Serum progesterone changes in luteal cyclicity and duration of estrous cycle in Formosan sika deer (Cervus nippon taiouanus) hinds

A study was conducted to investigate the serum progesterone (SP(4)) profiles and duration of estrous cycles in the farmed Formosan sika deer (FSD; Cervus nippon taiouanus) during the major breeding season. Five parous, open and non-milking hinds were allotted to collect peripheral blood samples twice weekly for P(4) measurement by radioimmunoassay beginning at the initiation of the rutting season indicated by rutting behaviors of the sexually mature stags. The hinds were polyestrous as proved by cyclic changes of SP4 levels. After the presumptive estrus shown by the lowest concentration of SP(4) (0.20+/-0.01 ng/ml), this ovarian hormone markedly elevated on day 7 of the cycle (1.67+/-0.11 ng/ml), reached plateau (3.15+/-0.16 ng/ml, P<0.01) during days 11 to 18, and then declined to the basal levels in the subsequent estrus. It is concluded that mean duration of the estrous cycle in FSD during the major rutting season is 19.3 days with a range of 17 to 21 days, and that the patterns of circulating progesterone profiles during the estrous cycles of the FSD are similar to those of other deer species so far investigated.

Intraindividual hormonal variability in ultrasonographically timed successive ovulatory menstrual cycles is detected only in the luteal phase in infertility patients

OBJECTIVE

To assess intraindividual variation of follicle stimulating hormone, luteinising hormone, estradiol, progesterone, inhibin A, and inhibin B in three successive ovulatory cycles correlated with transvaginal ultrasound monitored morphological changes in the ovary.

METHODS

Serial transvaginal color and pulsed Doppler ultrasound and serum hormone analysis were performed during midfollicular, periovulatory, and midluteal phase for three consecutive cycles in 19 patients with normal menstrual cycles.

RESULTS

Luteinising hormone and progesterone showed significant differences in the midluteal phase between the 1st and 2nd cycle (luteinising hormone p = 0.007 and progesterone p = 0.02). Progesterone showed a similar significant change (p = 0.013) between the 2nd and 3rd cycle. No significant differences were seen in the midfollicular or periovulatory phases or between the 1st and 3rd cycle.

CONCLUSIONS

Luteal phase progesterone and luteinising hormone concentrations showed individual variation in successive cycles suggesting early or late corpus luteolysis. Follicular and periovulatory hormone levels were similar in subsequent ovulatory cycles.

Effects of a low carbohydrate diet and graded exercise during the follicular and luteal phases on the blood antioxidant status in healthy women

The aim of this study was to examine the effect of a low-carbohydrate (L-CHO) diet and graded cycling exercise on the enzymatic and non-enzymatic blood antioxidant defence system in young eumenorrhoeic women. Seven healthy physical education students exercised incrementally until they were fatigued under four different phase-diet conditions of the menstrual cycle, i.e. twice either during the mid-follicular or the mid-luteal phase, in each case either after 3 days of eating a normal mixed diet (59% carbohydrate, 27% fat, 14% protein) or 3 days of eating an isoenergy L-CHO diet (5% carbohydrate, 52% fat, 43% protein). In venous blood samples obtained at rest, immediately post test and during recovery, the activity of antioxidant enzymes and concentrations of reduced glutathione and selenium were determined. Plasma samples were analysed for concentrations of malondialdehyde, vitamin E (alpha-tocopherol), uric acid and activity of creatine kinase. The 3 days of the L-CHO diet, which had been preceded by glycogen-depleting exercise, resulted in a stimulation of the blood antioxidant defence system in young eumenorrhoeic women both at rest and during the graded cycling exercise to maximal oxygen uptake. It seems justified to presume that higher daily doses of haem iron, selenium and alpha-tocopherol provided by the L-CHO diet contributed to the enhancement of catalase activity, the rise in plasma concentrations of alpha-tocopherol and selenium, which resulted in better protection of the cell membranes against damage from peroxides, as reflected by a limited release of creatine kinase into plasma. With the exception of the case of glutathione reductase, the phases of the menstrual cycle had only minor effects on the indices of the blood antioxidant defence system.

Fecal progesterone analysis by time-resolved fluoroimmunoassay (TR-FIA) for monitoring of luteal function in the sika doe (Cervus nippon centralis)

Fecal progesterone content was measured by time-resolved fluoroimmunoassay (TR-FIA) in the sika doe (Cervus nippon). The total recovery rate of fecal progesterone by twice extraction with diethylether was about 60%. The displacement curve of TR-FIA with serial doses of fecal extract (0.156-5.0 mg feces) was closely parallel to that of the reference standard. Fecal progesterone content was correlated with that of plasma (r=0.829, n=16), but the values were 100-fold higher in feces than in plasma. Fecal progesterone content periodically changed during the breeding season suggesting the estrous cycle in the doe. The fecal progesterone content was higher between the estruses, and decreased after estrus. The time between the onset of estrous signs and the lowest fecal progesterone content was 1-2 days suggesting the time required for hepatic metabolism and intestinal passage. Fecal progesterone content was also decreased around the time of vaginal discharge. The discharge took place within a few days, suggesting a short luteal phase. Not of all decreases in fecal progesterone values were preceded by estrous behavior or vaginal discharge. Fecal progesterone content was further increased in pregnancy rather than in the preceding estrous cycle and the levels were maintained up to term. These results suggest that fecal progesterone measurement is a useful tool for non-invasive analysis of luteal function in the sika doe. The TR-FIA kit, designed for the human hospital market, was shown to be successfully utilized for fecal assay in the sika doe with minor modifications.

Alterations in platelet function during the ovarian cycle

Steroid hormones may profoundly influence hemostasis; for example, as discussed for hormone replacement therapy, pregnancy and, being less obvious, for the ovarian cycle. We investigated primary hemostasis parameters using a platelet function analyzer (PFA-100) during the follicular and luteal phases in 18 healthy young women without oral contraceptives. During the follicular phase, the mean closure time (CT) was 164.7 +/- 56.7 s, and it decreased to 130.2 +/- 30.6 s in collagen/epinephrine cartridges in the luteal phase (P = 0.0095). No significant difference could be found for CT values in collagen/adenosine diphosphate cartridges during the follicular phase as compared with the luteal phase (97.2 +/- 24.2 s versus 89.6 +/- 18.4 s, P = 0.174). Negative correlations between the CT values in collagen/epinephrine cartridges and von Willebrand factor from both phases of the cycle were found (follicular phase: r = -0.53; luteal phase: r = -0.54). Fibrinogen and fibrinogen degradation products were significantly increased in the luteal phase (2.49 +/- 0.62 g/l versus 2.05 +/- 0.59 g/l and 0.12 +/- 014 versus 0.04 +/- 0.04, P = 0.02 for both parameters) as compared with the follicular phase. No significant differences could be detected for plasminogen, plasmin-antiplasmin complex, prothrombin fragment 1 + 2 and D-dimer between the groups. This study indicates that platelet function is periodically altered during the ovarian cycle due to the influence of progesterone and estrogen on von Willebrand factor concentrations.

Regulation of the 24h body temperature rhythm of women in luteal phase: role of gonadal steroids and prostaglandins

An investigation into whether the rise in the 24h body temperature rhythm observed in the luteal menstrual phase is antagonized by the administration of prostaglandin synthesis inhibitors has been made. Intravaginal body temperature was monitored continuously for 24h, once in the follicular and twice in the luteal phase. In the luteal phase, women were studied both without and with the simultaneous administration of a prostaglandin synthesis inhibitor (lysine acetylsalicylate; 1.8 g every 6 h orally). The progesterone/estradiol ratio (measured at 17:00h each day) was related to mesor (r = 0.825; P < 0.001), acrophase (r = 0.682; P < 0.02), and amplitude (r = -0.731; P < 0.001) of the 24h body temperature rhythm. Luteal phase elevation of the progesterone/estradiol ratio was associated with a 0.32 +/- 0.07 degrees C increase in mesor (P < 0.01), a 0.11 +/- 0.02 degrees C decrease in amplitude (P < 0.001), and a 34.8 +/- 11.6 min delay in acrophase (P < 0.03) of the 24h body temperature rhythm. Prostaglandin synthesis inhibitors did not counteract these modifications. The present data shows that the modifications of the circadian parameters of the 24h body temperature rhythm observed during the luteal phase of the menstrual cycle are strictly related to modifications of the progesterone/estradiol ratio, and presumably independent of prostaglandin synthesis.

Platelet cyclic guanosine monophosphate production during menstrual cycle in healthy women

The incidence of cardiovascular disease among women during their reproductive years is considerably less than in men and this difference decreases after menopause. Since in cultured endothelial cells and in platelets E2 increases nitric oxide (NO) production, it is possible that their cardioprotective effect may be mediated by NO. The aim of this study was to evaluate platelet cyclic guanosine monophosphate (cGMP), as a marker of NO production, during menstrual cycle. Fifteen women aged 26-40 yr were studied to evaluate: LH, FSH, E2, P and cGMP on the 5th follicular and 22nd luteal day of the cycle and during the ovulatory period. Platelet cGMP was evaluated in basal condition (3-isobuthyl 1-methylxanthine-IBMX) and with ionomycine (IONO) and sodium nitroprusside (SNP).

RESULTS

LH, FSH, E2 and P demonstrated the typical patterns of ovulatory cycle. During follicular and luteal IBMX, SNP and IONO phase were homogeneous while they increased during the ovulatory period. A correlation between IBMX cGMP and E2 (p<0.002, rs=0.456) was found. In conclusion the data show an increase in platelet cGMP during the ovulatory period and a correlation between E2 and cGMP suggesting that E2 modulates NO production. The cardioprotective effect of E2 may be, at least in part, mediated by the increase in NO production.

Effect of clomiphene citrate on follicular and luteal phase luteinizing hormone concentrations in in vitro fertilization cycles stimulated with gonadotropins and gonadotropin-releasing hormone antagonist

OBJECTIVE

To investigate the effect that clomiphene citrate exerts on luteinizing hormone (LH) concentrations in gonadotropin/gonadotropin-releasing hormone (GnRH) antagonist cycles.

DESIGN

Retrospective analysis.

SETTING

Tertiary referral center.

PATIENT(S)

Two groups of patients undergoing in vitro fertilization (IVF) were compared. In group I, 20 patients were stimulated with clomiphene citrate (CC) in combination with gonadotropins and 0.25 mg of Cetrorelix (ASTA Medica AG; Frankfurt am Main, Germany) and in group II, 20 patients were stimulated with gonadotropins and 0.25 mg of Cetrorelix.

INTERVENTION(S)

Blood sampling was performed in the late follicular, periovulatory, early, mid, and late luteal phases.

MAIN OUTCOME MEASURE(S)

Luteinizing hormone (LH), estradiol, and progesterone.

RESULT(S)

LH levels were significantly higher in group I than in group II on all the days studied. Progesterone serum concentrations were significantly higher in group II in the early luteal phase, but not in the follicular or the middle and late luteal phases.

CONCLUSION(S)

LH concentrations are significantly higher in the follicular and luteal phases in cycles stimulated with CC, despite GnRH antagonist administration. This observation might have implications for the dose of GnRH antagonist needed to suppress LH in the follicular phase and questions the need for luteal-phase supplementation in cycles in which CC was used.

FSH secretion patterns during pregnant and nonpregnant luteal periods and 24 h secretion patterns in male and female dogs

The aim of this study was to investigate the secretion patterns of FSH: (i) during the canine oestrous cycle with particular attention to the luteal period; and (ii) during 24 h in male and female dogs. Plasma FSH concentrations were measured by a highly specific homologous canine immunoradiometrical (IRMA) assay using monoclonal antibodies specific for canine FSH. In the first study, FSH concentrations were measured daily from +/- 15 days before until 150 days after the LH surge in groups of pregnant (n = 5) and nonpregnant (n = 5) Beagle bitches. Day 0 of the cycle was the day of the preovulatory LH peak as measured by LH radioimmunoassay. In the second study, FSH concentrations were measured at 1 h intervals for 24 h in five bitches at day 120 after the LH surge and in five males. From day 35 to day 40 after the LH peak, FSH concentrations were higher in pregnant than in nonpregnant luteal phases. A significant and abrupt decrease in FSH concentrations was observed at about the time of parturition (day 65) and was followed by lower FSH concentrations during lactation compared with nonpregnant bitches. FSH concentrations in nonpregnant animals were fairly constant from the end of oestrus to mid-anoestrus. In both post-lactation and anoestrous bitches, plasma concentrations of FSH increased consistently as anoestrus progressed. No significant differences in the mean hour-to-hour patterns of FSH secretion were observed over 24 h and no differences were detected between male and female dogs. However, a clear pulsatile pattern of secretion was observed in all individuals, both males and females, with an apparent 4.8 h interval between peaks. The results of this study demonstrate major differences in FSH secretion between pregnant and nonpregnant bitches. This finding indicates that there are differences in the regulation of the hypothalamo-pituitary-ovarian axis during pregnancy, possibly related to changes in activity of the corpus luteum. The results of this study also demonstrate a pulsatile pattern of FSH secretion in both male and female bitches, with a 4.8 h interval between peaks, and confirms the progressive increase in plasma FSH concentrations observed during anoestrus.

Ovarian function and regulation of the hypothalamic-pituitary-ovarian axis after tubal sterilization

OBJECTIVE

To assess the effects of laparoscopic tubal sterilization with Hulka or Filshie clip on ovarian function and regulation of the hypothalamic-pituitary-ovarian axis.

STUDY DESIGN

Hormonal changes were evaluated in 33 women undergoing sterilization with Hulka (n = 16) or Filshie clips (n = 17). All participants were healthy, with regular menstrual cycles. The levels of estradiol, follicle-stimulating hormone, luteinizing hormone, sex hormone binding globulin, prolactin, testosterone and androstenedione were measured in one cycle immediately before and 3 and 12 months after sterilization on cycle days 3-7 and 20-24. Repeated measures analysis of variance, paired t test and nonparametric Friedman two-way analysis of variance were used for statistical analysis.

RESULTS

The follicular phase estradiol values increased after sterilization. The highest values were observed three months after the procedure (204.8 +/- 119.1 pmol/L vs. 170.3 +/- 111.7 pmol/L) (P = .0407). The values declined to the presterilization level by 12 months (150.3 +/- 71.3 pmol/L). The luteal phase estradiol values did not change significantly. No change in any of the other hormones studied took place, with the exception of a slight increase in follicular phase luteinizing hormone levels (4.4 +/- 1.4 U/L in the first cycle, 5.1 +/- 1.3 U/L in the second cycle and 5.2 +/- 1.8 U/L in the third cycle) (P = .0553).

CONCLUSION

Laparoscopic tubal sterilization increases follicular phase estradiol levels, but the change seems to be only temporary.

The effects of smoked cocaine during the follicular and luteal phases of the menstrual cycle in women

RATIONALE

Few studies have systematically determined whether the response to cocaine in human females is related to hormonal fluctuations at different phases of the menstrual cycle.

OBJECTIVES

To investigate the responses to repeated doses of smoked cocaine in women during two phases of the menstrual cycle using a within-subject design.

METHODS

Eleven non-treatment seeking female cocaine smokers were administered smoked cocaine during the follicular and mid-luteal phases of the menstrual cycle. The order of menstrual cycle phase was counterbalanced across women and the order of cocaine doses was randomized. During each phase, there were four cocaine administration sessions. During each session, participants could smoke up to six doses of cocaine (either 0, 6, 12, or 25 mg cocaine base, depending on the session) at 14-min intervals.

RESULTS

The number of cocaine doses administered did not vary between the follicular and luteal phases. After cocaine administration, heart rate and several ratings - such as "good drug effect", "high", "stimulated", and "drug quality ratings" - were increased more during the follicular phase than the luteal phase, although, for some measures, these effects varied based on the cocaine dose. Further, dysphoric mood during the luteal phase was improved after cocaine administration.

CONCLUSIONS

These results indicate that the cardiovascular and subjective effects of repeated doses of smoked cocaine are complex and vary as a function of menstrual cycle phase and cocaine dose.

[Luteal and follicular phase inhibin A and B in regularly cycling women]

OBJECTIVE

To investigate the level of inhibin A nad B in luteal and follicular phase in women of reproductive age.

PATIENTS

Seventy women 39-52 years of age with regular menstrual cycle.

INTERVENTIONS

Blood samples obtained on days 3-8 and on days 22-25 of menstrual cycle were assayed for FSH, estradiol, inhibin A, inhibin B.

RESULTS

Luteal and follicular phase inhibin B was correlated inversely with age. Luteal phase inhibin A was correlated inversely with follicular phase FSH.

CONCLUSION

Main form of inhibin in follicular phase of the cycle is inhibin B and in luteal phase inhibin A. Inhibin B can be potential marker of ovarian aging.

Antiluteolytic strategies to improve fertility in cattle

During early pregnancy, a "critical period" may be defined between Days 15 and 17. Embryonic mortality associated with this period causes significant economic losses to the cattle industry. During this period, the endometrium will follow a default program to release luteolytic pulses of PGF2alpha, unless the conceptus sends appropriate antiluteolytic signals to block PGF2alpha, production. Maintenance of pregnancy is dependent on a successful blockage of endometrial PGF2alpha production. Biology of the critical period is complex and multifactorial. Endocrine, cellular and molecular factors, both from maternal and conceptus origins act in concert to determine whether luteolysis or maintenance of pregnancy will prevail. Understanding the influences of such factors in the biology of the critical period allowed researchers to produce a series of strategies aiming to favor maintenance of pregnancy in lieu of luteolysis. Strategies include hormonal and nutritional manipulations to decrease plasma concentrations of estradiol 17beta (E2) while increasing those of progesterone (P4), and inhibiting the PGF2alpha-synthesizing enzymatic machinery in the endometrium during the critical period. Experimental results indicate that use of such strategies has improved pregnancy rates following artificial insemination and embryo transfer programs.

Effect of high progesterone concentrations during the early luteal phase on the length of the ovulatory cycle of goats

The effect of exogenous progesterone exposure early in the oestrous cycle on the duration of the interovulatory interval was studied in dairy goats. A controlled intravaginal drug release (CIDR-G) device was inserted for 5 days starting at day 0 (D0 group, n=6) or day 3 (D3 group, n=5) postovulation. A third group was composed of untreated control goats (control group, n=7). Daily transrectal ultrasound was carried out during the interovulatory interval to assess the ovarian dynamics. Oestrous behaviour was checked twice a day and serum progesterone levels were assayed in daily jugular blood samples. Treated goats showed two different responses. In three D0 goats and one D3 goat, progesterone concentrations fell immediately after CIDR withdrawal and this was followed by oestrus and ovulation between days 8 and 11 (short cycles). In the other three D0 goats and in four D3 goats the treatment significantly reduced the interovulatory interval (18.3+/-0.3 and 18.5+/-0.3 days, respectively) (shortened cycles) compared with the control group (20.0+/-0.2 days; P<0.05), but the intervals with progesterone concentrations over 1 ng/ml were not different (15.7+/-0.3, 15.8+/-0.7 and 16.0+/-0.5 days for D0, D3 and control goats, respectively). In all D0 goats with a short cycle response, the ovulatory follicle arose from the first follicular wave but in the D3 goat with a short cycle it arose from the second follicular wave. These results showed that premature progesterone exposure early in the ovulatory cycle of the goat affected its length inducing short or shortened cycles. The effect of progesterone could either affect luteotropic support of the corpus luteum (CL) and/or stimulate a premature release of the luteolysin.

On the mechanisms of action of short-term levonorgestrel administration in emergency contraception

The effects of short-term administration of levonorgestrel (LNG) at different stages of the ovarian cycle on the pituitary-ovarian axis, corpus luteum function, and endometrium were investigated. Forty-five surgically sterilized women were studied during two menstrual cycles. In the second cycle, each women received two doses of 0.75 mg LNG taken 12 h apart on day 10 of the cycle (Group A), at the time of serum luteinizing hormone (LH) surge (Group B), 48 h after positive detection of urinary LH (Group C), or late follicular phase (Group D). In both cycles, transvaginal ultrasound and serum LH were performed from the detection of urinary LH until ovulation. Serum estradiol (E2) and progesterone (P(4)) were measured during the complete luteal phase. In addition, an endometrial biopsy was taken at day LH + 9. Eighty percent of participants in Group A were anovulatory, the remaining (three participants) presented significant shortness of the luteal phase with notably lower luteal P4 serum concentrations. In Groups B and C, no significant differences on either cycle length or luteal P4 and E2 serum concentrations were observed between the untreated and treated cycles. Participants in Group D had normal cycle length but significantly lower luteal P4 serum concentrations. Endometrial histology was normal in all ovulatory-treated cycles. It is suggested that interference of LNG with the mechanisms initiating the LH preovulatory surge depends on the stage of follicle development. Thus, anovulation results from disrupting the normal development and/or the hormonal activity of the growing follicle only when LNG is given preovulatory. In addition, peri- and post-ovulatory administration of LNG did not impair corpus luteum function or endometrial morphology.

The immune response during the luteal phase of the ovarian cycle: increasing sensitivity of human monocytes to endotoxin

OBJECTIVE

To test the hypothesis that during the luteal phase of the human ovarian cycle, as compared with the follicular phase, the percentage of cytokines producing peripheral monocytes after in vitro stimulation with endotoxin is increased.

DESIGN

Prospective study.

SETTING

Academic research institution.

PATIENT(S)

Women with regular menstrual cycles.

INTERVENTION(S)

Blood samples were collected between days 6 and 9 of the menstrual cycle (follicular phase) and between days 6 and 9 of the menstrual cycle following the LH surge (luteal phase).

MAIN OUTCOME MEASURE(S)

Percentages of tumor necrosis factor (TNF)-alpha-, interleukin (IL)-1 beta-, and IL-12-producing monocytes as well as total white blood cell (WBC) count, differential WBC counts, and plasma 17 beta-estradiol and progesterone concentrations.

RESULT(S)

Mean plasma 17 beta-estradiol and progesterone concentrations, percentage of TNF-alpha- and IL-1 beta-producing monocytes, WBC counts, and granulocyte cell count were significantly increased in the luteal phase as compared with the follicular phase of the ovarian cycle. The percentage of IL-12-producing monocytes, monocyte count and lymphocyte count did not vary between the 2 phases of the ovarian cycle.

CONCLUSION(S)

Together with an increase in progesterone and 17 beta-estradiol during the luteal phase, there is an increase in percentage TNF-alpha- and IL-1 beta-producing peripheral monocytes after in vitro stimulation with endotoxin as compared with the follicular phase of the ovarian cycle. Whether this increased sensitivity of monocytes for proinflammatory stimuli during the luteal phase is due to increased plasma levels of progesterone or 17 beta-estradiol needs further investigation.

Changes in premenstrual symptoms in women with schizophrenia: a prospective study

OBJECTIVE

We investigated whether the psychiatric symptoms and clinical features of schizophrenia change during the premenstrual phase in female patients.

METHODS

We observed 30 female schizophrenic inpatients over one menstrual cycle. All subjects met DSM-IV criteria for schizophrenia, and all had a regular menstrual cycle. All subjects completed the Daily Rating Form (DRF) every evening, and one psychiatrist rated the subjects (using the Brief Psychiatric Rating Scale [BPRS]) once during each of the three menstrual phases (premenstrual, menstrual, and postmenstrual). Serum levels of estradiol (E2) and progesterone were measured on the fifth to seventh day of both the premenstrual and postmenstrual phases. Data from the 24 subjects who completed the DRF correctly and completely were used for statistical analysis.

RESULTS

The mean total BPRS score for the 24 subjects was highest in the premenstrual phase and lowest in the postmenstrual phase, and a statistically significant difference was found among the three menstrual phases. Mean subtotal BPRS scores showed statistically significant differences among the three menstrual phases in anxiety/depression and withdrawal/retardation, but not in the psychotic symptom subscales. Mean serum E2 level showed a trend of increasing from the premenstrual phase to the postmenstrual phase. However, there was no significant correlation between DeltaBPRS and DeltaE2. When the criterion of 30% change was applied, the DRF items of depressed mood, anxious/nervous/restless, hostile/aggressive, and less/impaired work showed high frequencies of change in the premenstrual phase. Somatic items of abdominal pain, breast pain, and headache showed significant change with the 30% change rule on the DRF. On both the BPRS and DRF scores, premenstrual change of affective and behavioral symptoms was prominent, whereas the change of psychotic symptoms was minimal on the BPRS. In addition, in the premenstrual phase, there was a statistically significant correlation between the total BPRS score and the mean total DRF score. There was no correlation between premenstrual change in symptoms and hormonal levels of E2, progesterone, and the estradiol/progesterone (E/P) ratio.

CONCLUSIONS

The findings of this study suggest that premenstrual exacerbation of schizophrenic symptoms in female patients may not be a worsening of the schizophrenic symptoms but a concurrence of affective, behavioral, and somatic symptoms.

Secretion of prolactin and growth hormone in relation to ovarian activity in the dog

In pregnant bitches an apparent increase in plasma prolactin concentrations is observed during the second half of pregnancy, mean plasma prolactin concentrations peak on the day of parturition, fall for the next 24-48 h and then rise again. During lactation, high plasma prolactin concentrations are observed. Plasma prolactin levels in non-pregnant bitches appear to be lower than in pregnant animals, particularly in the last part of the luteal phase. Pulsatile secretion of prolactin has been observed during the luteal phase and mid-anoestrus. Progression of the luteal phase is found to be associated with an increase in prolactin release. The association of a strong increase of prolactin release and a decrease of plasma progesterone concentrations has also been demonstrated in overtly pseudopregnant bitches. Elevated prolactin secretion during progression of the luteal phase in the bitch may play a role in mammogenesis and is important because of the luteotrophic action of prolactin. Acromegaly is a syndrome of tissue overgrowth and insulin resistance due to excessive growth hormone (GH) production. In the bitch, acromegaly can be induced either by endogenous progesterone or by exogenous progestagens. Progestagen-induced GH production in this species originates from foci of hyperplastic ductular epithelium of the mammary gland. Pulsatile secretion of GH has been observed in normal cyclic bitches. In contrast with the pulsatile GH secretion seen in healthy dogs, the progestagen-induced plasma GH levels in bitches with acromegaly do not have a pulsatile secretion pattern. Just as with prolactin, the plasma progesterone levels influence the secretion pattern of GH in the bitch. The pulsatile secretion pattern of GH changes during the progression of the luteal phase in healthy cyclic bitches, with higher basal GH secretion and less GH being secreted in pulses during the first part of the luteal phase. The progesterone-induced GH production may promote the proliferation and differentiation of mammary gland tissue during the luteal phase of the bitch by local autocrine/paracrine effects and may exert endocrine effects.

Influence of midluteal serum prolactin on outcome of pregnancy after IVF-ET: a preliminary study

PURPOSE

To investigate the relationship between serum prolactin levels in the midluteal phase and the prognosis of pregnancy after IVF-ET.

METHODS

DESIGN

Prospective study;

SETTING

Shimane Medical University Hospital;

PATIENTS

29 patients completing their 34th IVF cycle; and

MAIN OUTCOME MEASURES

Serum levels of prolactin, estradiol-17 beta, and progesterone in the midluteal phase.

RESULTS

Midluteal prolactin levels were significantly lower in patients with early pregnancy loss than in the successful pregnancy group. The mean progesterone/prolactin ratio and the estradiol-17 beta/prolactin ratio were highest in patients with early pregnancy loss and were lowest in patients with successful pregnancies.

CONCLUSIONS

Findings of this study suggest that measurement of the serum prolactin concentration in the midluteal phase is useful for predicting the outcome of IVF-ET.

Luteal phase of the menstrual cycle in young healthy women is associated with decline in interleukin 2 levels

The aim of this study was to look at the possible changes in the blood levels of Interleukin 2 (IL2) during the sexual cycle in generally healthy, young, regularly menstruating women. The concentrations of progesterone and 17beta-estradiol were measured using radioimmunological assay. The bioactivity of interleukin 2 was measured using a biological test on the IL2-sensitive CTLL cell line. The percentage of lymphocytes with intracellular IL2 was determined by flow cytometry. Eighteen healthy volunteers (19-29 years old) were examined on days 5, 8, 14, 18 and 25 of the same cycle. All women were characterised by a regular menstrual cycle as per physiological levels of 17beta-es-tradiol and progesterone. The luteal phase of the cycle was characterised by both a decrease of IL2 blood levels and a decrease in the percentage of intracellular 1L2-containing lymphocytes stimulated in vitro. The IL2 level fluctuations observed during the menstrual cycle may be one factor causing pre-menstrual infections observed in young women. On the other hand, the decrease of IL2 may be seen as a start of the immune suppression necessary for an embryo's nidation.

Increased vasopressin and adrenocorticotropin responses to stress in the midluteal phase of the menstrual cycle

Accumulating evidence indicates that gonadal steroids modulate functioning of the hypothalamic-pituitary-adrenal (HPA) axis, which has been closely linked to the pathophysiology of anxiety and depression. However, the effect of the natural menstrual cycle on HPA axis responsivity to stress has not been clearly described. In nine healthy women, metabolic and hormonal responses to treadmill exercise stress during the early follicular phase of the menstrual cycle, when gonadal steroid levels are low, were compared with responses in the midluteal phase of the cycle, when both progesterone and estrogen levels are relatively high. Exercise intensity was gradually increased over 20 min to reach 90% of each subject's maximal oxygen consumption during the final 5 min of exercise. Basal plasma lactate, glucose, ACTH, vasopressin, oxytocin, and cortisol levels were similar in the two cycle phases. However, in response to exercise stress, women in the midluteal phase had enhanced ACTH (P < 0.0001), vasopressin (P < 0.01), and glucose (P < 0.001) secretion. These findings suggest that relatively low levels of gonadal steroids during the early follicular phase of the menstrual cycle provide protection from the impact of stress on the HPA axis.

Influence of menstrual cycle on NK activity

Natural killer (NK) cells are CD3- CD56+ and/or CD16+ cytotoxic lymphocytes that mediate first-line defense against various types of target cells without prior immunization. To assess the effect of the menstrual cycle and gender on NK activity we evaluated 30 healthy women (mean age 28.1 years, range 21-39) in follicular and luteal phases, 29 postmenopausal women (mean age 58.8 years, range 42-72) and 48 healthy men (mean age 31.6 years, range 21-40). In a flow cytometric test of NK activity, peripheral blood mononuclear effector cells were mixed with K562 targets cells labeled with DiO (3,3'-dioctadecyloxacarbocyanine perchlorate) at effector:target cell ratios of 40, 20, 10 and 5:1. Dead cells were stained with propidium iodide and results were expressed as lytic units per 10(7) cells. In addition, progesterone levels were determined in the luteal phase of the menstrual cycle of healthy women by a chemiluminescence assay. Our results showed that (1) NK cytotoxicity was higher in the follicular than in the luteal phase of the menstrual cycle (P < 0.0001); (2) postmenopausal women and men showed NK activity similar to women in the follicular phase but higher than women in the luteal phase of the menstrual cycle (P < 0.05); and (3) there was no correlation between NK activity and levels of progesterone. The data suggest that progesterone does not influence NK activity directly and that other factors may explain the reduction of NK activity in the luteal phase of the menstrual cycle.

The effects of sex, menstrual cycle, and oral contraceptives on the number and activity of natural killer cells

OBJECTIVES

The aim of this study was to study the impact of sex, the menstrual cycle, and the use of oral contraceptives (OC) on the number and activity of natural killer (NK) cells.

METHODS

Both the number and the activity of NK cells were assessed per milliliter of blood, and NK activity (NKA) per NK cell and per lymphocyte was calculated. NKA was measured in each subject using a whole blood assay, which preserves the plasma and all blood cells, and using a washed blood assay, in which plasma is replaced with an artificial medium. The subjects were young (20-29 years old) women with a regular menstrual cycle (n = 39; 26 tested on both the follicular and the luteal phases), age-matched women who use OC (n = 26), and age-matched men (n = 20).

RESULTS

Men showed markedly and significantly higher NKA than women with regular menstrual cycles or women using OC, who had the lowest levels of NKA. No significant differences in blood concentration of NK cell were found. Differences in NKA were of similar magnitude in the whole and washed blood assays per milliliter of blood, per NK cell, or per lymphocyte. The menstrual cycle had no significant effect on activity levels of NK cells, but during the periovulatory phase, the number of NK cells per milliliter of blood increased significantly.

CONCLUSIONS

The observed differences are independent of the presence of serum factors during the in vitro assessment of NKA, but may be related to chronic exposure to sex steroids and to fluctuation in the NK cell expression of beta-adrenoceptors.

Hyperprolactinemia and luteal insufficiency in infertile patients with mild and minimal endometriosis

The objective of the present paper was to assess the presence of hormonal alterations in infertile women with stage I or II endometriosis (Group III, n = 20) compared to fertile women without endometriosis (Group I, n = 14) and to fertile women with endometriosis (Group II, n = 7). Serum levels of FSH, LH, estradiol, TSH, and PRL were measured between days 1 and 5 of the early follicular phase; in the luteal phase, three serum samples were collected for progesterone measurement, and endometrial biopsies were performed. Serum estradiol levels were lower (p = 0.035) in infertile patients with endometriosis than in fertile patients without endometriosis. Six infertile patients with endometriosis presented prolactin levels above 20 ng/ml. This was not observed in the other groups. Luteal insufficiency was more frequent in infertile patients with endometriosis (78.9%) than in fertile patients with (42.9%) or without endometriosis (0%). In a multiple logistic regression analysis, only the presence of endometriosis and infertility was significantly associated with luteal insufficiency. The serum levels of LH, FSH, and TSH were not significantly different among the groups. Luteal insufficiency and altered prolactin secretion were associated with endometriosis, and could be important mechanisms causing infertility in this group of patients.

Ventilation is greater in women than men, but the increase during acute altitude hypoxia is the same

We wished to determine whether the previously reported lower arterial or alveolar P(CO2) in women than men, and in luteal (LUT) compared with follicular (FOL) menstrual cycle phase would persist during normal oral contraceptive use and during early altitude exposure. Ventilation and blood gases were measured at baseline (636 mmHg approximately 5400 ft, 1650 m) and during simulated altitude at 426 mmHg ( approximately 16000 ft, 4880 m), after 1 h (A1) and during the 12th h (A12), in 18 men (once) and in 19 women twice, during LUT and FOL and in 20 women twice while on placebo (PLA) or highest progestin dose (PIL) oral contraceptives. At baseline, Pa(CO2) was significantly higher in men than all women by 3.3 mmHg. When progesterone-progestin (PRO) was elevated in women, Pa(CO2) was significantly lower than in FOL and PLA, but the latter were still significantly lower than men. At altitude the P(CO2) differences between men and women and PRO levels persisted, with PA(CO2) falling by 3.6 and 7.3 mmHg at A1 and A12 in all, indicating an equivalent increase in alveolar ventilation. The mean arterial-end tidal P(CO2) difference was never >2 mmHg in the groups, indicating no VA/Q mismatch related to gender, PRO levels or altitude. All women had higher breathing frequency than men, resulting in greater deadspace ventilation. At altitude, the mean Pa(O2) was approximately 44 mmHg (Sa(O2) approximately 79%) for all, indicating equivalent oxygenation, but alveolar-arterial P(O2) differences were greater in women than men and higher when PRO was elevated. These results show that, relative to men, women have a compensated respiratory alkalosis, accentuated with elevated PRO. However, the ventilation response to acute altitude is the same in women and men.

Effects of cocaine on luteinizing hormone in women during the follicular and luteal phases of the menstrual cycle and in men

Cocaine stimulates luteinizing hormone (LH) release in rhesus monkeys and in men, but its effects on LH in women are unknown. Cocaine (0.2 and 0.4 mg/kg i.v.) was administered to groups of follicular and luteal phase women (N = 22) and to men (N = 12) to examine the influence of gender and menstrual cycle phase on cocaine and LH interactions. All subjects met American Psychiatric Association Diagnostic and Statistical Manual IV criteria for cocaine abuse, and menstrual cycle phase was verified by estradiol and progesterone measures. Baseline LH levels were equivalent between groups. Peak cocaine levels did not differ significantly between men and women and averaged between 87 +/- 21 and 124 +/- 18 ng/ml after 0.2 mg/kg cocaine and between 227 +/- 22 and 287 +/- 21 ng/ml after 0.4 mg/kg cocaine. The lower dose of cocaine (0.2 mg/kg) significantly increased LH levels in men (P < 0.001) but not in women at either phase of the menstrual cycle. The higher dose of cocaine (0.4 mg/kg) stimulated significant increases in LH in men (P < 0.001) and in women at both phases of the menstrual cycle (P < 0.004-0.001). Although cocaine's effects on LH in women were dose-dependent, there were no significant differences as a function of menstrual cycle phase. LH remained significantly elevated longer in men (32 min) than in women (8 and 12 min). This gender difference in cocaine's potency in stimulating LH was unexpected.

Glucose kinetics and substrate oxidation during exercise in the follicular and luteal phases

The purpose of this investigation was to determine whether plasma glucose kinetics and substrate oxidation during exercise are dependent on the phase of the menstrual cycle. Once during the follicular (F) and luteal (L) phases, moderately trained subjects [peak O(2) uptake (V(O(2))) = 48.2 +/- 1.1 ml. min(-1). kg(-1); n = 6] cycled for 25 min at approximately 70% of the V(O(2)) at their respective lactate threshold (70%LT), followed immediately by 25 min at 90%LT. Rates of plasma glucose appearance (R(a)) and disappearance (R(d)) were determined with a primed constant infusion of [6,6-(2)H]glucose, and total carbohydrate (CHO) and fat oxidation were determined with indirect calorimetry. At rest and during exercise at 70%LT, there were no differences in glucose R(a) or R(d) between phases. CHO and fat oxidation were not different between phases at 70%LT. At 90%LT, glucose R(a) (28.8 +/- 4.8 vs. 33.7 +/- 4.5 micromol. min(-1). kg(-1); P < 0.05) and R(d) (28.4 +/- 4.8 vs. 34.0 +/- 4.1 micromol. min(-1). kg(-1); P < 0.05) were lower during the L phase. In addition, at 90%LT, CHO oxidation was lower during the L compared with the F phase (82.0 +/- 12.3 vs. 93.8 +/- 9.7 micromol. min(-1) .kg(-1); P < 0.05). Conversely, total fat oxidation was greater during the L phase at 90%LT (7.46 +/- 1.01 vs. 6.05 +/- 0.89 micromol. min(-1). kg(-1); P < 0.05). Plasma lactate concentration was also lower during the L phase at 90%LT concentrations (2.48 +/- 0.41 vs. 3.08 +/- 0.39 mmol/l; P < 0.05). The lower CHO utilization during the L phase was associated with an elevated resting estradiol (P < 0.05). These results indicate that plasma glucose kinetics and CHO oxidation during moderate-intensity exercise are lower during the L compared with the F phase in women. These differences may have been due to differences in circulating estradiol.

Midcycle and luteal elevations of follicle stimulating hormone in squirrel monkeys (Saimiri boliviensis) during the estrous cycle

Follicle stimulating hormone (FSH) has fundamental importance in reproductive function, but its cyclic pattern has not previously been described in the squirrel monkey, due primarily to the lack of a suitable assay. An homologous radioimmunoassay (RIA) based on recombinant cynomolgus FSH measured changes in serum FSH relative to patterns of bioactive luteinizing hormone (LH), estradiol, and progesterone during the estrous cycle. FSH was observed to have a sharp peak during the late follicular phase coincident with the LH surge and then rose again during the luteal phase. Estradiol was low except for the midcycle rise, suggesting an inhibitory relationship. The rat granulosa cell in vitro FSH bioassay confirmed high levels of this hormone. Measurement of FSH in the squirrel monkey has found a pattern different from Old World primates in the luteal phase, which may provide insight into the reproductive mechanisms of this species.

Alteration in the hypothalamic-pituitary-ovarian axis in depressed women

BACKGROUND

Stress and corticotropin-releasing hormone inhibit the reproductive axis. We hypothesized that reproductive axis hormone secretion, particularly luteinizing hormone secretion, is inhibited in women with depression, similar to what has been observed to be caused by stress in numerous species.

METHODS

Blood samples were collected every 10 minutes for 12 hours in 25 untreated premenopausal women with depression and 25 nondepressed women who were matched by age and menstrual cycle day. Samples were assayed for luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone.

RESULTS

The mean plasma estradiol level was 30% lower in the follicular phase in women with depression than in their matched controls: 191 + 136 vs 261 + 169 pmol/L (52 + 37 vs 71 + 46 pg/mL). The half-life of luteinizing hormone was significantly shorter in women with depression than in their matched controls during both the follicular (22% shorter) and luteal (15% shorter) phases.

CONCLUSIONS

The blood levels of reproductive hormones were mostly normal in women with depression, but the blood level of estradiol was significantly lower. Estradiol is known to affect a number of neurotransmitter systems in the brain. Arch Gen Psychiatry. 2000;57:1157-1162.

Effect of an in vitro fertilization program on serum CA 125, tumor-associated trypsin inhibitor, free beta-subunit of human chorionic gonadotropin, and common alpha-subunit of glycoprotein hormones

OBJECTIVE

To investigate the impact of an IVF program on serum levels of tumor markers CA 125, tumor-associated trypsin inhibitor, free hCG beta-subunit, and free glycoprotein hormone alpha-subunit.

DESIGN

A prospective controlled clinical study.

SETTING

Outpatient university infertility clinic.

PATIENT(S)

Seventy-one infertile patients (with tubal occlusion, pelvic endometriosis, or unexplained infertility) undergoing IVF and nine control women with regular menstrual cycles.

INTERVENTION(S)

Serial blood sampling before, during, and after IVF, or during one ovulatory menstrual cycle in the controls.

MAIN OUTCOME MEASURE(S)

Serum levels of CA 125, tumor-associated trypsin inhibitor, hCG-beta, and glycoprotein hormone-alpha.

RESULT(S)

Before IVF, all tumor markers were within the normal range except for CA 125, which was elevated in patients with endometriosis. IVF led to significant increases in CA 125 and glycoprotein hormone-alpha that differed from the changes seen during normal menstrual cycles. The luteal phase increase in CA 125 correlated with levels of E(2) and P and the number of follicles. Two months after IVF, levels of CA 125 were 12% higher than levels before treatment. Tumor-associated trypsin inhibitor and hCG-beta revealed no cyclicity.

CONCLUSION(S)

An IVF regimen increased the release of CA 125 and glycoprotein hormone-alpha. The CA 125 elevation after IVF implies a persistent effect of ovarian hyperstimulation on CA 125 release.

Cortisol circadian rhythms during the menstrual cycle and with sleep deprivation in premenstrual dysphoric disorder and normal control subjects

BACKGROUND

In this study we extended previous work by examining whether disturbances in the circadian rhythms of cortisol during the menstrual cycle distinguish patients with premenstrual dysphoric disorder (PMDD) from normal control (NC) subjects. In addition, we tested the differential response to the effects of early and late partial sleep deprivation on cortisol rhythms.

METHODS

In 15 PMDD and 15 NC subjects we measured cortisol levels every 30 min from 6:00 PM to 9:00 AM during midfollicular (MF) and late luteal (LL) menstrual cycle phases and also during a randomized crossover trial of early (sleep 3:00 AM-7:00 AM) versus late (sleep 9:00 PM-1:00 AM) partial sleep deprivation administered in two subsequent and separate luteal phases.

RESULTS

In follicular versus luteal menstrual cycle phases we observed altered timing but not quantitative measures of cortisol secretion in PMDD subjects, compared with NC subjects: in the LL versus MF phase the cortisol acrophase was a mean of 1 hour earlier in NC subjects, but not in PMDD subjects. The effect of sleep deprivation on cortisol timing measures also differed for PMDD versus NC subjects: during late partial sleep deprivation (when subjects' sleep was earlier), the cortisol acrophase was almost 2 hours earlier in PMDD subjects.

CONCLUSIONS

Timing rather than quantitative measures of cortisol secretion differentiated PMDD subjects from NC subjects both during the menstrual cycle and in response to early versus late sleep deprivation interventions.

Plasma leptin concentrations are increased in women with premenstrual syndrome

Leptin is a metabolic regulator of the hypothalamic- pituitary-gonadal axis, and plays an important role in human reproduction. Its neuro-endocrine effects are mediated by interactions with receptors in the hypothalamus, where emotional drive is also controlled. We postulated that circulating leptin concentrations are increased in premenstrual syndrome (PMS), and that this may be associated with the psychological symptoms of the disease. We obtained fasting venous samples from 32 women with PMS and 28 women with asymptomatic menstrual cycles, matched for age, body mass index and menstrual cycle length. Leptin concentrations were measured by radioimmunoassay. Leptin concentrations increased significantly during the luteal phases of the menstrual cycles of the control and PMS groups as compared with the follicular phase, having excluded the 11 women with PMS and six controls found to be anovulatory on the basis of mid-luteal plasma progesterone concentrations from the analysis. A greater increase was observed in women with PMS than the controls (P: = 0.00006 and 0.003 respectively). Although leptin concentrations in the follicular and luteal phases were higher in PMS than the controls, the difference was only statistically significant between the follicular phases (P: = 0.001). There was no clear relationship between leptin and oestradiol or progesterone in this study. These findings suggest that leptin may play a role in the pathophysiology of the disease, and requires further evaluation.

Homeostatic joint amplification of pulsatile and 24-hour rhythmic cortisol secretion by fasting stress in midluteal phase women: concurrent disruption of cortisol-growth hormone, cortisol-luteinizing hormone, and cortisol-leptin synchrony

Short-term fasting as a metabolic stress evokes prominent homeostatic reactions of the reproductive, corticotropic, thyrotropic, somatotropic, and leptinergic axes in men and women. Although reproductive adaptations to fasting are incompletely studied in the female, nutrient deprivation can have major neuroendocrine consequences in the follicular phase. Unexpectedly, a recent clinical study revealed relatively preserved sex steroid and gonadotropin secretion during short-term caloric restriction in the midluteal phase of the menstrual cycle. This observation suggested that female stress-adaptive responses might be muted in this sex steroid-replete milieu. To test this hypothesis, we investigated the impact of fasting on daily cortisol secretion in healthy young women during the midluteal phase of the normal menstrual cycle. Eight volunteers were each studied twice in separate and randomly ordered short-term (2.5-day) fasting and fed sessions. Pulsatile cortisol secretion, 24-h rhythmic cortisol release, and the orderliness of cortisol secretory patterns were quantified. Within-subject statistical comparisons revealed that fasting increased the mean serum cortisol concentration significantly from a baseline value of 8.0+/-0.61 to 12.8+/-0.85 microg/dL (P = 0.0003). (For Systeme International conversion to nanomoles per L, multiply micrograms per dL value by 28.) Pulsatile cortisol secretion rose commensurately, viz. from 101+/-11 to 173+/-16 microg/dL/day (P = 0.0025). Augmented 24-h cortisol production was due to amplification of cortisol secretory burst mass from 8.2+/-1.5 to 12.9+/-2.0 microg/dL (P = 0.017). In contrast, the estimated half-life of endogenous cortisol (104+/-9 min), the calculated duration of underlying cortisol secretory bursts (16+/-7 min) and their mean frequency (14+/-2/day) were not altered by short-term fasting. The quantifiable orderliness of cortisol secretory patterns was also not influenced by caloric restriction. Nutrient deprivation elevated the mean of the 24-h serum cortisol concentration rhythm from 12.4+/-1.3 to 18.4+/-1.9 microg/dL (P = 0.0005), without affecting its diurnal amplitude or timing. Correlation analysis disclosed that fasting reversed the positive relationship between cortisol and LH release evident in the fed state, and abolished the negative association between cortisol and GH as well as between cortisol and leptin observed during nutrient repletion (P < 0.001). Pattern synchrony between cortisol and GH as well as that between cortisol and LH release was also significantly disrupted by fasting stress. In summary, short-term caloric deprivation enhances daily cortisol secretion by 1.7-fold in healthy midluteal phase young women by selectively amplifying cortisol secretory burst mass and elevating the 24-h rhythmic cortisol mean. Augmentation of daily cortisol production occurs without any concomitant changes in cortisol pulse frequency or half-life or any disruption of the timing of the 24-h rhythmicity or orderliness of cortisol release. Fasting degrades the physiological coupling between cortisol and LH, cortisol and GH, and cortisol and leptin secretion otherwise evident in calorie-sufficient women. We conclude that the corticotropic axis in the young adult female is not resistant to the stress-activating effects of short-term nutrient deprivation, but, rather, evinces strong adaptive homeostasis both monohormonally (cortisol) and bihormonally (cortisol paired with GH, LH, and leptin).

Serum group II phospholipase A(2) levels during menstrual cycle and pregnancy

The purpose of this study was to evaluate the circulating group II phospholipase A(2) (PLA(2)-II) levels during normal menstrual cycle and to assess alterations in maternal circulating PLA(2)-II concentrations during pregnancy and at puerperium. Circulating serum PLA(2)-II concentrations were compared between 38 nonpregnant women with normal menstrual cycle (15 at menstrual phase, 11 at follicular phase, and 12 at luteal phase), 61 normal pregnant women (13 in the first trimester, 12 in the second trimester, and 36 in the third trimester), and 14 normal postpartum women at 5th puerperal day. Serum PLA(2)-II concentrations were also measured in 11 patients with threatened premature labor. Maternal and fetal serum PLA(2)-II levels before and after delivery were made to determine differences in 11 neonates delivered vaginally and 11 neonates delivered by elective cesarean section. Serum PLA(2)-II level was measured with an immunoradiometric assay. Serum PLA(2)-II concentrations at luteal phase were significantly lower than those at menstrual or follicular phase (p< 0.05). There was no significant difference for PLA(2)-II levels between first trimester and menstrual phase or follicular phase. There were no significant differences among three trimesters during pregnancy. There was no significant difference in serum PLA(2)-II levels between normal pregnant women and patients with threatened premature labor. Labor stress did not affect both maternal and fetal serum PLA(2)-II concentrations. There was also no significant difference for circulating PLA(2)-II levels between maternal and fetal serum. Interestingly, serum PLA(2)-II concentrations in postpartum women were significantly higher than those in normal pregnant women (p<0.05). These results suggest that a regulatory mechanism of PLA(2)-II may exist during the normal menstrual cycle and at puerperium.

Natural and artificial methods for inducing the luteal phase in the koala (Phascolarctos cinereus)

An experiment was conducted in which female koalas were mated for different durations of intromission and ejaculation to confirm that the luteal phase of the oestrous cycle in koalas is induced by the physical act of mating. Results showed that induction of a luteal phase in the koala usually required a complete duration of penile thrusting behaviour from the male. It is proposed that induction of a luteal phase in koalas may involve a copuloceptive reflex, triggered by the thrusting of the male's penis into the female's urogenital sinus. Although interrupted mating in koalas may be used to induce a luteal phase in preparation for an artificial insemination programme, this study showed that there is a 12.5% probability that pregnancy will result from semen prematurely emitted by the teaser male. A dose of 250 iu hCG was administered intramuscularly to eight oestrous females to determine whether it was possible to induce a luteal phase artificially. In contrast to control females, which received sterile saline injections, all females injected with hCG showed a significant increase in progestogen concentration above that of basal values, indicating that a luteal phase had been induced successfully.

Corpus luteum response to exogenous HCG during the mid-luteal phase of the menstrual cycle

OBJECTIVE

To assess a range of exogenous HCG regimes designed to simulate the endocrine environment occurring in biochemical, single and multiple pregnancies and to study the response of the corpus luteum to those regimes.

DESIGN

Prospective clinical study.

PATIENTS

Twenty-five normally cycling women aged 24-35 years were given one of four regimes of HCG injections designed to mimic the HCG concentrations found following spontaneous implantation. Regimes A, B, C and D were designed with starting HCG doses of 60, 140, 250 and 1000 iu, respectively. The daily HCG injections were then increased to give a doubling concentration every 30 h for regime A, every 27 h for regime B, every 24 h for regimes C and D. HCG administration was started on either days 7 or 8 after the LH peak.

MEASUREMENTS

Plasma HCG and progesterone concentrations.

RESULTS

Subjects given regime A failed to demonstrate any rescue of the corpus luteum despite low-detectable amounts of HCG in the circulation equivalent to those seen in some biochemical pregnancies. In contrast, subjects given regimes B and C demonstrated prompt increases in progesterone secretion immediately after the first HCG injection achieving HCG and progesterone concentrations in plasma similar to those seen in normal singleton pregnancies. Subjects given regime D also showed rapid rescue of the corpus luteum but this time achieved plasma HCG concentrations in the range normally seen in multiple pregnancies. All subjects in regimes B, C and D secreted significantly higher amounts of progesterone than those in regime A (P<0.001). However, despite the greater amounts of HCG used in regime D, the amount of progesterone produced was not significantly different from regimes B or C.

CONCLUSIONS

The exogenous HCG regimes used in this study successfully mimicked the hormonal environment found in biochemical, single and multiple pregnancies and elicited appropriate corpus luteum responses.

Insulin sensitivity and sex steroid hormone levels during the menstrual cycle in healthy women with non-insulin-dependent diabetic parents

OBJECTIVE

To identify the effect of the menstrual cycle and sex steroid hormone levels on insulin sensitivity in healthy women with non-insulin-dependent diabetic parents.

METHODS

A clinical trial was realized in 6 healthy women with non-insulin-dependent diabetic parents and in 6 control subjects. In both phases of the menstrual cycle the following tests were made: insulin tolerance test, metabolic profile, and sex steroid hormone levels.

RESULTS

Insulin sensitivity was significantly lower in the follicular (p = 0.004) and luteal (p = 0.01) phases of the menstrual cycle in probands compared with controls. In the luteal phase dehydroepiandrosterone was higher in probands than in controls (p = 0.009).

CONCLUSIONS

Healthy women with non-insulin-dependent diabetic parents had a lower insulin sensitivity in both phases of the menstrual cycle compared with the control group. Dehydroepiandrosterone was higher in the luteal phase in probands than controls.

Sympathoadrenal responses to submaximal exercise in women after acclimatization to 4,300 meters

The purpose of this investigation was to determine the sympathoadrenal response to exercise in women after acclimatization to high altitude. Sixteen eumenorrheic women (age, 23.6 +/- 1.2 years; weight, 56.2 +/- 4.3 kg) were studied at sea level and after 10 days of high-altitude exposure (4,300 m) in either the follicular (n = 11) or luteal (n = 5) phase. Subjects performed two 45-minute submaximal steady-state exercise tests (50% and 65% peak O2 consumption [VO2 peak]) at sea level on a bicycle ergometer. Exercise tests were also performed on day 10 of altitude exposure (50% VO2 peak at sea level). As compared with rest, plasma epinephrine levels increased 36% in response to exercise at 50% VO2 peak at sea level, with no differences found between cycle phases. This increase was significantly greater (increase 44%) during exercise at 65% VO2 peak. At altitude, the epinephrine response was identical to that found for 65% VO2 peak exercise at sea level (increase 44%), with no differences found between phase assignments. The plasma norepinephrine response differed from that for epinephrine such that the increase with exercise at altitude (increase 61%) was significantly greater compared with 65% Vo2 peak exercise at sea level (increase 49%). Again, no phase differences were observed. It is concluded that the sympathoadrenal response to exercise (1) did not differ between cycle phases across any condition and (2) was similar to that found previously in men, and (3) the relative exercise intensity is the primary factor responsible for the epinephrine response to exercise, whereas altitude had an additive effect on the norepinephrine response to exercise.

Pulsatile secretion pattern of growth hormone during the luteal phase and mid-anoestrus in beagle bitches

The pulsatile secretion pattern of growth hormone was investigated during four stages of the luteal phase and during mid-anoestrus in six cyclic beagle bitches. Plasma samples were obtained via jugular venepuncture at 10 min intervals for 12 h at 19 +/- 2 (mean +/- SEM; luteal phase 1), 38 +/- 2 (luteal phase 2), 57 +/- 2 (luteal phase 3), 78 +/- 2 (luteal phase 4) and 142 +/- 4 days (mid-anoestrus) after ovulation. During all stages, growth hormone was secreted in a pulsatile fashion. The mean basal plasma growth hormone concentration during luteal phase 1 (2.2 +/- 0.3 microgram l(-1)) was significantly higher than that during luteal phase 4 (1.5 +/- 0.1 microgram l(-1)) and mid-anoestrus (1.4 +/- 0.2 microgram l(-1)). The mean area under the curve (AUC) above zero during luteal phase 1 (27.3 +/- 2.7 microgram l(-1) in 12 h) tended to be higher than that during luteal phase 4 (20.8 +/- 1.8 microgram l(-1) in 12 h) and mid-anoestrus (19.2 +/- 2.5 microgram l(-1) in 12 h). In contrast, the mean AUCs above the baseline during luteal phase 1 (1.1 +/- 0.5 microgram l(-1) in 12 h) and luteal phase 2 (1.2 +/- 0.5 microgram l(-1) in 12 h) were significantly lower than that during luteal phase 4 (2.8 +/- 0.5 microgram l(-1) in 12 h). In conclusion, the pulsatile secretion pattern of growth hormone changes during the luteal phase in healthy cyclic bitches: basal growth hormone secretion is higher and less growth hormone is secreted in pulses during stages in which the plasma progesterone concentration is high. It is hypothesized that this change is caused by a partial suppression of pituitary growth hormone release by progesterone-induced growth hormone production in the mammary gland. The progesterone-induced production of growth hormone in the mammary gland may promote the physiological proliferation and differentiation of mammary gland tissue during the luteal phase of the bitch by local autocrine-paracrine effects. In addition, progesterone-induced mammary growth hormone production may exert endocrine effects, such as hyperplastic changes in the uterine epithelium and insulin resistance.

Minimal requirements for a successful outcome in anovulatory patients treated with human menopausal gonadotropins

OBJECTIVE

To determine the minimal requirements for achieving a full-term singleton pregnancy in hMG-treated patients.

METHODS

One hundred and ninety-two pregnancy cycles resulting from hMG therapy in infertile patients were retrospectively studied to determine the minimal requirements for the occurrence of a pregnancy in those women. The cycles were divided into five groups: pregnancies ending in miscarriage, ectopic pregnancies, pregnancies ending in preterm delivery, full-term singleton pregnancies, and full-term multiple pregnancies. The number of hMG ampules, the number of preovulatory follicles reaching 18 mm or more in diameter, the cervical mucus score (Insler), the number of living spermatozoa per high-power field (HPF) observed in the cervical mucus on the day of hCG administration, and the midluteal plasma progesterone concentration were determined and correlated with the outcome of the pregnancy in the five groups studied. The minimal requirements for the occurrence of a full-term singleton pregnancy were also determined.

RESULTS

In this cohort of 192 women, the mean number of hMG ampules administered was 25.38 (1903.5 IU), the mean number of preovulatory follicles reaching 18 mm was 2.1, the mean cervical mucus score (Insler) was 9.48, and the mean number of motile spermatozoa per HPF in the cervical mucus on the day of hCG administration was 19.3. There were no statistically significant differences between the five groups studied regarding these four variables. The mean midluteal plasma progesterone concentration was 29.07 ng/mL and there was no statistically significant difference in midluteal plasma progesterone concentration between the cycles resulting in full-term deliveries and those ending in miscarriage. However, a statistically significant difference in midluteal plasma progesterone concentration was found between the cycles resulting in full-term singleton pregnancies and those resulting in full-term multiple pregnancies.

CONCLUSIONS

The minimal requirements for achieving a full-term singleton pregnancy were 9 ampules of hMG (675 IU), one 18-mm follicle, a cervical mucus score (Insler) of 6 on the day of hCG administration, and a midluteal plasma progesterone concentration of 10.83 ng/mL. The presence of motile spermatozoa in the cervical mucus was a reassuring sign in 92.7% of instances but was not an absolute necessity for a successful outcome.

Luteal estrogen supplementation in pregnancies associated with low serum estradiol concentrations

The role of luteal phase estrogen in pregnancy outcome has been a matter of considerable debate. In order to evaluate the effectiveness of estrogen supplementation in gonadotropin releasing hormone agonist (GnRHa)/human menopausal gonadotropin (hMG)-stimulated cycles associated with low luteal estrogen concentration, a study was performed comparing the ongoing pregnancy rates in cycles with serum concentrations of estradiol (E2) <100 pg/ml 11 days post embryo transfer (p-ET), treated with luteal phase progesterone (P4) vs. E2 and P4 supplementation. Among 1106 serum samples studied, 951 were from women receiving GnRHa and follicle stimulating hormone (FSH) prior to oocyte retrieval and P4 (50 mg-100 mg IM daily) as luteal phase supplementation beginning day 11 after retrieval. The remaining 155 were from women receiving both E2 (2 mg-6 mg estrace orally each day) and P4 during the luteal phase. Significantly greater frequencies of preclinical losses were observed among women with human chorionic gonadotropin (hCG) concentrations>5 mIU/ml and concurrent E2 concentrations <100 pg/ml compared with E2 >100 pg/ml (p<0.00001). Among the 128 women who had hCG concentrations >5 mIU/ml and E2 concentrations <100 pg/ml, 102 received P4 only during the luteal phase and 26 were treated with estrace 2 mg-6 mg daily, as well as P4 during the luteal phase. The frequency of preclinical pregnancy losses among the 102 women with hCG >5 mIU/ml and E2 <100 pg/ml who did not receive luteal E2 supplementation was 72%, compared with 50% who received luteal E2 supplementation (p=0.04) The increase in preclinical pregnancy loss rates among women not receiving luteal E2 resulted in a decrease in ongoing pregnancy rate (8%), compared to those receiving luteal E2 supplementation (31%) (p=0.002). Our results indicated that a subset of women losing pregnancies preclinically after GnRHa and FSH stimulation due to low luteal phase serum E2 level may benefit from luteal estrogen supplementation. More sensitive and specific markers are needed to identify prospectively women in this risk group.

Modulation of IL-6 production during the menstrual cycle in vivo and in vitro

During the menstrual cycle (MC), premenopausal women experience changes in basal temperature and their physical condition and well-being. Premenopausal female patients with chronic inflammatory diseases demonstrate changes in disease activity during the MC. The study was initiated to explore reasons for these phenomena. The sex hormone-modulated lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) secretion in a whole blood assay, serum IL-6 concentration, and serum sex hormone concentrations were studied throughout the MC in five healthy female subjects (median, 28 years; mean, 31.2+/-2.2 years, 26-38 years). Serum IL-6 concentration demonstrated a significant increase in the luteal phase of the MC and was elevated when serum dehydroepiandrosterone (DHEA) was low and vice versa. DHEA decreased LPS-induced IL-6 secretion at six of seven time points during the MC (DHEA, p = .047). In contrast, beta-estradiol and testosterone increased LPS-induced IL-6 secretion in six of seven time points during the MC (significant for testosterone, p = .005). The study demonstrates oscillation of serum IL-6 concentration during the MC and the marked MC-dependent modulation of IL-6 secretion by sex hormones. These mechanisms may be involved in the changes in the basal temperature, the general condition, and, in patients with chronic inflammatory diseases, of disease activity during the MC.

Allopregnanolone concentrations and premenstrual syndrome

OBJECTIVE

To evaluate basal allopregnanolone and progesterone in both phases of the menstrual cycle in women suffering from premenstrual syndrome (PMS) and their response to a GnRH test.

DESIGN

We selected 56 women (28 patients with PMS and 28 controls) aged between 18 and 32 years. Blood samples were drawn in both follicular and phases. Twenty-eight women (14 patients with PMS and 14 controls) underwent a GnRH test in the luteal phase.

METHODS

We evaluated allopregnanolone by RIA, using a specific antibody. Serum progesterone and oestradiol were determined using a commercially available RIA kit.

RESULTS

Luteal phase allopregnanolone concentrations were significantly lower in patients with PMS than in controls. Progesterone concentrations were significantly lower in patients with PMS in both the follicular and the luteal phase. Serum oestradiol concentrations were in the normal range in both groups of women, although slightly greater in those with PMS. Allopregnanolone and progesterone responses to a GnRH test were significantly blunted in women with PMS.

CONCLUSIONS

Diminished concentrations of allopregnanolone and progesterone, its precursor, and a blunted response to the GnRH test lead us to hypothesise that patients with PMS may suffer from an inadequate production of ovarian neuroactive steroids, especially in the luteal phase. This would lead to an impaired anxiolytic GABA(A)-mediated response in stressful physiological and psychological conditions, and may in part explain various psychoneuroendocrine symptoms that arise during PMS.

Short-term fasting selectively suppresses leptin pulse mass and 24-hour rhythmic leptin release in healthy midluteal phase women without disturbing leptin pulse frequency or its entropy control (pattern orderliness)

Nutritional signals strongly regulate neuroendocrine axes, such as those subserving release of LH, GH, and TSH, presumptively in part via the adipocyte-derived neuroactive peptide leptin. In turn, leptin release is controlled by both acute (fasting) and long-term (adipose store) nutrient status. Here, we investigate the neuroendocrine impact of short-term (2.5-day) fasting on leptin release in healthy young women studied in the steroid-replete midluteal phase of the normal menstrual cycle. Eight women each underwent 24-h blood sampling at 10-min intervals during a randomly ordered 2.5-day fasting vs. fed session in separate menstrual cycles. Pulsatile leptin release was quantified by model-free Cluster analysis, the orderliness of leptin patterns by the approximate entropy statistic, and nyctohemeral leptin rhythmicity by cosinor analysis. Mean (24-h) serum leptin concentrations fell by 4.6-fold during fasting; namely, from 15.2+/-2.3 to 3.4+/-0.6 microg/L (P = 0.0007). Cluster analysis identified 13.9+/-1.1 and 14.3+/-1.1 leptin peaks per 24 h in the fed and fasting states (P = NS), and unchanging leptin interpeak intervals (89+/-5.4 vs. 92+/-5.3 min). Leptin peak area declined by 4.2-fold (155+/-21 vs. 37+/-7 area units, P = 0.004), due to a reduction in incremental leptin pulse amplitude (4.4+/-0.7 vs. 1.0+/-0.13 microg/L, P = 0.0011). The cosine amplitude and mesor (mean) of the 24-h leptin rhythm decreased by 4-fold, whereas the acrophase (timing of the nyctohemeral leptin peak) remained fixed. The approximate entropy of leptin release was stable, thus indicating preserved orderliness of leptin release patterns in fasting. Cross-correlation analysis revealed both positive (fed) and negative (fasting) leptin-GH relationships, but no leptin-LH correlations. In summary, short-term (2.5-day) fasting profoundly suppresses 24-h serum leptin concentrations and pulsatile leptin release in the sex steroid-sufficient midluteal phase of healthy women via mechanisms that selectively attenuate leptin pulse area and incremental amplitude. In contrast, the pulse-generating, nyctohemeral phase-determining, and entropy-control mechanisms that govern 24-h leptin release are not altered by acute nutrient restriction at this menstrual phase. Leptin-GH (but not leptin-LH) showed nutrient-dependent positive (fed) and negative (fasting) cross-correlations. Whether similar neuroendocrine mechanisms supervise altered leptin signaling during short-term nutrient restriction in men, children, or postmenopausal women is not known.

No cyclicity in serum vascular endothelial growth factor during normal menstrual cycle but significant luteal phase elevation during an in vitro fertilization program

PROBLEM

To compare changes in serum vascular endothelial growth factor (VEGF) levels during normal and in vitro fertilization (IVF) cycles.

METHOD OF STUDY

Ten healthy women with ovulatory cycles and 37 infertile women participating in an IVF program were followed by frequent serum samples and with VEGF measurements throughout their cycles.

RESULTS

Serum VEGF remained unchanged during the normal menstrual cycle, whereas the IVF program participants showed elevations in serum VEGF in the luteal phase of the cycle. When data from controls and patients were pooled, redundant midluteal VEGF level correlated with progesterone and with peak follicular phase estrogen level. The midluteal VEGF level in the IVF cycles was associated with body mass index (P < 0.01) and progesterone level (P < 0.05) by multiple regression. The 14 women conceiving tended to have higher VEGF levels than those failing to become pregnant.

CONCLUSIONS

The IVF program was associated with increased synthesis of VEGF either in the ovaries, endometrium, or at other sites and this may be of significance for the outcome of IVF.

Sex steroid hormones in serum and tissue of benign and malignant breast tumor patients

The ability of breast tumors to synthesize sex steroid hormones is well recognized and their local production is thought to play a role in breast cancer development and growth. The aim of this study was to estimate local intra-tumoral and circulating levels of Estrone (E1), Estrone Sulfate (E1S), Estradiol (E2), Estriol (E3), and Testosterone (T) in 33 pre- and postmenopausal women with primary breast cancer in comparison to 12 pre- and postmenopausal women with benign breast tumors. The mean levels of the studied sex hormones were higher in serum and tumor tissue of breast cancer women than those with benign breast tumors apart from Testosterone which showed a significant decrease in pre- and postmenopausal women with breast cancer (P<0.001for follicular phase, P<0.05 for luteal phase, and P<0.005 for postmenopausal). The levels of the five hormones were significantly higher intra-tumoral than in serum of both benign and malignant breast tumor women with E1S as the predominant estrogen. There was only a positive significant correlation between serum and tumor tissue levels of E1 (rs=0.52, P<0.05 for follicular; rs=0.63, P<0.05 for luteal and rs=0.58, P<0.05 for postmenopausal) and a significant correlation between serum and tumor tissue of T (rs=0.64, P<0.05 for follicular; rs=-0.51, P<0.05 for luteal and rs=-0.81, P<0.04 for postmenopausal).

Reproducibility of plasma and urinary sex hormone levels in premenopausal women over a one-year period

Although endogenous sex steroid hormones in premenopausal women may be associated with the risk of breast cancer and other illnesses, direct evidence to support this hypothesis is limited in large part by methodological issues in the conduct of relevant studies. One major unresolved issue is whether a single blood sample (such as is available in most epidemiological studies), collected in a specific phase of the menstrual cycle, reflects long-term levels in that phase. To address this issue, two sets of blood and urine samples were obtained from 87 premenopausal women over a 1-year period in both the follicular and luteal phases. Plasma estradiol, estrone, and estrone sulfate were measured in the blood samples obtained in both phases, whereas progesterone and urinary 2- and 16a-hydroxyestrone were measured in luteal-phase samples only. For all of the women combined, intraclass correlation coefficients (ICCs) ranged, with one exception, from 0.52 to 0.71 for the plasma estrogens and the urinary estrogen metabolites. The sole exception was for estradiol in the luteal phase (ICC = 0.19); inclusion of only women who were ovulatory in both cycles and who collected each sample 4-10 days before their next period resulted in a substantially higher ICC for estradiol in the luteal phase (ICC = 0.62; 95% confidence interval, 0.43-0.78). These data indicate that, for several plasma and urinary sex hormones, a single follicular- or luteal-phase measurement in premenopausal women is reasonably representative of hormone levels in that phase for at least a 1-year period.

Effects of 17beta-oestradiol or oestrous stage-specific cow serum on the ability of bovine oviductal epithelial cell monolayers to prolong the viability of bull spermatozoa

The effect of 17beta-oestradiol and oestrous stage-specific cow serum on bovine oviductal epithelial cell monolayers to extend the viability of co-cultured bull spermatozoa was examined. Monolayers of cells from ampullary and isthmic segments were pre-treated with medium containing either oestrous cow serum, luteal-phase cow serum, 1 microg/ml 17beta-oestradiol + foetal bovine serum or foetal bovine serum alone (control) before the addition of motile frozen/thawed spermatozoa. Motility was visually assessed throughout a 48 h co-incubation period, while fertilising ability of spermatozoa was evaluated by adding in vitro matured bovine oocytes. Pre-treatment with 17beta-oestradiol or oestrous cow serum resulted in a higher percentage of motile spermatozoa after 18 h in isthmic and after 36 h in ampullary cultures compared with the control, but pre-treatment did not affect fertilisation rates. Only at 42 h in ampullary cultures was motility higher in luteal serum pre-treated cultures compared to the control. Motility was also assessed in medium conditioned by pre-treated monolayers. Pre-treatment with 17beta-oestradiol enhanced the ability of conditioned medium to prolong motility and medium conditioned with oestrous cow serum was superior to medium conditioned by luteal-phase serum at maintaining motility. In conclusion, the ability of oviductal epithelium to prolong the motility of spermatozoa is enhanced by 17beta-oestradiol.

Adrenomedullin and atrial natriuretic peptide concentrations in normal pregnancy and pre-eclampsia

Adrenomedullin (AM) is a peptide that elicits a long-lasting vasorelaxant activity, while atrial natriuretic peptide (ANP) has also been shown to be a potent vasodilatory agent. To clarify the possible role of AM and ANP in the physiology of pregnancy and pathophysiology of pre-eclampsia, we measured plasma concentrations of these peptides in non-pregnant women, normal pregnant women and women with pre-eclampsia. A gradual increase in plasma AM was observed as pregnancy progressed. The plasma AM concentrations during the second trimester (12.7 +/- 1.4 fmol/ml) were significantly elevated, in comparison with the non-pregnant follicular phase (6.4 +/- 0.61 fmol/ml), luteal phase (6.0 +/- 0.49 fmol/ml), and the first trimester (6.5 +/- 0.8 fmol/ml). The plasma AM concentrations of the third trimester (21.5 +/- 1.4 fmol/ml) were significantly elevated when compared with those of the second trimester (P < 0.05). Northern blot analysis confirmed the expression of the AM mRNA transcript (1.6 kb) in third trimester placentas. In comparison with those observed at term (25.3 +/- 4.5 fmol/ml), the plasma concentrations were significantly reduced post-partum (6.4 +/- 0.6 fmol/ml). In the third trimester, plasma AM concentrations did not differ significantly between women with pre-eclampsia (17.2 +/- 2.3 fmol/ml) and normal pregnant women. In contrast, the plasma ANP concentrations in pre-eclampsia (39.5 +/- 7. 1 pg/ml) were significantly elevated when compared with those of the normal third trimester (14.4 +/- 1.4 pg/ml) (P < 0.05). ANP concentrations were reasonably constant throughout the pregnancy.