Endocrine regulation of the menstrual cycle

Physiological data concerning the serum concentrations and the pituitary content of varian steroids and gonadotropins, respectively, are reviewed. On the basis of these physiological data results from experimental studies are critically evaluated as far as their significance for the understanding of the physiology of the cycle is concerned. Data from the literatur and results from own studies are incorporated in a concept of the endocrine regulation of the human menstrual cycle.     

Sleep and the menstrual cycle.

To evaluate changes in sleep across the phases of the menstrual cycle, sleep-wake diaries were completed by 32 healthy women twice daily for 2 menstrual cycles. There was a significant increase in sleep onset latency and a significant decrease in sleep efficiency and sleep quality during the luteal phase. This increase in sleep disturbance was observed in the entire sample and was not related to the severity of other premenstrual symptoms. However, women having increased severity of other premenstrual symptoms reported greater luteal increase in daytime sleepiness. Thus, although menstruating women are likely to show increased sleep disturbance during the luteal phase, those with other, more severe premenstrual symptoms are more likely to experience a luteal increase in daytime sleepiness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Women, alcohol and the menstrual cycle

This review presents evidence which implicates a role for menstrual cycle phase in the response of pre-menopausal women to moderate alcohol intake. It is concluded that the majority of published studies have suffered from poor methodological design and have employed inadequate means of cycle phase identification. Contradictory and ill-founded findings have been reported. The best evidence to date suggests that women eliminate alcohol more rapidly during the mid-luteal phase of the cycle. This finding needs to be substantiated by further studies.     

Does the menstrual cycle influence cystometry?

Alterations in the hormonal milieu associated with the menstrual cycle appear to influence the dynamic interaction between the bladder and urethra as well as detrusor function, probably because of the common embryological origin of the lower genital and urinary tracts. In this retrospective study we investigated the effect of the menstrual cycle on cystometric diagnosis. A retrospective case note review of 687 consecutive patients attending the urogynecology unit of St Georges University Hospital, a tertiary referral center, was carried out. The study group comprised 57 women with regular menstrual periods. In both patients whose symptoms were adversely affected premenstrually and those whose symptoms were not influenced by the menstrual cycle, the majority of normal cystometric diagnoses were made in the luteal phase: 45.5% vs. 25% (P < or = 0.002) and 38.5% vs. 4.8% (P < or = 0.05), respectively. Diagnoses of genuine stress incontinence, detrusor instability and mixed genuine stress incontinence and detrusor instability were most frequently made in the follicular phase of the cycle. More normal cystometric diagnoses were made in the influenced group (36.8%) than in the uninfluenced group (21%) (P < 0.02). The results of this preliminary study indicate that the timing of cystometric evaluation may influence the detection of a positive diagnosis. The luteal phase may not be the correct time to make an accurate diagnosis, especially in patients whose symptoms are influenced by their menstrual cycle.     

Effects of menstrual cycle on creativity

Activation of transfected muscarinic m1 acetylcholine receptors (m1AChR) has been linked to several signal transduction pathways which include phosphoinositide hydrolysis, arachidonic acid release and cAMP accumulation. In Chinese hamster ovary cells stably transfected with the rat m1AChR gene, carbachol elicited all three responses with EC50 values of 2.6, 3.8 and 76 microM, respectively. However, pilocarpine and the selective muscarinic agonist AF102B activated phosphoinositide hydrolysis (by 94 and 27% vs. carbachol, respectively), while antagonizing carbachol-mediated cAMP accumulation. Carbachol also activated (by 4-fold) adenylyl cyclase in membranes prepared from these cells, indicating independence of this signal from intracellular mediators. Moreover, carbachol and AF102B similarly elevated cytosolic Ca2+ in intact m1AChR-transfected cells. The ligand-selective cAMP accumulation, its independence from Ca2+ and the carbachol-activated adenylyl cyclase in membranes suggest that it represents an independent m1AChR-mediated signal, unrelated to phosphoinositide hydrolysis. Selective muscarinic ligands such as AF102B may independently activate distinct signalling pathways, which may be important for designing cholinergic replacement therapy for treating Alzheimer's disease.     

The regulation mechanism of the female menstrual cycle

The hormonal patterns during menstrual cycle, which consist of cyclic alterations in gonadotropins, estradiol, and progesterone, are controlled by hypothalamic-pituitary-ovarian feedback mechanism. GnRH produced in hypothalamus acts on the pituitary cells to secrete FSH and LH, which stimulate the follicular development. The developed follicles secrete estradiol, progesterone, inhibin, activin, and follistatin. Estradiol and progesterone, at different concentrations and/or ratios, either positively or negatively control the feedback of hypothalamic-pituitary axis in regulating the secretion of GnRH, FSH and LH. Inhibin and follistatin selectively suppress, whereas activin enhances the secretion of FSH in the pituitary. Recently, various additional factors produced by the ovary have been identified to contribute to the follicular development by paracrine and/or autocrine regulation as well as to feedback on hypothalamic-pituitary unit.     

The menstrual cycle and punitiveness.

Studied the levels of punishment and reliability of punishments/judgments made by menstruating or premenstrual women by having Ss read vignettes of 7 different college disciplinary cases and select a level of punishment. 12 menstrual, 10 premenstrual, and 13 intermenstrual women participated, as did 10 males of comparable age and background. Two additional groups of 7 women each were led to believe they were (1) in the premenstrual phase or (2) still several days away from it. Findings show that punitiveness and reliability of judgments did not differ across menstrual phases or between males and females. The task was perceived as more difficult by males and by females led to believe they were premenstrual. A relationship was found between severity of menstrual symptoms and punitiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do gastrointestinal symptoms vary with the menstrual cycle?

This systematic review presents both the physiological and symptom-based studies which have explored gastrointestinal variation across the menstrual cycle. Understanding this variation may be helpful in identifying the origin of pelvic pain, particularly as the symptoms associated with causes, such as endometriosis, also vary across the cycle. One-third of otherwise asymptomatic women may experience gastrointestinal symptoms at the time of menstruation, and almost 50% of women with irritable bowel syndrome report a perimenstrual increase in symptoms.     

The timing of breast cancer surgery during the menstrual cycle

A number of recent studies have suggested that survival among premenopausal women after primary treatment of breast cancer may be affected by the estimated hormonal milieu at the time of surgery, especially in those with axillary lymph node metastases. The concept has created considerable controversy and has resulted in the publication of many negative reports. However, several biological mechanisms have been suggested for the observed survival advantage. These include cyclical patterns of immune function, as well as cell division and cell death, that correlate with hormonal fluctuations of the menstrual cycle. Comparisons among studies of timing have been complicated by differences in menstrual cycle divisions, variability in the sources of study populations, limited availability of menstrual history data, and changes over the past 2 decades in primary and adjuvant breast cancer therapy. Several recent publications have been enhanced by the availability of serum collected at the time of surgery that enables accurate measurement of the hormonal milieu. In these studies, the likelihood of misclassification by menstrual cycle phase is reduced, and dependence on recalled menstrual history is eliminated. High progesterone levels have been associated with improved survival. These findings have encouraged some to suggest that perioperative administration of progesterone or tamoxifen (Nolvadex) may provide a preventive avenue comparable to scheduling surgery during the luteal phase. Further multidisciplinary studies are needed, however, to clarify the influence of the naturally occurring or medically induced hormonal milieu at the time of breast cancer surgery on survival in premenopausal women.     

Hormonal regulation of the menstrual cycle (author's transl)

The menstrual cycle is regulated by a complex hormonal system with positive and negative feedback mechanisms and changes in sensitivity of peripheral tissues. Four concepts appear to be fundamental: -- regular, pulsatile secretion of LHR is necessary to the functioning of the system; -- regulation is to a great extent effected by the pituitary gland in response to changes in ovarian steroid levels; -- changes in ovarian steroid levels are due to regulatory changes in receptivity to pituitary hormones, as well as to variations in enzyme activities; -- at the periphery, changes in hormonal impacts are accompanied by modifications of receptivity to steroid hormones.     

Effects of the menstrual cycle on dressing behavior in the cold

The purpose of the present study was to determine the effect of the menstrual cycle on dressing behavior in cold exposure. Rectal and skin temperatures, temperature sensation and metabolic rate were measured in seven women during the luteal (L) and the follicular (F) phases of the menstrual cycle, as was their dressing behavior in these two phases. The subjects were instructed to dress so as to feel comfortable when the ambient temperature was decreased from 30 degrees C to 15 degrees C (07:00-09:00). Most subjects dressed more quickly and with thicker clothing in the L phase. They felt cooler in the L phase during the last 30 min of the temperature fall. Rectal and skin temperatures showed significant differences between L and F phases and metabolic rate was significantly higher in the L phase. The results can be interpreted in terms of the establishment of a higher set-point in core temperature during the L phase.     

Sex hormones affect spatial abilities during the menstrual cycle.

The aim of this study was (a) to show that different measures of spatial cognition are modulated by the menstrual cycle and (b) to analyze which steroid is responsible for these cognitive alterations. The authors collected blood samples in 3-day intervals over 6 weeks from 12 young women with a regular menstrual cycle to analyze concentrations of estradiol, progesterone, testosterone, luteinizing hormone, and follicle-stimulating hormone. The performance on 3 spatial tests was measured during the menstrual and the midluteal phases. A significant cycle difference in spatial ability as tested by the Mental Rotation Test was found, with high scores during the menstrual phase and low scores during the midluteal phase. Testosterone had a strong and positive influence on mental rotation performance, whereas estradiol had a negative one. These results clearly indicate that testosterone and estradiol are able to modulate spatial cognition during the menstrual cycle. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermic effect of food during each phase of the menstrual cycle

The effect of the menstrual cycle on the thermic effect of food (TEF) was examined in eight healthy, normal-weight [mean +/- SD: 56.1 +/- 5.6 kg and body mass index (in kg/m2) 21.3 +/- 1.8] women aged 22-38 y. Their lean body mass and fat mass were 39.4 +/- 2.7 kg and 16.9 +/- 6.5 kg, respectively. TEF was measured on 4 separate days selected to match the four phases of a menstrual cycle: early follicular, follicular, luteal, and late luteal. The volunteers consumed a 3138-kJ liquid meal (54.5% carbohydrate, 14.0% protein, and 31.5% fat) on each test day. Resting metabolic rate was measured for 55 min before the meal and every 30 min after the start of the meal for 205 min. Although resting metabolic rate remained unchanged, there was a significant difference (P < 0.01 by ANOVA) in mean (+/- SEM) values for TEF among the four phases of the cycle: 0.94 +/- 0.05 kJ/min during the early follicular phase, 0.86 +/- 0.09 kJ/min during the follicular phase, 0.70 +/- 0.10 kJ/min during the luteal phase, and 0.76 +/- 0.07 kJ/min during the late luteal phase. TEF decreased significantly (P < 0.025 by paired t test) during postovulation (average of luteal and late luteal phases), when it was 0.73 +/- 0.07 kJ/min, compared with preovulation (average of early follicular and follicular phases), when it was 0.90 +/- 0.06 kJ/min. In conclusion, TEF decreased during the luteal phase of the menstrual cycle, possibly as a result of impairment of glucose uptake and slower transit of food through the upper gastrointestinal tract.     

Changes in cognitive task performance across the menstrual cycle.

Examined the effect on cognitive tests of menstrual-cycle-related changes in estrogen in 87 undergraduates. The estrogen peak was expected to facilitate performance of 4 "automatized" tasks and to impair performance of "perceptual-restructuring" tasks, compared with performance in the postovulatory phase when progesterone is thought to counteract the action of estrogen. Daily basal body temperature (BBT) records suggested that 21 Ss did not ovulate in the cycle(s) studied. No main effect of Day 10 of the cycle vs Day 20 occurred for any task in the 66 Ss who did appear to ovulate. However, the magnitude of predicted shifts in performance was significantly correlated with proximity of the "Day 10" testing day to the lowest BBT, the presumed preovulatory estrogen peak; and to the "Day 20" proximity to the highest BBT, the presumed progesterone peak. Ss tested 3 or fewer days before the thermal nadir and on or after the thermal peak had the predicted significant changes on 3 of the 4 tasks. Results support the hypotheses and indicate that precise timing is essential to demonstrate the phenomena. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The menstrual cycle and response to erotic literature

133 undergraduate females responded to a pre-experimental questionnaire assessing their contraceptive use (28% on contraceptive pills), sexual experience (71% had had sexual intercourse), and present phase of menstrual cycle. Ss then read an erotic story intended to induce sexual arousal. Results of a self-report postexperimental questionnaire assessing sexual arousal and genital stimulation show no significant response differences based on menstrual cycle phases for Ss not using contraceptive pills. Greatest degree of arousal and sensation was experienced by Ss on contraceptive pills who were in the menstrual phase of the cycle; least arousal and sensation was experienced by Ss on contraceptive pills who were in the premenstrual phase of the cycle. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serum immunoglobulins E are related to menstrual cycle

During a cross sectional epidemiological survey on a general population sample, 596 fertile women underwent total serum IgE determination. They completed an interviewer-administered standardized questionnaire and were categorized according to their menstrual period. They were divided into two groups: those from days 10 to 20, who were considered to be in the periovulatory phase, and those in the other phases. IgE mean values were significantly different (p = 0.01) in the two groups: particularly, lower IgE values were found in those in periovulatory phase, after accounting for smoking habit and atopic status. By multiple regression analysis, taking into account the independent effects of menstrual period, age, smoking habit, hours of fast, skin prick test reactivity and presence of cough, significantly lower IgE values in the periovulatory phase were found. We hypothesize the possibility that a decrease of IgE concentration occurs during midcycle: a reduced immune response might facilitate the ovuli implantation. Further studies are necessary to longitudinally investigate the trend of IgE in the same women, as well as the distributions and the trends of other immunoglobulins.     

Serum levels of the pregnancy zone protein during the normal menstrual cycle

pregnancy zone protein (PZ), low polar estrogen, progesteorne, luteinizing hormone, and follicle stimulating hormone levels during normal menstrual cycles were studied. Serum samples were taken from 12 healthy women of different ages throughout their menstrual cycle. PZ levels showed no significant pattern and no statistically significant association was shown between PZ levels and any of the hormones. PZ levels were higher in older women and varied within each women's cycle. The study results indicate that peak estrogen levels during the menstrual cycle are not sufficient in duration or magnitude to cause increased serum levels of PZ.     

Effect of post-coital contraceptive methods on the endometrium and the menstrual cycle

STUDY OBJECTIVE: To evaluate the effect of treatment with ethinylesteradiol-levonorgestrel or danazol on ovarian function, gonadotrophin release and endometrial development during the time when a pregnancy may occur following unprotected intercourse. METHODS: Women with regular menstrual cycles were followed during one control, one treatment and one follow-up month. The women obtained either a combination of 0.5 mg levonorgestrel and 0.1 mg ethinylestradiol (Yuzpe regimen: n = 16) or 600 mg danazol orally and repeated after 12 hours (n = 16). The treatment was administered on either cycle day (cd) 12 or day LH +2. An endometrial biopsy was obtained once on cd LH +6 to +8 in the subjects treated on cd LH +2 both in control and treatment cycles, and morphometric analysis was performed. The concentrations of LH, pregnandiol (P2G), and estrone (EIG) glucuronide were followed daily in morning urine during control and treatment cycles. RESULTS: Following treatment with the Yuzpe regimen on cd 12 the LH surge was either undetectable (three subjects), postponed to cd 16 to 22 (three subjects) or cd 38 to 39 (two subjects) with lower P2G and LH levels than in the control cycle. Following preovulatory treatment with danazol, no LH peak could be detected in four subjects and in the remaining four subjects the LH peak varied between cd 13 and cd 24. The mean area under the curve for LH was significantly lower, the levels of EIG were slightly higher and the P2G levels were unaffected in comparison with the control cycle. Neither of the two treatments administered on cd LH +2 affected the hormonal pattern and only a discreet effect on the development of the endometrium was seen after the EE/LNG treatment. CONCLUSION: The findings indicate that the contraceptive effect of postcoital treatment with EE/LNG and danazol is mainly due to an inhibition or delay of ovulation and insufficient corpus luteum function. The direct effect on the endometrium is limited, if any.