Disease relevance of Anovulation

• Epidemiological studies that have focused on isolated signs and stigmata of PCOS, such as polycystic ovaries, hyperandrogenism, or chronic anovulation, have found mixed results [1].
• Furthermore, there are less data to substantiate an increased risk of events in women with PCOS identified on the basis of a combination of signs and symptoms, such as hyperandrogenic chronic anovulation [1].
• This study provides evidence for the hypothesis that increased androgenic activity is an important risk indicator for breast cancer, particularly when associated with anovulation, as indicated by low serum progesterone level [2].
• Polycystic ovary syndrome (PCOS) is a common disorder characterized by chronic anovulation and infertility, hyperandrogenaemia, and frequently insulin resistance [3].
• These data suggest that elevated serum PRL reduces the frequency of LH (GnRH) secretion by increasing hypothalamic opioid activity and suggest that the anovulation in hyperprolactinemia is consequent upon persistent slow frequency LH (GnRH) secretion [4].

Psychiatry related information on Anovulation

• It is proposed that these closely interlinked phenomena that, particularly in overweight subjects, are associated with anovulation, may confer a biological advantage for women with PCOS at times of food deprivation, when such women may reproduce more successfully than those without PCOS [5].

High impact information on Anovulation

• We administered pulsatile low doses of gonadotropin-releasing hormone (GnRH) (1 to 5 micrograms) to patients whose anovulation was caused by relative and absolute deficiency of endogenous GnRH [6].
• These data indicate that in these PCO patients the abnormalities of the hypothalamic-pituitary regulation of gonadotropin secretion was not an inherent defect but represented a functional derangement consequent to inappropriate estrogen feedback, which led to a vicious cycle of chronic anovulation and inappropriate gonadotropin secretion [7].
• It has been shown previously that female mice homozygous for an alpha-fetoprotein (AFP) null allele are sterile as a result of anovulation, probably due to a defect in the hypothalamic-pituitary axis [8].
• CONTEXT: For the last 40 yr, the first line of treatment for anovulation in infertile women has been clomiphene citrate (CC) [9].
• CONTEXT: Metformin is successfully used in the treatment of cycle disorders and anovulation in women with polycystic ovary syndrome (PCOS) [10].

Chemical compound and disease context of Anovulation

• Right amygdala kindling in adult female rats causes acyclicity, the development of polycystic ovaries and premature aging of the hypothalamic-pituitary neuroendocrine axis, leading to chronic anovulation and continuous estrogen exposure [11].
• Changing pituitary reactivity to follicle-stimulating hormone and luteinizing hormone-releasing hormone after induced ovulatory cycles and after anovulation in patients with polycystic ovarian disease [12].
• Previously, it was shown that female LHbetaCTP mice are infertile due to anovulation, develop granulosa cell tumors, and undergo precocious puberty from elevated LH and steroid hormones that fail to completely repress the alpha-subunit promoter [13].
• Results revealed that EV administration during juvenile period advanced pubertal onset, suppressed circulating LH, FSH, and Delta4 androstenedione, increased ovarian NE, estradiol, and 3beta-HSD activities, disrupted ovarian dynamics evidenced as absent corpus luteum and presence of ovarian cysts and culminated in anovulation [14].
• Prenatally testosterone (T)-treated female sheep exhibit ovarian and endocrinological features that resemble those of women with polycystic ovarian syndrome (PCOS), which include luteinizing hormone excess, polyfollicular ovaries, functional hyperandrogenism, and anovulation [15].

Biological context of Anovulation

• CONTEXT: Although metformin has been shown to be effective in the treatment of anovulation in women with polycystic ovary syndrome (PCOS), clomiphene citrate (CC) is still considered to be the first-line drug to induce ovulation in these patients [16].
• Women with PCOS have risk factors, including anovulation, hyperandrogenism, and insulin resistance, that suggest a male coronary heart disease risk-factor profile [17].
• The purposes of this investigation were to evaluate the characteristics of three consecutive menstrual cycles and to determine the frequency ofluteal phase deficiency (LPD) and anovulation in a sample of sedentary and moderately exercising, regularly menstruating women [18].
• It is concluded that inhibition of FSH receptor activation by proteins present in serum or follicular fluid is constant (60 and 40%, respectively) and independent from the developmental stage of the follicle, either during the normal follicular phase or in patients with normogonadotropic anovulation [19].
• Lesions of the SCN induce persistent estrus (anovulation) in intact female rats, whereas estrogen implantation in ovariectomized rats results in daily LH surges, which disappear after SCN lesions [20].

Anatomical context of Anovulation

• The serum concentrations of inhibin (P < 0.01) and estradiol (P < 0.001) on the day of hCG treatment were higher in women with anovulation than in normal subjects, as was the number of oocytes retrieved (P < 0.001) [21].
• Polycystic ovary syndrome (PCOS) is a heterogeneous clinical entity that is defined as the association of hyperandrogenism with chronic anovulation in women without specific underlying diseases of the adrenal or pituitary glands [22].
• PAI-1 and plasminogen are involved in ovarian follicle maturation and the present finding suggests a biologically plausible link between hyperinsulinaemia, anovulation and vascular risk in PCOS [23].
• Exposure of females to testosterone in utero can induce masculine characteristics such as anovulation, increased anogenital distance (AGD), absence of nipples, retention of male-like tissues, and agenesis of the lower vagina [24].
• BACKGROUND: The aim of this study was to evaluate the action of tamoxifen on the endometrium in states of chronic anovulation [25].

Associations of Anovulation with chemical compounds

• In a randomized cross-over study of 10 women with PCOD, GnRH (100 micrograms) was injected iv on the fifth day of 2 consecutive cycles, 1 of them following anovulation and progesterone withdrawal bleeding and the other following an induced ovulatory cycle [12].
• Instead, a central and/or peripheral defect, resulting in overproduction of androgen, may also exist and lead to anovulation in OA women [26].
• Testosterone, a follicular regulator: key to anovulation [27].
• To determine whether increased GnRH-LH drive in HAA reflects altered sex steroid exposure caused by chronic anovulation or is an intrinsic hypothalamic attribute, we compared the pulsatile LH response to oral contraceptive (OC)-induced suppression in seven women with HAA, with that of seven eumenorrheic women (EW) [28].
• Thus, similarly to obese PCOS women, nonobese PCOS subjects with anovulation may also benefit from metformin treatment [29].

Gene context of Anovulation

• Anovulation in cyclooxygenase-2-deficient mice is restored by prostaglandin E2 and interleukin-1beta [30].
• This study evaluates the thyrotropin-releasing hormone (TRH)-induced PRL and thyroid-stimulating hormone (TSH) response in normal women (NL, n = 6), women with anovulation and/or inphase endometrial biopsies (AN/IN, n = 12), and women with histologic evidence of luteal phase deficiency (LPD, n = 12) [31].
• Low IL-6 levels in chronic anovulation may be a marker of resistance to clomiphene citrate [32].
• While PCOS-associated hyperandrogenaemia was inversely related to ghrelin levels, anovulation and polycystic ovary morphology were associated with higher concentrations [33].
• In the main study, serum concentrations of IGF-1, IGFBP-1, insulin and LH in women with anovulation associated (n = 23) and not associated (n = 47) with PCOS were determined [34].

Analytical, diagnostic and therapeutic context of Anovulation

• LH activity is also contained in many medications used to treat anovulation and to stimulate multiple folliculogenesis for assisted reproduction techniques [35].
• METHODS: An economic evaluation was set up alongside a multicentre randomized clinical trial comparing laparoscopic electrocautery of the ovaries, followed by clomiphene citrate and rFSH when anovulation persisted, and treatment with rFSH in 168 women with clomiphene citrate-resistant PCOS [36].
• MATERIALS AND METHODS: The search term of subfertile women with anovulation and PCOS was used for identification of randomized controlled trials [37].
• Oral administration of cabergoline (0.03 mg/kg) or terguride (0.1 mg/kg) restored ovarian function and abolished the anovulation following a reduction in serum prolactin concentrations [38].
• This is the first report of ovulation induced by CC in the Indian tropical bat as well as in any animal model that exhibits temporary anovulation similar to polycystic ovary syndrome (PCOD) during the normal physiology of reproduction [39].

References