The effect of oxytocin administration upon the pulsatile secretion of luteinizing hormone in humans

1989 ◽  
Vol 121 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Janet A. Amico ◽  
Donald W. Richardson ◽  
Stephen J. Winters

Abstract. The effect of iv administration of synthetic oxytocin upon the pulsatile pattern of LH secretion was studied in 5 healthy men and 10 healthy women. Five of the women were studied in the follicular phase of a menstrual cycle and the other 5 were studied in the luteal phase of a cycle. Synthetic oxytocin in 0.9% saline or saline alone was administered via continuous iv infusion for 8 h on 2 consecutive days. Infusions were administered using a double-blinded and radomized schedule. The rate of the oxytocin infusion commenced at 1 mU/min and was increased 1 mU/min every 40 min to a final rate of 12 mU/min. The plasma oxytocin concentration during oxytocin infusion ranged from 2–70 fmol/l. Blood for LH determination was sampled every 20 min in the 5 follicular phase women and every 10 min in the 5 men and 5 luteal phase women. The detect algorithm was used to analyze LH pulsatile secretion. Oxytocin infusion was without significant effect on mean LH, number of LH pulses, or area under the LH curve in men or women studied for the period of observation. Thus it is unlikely that increases in plasma oxytocin regulate the pulsatile secretion of LH in humans.

1987 ◽  
Vol 116 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Jocelyne Brun ◽  
Bruno Claustrat ◽  
Michel David

Abstract. Nocturnal urinary excretion of melatonin, LH, progesterone and oestradiol was measured by radioimmunoassay in nine normal women during a complete cycle. In addition, these hormonal excretions were studied in two women taking an oral contraceptive. A high within-subject coefficient of variation was observed for melatonin excretion in the two groups. In the nine normal cycling women, melatonin excretion was not decreased at the time of ovulation, but was significantly increased during the luteal phase compared with that of the follicular phase (P < 0.01). These data are consistent with a positive relationship between melatonin and progesterone during the luteal phase. In the two women under an oral contraceptive, melatonin excretion was found within the same range as for the other nine. The results are discussed in terms of pineal investigation in human.


1981 ◽  
Vol 240 (5) ◽  
pp. E489-E492
Author(s):  
J. A. Resko ◽  
W. E. Ellinwood ◽  
E. Knobil

To obtain new information on the site of the inhibiting actions of progesterone (P) during the follicular phase of the cycle, we administered P continuously to 13 rhesus macaques (Macaca mulatta) from days 5 through 12 of the menstrual cycle. This treatment produced luteal-phase levels (approximately 6 ng/ml of serum) within 4 h. (FSH) concentrations dropped significantly from pretreatment amounts (P less than 0.01). During this time, both immunoreactive luteinizing hormone (LH) (n = 8 animals) and bioactive LH (n = 5) remained stable. The 17 beta-estradiol (E2) concentrations dropped significantly below base line 24 h after treatment (P less than 0.05). The decline in E2 occurred after the decline in FSH. Inhibition of FSH continued for 40 h, after which both FSH and LH rose steadily in a way that resembled a preovulatory surge on days 8 or 9 of the menstrual cycle, and then returned to base line by day 10. When gonadotropins were at their zenith, the ovary did not respond by secreting E2. None of the effects mentioned above were found in control animals treated with blank implants. These data demonstrate that P administered during the follicular phase inhibits FSH but not LH secretion. This initial inhibition probably occurs at a hypothalamic-pituitary site, but after 40 h direct inhibitory effects on the ovary cannot be ruled out. P stimulates the release of gonadotropin in female monkeys despite reduced production of E2 by the ovary.


1984 ◽  
Vol 100 (1) ◽  
pp. 75-80 ◽  
Author(s):  
M. G. Metcalf ◽  
J. J. Evans ◽  
J. A. Mackenzie

ABSTRACT An increased daily excretion of pregnanediol, relative to that early in the menstrual cycle, is often taken to be evidence that a woman has ovulated. This paper assesses the value of alternative procedures for this purpose. Urine, plasma and saliva samples were collected during a 24-h period from 20 women during the follicular phase and from 20 women during the luteal phase. The 24-h excretion of pregnanediol was compared with (1) the concentration of progesterone in plasma, (2) the concentration of progesterone in saliva, (3) the concentration of pregnanediol in small urine samples, (4) the rate of excretion of pregnanediol and (5) the ratio of pregnanediol to creatinine in small urine samples. Each analyte increased substantially during the luteal phase. The median increases (ratio of luteal to follicular phase values) were 14·8, 3·2, 10·6, 11·9 and 11·1 respectively. By comparison, the median increase in 24-h pregnanediol output was 9·2. When the other analytes were used instead of the 24-h excretion of pregnanediol to assess the possibility of ovulation, the incidence of misclassifications (follicular samples classed as luteal and luteal samples classed as follicular) was 0, 12·8, 5·9, 2·0 and 1·0% respectively. It was concluded that the most satisfactory alternative to the measurement of 24-h pregnanediol output for the biochemical assessment of ovulation based on progesterone production was the measurement of the concentration of progesterone in plasma; the least satisfactory alternative was determination of the concentration of progesterone in saliva. If blood was not available, measurement of the ratio of pregnanediol to creatinine in a small urine sample was the preferred method. J. Endocr. (1984) 100, 75–80


1988 ◽  
Vol 116 (1) ◽  
pp. 123-135 ◽  
Author(s):  
J. M. Wallace ◽  
G. B. Martin ◽  
A. S. McNeilly

ABSTRACT It has previously been shown that treatment of ewes with bovine follicular fluid (bFF) throughout the luteal phase of the oestrous cycle lowers plasma levels of FSH but increases the frequency and amplitude of the pulses of LH. Under these conditions, ovarian follicles grow to a maximum diameter of 2·7 mm and have a reduced capacity to release oestradiol. We have examined the nature of the gonadotrophin signals controlling follicular development in the normally cycling ewe and have investigated the effects of previous exposure to bFF on these signals and the follicular responses to them. Control ewes (n = l) were injected i.v. with 9 ml bovine serum and treated ewes were injected with 9 ml bFF, twice daily from days 1 to 10 of the luteal phase (day 0 = oestrus). The ewes were injected with prostaglandin analogue on day 11 of the cycle to induce luteolysis and the gonadotrophin patterns were studied in blood sampled from these animals every 10 min for up to 72 h during the subsequent follicular phase. Following luteolysis (and the end of bFF treatment), LH pulse frequency increased rapidly in both groups and reached 1 pulse/h within 6 h. Thereafter, pulse frequency increased marginally and reached 1 pulse/50 min by the onset of the LH surge. This pattern was not affected by previous treatment with bFF. In the control ewes, the amplitude of the LH pulses did not change significantly following luteolysis or at any time during the follicular phase, while the levels of FSH declined slowly until the onset of the surge. In the treated ewes, on the other hand, there was an immediate increase in both LH pulse amplitude and the concentration of FSH immediately after the end of bFF treatment at luteolysis, and they remained above control levels for 24 and 16 h respectively. Plasma prolactin levels did not appear to change around the time of luteolysis but showed a marked and significant diurnal rhythm (nadir around noon and peak around midnight) in both groups. The concentrations of prolactin were significantly (P<0·001) lower and the preovulatory peak was delayed and reduced in the bFF-treated ewes relative to controls. The onset of oestrus was also significantly (P<0·01) delayed by bFF treatment, but the ovulation rates did not differ between the groups. Furthermore, comparisons within or between groups revealed no significant relationships between any of the variables of plasma LH secretion during the follicular phase and the subsequent ovulation rate. These observations provide a complete description of gonadotrophin patterns during the follicular phase of the ewe and confirm the suggestion that an increase in LH pulse frequency is the major driving force behind the follicular growth that ultimately leads to ovulation. On the other hand, it appears most unlikely that the pattern of LH secretion during the follicular phase has any influence on ovulation rate. The levels of FSH declined in the period leading up to the preovulatory surge, presumably as a consequence of rising peripheral levels of oestrogen (and/or inhibin). We also expected LH pulse amplitude to decline during the follicular phase because it has been proposed that pulse amplitude is also controlled by oestrogen. The absence of any significant fall in amplitude suggests that hypotheses about the control of LH secretion drawn from studies with ovariectomized ewes require further verification in the intact ewe. The effect of bFF on prolactin levels probably reflects the low rates of secretion of oestradiol by the small ovarian follicles in these ewes. J. Endocr. (1988) 116, 123–135


1981 ◽  
Vol 91 (3) ◽  
pp. 399-403 ◽  
Author(s):  
H. VIERHAPPER ◽  
W. WALDHÄUSL ◽  
P. NOWOTNY

The effect of ACTH on serum concentrations of LH and FSH was studied in six healthy women in the follicular phase of the menstrual cycle, in six healthy men and in six patients (five men, one woman) with adrenocortical insufficiency. In healthy women the i.v. administration of synthetic 1–24 ACTH (0·25 mg) induced a fall in serum concentrations of LH from 11·1 ± 1·2 (s.d.) to 7·8 ± 0·6 i.u./l (P < 0·005) after 30 min and to 8·2 ± 0·7 i.u./l after 60 min. Upon continuous infusion of 1–24 ACTH (0·25 mg i.v., t = 480 min) LH fell to 6·7 ± 0·9 i.u./l (P < 0·005) in healthy women and to 6·1 ± 3·7 i.u./l (basal, 8·7 ± 3·9 i.u./l) in healthy men. In patients with adrenocortical insufficiency serum concentrations of LH were unchanged by 1–24 ACTH. Serum concentrations of FSH were not altered by 1–24 ACTH in any of the three groups. It is suggested that the effect of ACTH on LH secretion in healthy women is mediated by the acute rise of endogenous cortisol concentrations.


Author(s):  
Shehnaz Shaikh

Introduction: Menstrual cycle or menstruation involved discharge of sanguinous fluid and a sloughing of uterine wall. In women menstruation occurs at regular intervals on an average of 28 days, although most women gave a history of regular intervals of 28 to 30 days. About 10% -15% of women showed cycle at the precise 28 ± 2 days intervals when menstrual calendar was utilized. Normally in young women in different phases of ovarian cycles the plasma levels of estrogen vary. Ovulation occurs in the first 12-13th day of menstrual cycle, which is termed estrogen surge and second occurs in mid-luteal phase. During mid cycle or follicular phase of menstrual cycle the plasma concentration of progesterone is very low about 0.9 ng/mL. its level starts rising owing to secretion from the granulose cells. During luteal phase progesterone level reaches its peak value of 18 ng/mL and its level fall to a minimum value toward the end of the cycle. Estrogen affects local and systemic vasodilation. The menstrual cycle envelops two fundamental stages, the follicular stage (FP) and the luteal stage (LP). The follicular stage can part advance into two substages; the early FP, which is characterised with moo concentrations of both the key hormones estrogen and progesterone; and the mid FP where estrogen is tall autonomously from progesterone. The LP is epitomized by tall concentration of both estrogen and progesterone. These two fundamental stages are isolated by a soak surge in luteinizing hormone activating ovulation. These recurrent changes are said to be frequency unsurprising while long time. Aim: The main aim of this study is to evaluate the Cardiorespiratory functions changes during different Phases of Menstrual Cycle.   Material and methods: In this study, 20 with normal weight, 20 with obese and 20 with overage were included and taken them as a sample size. In this study all the young women those were recruited as a sample size are unmarried, undergraduate female student with the between the age group of 18-22years, having regular 28+6 days menstrual cycle for at least last 6months prior to this study. For the collection of data all the participants were instructed to attend the physiology lab department during each of three different phases. Day-2 during menstrual phase, Day-7, during follicular phase and Day-22 during luteal phase and the following parameters were recorded as Anthropometric measurements, measuring of pulse rate and blood pressure and cardiac efficiency test. Result: In general, work out proficiency changed essentially amid the distinctive stages of the menstrual cycle with the most elevated amid luteal stage and least amid menstrualo stage. There was no critical contrast in impact test amid menstrual stage, follicular stage and luteal stage of menstrual cycle among three bunches of people. Conclusion: We have watched noteworthy increment in cardiac and respiratory proficiency within the luteal stage of the menstrual cycle in ordinary weight people. Lower wellness levels were watched in overweight and stout females. In this manner hone of customary work out and admissions of solid slim down which offer assistance in lessening the weight and in turn the BMI will offer assistance in improving the physical wellness of the people. Keywords: Cardiorespiratory, Menstrual cycle, expiratory blast test


Author(s):  
Hannah N. Willett ◽  
Kristen J. Koltun ◽  
Anthony C. Hackney

This study examined the effect of estradiol-β-17 across the menstrual cycle (MC) during aerobic exercise on energy substrate utilization and oxidation. Thirty-two eumenorrheic (age = 22.4 ± 3.8 y (mean ± SD)), physically active women participated in two steady-state running sessions at 65% of VO2max, one during the early follicular and one during the luteal phase of the MC. Blood samples were collected at rest before each exercise session and analyzed for Estradiol-β-17 to confirm the MC phase. Carbohydrate (CHO) utilization and oxidation values were significantly lower (p < 0.05) in the luteal (utilization: 51.6 ± 16.7%; oxidation: 1.22 ± 0.56 g/min; effect size (ES) = 0.45, 0.27) than follicular phase (utilization: 58.2 ± 15.1%; oxidation: 1.38 ± 0.60 g/min) exercise sessions. Conversely, fat utilization and oxidation values were significantly (p < 0.05) higher in the luteal (utilization: 48.4 ± 16.7%; oxidation: 0.49 ± 0.19 g/min; ES = 0.45,0.28) than follicular phase (utilization: 41.8 ± 15.1%; oxidation: 0.41 ± 0.14 g/min). Estradiol-β-17 concentrations were significantly (p < 0.01) greater during the luteal (518.5 ± 285.4 pmol/L; ES = 0.75) than follicular phase (243.8 ± 143.2 pmol/L). Results suggest a greater use of fat and reduced amount of CHO usage during the luteal versus follicular phase, directly related to the change in resting estradiol-β-17. Future research should investigate the role these changes may play in female athletic performance.


1989 ◽  
Vol 122 (2) ◽  
pp. 509-517 ◽  
Author(s):  
R. J. E. Horton ◽  
H. Francis ◽  
I. J. Clarke

ABSTRACT The natural opioid ligand, β-endorphin, and the opioid antagonist, naloxone, were administered intracerebroventricularly (i.c.v.) to evaluate effects on LH secretion in ovariectomized ewes and in ovariectomized ewes treated with oestradiol-17β plus progesterone either during the breeding season or the anoestrous season. Ovary-intact ewes were also studied during the follicular phase of the oestrous cycle. Jugular blood samples were taken at 10-min intervals for 8 h and either saline (20–50 μl), 100 μg naloxone or 10 μg β-endorphin were injected i.c.v. after 4 h. In addition, luteal phase ewes were injected i.c.v. with 25 μg β-endorphin(1–27), a purported endogenous opioid antagonist. In ovariectomized ewes, irrespective of season, saline and naloxone did not affect LH secretion, but β-endorphin decreased the plasma LH concentrations, by reducing LH pulse frequency. The effect of β-endorphin was blocked by administering naloxone 30 min beforehand. Treating ovariectomized ewes with oestradiol-17β plus progesterone during the breeding season reduced plasma LH concentrations from 6–8 μg/l to less than 1 μg/l. In these ewes, saline did not alter LH secretion, but naloxone increased LH pulse frequency and the plasma concentrations of LH within 15–20 min. During anoestrus, the combination of oestradiol-17β plus progesterone to ovariectomized ewes reduced the plasma LH concentrations from 3–5 μg/l to undetectable levels, and neither saline nor naloxone affected LH secretion. During the follicular phase of the oestrous cycle, naloxone enhanced LH pulse frequency, which resulted in increased plasma LH concentrations; saline had no effect. In these sheep, β-endorphin decreased LH pulse frequency and the mean concentrations of LH, and this effect was prevented by the previous administration of naloxone. The i.c.v. administration of β-endorphin(1–27) to luteal phase ewes did not affect LH secretion. These data demonstrate the ability of a naturally occurring opioid peptide to inhibit LH secretion in ewes during the breeding and non-breeding seasons, irrespective of the gonadal steroid background. In contrast, whilst the gonadal steroids suppress LH secretion in ovariectomized ewes during both seasons, they only appear to activate endogenous opioid peptide (EOP)-mediated inhibition of LH secretion during the breeding season. Furthermore, these data support the notion that LH secretion in ovariectomized ewes is not normally under the control of EOP, so that naloxone has no effect. Journal of Endocrinology (1989) 122, 509–517


1991 ◽  
Vol 81 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Karin Manhem ◽  
Christina Jern ◽  
Martin Pilhall ◽  
Guy Shanks ◽  
Sverker Jern

1. The haemodynamic effects of hormonal changes during the menstrual cycle were examined in 11 normotensive women (age 20–46 years). The subjects were studied on days 2–8 (follicular phase) and days 18–26 (luteal phase) in a randomized order. A standardized mental stress test and a 24 h recording of ambulatory blood pressure and heart rate were performed. 2. Pre-stress resting levels of heart rate and blood pressure were similar during the two phases of the menstrual cycle. 3. During mental stress, the heart rate response was significantly greater during the luteal phase than during the follicular phase (14.7 versus 9.7 beats/min; P < 0.05). 4. Blood pressure, plasma catecholamine concentrations and subjective stress experience increased significantly in response to stress, without any significant differences between the two phases. 5. During 24 h ambulatory monitoring, higher levels of systolic blood pressure and heart rate were observed in the luteal phase than in the follicular phase (P < 0.005 and P < 0.0001, respectively). 6. These data indicate that cyclic variations in female sex hormones not only affect systolic blood pressure and heart rate, but also alter the haemodynamic responses to psychosocial stress.


2019 ◽  
Vol 1 (1) ◽  
pp. 53-60
Author(s):  
Rizky Aprilia Wikayanti ◽  
Andre Parmonangan Panjaitan

Kedelai merupakan tanaman Leguminoceae, yang mengandung senyawa isoflavon. Struktur kimianya menyerupai 17β-estradiol yang memiliki kemampuan untuk berikatan dengan reseptor estrogen yang dapat berpengaruh terhadap sistem reproduksi manusia. Tujuan literatur review ini untuk mengetahui efek kedelai terhadap sistem reproduksi manusia. Metode yang digunakan adalah metode literatur review dari 50 artikel PubMed NCBI, Elsevier dan BMJ Journal yang diperoleh hanya 38 artikel yang digumakan dari tahun 2000 sampai dengan tahun 2018. Berbagai penelitian eksperimental yang dilakukan menunjukkan bahwa kedelai memiliki efek terhadap sistem reproduksi manusia. Kedelai dapat menyebabkan sekresi FSH, sekresi LH menurun dan meningkatkan konsentrasi estradiol bebas. Penurunan FSH dan LH dapat menyebabkan gangguan dalam siklus menstruasi terutama pada fase folikular dan  ovulasi, jika fase folikular terganggu maka siklus menstruasi akan menjadi  tidak teratur. Selain itu fitoestrogen yang terkandung dalam kedelai diketahui dapat menghambat 17-β hidroksisteroidoksidoreduktase sehingga mengakibatkan penurunan kadar testosteron.   Kata kunci: kedelai, manusia, reproduksi   THE ROLE OF SOYBEAN FOR REPRODUCTIVE SYSTEM   ABSTRACT Soybean is a Leguminoceae plant, which contains isoflavone compounds. Its chemical structure resembles 17β-estradiol which has ability to bind to estrogen receptors which can affect the human reproductive system. The purpose of this review literature is to determine the effect of soy on the human reproductive system. Using research articles and books related to the effect of soy on the reproductive system from 2000 to 2018. Various experimental studies conducted showed that soy has an effect on the human reproductive system. Soy can cause FSH secretion, decreased LH secretion and increasing the free concentration of estradiol. Decreased FSH and LH can cause disruption in the menstrual cycle, especially in the follicular phase and ovulation, if the follicular phase is disrupted then the menstrual cycle will become irregular. In addition, phytoestrogens contained in soy are known to inhibit 17-β hydroxysteroidoxidoreductase, resulting in a decrease in testosterone levels.   Keywords : human, reproductive, soybean


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