THE SEQUENCE OF PITUITARY RESPONSES TO SYNTHETIC LUTEINIZING HORMONE RELEASING HORMONE (LH-RH) THROUGHOUT THE NORMAL MENSTRUAL CYCLE

1975 ◽  
Vol 79 (4) ◽  
pp. 625-634 ◽  
Author(s):  
Elwyn M. Grimes ◽  
Irwin E. Thompson ◽  
Melvin L. Taymor

ABSTRACT Thirty-one ovulatory women between 20 and 33 years of age were given 150 μg of synthetic LH-RH during different phases of the menstrual cycle. Five patients were studied during the early follicular phase (days 4–7); 10 patients during the late follicular phase (days 9–12); 6 patients during the "LH Surge"; 5 patients during the early luteal phase (days 14–16); 3 patients during mid-luteal phase (days 17–21); and 2 patients during late luteal phase (days 22–27). Oestrogen, progesterone, FSH and LH levels were determined from 30 min prior to LH-RH administration to 90 min thereafter in all cases. LH response to LH-RH increased progressively during the follicular phase. Enhanced pituitary responsiveness to LH-RH occurred at mid-cycle for both LH and FSH and maximum LH responses occurred during the "LH Surge" and early luteal phase. LH responses during the mid and late luteal phases were similar to late follicular phase responses. There were no significant differences between FSH responses during the early follicular, late follicular, mid-luteal and late luteal phases. Maximum pituitary responsiveness appears to occur in a gonadal steroid milieu of high oestrogen levels in association with rising but low progesterone levels. Progesterone or a crucial oestrogen: progesterone ratio may in fact potentiate pituitary release of LH during the early stages of corpus luteum formation. Pituitary responsiveness to LH-RH correlates positively with basal LH and oestrogen levels during the menstrual cycle and with the oestrogen:progesterone ratio during the luteal phase.

1978 ◽  
Vol 89 (1) ◽  
pp. 48-59 ◽  
Author(s):  
M. Ferin ◽  
J. Bogumil ◽  
J. Drewes ◽  
I. Dyrenfurth ◽  
R. Jewelewicz ◽  
...  

ABSTRACT The effects of prolonged gonadotrophin-releasing hormone (GnRH) infusions on LH, FSH, oestrogens and progesterone secretion were studied in female rhesus monkeys at various times of the menstrual cycle and after castration. GnRH was infused at the rate of 15 μg/h for 48 h. This resulted in mean peripheral GnRH levels of 398 ± 31.5 pg/ml (± se) as measured by radioimmunoassay. As expected the pattern of gonadotrophin responses to GnRH varied considerably with the phase of the menstrual cycle. The largest LH increase was seen during the late follicular phase (6-fold over baseline), with a 3-fold increase during the luteal phase and a 2-fold one during the early follicular phase and in the period following the LH surge. Significant FSH increases (4-fold) were seen only during the follicular phase. Oestrogens increased about 2-fold within 4 h of the start of the infusion during the early follicular phase. In the late follicular phase and during the LH surge, they declined within 24 and 1 h, respectively. Large progesterone increases were seen only during the luteal phase. Of special interest is the fact that the increase in gonadotrophin secretion could not be maintained for the entire duration of the experiment even though GnRH continued to be infused at rates sufficient to elicit initial increases of several fold over baseline. Gonadotrophin release declined 4–28 h after the initial stimulation. A further decrease below pre-infusion control levels was particularly evident during the midcycle surge and, for FSH, after ovariectomy. These results indicate that a continuous mode of administration may rapidly induce a desensitization phenomenon at the level of the gonadotroph.


1982 ◽  
Vol 100 (3) ◽  
pp. 427-433 ◽  
Author(s):  
N. Kruyt ◽  
R. Rolland

Abstract. The release of cortisol, 17α-OH-progesterone, androstenedione and testosterone during a standardized ACTH-stimulation test was investigated in three different stages of the normal menstrual cycle, to conclude if there is any stage dependency on the release of these hormones. No statistically significant differences were observed between the three stages concerning cortisol and testosterone increase. The increase of androstenedione in the pre-ovulatory stage was significantly higher than that seen during the early follicular phase of the cycle. The increase of 17α-OH-progesterone in the luteal phase was significantly less than that of both the early and late follicular stages of the cycle. Progesterone levels showed a small, but significant increase after ACTH-stimulation, in both the early and late stage of the follicular phase. However, the levels remained within the normal range of the follicular phase. In the luteal phase no increase was seen after ACTH-stimulation. Oestradtiol-17β levels did not change at all after ACTH-stimulation. The stage dependency of androstenedione and 17α-OH-progesterone is discussed. The described stage-dependency different increase of 17α-OH-progesterone release can be of importance when the results of ACTH-tests are evaluated to detect carriers of congenital adrenal hyperplasia.


1997 ◽  
Vol 43 (10) ◽  
pp. 1862-1867 ◽  
Author(s):  
Nosratollah Zarghami ◽  
Linda Grass ◽  
Edward R Sauter ◽  
Eleftherios P Diamandis

Abstract We previously found that prostate-specific antigen (PSA) expression in the female breast is regulated by steroid hormones and their receptors. We have now examined whether the PSA concentration in serum changes during the menstrual cycle of healthy women. Among 14 women studied, 3 had serum PSA ≥4 ng/L; their changes in PSA content during the menstrual cycle were studied in 7 informative cycles. We found that PSA concentrations in serum are highest during the mid- to late follicular phase, drop continuously with a half-life of 3–5 days between the late follicular phase and midcycle, and reach a minimum during the mid- to late luteal phase. PSA changes do not correlate with changes in lutropin (LH), follitropin (FSH), or estradiol concentrations. However, PSA peaks seem to follow the progesterone concentration peaks, with a delay of 10–12 days. Sera of some volunteers were tested for their ability to upregulate PSA protein and PSA mRNA in a tissue culture system based on the T-47D breast carcinoma cell line. Only sera obtained during the mid- to late luteal phase were able to upregulate the PSA mRNA and protein. In stimulation experiments in vitro, progesterone, but not LH, FSH, estradiol, human chorionic gonadotropin, prolactin, or growth hormone, was able to upregulate PSA mRNA and protein in the T-47D cell line. These data suggest that PSA is produced in a cyclical manner during the menstrual cycle.


1994 ◽  
Vol 142 (1) ◽  
pp. 181-186 ◽  
Author(s):  
H M Fraser ◽  
C G Tsonis

Abstract The pattern of inhibin concentrations in blood during the menstrual cycle in primates has suggested an endocrine role of inhibin in the negative feedback control of FSH secretion during the luteal phase. Conversely, the fall in inhibin during the late luteal phase may play a role in the rise in serum FSH during the luteal-follicular phase transition. This hypothesis was examined by determining the effects of manipulation of inhibin on FSH secretion in stumptailed macaques. During the mid-luteal phase the putative inhibin feedback was inhibited by i.v. administration of 20 ml of ovine antiserum to human recombinant inhibin in 4 macaques. FSH secretion was unaffected during the initial 24 h period post-treatment and the timing of the rise in FSH which occurred during the subsequent luteal-follicular phase transition was normal. To determine whether the elevated serum concentrations of FSH observed during the early follicular phase could be reduced by administration of inhibin, 5 cyclic macaques were treated with 200 μg of recombinant human inhibin i.v. Serum FSH concentrations were unaltered. These results suggest that inhibin does not play a major role in modulating FSH secretion during the luteal-follicular phase transition. Journal of Endocrinology (1994) 142, 181–186


2021 ◽  
Vol 3 ◽  
Author(s):  
Dan Martin ◽  
Kate Timmins ◽  
Charlotte Cowie ◽  
Jon Alty ◽  
Ritan Mehta ◽  
...  

Objectives: This study aimed to assess how menstrual cycle phase and extended menstrual cycle length influence the incidence of injuries in international footballers.Methods: Over a 4-year period, injuries from England international footballers at training camps or matches were recorded, alongside self-reported information on menstrual cycle characteristics at the point of injury. Injuries in eumenorrheic players were categorized into early follicular, late follicular, or luteal phase. Frequencies were also compared between injuries recorded during the typical cycle and those that occurred after the cycle would be expected to have finished. Injury incidence rates (per 1,000 person days) and injury incidence rate ratios were calculated for each phase for all injuries and injuries stratified by type.Results: One hundred fifty-six injuries from 113 players were eligible for analysis. Injury incidence rates per 1,000 person-days were 31.9 in the follicular, 46.8 in the late follicular, and 35.4 in the luteal phase, resulting in injury incidence rate ratios of 1.47 (Late follicular:Follicular), 1.11 (Luteal:Follicular), and 0.76 (Luteal:Late follicular). Injury incident rate ratios showed that muscle and tendon injury rates were 88% greater in the late follicular phase compared to the follicular phase, with muscle rupture/tear/strain/cramps and tendon injuries/ruptures occurring over twice as often during the late follicular phase compared to other phases 20% of injuries were reported as occurring when athletes were “overdue” menses.Conclusion: Muscle and tendon injuries occurred almost twice as often in the late follicular phase compared to the early follicular or luteal phase. Injury risk may be elevated in typically eumenorrheic women in the days after their next menstruation was expected to start.


1975 ◽  
Vol 79 (2) ◽  
pp. 329-336 ◽  
Author(s):  
F. Lehmann ◽  
I. Just-Nastansky ◽  
B. Behrendt ◽  
P.-J. Czygan ◽  
G. Bettendorf

ABSTRACT The effect of orally given diethylstilboestroldiphosphate (DES) and 17α-ethinyl-oestradiol-3-methylether (EEM) on plasma progesterone levels was studied. Both compounds were administered for 5 days to 5 women in daily doses of 60 mg (DES) and 30 mg (EEM). The fully informed volunteers were found to have a normal menstrual cycle before the study. The mean corpus luteum phase (corpus luteum phase = days between LH surge and onset of menstruation) of all control cycles lasted 12.8 days. Daily plasma samples were collected for radioimmunoassay (RIA) of progesterone, immunoreactive oestrogens and LH. After a control cycle the first treatment was carried out with DES. The third and the fifth cycle were control cycles again. The EEM-treatment was done in the fourth cycle. Although the effect of the two compounds was different, a dependence of the age of the corpus luteum (CL) could be demonstrated for both. DES-treatment lowered plasma progesterone levels during administration. This effect was only demonstrable if the treatment was begun on the day of the LH-peak. The length of the CL-phase remained unaltered. EEM-treatment if started on the day of the LH surge, suppressed corpus luteum function in the late luteal phase. If the treatment was started later, the effect was less pronounced. The administration of both compounds did not shorten the time between ovulation and the next bleeding. After DES-treatment this interval was not altered. After EEM-treatment the subsequent bleeding was even delayed depending on slowly decreasing levels of plasma oestrogens.


2002 ◽  
Vol 13 (2) ◽  
pp. 446-452
Author(s):  
Mala Chidambaram ◽  
John A. Duncan ◽  
Vesta S. Lai ◽  
Daniel C. Cattran ◽  
John S. Floras ◽  
...  

ABSTRACT. It has been demonstrated elsewhere that circulating renin angiotensin system (RAS) components peak when plasma estrogen levels are highest, during the luteal phase of the normal menstrual cycle. This phenomenon has been attributed to “activation” of the RAS. The end-organ vasoconstrictive response to this phenomenon has not been well established. In two related experiments, the RAS was studied in healthy, premenopausal women during predefined phases of the normal menstrual cycle. In the first experiment, the circulating components of the RAS and the systemic hemodynamic response to incremental lower body negative pressure (LBNP) during the follicular and luteal phases of the menstrual cycle were examined. Response variables included mean arterial pressure (MAP), renin, plasma renin activity (PRA), angiotensin II (AngII), and aldosterone. Baseline levels of renin, PRA, and aldosterone were significantly higher in the luteal phase. In response to LBNP, there were significant increases in all variables in both phases; however, the humoral response to this stimulus was significantly augmented in the luteal phase compared with the follicular phase. Despite these elevations in circulating components of the RAS during the luteal phase, subjects were unable to maintain MAP in response to LBNP, exhibiting a dramatic depressor response that did not occur during the follicular phase. In the second experiment, renal and peripheral hemodynamic function at baseline, and in response to AngII blockade with losartan, were examined in women during these high and low estrogen phases of the menstrual cycle. The renal and peripheral hemodynamic responses were similar in the luteal phase and the follicular phase. These results demonstrate that, despite an increase in circulating RAS components during the luteal phase of the menstrual cycle, the system is blunted rather than “activated,” at least at a tissue level. Further studies are needed to clarify this mechanism.


2018 ◽  
Author(s):  
Rebecca Pierson ◽  
Kelly Pagidas

A normal menstrual cycle is the end result of a sequence of purposeful and coordinated events that occur from intact hypothalamic-pituitary-ovarian and uterine axes. The menstrual cycle is under hormonal control in the reproductively active female and is functionally divided into two phases: the proliferative or follicular phase and the secretory or luteal phase. This tight hormonal control is orchestrated by a series of negative and positive endocrine feedback loops that alter the frequency of the pulsatile secretion of gonadotropin-releasing hormone (GnRH), the pituitary response to GnRH, and the relative secretion of luteinizing hormone and follicle-stimulating hormone from the pituitary gonadotrope with subsequent direct effects on the ovary to produce a series of sex steroids and peptides that aid in the generation of a single mature oocyte and the preparation of a receptive endometrium for implantation to ensue. Any derailment along this programmed pathway can lead to an abnormal menstrual cycle with subsequent impact on the ability to conceive and maintain a pregnancy. This review contains 7 figures and 26 references Key words: follicle-stimulating hormone, follicular phase, gonadotropin-releasing hormone, luteal phase, luteinizing hormone, menstrual cycle, ovulation, progesterone, proliferative phase, secretory phase


1998 ◽  
Vol 156 (1) ◽  
pp. 91-98 ◽  
Author(s):  
L Riboni ◽  
C Escamilla ◽  
R Chavira ◽  
R Dominguez

The effects of peripheral sympathetic denervation induced by guanethidine administration to newborn and 10-day-old female guinea pigs on puberty, ovulation and the follicular population were analysed. Peripheral sympathetic denervation beginning at birth resulted in the loss of ovarian norepinephrine content (0.95. +/- 0.1 ng/mg wet tissue in untreated control animals vs non detectable in treated animals). Guanethidine administration to newborn or 10-day-old guinea pigs advanced puberty (age of vaginal opening: 27 +/- 1.2 days (newborn), 26 +/- 1.7 (10-day-old) vs 37 +/- 0.7 (control), P < 0.001) and ovulation. The number of corpora lutea in control and denervated animals was similar (3.5 +/- 0.2 vs 3.3 +/- 0.3). The relative weight (mg/100 g body weight) of the ovaries and adrenals in the denervated animals autopsied during the late follicular phase (24-48 h after vaginal opening) increased (ovaries: 27.8 +/- 1.3, 28.9 +/- 3.0 vs 20.9 +/- 0.8, P < 0.05; adrenals 36.4 +/- 1.4, 37.0 +/- 0.8 vs 31.6 +/- 1.5, P < 0.05), while the uterine weight diminished (179 +/- 13, 149 +/- 28 vs 292 +/- 20). When the animals were killed during the late luteal phase (9-11 days after vaginal closure), the relative weight of the ovaries of newborn guanethidine-treated animals was higher than that of the control animals (21.4 +/- 1.7 vs 16.8 +/- 1.4, P < 0.05). The mean number of follicles counted in the ovaries of denervated animals was significantly higher than in control animals (1736 +/- 230 vs 969 +/- 147, P < 0.05). The mean diameter of the follicles in the untouched control ovary in animals killed in the late follicular phase was significantly larger than from animals killed in the late luteal phase (263 +/- 3.9 microns vs 248 +/- 3.0 microns, P < 0.01). The mean diameter of the follicles measured in the ovaries of denervated animals was significantly higher than in controls (animals treated from birth 274 +/- 2.0 microns vs 255 +/- 2.4, P < 0.05; animals treated from day 10, 286 +/- 2.3 microns vs 257 +/- 2.3, P < 0.05). When the mean diameter of the follicles in the left and right ovary of the untouched control was analysed, the follicular diameter in the left ovary was significantly larger than in the right ovary (309 +/- 6.0 microns vs 214 +/- 3.9, P < 0.01); the response of the left and right ovaries to sympathetic denervation was the opposite. The results obtained in the present study suggest that ovarian innervation plays a role in the regulation of follicular growth, maturation and atresia which is not related to changes in steroid secretion by the ovary, but to other regulatory mechanisms.


2004 ◽  
Vol 172 (3) ◽  
pp. 248-254 ◽  
Author(s):  
Emily C. Bell ◽  
Glen B. Baker ◽  
Christina Poag ◽  
Francois Bellavance ◽  
Janisse Khudabux ◽  
...  

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