Inhibition by somatostatin of LH-RH-induced LH release in normal menstruating women

The present study was carried out in order to establish whether the concomitant treatment with somatostatin (SRIH) is capable of modifying gonadotrophin release in response to LH-RH administration in normal women during follicular, periovulatory, and luteal phases. SRIH was administered in a dose of 5.55 micrograms/min over 180 min and LH-RH (100 micrograms) was injected as a bolus at 90 min after the beginning of SRIH infusion. Within the dose used, SRIH significantly reduced LH response to LH-RH, whereas it did not alter FSH response to LH-RH. These results suggest that SRIH may play a part in the regulation of LH secretion in normal women.     

Gonadotropin-releasing hormone-induced changes in testosterone secretion in normal women

This study investigated the pattern of testosterone (T) secretion in spontaneous (n = 14) and gonadotropin-releasing hormone (GnRH)-treated (n = 6) menstrual cycles in normal women. In spontaneous cycles, T was found to increase progressively over the follicular phase (P less than or equal to 0.001), with the peak T value occurring on cycle day 0 (luteinizing hormone [LH] surge). The mean (+/- standard error of the mean [SEM]) T values on cycle day -14 and cycle day 0 were 35 +/- 4 and 51 +/- 4 ng/dl, respectively. GnRH was administered intravenously to six women at 1.3 to 1.7 micrograms per dose every 30 minutes in a study that assessed the ovarian effects of a rapid gonadotropin pulse frequency. In three of the women, the T levels followed a normal follicular phase pattern, whereas in the remaining three GnRH-treated women, there were marked increases in T with peak levels of 97, 123, and 81 ng/dl on day 0. The GnRH-treated subgroup with increased T levels had significantly increased follicular levels of LH, follicle-stimulating hormone (FSH), LH-bio and number of preovulatory ovarian follicles. This study demonstrated that increased levels of LH, FSH, and LH/FSH are capable of acutely increasing the secretion of ovarian androgens.     

Exogenous melatonin enhances the TRH-induced prolactin release in normally cycling women: A sex-specific effect

The aim of the present study was to analyze the effects of exogenous melatonin (MT) upon pituitary and adrenal responsiveness to releasing hormones in different phases of the menstrual cycle. We evaluated the response of FSH and LH to 100 pg gonadotropin releasing hormone, of TSH and prolactin (PRL) to 200 (ig thyrotropin releasing hormone (TRH), and of cortisol to 10 pg ACTH 1–17. We studied eight young women with normal ovulatory cycles in the early follicular (days 5–7) and luteal (days 22–24) phases. Stimulation tests were performed at 18.00 in baseline conditions as well as 1 h after oral intake of exogenous MT (2 mg as a gelatine capsule). We did not observe any significant change in FSH, LH, TSH and cortisol responses to their respective releasing hormones in either phase of the cycle. PKL response to TKH was higher after MT in the follicular phase, when evaluated in ternis of net increment and integrated area of response (p < 0.02 versus baseline conditions for both variables). In the luteal phase, we recorded larger interindividual variability and higher responses after MT were observed in five out of eight subjects. These results suggest that MT may play a facilitatory role in the TRH-induced PRL release in women of reproductive age.     

Exogenous melatonin enhances the TRH-induced prolactin release in normally cycling women: a sex-specific effect.

The aim of the present study was to analyze the effects of exogenous melatonin (MT) upon pituitary and adrenal responsiveness to releasing hormones in different phases of the menstrual cycle. We evaluated the response of FSH and LH to 100 micrograms gonadotropin releasing hormone, of TSH and prolactin (PRL) to 200 micrograms thyrotropin releasing hormone (TRH), and of cortisol to 10 micrograms ACTH 1-17. We studied eight young women with normal ovulatory cycles in the early follicular (days 5-7) and luteal (days 22-24) phases. Stimulation tests were performed at 18.00 in baseline conditions as well as 1 h after oral intake of exogenous MT (2 mg as a gelatine capsule). We did not observe any significant change in FSH, LH, TSH and cortisol responses to their respective releasing hormones in either phase of the cycle. PRL response to TRH was higher after MT in the follicular phase, when evaluated in terms of net increment and integrated area of response (p less than 0.02 versus baseline conditions for both variables). In the luteal phase, we recorded larger interindividual variability and higher responses after MT were observed in five out of eight subjects. These results suggest that MT may play a facilitatory role in the TRH-induced PRL release in women of reproductive age.     

Timing of sonohysterography in menstruating women

A prospective, blind study was carried out on 44 patients to evaluate the most suitable time to perform transvaginal sonohysterography. On the day of arrival at our unit, regardless of their cycle day, the women underwent sonohysterographic evaluation, which was repeated during the first 10 days of the next cycle. Patients with sonohysterographic findings underwent hysteroscopy. According to the timing of the first examination, they were divided into two groups, i.e. group 1 for the first 10 days of the cycle, and group 2 for days 16 through 28. At the end of the study the groups were compared. The results showed a false-positive rate of 27% in group 2, while no false-positive was found in group 1. We concluded that the best time for sonohysterography in patients who still have their menstrual period is during the first 10 days of the cycle. Copyright Copyright 1999 S. Karger AG, Basel     

Early and late hormonal responses to the microdose gonadotropin-releasing hormone agonist in normal menstruating women

OBJECTIVE: To assess the effect of a microdose gonadotropin-releasing hormone (GnRH) agonist on the LH, FSH, and E2 secretion in normal menstruating women. DESIGN: Prospective study. SETTING: Tertiary teaching hospital. PATIENT(S): Five normal menstruating women. INTERVENTION(S): Five microg of triptorelin was injected daily in 5 women for 7 days beginning from the cycle day 3. In the next cycle, the same amount of triptorelin was injected into the same women daily for 3 days. MAIN OUTCOME MEASURE(S): Serial serum FSH, LH, and E2 levels. RESULT(S): The FSH levels peaked (27.53 +/- 6.34 IU/L) after 5 hours, and the LH levels peaked (34.35 +/- 7.81 IU/L) by 4 hours. The increased gonadotropin levels persisted even after the second and third day of the GnRH-agonist injections, although the peak levels were not as high as observed with the first injection (19.56 IU/L in the second day, 9.15 IU/L in the third day for FSH; 32.18 IU/L in the second day, 13.59 IU/L in the third day for LH). The down-regulation of gonadotropins was established in 4 days. When the GnRH-agonist was administered for 7 days, the E2 level began to increase 6 days after the last injection. When the GnRH-agonist was administered for 3 days, the E2 level began to increase 3 days after the last injection. CONCLUSION(S): Pituitary down-regulation could be achieved even with a microdose of GnRH agonist. The increased level of gonadotropins persisted for 3 days at this dose. The duration of the down-regulation was influenced by the duration of GnRH-agonist administration.     

Oxytocin and prolactin responses in long-term breast-feeding

Plasma levels of oxytocin and prolactin were measured before and during 12 minutes of breast pump stimulation in five healthy, lactating, amenorrheic women on three occasions: ten to 90 days post partum, 90 to 180 days post partum, and 180 days to one year post partum. Baseline mean (+/- SEM) plasma oxytocin levels were similar in the three study periods. Mean stimulated plasma oxytocin levels increased in the three study periods (each P less than .001; mean baseline versus stimulated). Stimulated plasma oxytocin values were significantly greater at ten to 90 than at 90 to 180 days (P less than .05; analysis of variance). Baseline serum prolactin levels were 61 +/- 9.5, 36 +/- 8.6, and 33 +/- 10.8 ng/ml, respectively (not significant; one-way analysis of variance). Mean stimulated prolactin levels were 71 +/- 8.1, 43 +/- 4.5, and 43 +/- 2.8 ng/ml, respectively (not significant). Thus, the oxytocin secretory reflex continues in long-term lactation for the first year post partum. In addition, breast stimulation in long-term lactating women continues to produce a slight increase in serum prolactin levels.     

Exaggerated prolactin response to thyrotropin-releasing hormone in infertile women with the luteinized unruptured follicle syndrome

Summary Ten cases of luteinized unruptured follicle (LUF) syndrome out of 250 women with unexplained infertility were detected on ultrasonography, giving a frequency of 4%. Hormonal analysis revealed lower serum progesterone levels at mid-luteal phase in LUF cases, suggesting a link between LUF syndrome and inadequate luteal phase. Prolactin response to thyrotropin-releasing hormone was exaggerated in LUF cases as compared with ovulatory cases. Aberrant prolactin release may be a contributory factor in the pathophysiology of the LUF syndrome.     

Reproductive hormone profiles in regularly menstruating Sudanese women

Venous blood samples were taken daily from 21 regularly menstruating Sudanese women throughout one complete menstrual cycle. FSH, LH, estradiol-17 beta and progesterone were assayed in all plasma samples and normal reference ranges were thus established. Fifteen subjects had a luteal phase of more than 12 days whilst in 3 subjects it was shorter. Two subjects were found to be hyperprolactinemic and one had an anovulatory cycle with an elevated LH. The plasma concentrations of estradiol-17 beta in the follicular phase and progesterone in the luteal phase were significantly lower in subjects with short luteal phase than in those with a luteal phase of more than 12 days. The hormonal profile of FSH, LH, estradiol-17 beta and progesterone throughout a normal menstrual cycle in regularly menstruating Sudanese women was similar to what has been reported in the literature for other ethnic groups.     

Oxytocin and prolactin levels in breast-feeding women. Correlation with milk yield and duration of breast-feeding

The aim of the present study was to examine suckling-related plasma levels of oxytocin and prolactin in early and established lactation and to correlate hormone profiles to success of lactation performance. Fifty-five primiparous women participated in the study. From each, 18 blood samples were drawn in connection with breast-feeding on day 4 post partum and after 3-4 months. Oxytocin and prolactin levels were determined with radio-immunoassay. Basal levels of both hormones were significantly higher 4 days post partum than 3-4 months later and after weaning. Basal prolactin levels fell significantly within 24 h of weaning. Oxytocin and prolactin levels rose in response to breast-feeding--an effect which persisted during the lactation period. The suckling-induced release of prolactin--but not that of oxytocin--was related to basal hormone levels. Basal as well as stimulated oxytocin levels obtained 4 days and 3-4 months post partum correlated significantly, indicating that each woman has an individual, characteristic level of this hormone. Milk yield did not correlate with oxytocin or prolactin levels, but prolactin levels recorded 3-4 months post partum did correlate with the remaining period of breast-feeding. In addition, mothers who breast-fed exclusively 3-4 months post partum had significantly higher oxytocin and prolactin levels than those who gave supplementary feed. There was a significant correlation between oxytocin levels at 4 days and birth weight of the infant.     

Prolactin response to thyrotropin-releasing hormone in women with infertility and/or randomly elevated serum prolactin levels

Infertile women with normal serum prolactin (PRL) levels have been known to establish a pregnancy after the use of bromocriptine, a dopamine agonist. These data imply that there may be a group of women with a slight but significant increase in PRL secretion that may have resulted in their infertility. 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). Most of these women were found to have elevated serum PRL values on random testing. There was a statistically significant increase in PRL response at all time intervals after TRH between the NL and AN/IN groups compared with the group with LPD on the basis of repeated measures analysis (P = 0.0013). There was no statistical difference in the TSH response between these three groups. Although the PRL response was statistically different, individual PRL response patterns were not diagnostic. It appears from these data that there is an increased PRL secretion in infertile women who have histological evidence of a LPD.     

Vaginal bromocriptine: pharmacology and effect on serum prolactin in normal women

Oral bromocriptine treatment of hyperprolactinemia is frequently associated with gastrointestinal side effects. To assess the efficacy and safety of an alternate route of treatment, we randomly administered 2.5, 5.0, and 7.5 mg of bromocriptine vaginally to five normal women at 1-week intervals. Plasma bromocriptine and prolactin (PRL) levels were measured hourly for 12 hours, then every 2 hours for 12 hours after each dose. At the end of each study, the vagina was flushed with saline for measurement of residual drug. For comparison of serum PRL levels, six additional women were given 2.5 mg bromocriptine orally. After administration of 2.5, 5.0, and 7.5 mg vaginally, plasma bromocriptine was initially detectable at 5.4 +/- 0.4, 4.4 +/- 0.7, and 3.5 +/- 0.6 hours, respectively. For the same vaginal doses, the mean (+/- SEM) peak plasma levels were 555 +/- 164 pg/mL at 12 +/- 0.6 hours, 702 +/- 252 pg/mL at 11.2 +/- 0.9 hours, and 1055 +/- 220 pg/mL at 10.7 +/- 1.7 hours, respectively. After each dose, there was a slow decline in plasma bromocriptine levels, remaining above 50% of peak values at 24 hours. Less than 1% of the administered drug was recovered from the vagina at 24 hours. The pattern of PRL inhibition with all three doses was similar. The mean plasma PRL level decreased by 7 hours, the maximum PRL decrease (64 +/- 3, 75 +/- 1, and 66 +/- 4% after 2.5, 5.0, and 7.5 mg, respectively) occurring at 11 hours, and the plasma PRL levels changed little during the remaining 13 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Low maternal but normal fetal prolactin levels in cigarette smoking pregnant women

In the 36th week of pregnancy, levels of serum prolactin (PRL) (p less than 0.01) and estriol (p less than 0.05) were significantly lower in 101 consecutive women smoking 10 cigarettes or more per day, compared with a control group of 104 non-smoking pregnant women. Cord serum PRL was not related to maternal smoking habits, whereas estriol was significantly (p less than 0.05) lower in the infants of smokers, compared with the control group. The lower PRL levels in cigarette-smoking pregnant women may be due either to a direct effect of nicotine or secondary to lower estrogen levels, and the finding may be of clinical importance in relation to lactation.     

Vasoactive intestinal polypeptide (VIP) selectively stimulates prolactin release in healthy women

The neuropeptide, vasoactive intestinal polypeptide (VIP), is released from the hypothalamus to the portal circulation, and experiments on animals provide evidence that it might modulate hormone secretion from the pituitary. Here we report the effects of VIP on the release of different pituitary hormones, including prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyrotropin-releasing hormone (TSH), in normal women. Seven healthy women (aged 27-32; body weight 53-60 kg), with normal menses and receiving no medication, were tested on days 20-23 of their cycle. Porcine VIP was injected i.v. as a bolus dose of 1 mcg/kg body weight. Blood samples were collected 10 minutes prior to VIP administration and 5, 15, 30, 45, 60 and 90 minutes after VIP injection. Blood pressure and heart rate were continuously monitored. Hormone levels were determined by RIA. Stress, which can stimulate PRL release, was assayed by measuring the effect of placebo on hormone release (5 controls). VIP injection induced a significant (p less than 0.01) increase in plasma PRL levels. Basal PRL was 20.25 +/- 9.14 ng/ml; 5 minutes after VIP injection PRL levels rose to 45.0 +/- 14.9 ng/ml (p less than 0.01). At 15 minutes a plateau was reached (46.0 +/- 14.5 ng/ml), then the levels slowly decreased. VIP administration did not modify the plasma concentration of LH, FSH or TSH at any time during the observation period. The present study indicates that VIP might play a physiological role as a RPL-releasing factor in human beings.     

Urinary unconjugated cortisol in normally menstruating women and during estrogen-gestagen treatment

Changes in 24-hour excretion of unconjugated urinary cortisol and creatinine clearance were determined in 9 normally menstruating women and in 9 women undergoing estrogen-gestagen treatment on 3 consecutive days. A correlation between the cortisol excretion and the creatinine clearance was found only in the luteal phase of the menstrual cycle. The cortisol excretion increased neither during the menstrual cycle nor during the estrogen-gestagen treatment. A marked intra-individual variation in the excretion of unconjugated urinary cortisol was demonstrated in both groups.     

Changes in soluble proteins in cervical mucus during midcycle in normally menstruating women

Albumin, IgG and complement C3c were analyzed by immunonephelometry in cervical mucus collected daily at midcycle. There was a statistically significant difference in the amount of mucus recovered on the day of the luteinizing hormone (LH) surge and on the following day. Several nadirs in protein concentration could be visualized in 8 out of 14 subjects, whereas in 6 subjects, no such changes in concentration were found. In terms of soluble protein concentrations and amounts there were no differences between cycle days. For changes in soluble protein concentrations and amounts, no systematic time relation to the LH peak could be found.     

Exaggerated prolactin response of thyrotropin-releasing hormone in women with anovulatory cycles: possible role of endogenous estrogens and effect of bromocriptine

Twenty-one women 18 to 36 years old, presenting with chronic anovulation, were compared with 10 normally cycling women. The patients were characterized by low progesterone (P) levels (0.93 +/- 0.14 ng/ml versus 15.5 +/- 1.4 in controls), whereas 17 beta-estradiol (E2) was moderately decreased (110.2 +/- 8.3 pg/ml versus 162.8 +/- 14.5 in controls) realizing a relative hyperestrogenism. Basal prolactin (PRL) levels were not elevated (12.1 +/- 0.97 ng/ml versus 9.2 +/- 0.7 in controls), but after thyrotropin-releasing hormone (TRH) stimulation an exaggerated response was observed (114.5 +/- 7 ng/ml versus 55.8 +/- 9 in controls). Patients were treated with bromocriptine (1.25 mg 2 times a day) for 3 months. Fifteen responded with ovulatory cycles, and five became pregnant. Progesterone increased significantly (10.2 +/- 1.3 ng/ml), whereas in patients who did not ovulate P increased only slightly (1.56 +/- 0.18 ng/ml). The particular endocrine profile of these patients (P/E2 imbalance) realizing relative hyperestrogenism may be responsible for the exaggerated PRL response to TRH. Bromocriptine, in reducing this transient, or masked, hyperprolactinemia, allows in many patients the return to ovulatory cycles. This mechanism may be one of the possible pathways leading to chronic functional or organic hyperprolactinemia.     

Oxytocin plasma levels in orgasmic and anorgasmic women

The study aimed to evaluate oxytocin (Oxt) serum levels before and after sexual intercourse in women affected by anorgasmia. The sample was constituted of 15 anorgasmic women and 16 orgasmic women. The Female Sexual Function Index (FSFI, cutoff ≤26.55) and the Female Sexual Distress Scale (FSDS, cutoff ≥15) questionnaires were used to assess sexual function and sexual distress, respectively. Serum Oxt levels were measured before sexual intercourse (T0) and 5?min after coital sexual activity (T1). Anorgasmic women had an unpleasant sexual experience (FSFI total score, 20.1?±?1.2;) and were stressed (FSDS score, 19.4?±?1.3), whereas orgasmic women were fully satisfied with their sexual activity (FSFI total score 28.7?±?1.3; FSDS score 11.5?±?1.8). At T0, anorgasmic women had lower levels of Oxt than orgasmic women, 1.8?±?0.2?pg/mL versus 2.1?±?0.5?pg/mL, respectively, [95% CI: (?0.58, ?0.01); p?p?=?.09). Finally, orgasmic women had higher levels of Oxt than anorgasmic women, 4.6?±?0.7?pg/mL versus 2?±?0.4?pg/mL, respectively [95% CI: (?3.02, ?2.17); p?相似文献