in cell division and DNA replication . Eukaryotic cells respond to damaged DNA by stimulating or impairing G1, S, or G2 phases of the cell cycle to initiate DNA repair . As

3710-505: The gonads usually results in elevated levels of LH and FSH in the blood. LH insensitivity , which results in Leydig cell hypoplasia in males, and FSH insensitivity , are conditions of insensitivity to LH and FSH, respectively, caused by loss-of-function mutations in their respective signaling receptors. Another closely related condition to these is GnRH insensitivity . There are various preparations of gonadotropins for therapeutic use, mainly as fertility medication . For example,

3780-632: The heat shock protein 90 (HSP90), containing p23 protein, and immunophilin, and located in majority in cytoplasm and partially in nucleus. In the E2 classical pathway or estrogen classical pathway, estradiol enters the cytoplasm , where it interacts with ERs. Once bound E2, ERs dissociate from the molecular chaperone complexes and become competent to dimerize, migrate to nucleus, and to bind to specific DNA sequences ( estrogen response element , ERE), allowing for gene transcription which can take place over hours and days. Given by subcutaneous injection in mice, estradiol

3850-431: The highest incidence of bone fracture . Women past menopause experience an accelerated loss of bone mass due to a relative estrogen deficiency. The estrogen receptor , as well as the progesterone receptor , have been detected in the skin , including in keratinocytes and fibroblasts . At menopause and thereafter, decreased levels of female sex hormones result in atrophy , thinning, and increased wrinkling of

3920-407: The hips , a feminine fat distribution (with fat deposited particularly in the breasts, hips, thighs, and buttocks), and maturation of the vagina and vulva , whereas it mediates the pubertal growth spurt (indirectly via increased growth hormone secretion) and epiphyseal closure (thereby limiting final height ) in both sexes. In the female, estradiol acts as a growth hormone for tissue of

3990-466: The menstrual cycle. Circulating levels are typically between 130 and 200 pg/mL at this time, but in some women may be as high as 300 to 400 pg/mL, and the upper limit of the reference range of some laboratories are even greater (for instance, 750 pg/mL). Following ovulation (or mid-cycle) and during the latter half of the menstrual cycle or the luteal phase, estradiol levels plateau and fluctuate between around 100 and 150 pg/mL during

4060-420: The other hand, did not significantly change with topical progesterone. These findings suggest that progesterone, like estrogen, also has beneficial effects on the skin, and may be independently protective against skin aging. Estrogens can be produced in the brain from steroid precursors. As antioxidants , they have been found to have neuroprotective function. The positive and negative feedback loops of

4130-405: The ovaries stops and estradiol levels decrease to very low levels. In addition to its role as a natural hormone, estradiol is used as a medication , for instance in menopausal hormone therapy and feminizing hormone therapy for transgender women ; for information on estradiol as a medication, see the estradiol (medication) article. The development of secondary sex characteristics in women

4200-454: The rat, but is not directly correlated with an increase in circulating FSH. GnRH has been shown to play an important role in the secretion of FSH, with hypothalamic-pituitary disconnection leading to a cessation of FSH. GnRH administration leads to a return of FSH secretion. FSH is subject to oestrogen feed-back from the gonads via the hypothalamic pituitary gonadal axis. FSH stimulates the growth and recruitment of immature ovarian follicles in

4270-408: The receptor are relayed within the cells by the cyclic AMP second messenger system. Gonadotropins are released under the control of gonadotropin-releasing hormone (GnRH) from the arcuate nucleus and preoptic area of the hypothalamus . The gonads — testes and ovaries — are the primary target organs for LH and FSH. The gonadotropins affect multiple cell types and elicit multiple responses from

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4340-411: The reproductive organs, supporting the lining of the vagina , the cervical glands, the endometrium , and the lining of the fallopian tubes. It enhances growth of the myometrium . Estradiol appears necessary to maintain oocytes in the ovary . During the menstrual cycle , estradiol produced by the growing follicles triggers, via a positive feedback system, the hypothalamic-pituitary events that lead to

4410-406: The reproductive years of human females, levels of estradiol are somewhat higher than that of estrone, except during the early follicular phase of the menstrual cycle; thus, estradiol may be considered the predominant estrogen during human female reproductive years in terms of absolute serum levels and estrogenic activity. During pregnancy, estriol becomes the predominant circulating estrogen, and this

4480-405: The skin and a reduction in skin elasticity , firmness, and strength. These skin changes constitute an acceleration in skin aging and are the result of decreased collagen content, irregularities in the morphology of epidermal skin cells , decreased ground substance between skin fibers , and reduced capillaries and blood flow . The skin also becomes more dry during menopause, which

4550-471: The skin of postmenopausal women. These benefits include increased skin collagen content, skin thickness and elasticity, and skin hydration and surface lipids. Topical estrogen has been found to have similar beneficial effects on the skin. In addition, a study has found that topical 2% progesterone cream significantly increases skin elasticity and firmness and observably decreases wrinkles in peri- and postmenopausal women. Skin hydration and surface lipids, on

4620-417: The so-called menotropins (also called human menopausal gonadotropins ) consist of LH and FSH extracted from the urine of menopausal women. There are also recombinant variants. Besides the aforementioned legitimate pharmaceutical drugs , there are fad diet or quack preparations, which are illegal in various countries. Estradiol Estradiol ( E2 ), also called oestrogen , oestradiol ,

4690-413: The state of hypoestrogenicity and menopause. Furthermore, estrogen monitoring during fertility therapy assesses follicular growth and is useful in monitoring the treatment. Estrogen-producing tumors will demonstrate persistent high levels of estradiol and other estrogens. In precocious puberty , estradiol levels are inappropriately increased. Individual laboratory results should always be interpreted using

4760-409: The target organs. As a simplified generalization, LH stimulates the Leydig cells of the testes and the theca cells of the ovaries to produce testosterone (and indirectly estradiol ), whereas FSH stimulates the spermatogenic tissue of the testes and the granulosa cells of ovarian follicles , as well as stimulating production of estrogen by the ovaries. Although gonadotropins are secreted in

4830-491: The theca folliculi cells) to estrone, followed by conversion of estrone to estradiol by 17β-HSD. Smaller amounts of estradiol are also produced by the adrenal cortex , and, in men, by the testes. Estradiol is not produced in the gonads only; in particular, fat cells produce active precursors to estradiol, and will continue to do so even after menopause. Estradiol is also produced in the brain and in arterial walls . In men, approximately 15 to 25% of circulating estradiol

4900-423: Was shown to be effective after levels of estrogen were stabilized and/or restored. The volumes of sexually dimorphic brain structures in transgender women were found to change and approximate typical female brain structures when exposed to estrogen concomitantly with androgen deprivation over a period of months, suggesting that estrogen and/or androgens have a significant part to play in sex differentiation of

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