Luteal Phase Of Cycle Research Articles

Symptomatology and energy intake during the menstrual cycle in smoking women.

This study extends our understanding of smoking behavior, withdrawal, and premenstrual symptomatology in smoking women, as well as energy intake as a function of cycle phase. Thirty-two women age 18 to 40 years, smoking ad lib, were followed for an average of two menstrual cycles with hormonal verification. Withdrawal and premenstrual symptomatology as well as energy intake were reported during the follicular (F), luteal (L), and late luteal (LL) cycle phases. Both premenstrual symptomatology and withdrawal symptomatology were higher during the LL phase. Subject response on measurements of craving, irritability, restlessness, increased appetite, and depressed mood tended to be higher in the LL phase. Energy intake did not vary as a function of cycle phase. Participants perceived that they smoked more and had increased appetite in the LL phase but related measurements did not confirm this. Premenstrual and withdrawal symptoms are highly correlated and one needs to be cautious in interpreting cycle effects on withdrawal. Overall symptomatology seems to be lower during the F phase, indicating that this may be a more opportune time for women to quit smoking.

Evidence that the switch from negative to positive feedback at the level of the pituitary gland is an important timing event for the onset of the preovulatory surge in LH in the ewe.

Experiments were performed to test the hypothesis that there is a negative feedback 'clamp' of ovarian hormones on the hypothalamus and pituitary gland during the follicular phase of the oestrous cycle that limits the secretion of GnRH and LH. GnRH secretion was monitored by sampling the hypophysial portal blood of ewes during the luteal phase of the oestrous cycle and either 24 h or 48 h after the induction of luteolysis by the injection of cloprostenol, a prostaglandin analogue. There was an increase in GnRH pulse frequency in the transition from the luteal to the follicular phase of the cycle. A reduction in the amplitude of GnRH pulses did not occur until 48 h after cloprostenol, suggestive of negative feedback at the level of the hypothalamus that is more profound in the latter part of the follicular phase. The responsivity of the pituitary gland to GnRH was monitored in ewes during the luteal phase of the oestrous cycle and 24 h or 48 h after cloprostenol. Injections of 250 ng or 1000 ng GnRH were given (i.v.) to ewes that had been anaesthetised to suppress endogenous secretion of GnRH and LH. Using the lower dose, the responses 48 h after cloprostenol were not significantly different from those in the luteal phase. With the higher dose of GnRH, a significant (P < 0.05) increase in mean responsivity was seen 48 h after cloprostenol. There was, however, a marked variation in response, with some ewes showing profound increases in LH secretion in response to GnRH and others showing responses that were similar to those obtained during the luteal phase of the cycle. These data are interpreted to mean that the secretion of LH is 'clamped' during the follicular phase of the oestrous cycle and the 'clamp' is only released near the time of the preovulatory LH surge. To test whether or not a rise in GnRH input to the pituitary gland could over-ride the 'clamp' on the pituitary secretion of LH in the late follicular phase of the cycle, sheep were treated 40 h after cloprostenol with either a bolus injection of 500 ng GnRH or four pulses of 125 ng GnRH given at 10-min intervals. These treatments caused small elevations in LH secretion but did not always cause preovulatory LH surges. In some cases, a small rise in LH secretion was induced by GnRH treatments and levels of LH in plasma returned to baseline with the preovulatory LH surge occurring a few hours later.(ABSTRACT TRUNCATED AT 400 WORDS)

Induced luteal regression: differential effects on follicular and luteal inhibin/activin subunit mRNAs in the marmoset monkey.

During the luteal phase of the primate ovulatory cycle the predominant inhibin/activin subunit mRNAs produced by the corpus luteum and antral follicles are those for the alpha- and beta B-subunits respectively. The control of expression of these mRNAs and the resultant nature of the endocrine and paracrine signals which they may potentially generate has yet to be elucidated. Inhibin/activin subunit mRNAs may have a role in both the paracrine regulation of follicular and luteal function and modulation of FSH secretion. The aim of this study was to investigate the expression of inhibin/activin subunit mRNAs following luteal regression induced by either withdrawal of LH support (GnRH antagonist treatment), or by a direct inhibitory action (prostaglandin administration). Marmoset monkeys with regular ovulatory cycles were treated on day 8 and 9 of the luteal phase with either GnRH antagonist, prostaglandin or vehicle (n = 3 per group). Ovaries were studied 48 h after onset of treatment (on day 10 of the luteal phase) by hybridizing frozen tissue sections with radiolabelled riboprobes specific to the inhibin/activin alpha-, beta A- and beta B-subunit mRNAs. After autoradiographic exposure, grain concentrations were quantified by image analysis. In corpora lutea from control marmosets there was high expression of alpha-mRNA with only marginal expression of beta B-mRNA. Corpora lutea in animals treated with GnRH antagonist or prostaglandin had markedly reduced expression of alpha-mRNA while beta B-mRNA was unchanged. In controls, all healthy antral follicles exhibited a high level of expression of beta B-mRNA in the granulosa cells and low expression of alpha-mRNA in theca cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy intakes are higher during the luteal phase of ovulatory menstrual cycles

We compared energy and macronutrient intakes across the menstrual cycle in participants (n = 42) in a study that assessed the frequency of ovulatory disturbances in regularly cycling vegetarians and nonvegetarians. Women kept daily basal body temperature records for six consecutive menstrual cycles and provided 3-d diet records near the beginning, middle, and end of different cycles. On completion of the study, temperature records were quantitatively analyzed to determine whether cycles were ovulatory, and if so, the date the luteal phase began. Diet records kept near the beginning and end of cycles were matched with temperature analysis results, and women were grouped according to whether the end-of-cycle record was kept during the luteal phase of an ovulatory cycle (group 1, n = 29), or during an anovulatory cycle or before luteal phase onset of a short luteal phase cycle (group 2, n = 13). Group 1 had higher energy intakes during the luteal than during the follicular phase (9.27 +/- 2.69 vs 8.01 +/- 2.36 MJ/d, P < 0.0001), whereas intakes of group 2 did not differ across the cycle (7.91 +/- 2.18 vs 8.20 +/- 1.48 MJ/d, NS). Both groups' macronutrient intakes were similar in records kept near the beginning and end of cycles. Documentation of ovulation is necessary in studies assessing premenopausal women's energy intakes.

Effects of pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) on prolactin, luteinizing hormone and growth hormone secretion in the ewe.

This study was undertaken to investigate the roles of PACAP and VIP in the control of pituitary hormone secretion in the ewe. The first experiment was designed to identify any direct effects at the level of the pituitary and was conducted during the luteal phase of a prostaglandin-synchronized oestrous cycle. PACAP (0.008, 0.04, 0.2 and 1.0 nmol/min) or VIP (0.06, 0.2, 0.6 and 1.8 nmol/min) was infused into the carotid artery over a 10 min period. Blood samples were taken before and after the infusions so that plasma PRL, LH and GH concentrations could be measured. Blood pressure was also monitored to determine if the doses used were biologically active. In no case was an effect on hormone secretion observed. In contrast, the highest dose of each peptide induced an increase in heart rate to almost three-fold the resting value. Although both peptides are active in vivo, this result suggests that neither peptide has a direct effect on hormone release from the pituitary of prostaglandin-synchronized ewes. In a second experiment, we investigated whether the peptides had central effects on hormone secretion. Intracerebroventricular (ICV) injection of PACAP or VIP at the dose 10 nmol was tested in ovariectomized ewes. After injection, PACAP suppressed PRL and GH secretion so that plasma hormone concentrations from 1-3 h after injection were significantly different from the control (P < 0.05 for PRL, P < 0.01 for GH). In addition, PACAP significantly reduced mean LH concentration (P < 0.05) and LH pulse frequency (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cyclic medroxyprogesterone treatment increases bone density: A controlled trial in active women with menstrual cycle disturbances

objective: Bone loss occurs in young women who experience amenorrhea or ovulatory disturbances. The purpose of this study was to determine whether bone loss could be prevented by stimulating a more normal hormonal pattern, using treatment with cyclic medroxyprogesterone, with or without calcium supplementation, in physically active women with disturbed menstruation. design: This study was a 1-year randomized, double-blind, placebo-controlled trial. Women who were stratified by menstrual cycle disturbance were randomized into four groups. The outcome variable was the change in spinal bone density measured by dual energy techniques. setting: A large metropolitan area. participants: Sixty-one healthy, normal-weight physically active premenopausal women aged 21 to 45 years who experienced amenorrhea, oligomenorrhea, anovulation, or short luteal phase cycles completed the study. intervention: Therapies were cyclic medroxyprogesterone (10 mg/day for 10 days per month) and calcium carbonate (1,000 mg/day of calcium) in four groups: (A) (n = 16) cyclic medroxyprogesterone plus calcium carbonate; (B) (n = 16) cyclic medroxyprogesterone with calcium placebo; (C) (n = 15) placebo medroxyprogesterone with active calcium; or (D) (n = 14) both medroxyprogesterone and calcium placebos. results: The initial bone density (mean = 1.12 g/cm 2) did not differ by group ( P = 0.85). The 1-year bone density change was strongly related to treatment with medroxyprogesterone ( P = 0.0001) and weakly to calcium ( P = 0.072) treatment. Bone density increased significantly (+1.7% ± 0.5%, ±SEM, P = 0.004) in the medroxyprogesterone-treated groups (A and B), did not change in the calcium-treated group (C) (−0.7% ± 0.6%, P = 0.28), and decreased on both placebos (D) (−2.0% ± 0.6%, P = 0.005). conclusions: Cyclic medroxyprogesterone increased spinal bone density in physically active women experiencing amenorrhea or ovulatory disturbances. potential clinical significance: Amenorrhea, oligomenorrhea, anovulation, and short luteal phase cycles are common in premenopausal women and associated with spinal bone loss occurring at a stage of life when bone density would normally be stable or increasing. This controlled trial shows a significant gain in bone in women in the cyclic medroxyprogesterone intervention group, whereas those subjects in the placebo group lost bone. Calcium supplementation appeared to be helpful but did not reach statistical significance. The implications of these findings for the prevention of osteoporosis warrant further investigation.

Exercise-induced menstrual cycle changes. A functional, temporary adaptation to metabolic stress.

Chronic exercise is now known to alter the menstrual cycle. Yet, we do not yet know the true incidence of menstrual cycle alterations in athletes, because good normative data do not exist and the metabolic cost of training has not been considered in many studies. Secondary amenorrhoea is not easily induced by exercise training alone but seems to require additional metabolic stressors. Induction of secondary amenorrhoea in prospective exercise studies has not occurred, although the onset of short luteal or inadequate luteal phase cycles may occur in women even when running distances are not extensive. Such menstrual cycles may cause infertility, but this is only a temporary phenomenon since pregnancy, if desired, will usually occur upon cessation of training. Exercise-related changes in the menstrual cycle can be viewed as a functionally adaptive rather than a maladaptive dysfunction. A strong case can be made that the changes in the menstrual cycle as a result of exercise are an energy conserving strategy to protect more important biological processes. This hypothesis is consistent with the theory of metabolic arrest that has been identified in lower organisms and hibernating mammals.

Increased PGE 2 from human monocytes isolated in the luteal phase of the menstrual cycle. Implications for immunity?

The reproductive hormones are implicated in the well documented sexual dimorphism in cellular and immune responses. Prostaglandins (PGs) are mediators of the immune response with their concentration and relative amounts being pivotal to their impact. In resident peritoneal macrophages isolated from mice we had previously noted that the cells from females synthesized significantly more PG than males. In these experiments we investigated whether PG metabolism in the human monocyte was influenced by gender and by stage of the menstrual cycle. Monocytes isolated from the female and activated in vitro with LPS produced on average significantly more PG into the medium than the males. Among females, significantly more PG was found in the medium from cells isolated during the luteal phase of the cycle than during the early follicular phase. It was also in this luteal phase in which the female differed substantially from males. We suggest that the in vivo hormonal changes associated with the menstrual cycle modulate monocyte synthesis of PG and other immune modulators such as interleukin-1 (IL-1). This could be a key to understanding differences in vulnerability between males and females as well as within phases of the cycle, to immune and inflammatory insult.

CaBP9K levels during the luteal and follicular phases of the estrous cycle in the bovine uterus.

The expression of calbindin-D9K (CaBP9K) and calbindin-D28K (CaBP28K) genes in the reproductive system is well established for rodent and avian species, but not for domestic livestock. This investigation expanded the study of these proteins to include the bovine uterus and examined the levels of CaBP9K and CaBP9K mRNA in the nonpregnant bovine uterus during the estrous cycle. Immunohistochemical studies revealed that CaBP9K was present in all uterine glandular and luminal epithelial cells. In contrast, the closely related calcium binding protein CaBP28K was present in only one to two glandular cells in the samples examined. Neither protein was localized in the myometrium or in the stromal cells of the endometrium. RIA and dot blot hybridization were used to quantify the amount of CaBP9K and CaBP9K mRNA. The levels of both the protein and its mRNA were threefold higher during the luteal phase than during the follicular phase. RIA was also used to determine bovine uterine levels of 17 beta-estradiol and progesterone. Progesterone levels were higher during the luteal phase than during the follicular phase, while 17 beta-estradiol levels were higher during the follicular phase. This investigation represents the first characterization of CaBP9K gene expression in the bovine uterus. It demonstrated that the expression of CaBP9K and CaBP9K mRNA was greatest during the progesterone-dominated luteal phase of the bovine estrous cycle. These results indicated that CaBP9K may be involved in uterine glandular function during the luteal phase.

Increased PGE 2 from human monocytes isolated in the luteal phase of the menstrual cycle. Implications for immunity?

The reproductive hormones are implicated in the well documented sexual dimorphism in cellular and immune responses. Prostaglandins (PGs) are mediators of the immune response with their concentration and relative amounts being pivotal to their impact. In resident peritoneal macrophages isolated from mice we had previously noted that the cells from females synthesized significantly more PG than males. In these experiments we investigated whether PG metabolism in the human monocyte was influenced by gender and by stage of the menstrual cycle. Monocytes isolated from the female and activated in vitro with LPS produced on average significantly more PG into the medium than the males. Among females, significantly more PG was found in the medium from cells isolated during the luteal phase of the cycle than during the early follicular phase. It was also in this luteal phase in which the female differed substantially from males. We suggest that the in vivo hormonal changes associated with the menstrual cycle modulate monocyte synthesis of PG and other immune modulators such as IL-1. This could be a key to understanding differences in vulnerability between males and females as well as within phases of the cycle, to immune and inflammatory insult.

Progesterone, 17 beta-estradiol, and opioid neuropeptides modulate pattern of luteinizing hormone in circulation of the cow.

The working hypothesis for this study was that 17 beta-estradiol (E2), progesterone (P4), and opioid neuropeptides modulate frequency of pulsatile release of LH during the luteal phase of the bovine estrous cycle. On Day 8 of the estrous cycle (Day 0 = estrus), 20 cows were ovariectomized (OVX) and immediately received one of three steroid replacement treatments: P4 alone (n = 6), E2 alone (n = 7), or P4 and E2 (n = 7). To characterize the pattern of LH in peripheral circulation, serial blood samples were collected (12-min intervals for 22 h) on the fifth day following OVX. LHRH was administered after the 22-h sample was taken. Naloxone (opioid neuropeptide antagonist; 0.5 mg/kg) was administered on the sixth day after OVX, and change of concentration of LH in peripheral circulation was monitored. Pulse frequency of LH and mean concentration of LH were lower (p < 0.01) in cows treated with P4 and E2 compared to cows treated with P4 alone. Moreover, cows treated with E2 alone had a greater (p < 0.01) frequency of LH pulses and mean concentration of LH compared to cows treated with P4 alone. The greatest amplitude (p < 0.01) of LH release after LHRH was in cows treated with E2 alone. The greatest percentage increase (p < 0.01) in LH after administration of naloxone occurred in cows treated with P4 alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Dependence of spectral power of EEG rhythms on menstrual cycle phases in women suffering from epilepsy

The effect of menstrual cycle on EEG parameters is investigated in norm, in epilepsy becoming acute in menstrual and perimenstrual periods (catamenial), and in epilepsy whose exacerbation is not connected with menstrual cycle. The ten dencies to the decrease of spectral power in cycle luteal phase in healthy women and women suffering from epilepsy are mentioned. The primary role of spectrum low-frequency components and total power level in neurodynamics of catamenial epilepsy is shown.

Ambulatory Blood Pressure Changes in the Menstrual Cycle of Hypertensive Women Significance of Plasma Renin Activity Values

Blood pressure (BP) changes during the menstrual cycle (MC) have not been studied in hypertensive women in relationship to changes in sex hormone levels and plasma renin activity (PRA). We therefore carried out 24 h ambulatory BP recordings and hormonal measurements in 34 hypertensive and 27 matched normotensive women during the follicular ovulatory and luteal phases of the menstrual cycle. Plasma renin activity was similar in the two groups and rose significantly during the luteal phase only in the hypertensives (P < .01). There were no differences in plasma estradiol or progesterone between the normotensives and hypertensives, but testosterone was higher in the hypertensives during the ovulatory (P < .01) and luteal (P < .001) phases. Blood pressure did not change in the normotensives throughout the cycle, but it increased in the hypertensives during ovulation (P < .01). When patients were divided according to mean menstrual cycle PRA, only those with relatively low PRA (< 2 ng/mL/h) had a significant BP rise during ovulation and it primarily occurred at night (P < .05). The results demonstrate that premenopausal hypertensive women have increased testosterone during ovulation and increased testosterone and PRA during the luteal phase of the cycle. Like normotensives, hypertensives with relatively high PRA exhibit no change in BP during the cycle, whereas those with relatively low PRA have a nighttime increase in BP during ovulation.

Connexin43 and gap junction content in the porcine myometrium during the estrous cycle

The amount of the gap junction protein Connexin43 in myometrium from pig uteri at specific stages of the estrous cycle was studied using 2 different immunochemical methods. Western blot analysis showed the presence of Connexin43 protein in 43 and 47 kD bands at all stages of the cycle. Immunohistochemistry demonstrated only a few small junctional complexes in the myometrium during the luteal phase of the cycle. Gap junctions appeared to increase both in number and size during proestrus and estrus.

Is endometrial development in the peri-implantation period influenced by high concentrations of luteinizing hormone in the follicular phase?

A retrospective study was designed to examine the relationship between luteinizing hormone (LH) concentrations in the follicular phase and endometrial development in the luteal phase of natural and artificial cycles. Two types of cycle were studied: natural cycles (n = 51) in subjects with unexplained infertility were divided into two subgroups, depending on whether LH measurements in the late follicular phase were based on urine (n = 24) or plasma (n = 27) samples; and artificial cycles (n = 17), produced by the administration of a standard hormone replacement therapy, in two subgroups of women, those with premature ovarian failure (n = 10) in whom plasma LH concentrations were high, and those with unexplained infertility (n = 7) who had their hypothalamic pituitary-ovarian axis down-regulated and in whom plasma LH concentrations were low. The correlation between plasma or urine concentrations of LH in the follicular phase and the results of endometrial biopsy obtained in the luteal phase was calculated. In natural cycles, LH concentrations were similar in those with normal or retarded endometrium, and there was no significant correlation between high LH concentration and retarded endometrial development. In artificial cycles, endometrial development was not different between those with low LH concentrations (down-regulated by Zoladex) and those with high LH concentrations (premature ovarian failure). Endometrial development in the peri-implantation period does not appear to be influenced by LH concentration in the follicular phase. The reported association between high LH concentration and poor reproductive performance cannot therefore be explained by abnormal implantation consequent upon retarded endometrial development.

Pulsatile release of oxytocin after suppression of prostaglandin synthesis in hysterectomised ewes

On days 13 and 14 after oestrus (day 0) oxytocin and 13,14-dihydro-15-keto-prostaglandin ( fg)F 2α (PGFM) concentrations were measured in jugular plasma of hysterectomised sheep with or without systemic treatment with the PG cyclo-oxygenase inhibitor indomethacin (4 mg kg −1 three times a day on days 12, 13 and 14 subcutaneously. Pulsatile increases of oxytocin were observed in both untreated and treated sheep with mean (±SD) peak heights of 18-4 ± 9·6 pg ml −1 (n=11) and 23·5 ± 9·4 pg ml −1 (n=8), respectively; these means were not significantly different. Plasma concentrations of PGFM remained consistently low in both groups (under 100 pg ml −1 with no significant peaks observed. The data suggest that PGF 2α may not be the only stimulus for the release of luteal oxytocin, or that there may be a contribution by the posterior pituitary to oxytocin secretion during the luteal phase of the ovine oestrous cycle.

Enhanced ovarian steroid secretion before implantation in early human pregnancy.

Previous studies have compared ovarian steroid production in the luteal phase of nonconceptive and conceptive cycles. Some investigators reported higher preimplantational levels of progesterone in conceptive cycles vs. nonconceptive cycles, but other studies have found no differences. Many of these results were difficult to interpret because the studies included infertile women and/or women who received exogenous hormones. In this study we have characterized the profiles of gonadotropin secretion and ovarian steroid response during early pregnancy in a population of spontaneously ovulating women and compared them to those in nonconceptive cycles of recently fertile women. Blood samples were collected daily during the luteal phase from 24 women during 51 cycles of artificial insemination with donor semen. Cycles were segregated to those from women who had a successful term pregnancy (normal group) and those having an early spontaneous abortion (SAB group) and were also classified as nonconceptive or conceptive based on measurements of hCG. Serum LH and FSH did not show marked differences between nonconceptive and conceptive cycles in the periimplantation period in either the normal or SAB group. In the normal group, estradiol concentrations were significantly higher in conceptive cycles than in nonconceptive cycles beginning 6 days after the LH peak and continuing through the end of the cycle, while differences in progesterone concentrations bordered on or exceeded significance during the same time period. In the SAB group, preimplantation differences in pituitary gonadotropin and ovarian steroid secretion were not observed, whereas the postimplantation hCG concentrations in the SAB group were significantly lower than those in the normal group. It is reasoned that embryos with defective post-implantation hCG secretion may have had this defect before detection of hCG in serum, thus accounting for the lack of stimulation of steroid secretion in these pregnancies. These findings suggest that the enhanced ovarian steroid secretion in conceptive cycles may be due to a gonadotropic stimulus from the preimplantation embryo.

The luteal phase after ovulation induction with human menopausal gonadotropin and one versus two doses of a gonadotropin-releasing hormone agonist

To use a GnRH agonist (GnRH-a) to induce ovulation after priming with exogenous hMG. Prospective, randomized double-blind protocol using one or two doses of intranasal nafarelin. Office-based ovulation induction program. PATIENTS, INTERVENTIONS: Infertile women not conceiving after use of clomiphene citrate for at least 6 months who were given hMG and nafarelin. No luteal support was given. Serum concentrations of FSH, LH, E2, and P acutely and at 6 days after GnRH-a administration. Duration of the luteal phase was assessed. Ovulation with elevation of both FSH and LH was achieved. The two-dose regimen was more effective than one dose for sustained LH release. Luteal phase P values and luteal phase duration were both less than usually seen with gonadotropin hCG therapy in the absence of luteal phase support. Ovulation induction with GnRH-a after hMG priming produces unacceptable luteal phase cycles in the absence of hormonal support.

Exogenous prolactin elevates plasma progesterone concentrations and reduces androgen concentrations during the early luteal phase of the porcine estrous cycle

Sixteen crossbred sows were used after second farrowing in a study performed on a commercial unit. Three days after weaning, polyvinyl catheters were placed into both jugular veins of control ( n = 9) and prolactin (PRL) treated ( n = 7) sows for blood sampling and PRL administration. Blood was sampled at 2-h intervals, beginning on the first day of estrus and continuing for 6 subsequent days. Injections of 0.3 mg PRL (in 1 ml of saline) were given every 2 h for 3 days starting from the second day of blood sampling, always 3–4 min before blood collection. Controls were injected similarly with an equal volume of saline. Blood samples were assayed for luteinizing hormone (LH), PRL, progesterone (P 4), androstenedione (A 4) and testosterone (T) by radioimmunoassay (RIA) procedures. All data were standardized to maximum LH concentrations (Day 0). Non-linear regression analysis with known covariance matrix was used in statistical calculations of the presented data. The χ 2 test was applied to verify the significance of all regression coefficients and to test the differences between the control and PRL-treated groups. In control sows, all studied hormones excluding P 4 were at their highest concentrations in the peri-estrous period. When PRL administration was started 24–48 h after the LH surge, plasma P 4 concentrations in particular PRL-treated sows were elevated in comparison with those of control sows ( P < 0.01). This elevation was observed during, as well as after the PRL injection period. Prolactin also significantly inhibited plasma concentrations of A 4 and T in most of the treated sows. Results suggest a luteotrophic effect of exogenous PRL during the early luteal phase in sows.

Suppression of Ovarian Function With the Transdermally Given Synthetic Progestin ST 1435

Objective To study transdermal administration of the synthetic progestin ST 1435 and effectiveness of the steroid in suppression of ovarian function. Design, Patients The effect of transdermal administration of the synthetic progestin ST 1435 in suppression of ovarian function was studied in a short term (17 to 93 days) study in healthy regularly menstruating women. Setting The outpatient clinic of the City Maternity Hospital, Helsinki, Finland. Intervention Nine women used the progestin ST 1435 transdermally during a total of 21 menstrual cycles. Treatment was started on the 5th day of the menstrual cycle and continued for 17 to 93 days. Three different daily doses (0.5, 0.8, and 1.0mg) were tested. The steroid was applied to the periumbical area once a day in a gel. Main Outcome Measures Serum concentrations of ST 1435, progesterone, and estradiol (E 2 ) were determined during the luteal phase of control cycles and in a total of 16 treatment cycles. Bleeding records were kept and side effects registered. Results Transdermal absorption of the progestin ST 1435 resulted in relatively constant serum concentrations in each subject, depending on the dose used. All doses caused changes in ovarian function. With the 0.5-mg/d dose, inhibition of ovulation was observed in three of five treatment periods. The 0.8-mg/d dose was high enough to inhibit ovulation in 7 of 10 cycles analyzed. With the 1.0-mg/d dose, the serum concentrations of the progestin were high, and anovulation was seen. Serum E 2 concentrations were variable in all cases; occasional high peak values were seen, typical of progestin treatment. Bleeding control was variable; irregular bleeding was seen, especially in anovulatory cases. Conclusions A 0.8-mg dose of the progestin ST 1435 administered transdermally once a day appeared to suppress ovulation, if properly applied, and excessive suppression of ovarian function was not seen. The steroid was well accepted. The synthetic progestin ST 1435 given transdermally represents an effective alternative for inhibition of ovulation and for progestin therapy.