Pharmacokinetics of natural progesterone administered in the form of a vaginal tablet

Our study was conducted to assess the pharmacokinetics of natural progesterone administered in the novel formula of an effervescent vaginal tablet. Fifty post-menopausal women, with a median age of 43.5 years (range 28-55), volunteered to participate in the research. All women discontinued their hormonal replacement therapy 1 month prior to the study. The pharmacokinetics of 50 and 100 mg of progesterone administered as a vaginal tablet were evaluated. After the initial administration of 50 mg or 100 mg, a mean serum Cmax of 20.43 +/- 8.01 nmol/l and 31.61 +/- 12.62 nmol/l (P < 0.0004) was reached at a Tmax of 6.1 +/- 2.63 and 6.4 +/- 3.35 h respectively. The terminal half-life was 13.18 +/- 1.3 and 13.7 +/- 1.05 h respectively. Continuous use of the 100-mg tablet resulted in a mean serum progesterone concentration of 26.08 +/- 13.96 nmol/l and 21.42 +/- 16.32 nmol/l after 14 and 30 days respectively. Women >40 years were found to have a significantly lower Tmax compared to younger women (P = 0.02). The continuous use of vaginal progesterone did not influence the hormonal, liver or lipid profiles evaluated. Only three (6%) women suffered from mild vaginal irritation. Natural progesterone given as a vaginal tablet is well tolerated, safe and an easily administered treatment. Even in a non-oestrogenized vagina the absorption was efficient and the 100 mg dosage resulted in adequate serum progesterone concentrations.

Micronized progesterone: a new therapeutic option

The recent release of micronized progesterone adds a new physiologic alternative to the available therapeutic agents for common indications in both pre- and postmenopausal women. This compound overcomes problems with absorption through the gut associated with exogenous progesterone administration so that it can be used orally to achieve required serum and tissue levels of a hormone that is structurally identical to endogenous progesterone. Available data suggest that it is functionally equivalent to synthetic progestogens for common applications, such as secondary amenorrhea, while offering the advantage of a more physiologic metabolic profile that could be important for sustained use in applications such as postmenopausal hormone replacement therapy.

Interleukin-6 and tumor necrosis factor-alpha concentrations in the intrauterine cavity of postmenopausal women using an intrauterine delivery system releasing progesterone. A possible mechanism of action of the intrauterine device

Intrauterine devices (IUD) provide effective contraception. The current study evaluates the concentration of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in the intrauterine fluid of postmenopausal women using an intrauterine delivery system releasing progesterone (IDS-P). Intrauterine fluid was obtained by lavage, and IL-6 and TNF-alpha were analyzed using an enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed with a one-way analysis of variance (ANOVA). Intrauterine fluid IL-6 levels were 33.6 vs 6.09 pg/sample IDS-P vs no IDS-P (p = 0.0301). Intrauterine TNF-alpha levels for women using the IDS-P were higher than in nonusers, but the differences did not reach statistical significance. IL-6 and TNF-alpha levels were increased in the intrauterine cavity of postmenopausal women with an IDS-P. These data suggest that secreted cytokines could be a potential mechanism of IUD contraceptive efficacy.

Ovarian responses to progesterone and oestradiol benzoate administered intravaginally during dioestrus in cattle

This study examined the effects of administering progesterone and oestradiol benzoate (ODB) during mid-dioestrus, on ovarian follicular dynamics in cattle. Twelve cycling cows were used in a 4 x 4 latin square design, with the 4 treatments being initiated on Day 13 of the cycle (oestrus = Day 0) and comprising intravaginal insertion for 5 days of: (i) a progesterone releasing device (CIDR; 'P4'); (ii) a CIDR device with a gelatin capsule containing 10 mg ODB and 1 g lactose (CIDIROL; 'P4/ODB') attached; (iii) a placebo CIDR device with the 10 mg ODB capsule (ODB); and, (iv) a placebo CIDR device alone (CTRL). The ovaries of each cow were examined daily by transrectal ultrasonography from Day 7 of the cycle until subsequent ovulation. Blood samples were collected daily from Day 11, and at intervals of 2-4 h during the 24 h period either side of treatment initiation. The second dominant follicle (DF2) emerged on Day 10.7 +/- 0.2 (mean +/- SEM), and was 8.5 +/- 0.2 mm in diameter by Day 13. The DF2 developed through to ovulation (2-wave cycles) in half of the animals in the CTRL group; while in the other half of cases, the ovulatory follicle originated from the third follicle wave that emerged on Day 17.2 +/- 0.4. Administration of a CIDR device alone (P4 group) did not alter the 1:1 ratio of 2 and 3-wave cycles, but the third dominant follicle (DF3) in those cows with 3-wave cycles emerged earlier on Day 15.6 +/- 0.2. In contrast, the DF2 of every animal in the ODB and P4/ODB groups became atretic and was replaced by a DF3 which emerged 4.0 +/- 0.3 days later. The effects of ODB on luteal function were limited to an earlier decline in plasma progesterone concentrations from 2 to 4 days after device insertion and a reduction in diameter of the corpus luteum when administered concurrently with progesterone. Intravaginal administration of 10 mg ODB on Day 13 of the oestrous cycle, with or without progesterone, was effective in promoting follicle wave turnover. In the absence of ODB, progesterone administration alone (P4 group) did not alter the ratio of animals with 2 or 3-wave cycles from that observed in animals in the CTRL group, but did advance the timing of subsequent follicle wave emergence in those animals with 3-wave cycles.

Effect of roughage type and concentrate supplementation on follicle numbers and in vitro fertilisation and development of oocytes recovered from beef heifers

Increasing dietary energy tends to decrease the ovulatory response and produce fewer viable embryos following superovulation of beef cattle. Data in sheep indicate that high energy intake can decrease progesterone concentrations (P4), although effects in cattle are not as clear. The objectives were to evaluate the effects of roughage type and concentrate supplementation on P4 concentrations, follicle growth and subsequent oocyte fertilisation and embryo development in vitro. Forty-two beef heifers were allocated to 3 treatment groups: (i) silage ad libitum plus 6 kg concentrates (silage + conc.; n = 14); (ii) silage ad libitum (silage; n = 14) or (iii) hay ad libitum (hay; n = 14) for 40 days. Oestrus was synchronised using a controlled intravaginal progesterone releasing device (CIDR) for 7 days plus prostaglandin F2 alpha (15 mg luprostiol) administered 2 days before CIDR withdrawal. Ovaries were stimulated with 600 i.u. of follicle stimulating hormone (pFSH) administered in 6 equal doses at 12-h intervals, starting 12 days after CIDR withdrawal. Daily blood samples were collected from 3 days after CIDR insertion until CIDR withdrawal, and for another 3 days prior to pFSH, for P4 determination. Oocytes were recovered postmortem 12 h after the last pFSH injection, matured, fertilised and cultured in vitro. There was no overall effect of diet (P > 0.05) on P4 concentrations. The number of follicles grown in heifers on silage + conc (18.8 +/- 3.3), silage (23.5 +/- 3.4) or hay (18.1 +/- 2.6) were not affected by the dietary treatment (P > 0.05). The percentage of oocytes fertilised from heifers on hay (88%) was higher compared to oocytes from heifers on silage (79%; P < 0.05), but was not different (P > 0.05) compared to the proportion of oocytes from heifers on silage + conc. (86%). The percentage of fertilised oocytes that cleaved was higher from heifers on silage (94%; P < 0.01) compared with oocytes from heifers on hay (82%) or silage + conc. (86%). The proportion of embryos that developed to blastocyst was not different (P > 0.05) between groups of oocytes from heifers on silage + conc. (8%), silage (14%) or hay (15%). Heifers on silage produced numerically more blastocysts (silage: 19 from 14 heifers; silage + conc.: 8 from 14 heifers; hay: 12 from 14 heifers). These results suggest that dietary treatment used prior to oocyte recovery did not significantly influence the developmental competence of the oocytes in vitro.

Protecting the endometrium. Opposing the hyperplasia/malignancy potential of ERT

Many trials have examined the clinical and histologic effects of various hormone replacement therapy combinations with the objective of minimizing the incidence of hyperplasia and the potential for subsequent development of adenocarcinoma. Reviewing the results of these trials, it appears that high-dose, long-term progestogen therapy is effective in protecting the endometrium, with duration having a greater impact than dose. Among women given 0.625 mg conjugated equine estrogen (CEE), sequential regimens should include 5 or 10 mg medroxyprogesterone acetate (MPA) or 200 mg micronized progesterone for 12 days or more. Continuous combined regimens require 2.5-5 mg MPA. With women who are taking 1.25 mg CEE the data are less clear, but recommendations include administration with 10 mg MPA for 12-14 days or 5 mg MPA continuous combined therapy.

Pharmacokinetics of progesterone administered by the oral and parenteral routes

Progestogens, which include the natural hormone, progesterone, and synthetic steroid derivatives, are used to treat a variety of reproductive disorders. Since synthetic progestogens are often associated with undesirable side effects, improved formulations and modes of administration of progesterone have been sought. In order to find an optimal therapeutic agent, different progesterone formulations and routes of administration have been studied. This paper explains several methods of measuring progesterone levels and summarizes clinical data on the pharmacokinetic profiles of natural progesterone administered by the oral, intramuscular, vaginal, intranasal, percutaneous, sublingual and rectal routes.

Endometrial hyperplasia. Risks, recognition and the search for a safe hormone replacement regimen

Endometrial hyperplasia is an acknowledged risk of unopposed estrogen replacement therapy (ERT). Several categories of hyperplasia are now recognized, among which atypical complex hyperplasia is the most likely to progress to carcinoma. Adding a synthetic progestin or natural progesterone to estrogen therapy has been shown to decrease or eliminate the endometrial risk associated with ERT. However, the addition of synthetic progestins has been associated with uncomfortable side effects, reversal of some of the cardiovascular and metabolic benefits of estrogen, and unwanted bleeding. The use of natural micronized progesterone in lieu of synthetic progestins alleviates the former two drawbacks, while careful scheduling of estrogen and progesterone dosing can eliminate the latter. In Europe, where natural progesterone has been in use for some time, a cyclic combined regimen comprising estrogen and 100 mg micronized progesterone administered on days 1-25 has been shown to provide endometrial safety, absence of bleeding and a high rate of tolerability.

Progestogens in the treatment of secondary amenorrhea

Secondary amenorrhea is usually the primary purpose for which manufacturers of new progestogens seek FDA approval. Standards for safe and efficacious treatment of this condition have evolved throughout the past two decades. Studies have evaluated a variety of patient populations, corresponding with the several definitions of secondary amenorrhea that may be found in the literature. Ongoing research seeks to expand the indications for progestogen therapy to include hormone replacement in perimenopausal and postmenopausal women.

Effects of implants on daily gains of steers wintered on dormant native tallgrass prairie, subsequent performance, and carcass characteristics

Fall-weaned crossbred steer calves (n = 300; 184 +/- 2.9 kg) received either no implant (Control) or were implanted with Synovex-C (SC = 10 mg estradiol benzoate + 100 mg progesterone), Synovex-S (SS = 20 mg estradiol benzoate + 200 mg progesterone), or Revalor-G (RG = 8 mg estradiol-17beta + 40 mg trenbolone acetate) to determine the effects of implants on weight gain during winter grazing on dormant tallgrass prairie, subsequent grazing and finishing performance, and carcass characteristics. Steers grazed two dormant tallgrass prairie pastures from October 16, 1996, until March 29, 1997 (164 d), and received 1.36 kg/d of a 25% CP supplement that supplied 100 mg of monensin/steer. Following winter grazing, all steers were implanted with Ralgro (36 mg zeranol) and grazed a common tallgrass prairie pasture until July 17 (110 d). After summer grazing, all steers were implanted with Revalor-S (24 mg estradiol-17beta + 120 mg trenbolone acetate), and winter implant treatment groups were equally allotted to four feedlot pens. Steers were harvested November 17, 1997, after a 123-d finishing period. Daily gains during the winter grazing phase averaged .28, .32, .32, or .35 kg/d, respectively, for Control, SC, SS, or RG steers and were greater (P < .01) for implanted steers than for Controls. Summer daily gains were similar (1.05 +/- .016 kg/d; P > or = .61) for all treatment groups. Feedlot daily gains were also similar (1.67 +/- .034 kg/d; P > or = .21), with implanted steers weighing 14 kg more than Control steers (P = .05) at harvest, despite similar management during summer grazing and feedlot phases. Control steers tended (P = .06) to have lower yield grades. There were no differences (P = .99) in marbling between implanted and nonimplanted steers. Steers implanted during the wintering phase had increased skeletal and overall (P < .01) carcass maturities compared with nonimplanted steers, which resulted in more "B" and "C" maturity carcasses. Because carcass maturity score affects quality grade, the increased maturities of implanted steers resulted in a $9.04 decrease in carcass value/100 kg (P < .01) compared with Controls. The results of this study indicate that growth-promoting implants are efficacious for cattle wintered on dormant native range despite low daily gains. This increased weight is maintained through the summer grazing and feedlot phases; however, the benefit of the increased weight may be offset by decreased carcass quality grade and value due to increased carcass maturity.

Progesterone can block transmission of the estradiol-induced signal for luteinizing hormone surge generation during a specific period of time immediately after activation of the gonadotropin-releasing hormone surge-generating system

The preovulatory GnRH/LH surge in the ewe is stimulated by a rise in the circulating estradiol concentration that occurs in conjunction with preovulatory ovarian follicle development. In the presence of high levels of progesterone, such as during the luteal phase of the estrous/menstrual cycle, the stimulatory effects of elevated estradiol on GnRH/LH secretion are blocked. Recent work in the ewe has shown that a relatively short period of estradiol exposure can stimulate a GnRH/LH surge that begins after estrogenic support has been removed. This result suggests that surge generation is characterized by an estradiol-dependent period (during which the signal is read) and an estradiol-independent period (during which a cascade of neuronal events transmits the stimulatory signal to the GnRH neurosecretory system, which releases a surge of GnRH). In this series of studies, we addressed the hypothesis that progesterone can block transmission of the stimulatory estradiol signal after it has been read. Nine ovariectomized ewes were run through repeated artificial estrous cycles by sequential addition and removal of exogenous steroids. In study one, ewes received three treatments in a randomized cross-over design. Exposure to a follicular phase estradiol concentration for 10 h (positive control treatment) stimulated an LH surge in all ewes, as determined in hourly jugular blood samples. Maintenance of luteal phase progesterone concentrations throughout the artificial follicular phase (2 x CIDR-G devices, negative control) blocked the stimulatory effects of a 10-h estradiol signal, and no ewes that received this treatment expressed an LH surge. In the experimental group, exposure to luteal phase levels of progesterone, during the period after the surge generating system had been activated by estradiol, blocked the LH surge in six of nine ewes. This result demonstrates that progesterone can block the surge, even when applied after the surge-generating system has been activated and, therefore, that it inhibits either the transmission of the estradiol signal and/or the release of the GnRH/LH surge. In study 2, we assessed whether sensitivity to the inhibitory effects of progesterone was confined to a specific stage of the transmission of the estradiol signal. Eight ewes were exposed to four treatments, over successive artificial estrous cycles. Positive and negative controls were similar to those described in Study 1, except the duration of the stimulatory estradiol signal was reduced to 8 h. The two experimental groups consisted of an EARLY P (progesterone) treatment, in which progesterone was given from hours 8-13 after estradiol insertion (immediately after estradiol removal), and a LATE P treatment, in which progesterone was given from hours 13-18 (immediately before LH surge secretion). As expected, LH surges were stimulated and blocked, in response to the positive and negative controls, respectively. Whereas the EARLY P treatment blocked the LH surge in seven of eight ewes, the LATE P treatment was only successful in inhibiting a surge in one of eight animals. This result demonstrates that progesterone can block the estradiol-induced surge-generating signal soon after the onset of signal transmission (immediately after estradiol removal) but not during the later stages of signal transmission (at the time of GnRH/LH surge onset).

[Therapeutic and prophylactic effect of LH-release in cattle]

In this study, LH release in response to the GnRH agonist buserelin and during treatment with a progesterone-releasing intravaginal device (PRID) was studied. A dose of 20 micrograms buserelin induced a more pronounced LH release than 4, 8, 40 and 80 micrograms. After injection of buserelin, pituitary response to a second buserelin injection was markedly reduced for at least 24 hours. Repeated buserelin injections at an interval of several hours therefore cannot be recommended. LH release was markedly suppressed by treatment with PRID. Two PRID tended to be more effective than one. After PRID removal, LH release increased significantly.

Progesterone has rapid and membrane effects in the facilitation of female mouse sexual behavior

Ovariectomized (ovx) mice require both estradiol (E2) and progesterone (P) administration to reinstate feminine sexual behavior (lordosis). The importance of P's actions at E2-induced intracellular progestin receptors (PRs) to facilitate lordosis was investigated in PR knockout (PRKO) mice, PRKO's wild type littermates (C57X129), and wild type C57BL/6J (C57) mice. Subjects were ovx, E2-primed (0.5 microg) and tested following intravenous (i. v.) and intercereberal P. Intravenous P (200 microg) significantly increased lordosis of all mice within 10 min of P, but vehicle infusion did not (Experiment 1). Intravenous P significantly increased the amount and duration and reduced the latency of lordosis, over that seen with vehicle infusion, in PRKO and wild type mice. Whole brain concentrations of P and its 5alpha-reduced metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), which has low affinity for intracellular PRs, were also increased following P compared to vehicle infusion. Progesterone, but not vehicle infusions, significantly increased the number of PR-immunoreactive (PR-IR) cells in the ventromedial hypothalamus (VMH) of C57 and C57X129 mice and increased number of 3alpha, 5alpha-THP-immunoreactive (3alpha,5alpha-THP-IR) cells in the ventral tegmental area (VTA) of all mice. In Experiment 2, P conjugated to bovine serum albumin (P:BSA) increased lordosis when applied bilaterally to both the VMH and VTA of E2-primed mice more than BSA implants. Progesterone implants increased the number of PR-IR cells in the VMH of C57 and C57X129 mice and the number of 3alpha,5alpha-THP-IR cells in the VTA of all mice. The rapid facilitation of lordosis with i.v. P infusion and increases in lordosis when P's effects are relegated to the membrane in the VMH and VTA of PRKO and wild type mice suggest that P may facilitate lordosis through actions at substrates other than intracellular PRs. The present findings suggest a role of 3alpha,5alpha-THP.

A new clinical option for hormone replacement therapy in women with secondary amenorrhea: effects of cyclic administration of progesterone from the sustained-release vaginal gel Crinone (4% and 8%) on endometrial morphologic features and withdrawal bleeding

OBJECTIVE

The objective of this study was to evaluate the safety and efficacy of 2 doses of a transvaginal polycarbophil-based progesterone gel (4% and 8%) in hormone replacement therapy.

STUDY DESIGN

This multicenter, randomized, parallel-group, open-label 3-month study included 127 women with secondary amenorrhea. Estrogenized patients applied transvaginal progesterone (4% or 8%) every other day for 6 doses per month. Efficacy was based on endometrial biopsy findings and withdrawal bleeding. McNemar's test was used to compare incidence of adverse events before and during treatment.

RESULTS

Progestational changes were found in 92% (Crinone 4%) and 100% (Crinone 8%) of patients with evaluable biopsies. Withdrawal bleeding was experienced by 81% (Crinone 4%) and 82% (Crinone 8%) of the patients. No patient experienced any serious side effect related to treatment. The incidence of most side effects, including psychologic symptoms, decreased with progesterone treatment compared with estrogen alone therapy. Compliance exceeded 98% for both doses.

CONCLUSIONS

Crinone is a novel, effective, and well-tolerated option for hormone replacement therapy in women with secondary amenorrhea.

Influence of age and postmenopausal estrogen replacement therapy on carotid arterial stiffness in women

OBJECTIVE

This study examines the influence of age and current estrogen replacement therapy (ERT) on common carotid arterial (CCA) stiffness in women.

METHODS

The subjects comprised 172 women (age 55.6 +/- 16.4 years) from the Baltimore Longitudinal Study of Aging, including 37 current postmenopausal ERT users. The ERT users included 18 women taking estrogen alone and 19 women taking estrogen and progesterone. Bilateral CCA were examined by B-mode carotid ultrasonography, and the stiffness index was defined as the logarithm of the ratio of systolic to diastolic blood pressure (BP) divided by the fractional diameter increase during the cardiac cycle.

RESULTS

The stiffness index increased linearly with age (r = 0.69, p < 0.001), and was lower in ERT users than in postmenopausal nonusers (8.0 +/- 2.0 vs 9.7 +/- 3.1, p < 0.01). Furthermore, the effects of age (beta = 0.67, p < 0.0001) and ERT (beta = -0.23, p < 0.001) on the stiffness index persisted after adjustments for systolic BP (beta = 0.23, p < 0.01), diastolic BP (beta = -0.26, p < 0.001) and other cardiovascular risk factors (model r2 = 0.59, p < 0.0001). The stiffness index was similar in both ERT users with and without progesterone and lower than in postmenopausal nonusers (p < 0.05) after considering the age effects.

CONCLUSION

Age-associated increases in CCA stiffness are reduced by postmenopausal ERT.

Response of Corriedale ewes to the "ram effect" after priming with medroxyprogesterone, fluorogestone, or progesterone in the non-breeding season

One hundred eighty-nine Corriedale ewes were used during the non-breeding season to study the "ram effect" stimulus after priming with progestogens. Intravaginal sponges containing either medroxyprogesterone acetate (MAP group, n = 49), fluorogestone acetate (FGA group, n = 49), or progesterone devices (CIDR group, n = 46) were inserted on Day-6 (Day 0 = introduction of the rams). Forty-five ewes were untreated and kept as a control group. On Day 0 the sponges were removed and rams provided with marking harnesses for oestrous detection were placed with the ewes. Onset of estrus was monitored until Day 25, and conception was determined by transrectal ultrasonography. Ewes came into heat during 4 periods: Days 0-3, 5-7, 17-20, and 21-23. The overall number of oestrus ewes were 29%, 53%, 35%, and 50% for the control, MAP, FGA, and CIDR groups, respectively (MAP and CIDR > control, p < 0.05). Control ewes presented oestrus only on Days 17-20 and 21-23. Oestrus in the progestogen-primed ewes was concentrated during Days 0-3 and 17-20, and some ewes came into oestrus on Days 5-7. There were no differences between different primings neither in oestrous response nor in conception rate. The conception rate from matings occurring on Days 0-3 was higher than on those occurring on Days 17-20. We conclude that MAP, FGA, and CIDR is equally effective in improving the response to the ram effect, and the pattern of oestrus in primed ewes was different than previously reported.

The application of microspheres from the copolymers of lactide and epsilon-caprolactone to the controlled release of steroids

The microspheres made of the copolymers of lactide and epsilon-caprolactone were used for the controlled release of progesterone and beta-estradiol. The copolymers contained 83-94% of l or d,l-lactide. The influence of the microstructure of lactidyl blocks in the copolymer chains on the drug release rate was studied. More uniform release rate was observed in the case of the copolymer derived from d,l-lactide as composed to l-lactide. For the copolymer containing 83-94% of d,l-lactide units the progesterone and beta-estradiol release rate in vitro was found to be practically constant within over 40 days. The in vivo studies performed on rats revealed that the period of constant release rate of beta-estradiol can be prolonged to about 70 days. The microspheres made of the applied poly-(d,l-lactide-co-epsilon-caprolactone) are the convenient system for long time release of steroids.

[Estrogen and progestin treatment in postmenopause. Effects on the endometrium]

BACKGROUND AND AIMS

It has been well demonstrated that menopausal disorders resulting from the lack of estrogens may be delayed and partly eliminated by appropriate hormone replacement therapy. The aim of this study was to demonstrate the absolute innocuity of the association of estrogen and progestin.

METHODS

The authors used an association of conjugated equine estrogens and medroxi-progesterone acetate to treat menopausal syndrome in 80 women aged between 48 and 55 years old. The study lasted 2 years.

RESULTS AND CONCLUSIONS

The results obtained showed the good tolerability and marked efficacy of the drugs used, as well as the absolute innocuity in relation to the target organs, namely the breast and endometrium. No cases of endometrial hyperplasia with atypical development or malignant evolution were reported during the study and there was a significant improvement in lipid metabolism, vasomotor or psychomotive disorders, as well as increased trophism of the genitourinary tract and skeleton.

Effect of the British warning on contraceptive use in the General Medical Service in Ireland

In October 1995 the UK Committee of Safety of Medicine (CSM) issued a warning about the safety (thromboembolic disease) of the third generation oral contraceptive steroids (OCS) recommending a switch to older agents except where women were intolerant of first and second generation OCS. Advice by the Irish regulatory authority (Irish Medicines Board) did not recommend such a switch. This pill scare lead to some UK users stopping OCS mid-cycle and a rise subsequently in abortions and pregnancies was noted. To determine whether local or UK advice was followed we obtained data from the General Medical Service (GMS) Scheme on the use of contraceptive steroids prescribed before and after the CSM's warning. The results show a clear shift from usage of the third generation OCS to the second generation OCS and norgestimate-containing OCS. We have also noted a marked fall in the overall use of the combined OCS, a trend that was noted in the U.K. It is clear that prescribers and pill users were influenced more by advice from the UK than by Irish regulatory authority. There is now a centralised European mechanism to licence drugs in the European Union (EU). We need to develop an EU perspective to issues of drug safety, as constituent nations are no longer isolated islands.

Matrix metalloproteinase expression in Macaca mulatta endometrium: evidence for zone-specific regulatory tissue gradients

Matrix metalloproteinases (MMPs) are highly expressed in the human endometrium during menstruation, and these enzymes participate in the cyclic destruction and regeneration characteristic of the primate endometrium. To examine hormonal regulation of MMPs in vivo, we evaluated MMP expression and localization in the endometrium of ovariectomized rhesus macaques under various hormonal conditions. Although all MMPs were up-regulated by progesterone (P4) withdrawal, their expression declined spontaneously after menstruation in the absence of P4. Of 7 MMPs examined, only matrilysin and stromelysin-3 were suppressed any further when P4 levels were experimentally re-elevated. MMP expression was confined to the upper functionalis zone during menstruation, but after menstrual breakdown was complete, matrilysin and the tissue inhibitor of MMPs, TIMP-1, shifted expression from the functionalis to the basalis zone in the absence of both estradiol and P4. The spiral arteries in the functionalis, but not the basalis, were intense foci of MMP and TIMP-1 expression. Menstruation and MMP expression after P4 withdrawal were similar in both the presence and absence of estradiol. In sum, endometrial MMPs in vivo are strongly up-regulated by P4 withdrawal, but zone-specific tissue gradients greatly influence the pattern and degree of MMP expression.

Noradrenergic neurotoxin suppresses gonadotropin-releasing hormone (GnRH) and GnRH receptor gene expression in ovariectomized and steroid-treated rats

The present study was designed to investigate whether noradrenergic neurotransmission regulates the gene expression of gonadotropin-releasing hormone (GnRH) in the preoptic area and GnRH receptor in the pituitary. To this end, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4, 50 mg/kg), an intraperitoneal (i.p.) injection of selective noradrenergic neurotoxin, was administered 1 h before progesterone (1 mg) treatment in ovariectomized and estradiol-treated prepubertal rats. Treatment with DSP4 effectively blocked the progesterone-induced increase in hypothalamic noradrenaline content, but not dopamine content, indicating that DSP4 selectively inhibits noradrenergic neurotransmission. DSP4 significantly blocked progesterone-induced increase in serum luteinizing hormone (LH) concentrations as well as GnRH release from hypothalamic fragments incubated in vitro. DSP4 concomitantly down-regulated GnRH mRNA levels in the preoptic area, as determined by competitive reverse transcription-polymerase chain reaction. DSP4 also clearly down-regulated progesterone-induced GnRH receptor mRNA levels in the pituitary, whereas it failed to alter LHbeta mRNA levels. In summary, blockade of noradrenergic neurotransmission with DSP4 resulted in profound reductions of hypothalamic GnRH and pituitary GnRH receptor gene expression.

[Contraception after heart transplantation]

It was observed that fertility and menstrual function in heart-transplanted women, impaired before the operation, become normal with a new heart. The restoration of reproductive function is also confirmed by many cases of pregnancy in heart-transplant recipients, reported in the literature. Twenty-four cases were published worldwide up to 1997, out of which eighteen had a positive result. Also a case personally treated was successful. The outcome of a pregnancy after heart transplantation is, then, generally positive. Nevertheless, such a pregnancy involves important maternal and fetal risks. Thus, the gynecologist has to provide correct information about both such risks and the most suitable contraceptive methods, for these patients. Oral contraceptives are very effective and, in the new low-dose formulations, free from serious adverse effects. No adverse effects have been observed in our patient, who represents the only case, reported in the literature, in which an estroprogestinic contraception was utilized before a pregnancy. In conclusion, during an oral contraception or after a tubal sterilization, pregnancy is really unlikely to occur. Thus, when the couple either has completed the familial nucleus or does not desire offspring, a doubt is at least justified as to whether these safer methods of contraception are advisable in such women.

Preparation of endometrium for egg donation

Nowadays oocyte donation is a well established method of assisted reproduction and offers the unique opportunity to treat patients with various clinical indications, with or without ovarian function, in a novel way. In women with ovarian failure, artificial menstrual cycles are required before proceeding to oocyte donation. Oestrogen may be delivered in the form of oral tablets, transdermal patches in order to bypass the gastrointestinal tract thus avoiding first pass metabolism and by vaginal application. Our regimen is oestradiol valerate given in various concentrations, in order to mimic the regular cyclic fluctuations throughout the cycle. Progesterone may be administered in the form of oral tablets, intravaginal suppositories or rings and i.m. injections. Our results, as of most other groups, strongly support the vaginal route of progesterone administration. In women with retained ovarian function, synchronization of donor-recipient cycle presents a special problem, as there is strong evidence that a temporal window of maximal endometrial receptivity exists. Cryopreservation of donated embryos may be used to overcome the problem, but this approach has the important drawback of embryonic loss occurring after freezing and thawing. The method of choice is the administration of gonadotrophin-releasing hormone agonists (GnRHa) to render the patients functionally agonadal in order to circumvent cycle asynchrony between the donor and recipient.