Exogenous sex steroids regulate genital epithelial barrier function in female rhesus macaques.

There is concern that using depot-medroxyprogesterone acetate (DMPA) for pregnancy prevention heightens HIV susceptibility. While no clinical data establishes causal link between HIV acquisition and use of this injectable progestin, prior work from our laboratory showed that DMPA comparably lowers genital levels of the cell-cell adhesion molecule desmoglein-1 (DSG1) and weakens genital epithelial barrier function in female mice and women. We likewise saw DMPA increase mouse susceptibility to multiple genital pathogens including HIV. Herein, we sought to confirm and extend these findings by comparing genital epithelial barrier function in untreated rhesus macaques (RM) vs. RM treated with DMPA or DMPA and estrogen (E). Compared to controls, genital tissue from RM with pharmacologically relevant serum levels of medroxyprogesterone acetate displayed significantly lower DSG1 levels and greater permeability to low molecular mass molecules. Conversely, DMPA-mediated effects on genital epithelial integrity and function were obviated in RM administered DMPA and E. These data corroborate the diminished genital epithelial barrier function observed in women initiating DMPA and identify RM as a useful preclinical model for defining effects of exogenous sex steroids on genital pathogen susceptibility. As treatment with E averted DMPA-mediated loss of genital epithelial barrier function, our results also imply that contraceptives releasing progestin and E may be less likely to promote transmission of HIV and other sexually transmitted pathogens than progestin-only compounds.

Homologous ELISA for measurement of medroxyprogesterone acetate in serum.

In order to develop ELISA for medroxyprogesterone acetate, medroxyprogesterone acetate-3-carboxymethyloxime (MPA-3-CMO) was coupled to bovine serum albumin (BSA) for immunogen preparation and to horseradish peroxidase (HRP) for enzyme conjugate preparation by N-hydroxysuccinimide mediated carbodiimide reaction. The immunogen was used to raise the antiserum in New Zealand white rabbit. The immunoreactivity of MPA-3-CMO-BSA-antibody and MPA-3-CMO-HRP enzyme conjugate was checked by checkerboard assay. The MPA-3-CMO-HRP enzyme conjugate and MPA-3-CMO-BSA-antibody were used for further development, standardization and validation of the assay. Sensitivity, ED50 and affinity of the assay were found to be 0.114 ng/mL, 2.75 ng/mL and 9.9 × 10⁻8 L/mol respectively. The % cross-reaction of analogous steroids with MPA-3-CMO-BSA-antibody was less than 0.025%. The recovery of the exogenously spiked MPA serum pools were in the range of 96.83-105.47%. The intra- and inter-assay coefficients of variation was less than 7.02%. The correlation coefficient of the serum level of MPA measured by the developed assay with the commercially available kit was found to be 0.95 (n = 37). This developed ELISA was further validated by measuring serum level of MPA in rat after administering them different doses of MPA intramuscularly.

Simultaneous TLC-densitometric determination of tamoxifen citrate and medroxyprogesterone acetate and UV-degradation kinetic study of medroxyprogesterone acetate.

Coadministration of tamoxifen citrate (TMC) and medroxyprogesterone acetate (MPA) is preferred to increase the response rate and the percentage recovery in patients with endometrial carcinoma. Administration of TMC and MPA and their combination affects estrogen and progestin receptor concentrations in advanced endometrium carcinoma by affecting 17ß-hydroxyl steroid dehydrogenase activity and serum hormone concentrations. A sensitive, accurate and robust thin-layer chromatography method has been established for simultaneous analysis of TMC and MPA. Method development was carried out on silica gel F254 using butanol-acetic acid-water (6:0.5:0.5, v/v/v) as mobile phase. Densitometric scanning was carried out at 241 nm for simultaneous detection of TMC and MPA. Retardation factor (Rf ) values for TMC and MPA were 0.21 and 0.85, respectively. The method was validated according to ICH guidelines. Regression plots revealed linear relationships in the concentration range of 50-500 and 25-250 ng/band for TMC and MPA, successively. Accuracy was ≥99.60 and 98.72% for TMC and MPA, respectively. Forced degradation studies using UV photodegradation was applied on MPA after exposure to UV light for different times and applying a kinetic study for calculating the degradation rate constant (k) and half-life time (t1/2 ).

A phase II study of medroxyprogesterone acetate in patients with hormone receptor negative metastatic breast cancer: translational breast cancer research consortium trial 007.

Preclinical data suggest that medroxyprogesterone acetate (MPA) has both anti-metastatic and anti-angiogenic activity in the absence of hormone receptors (HR). This phase II trial assessed the activity of MPA alone or in combination with low-dose chemotherapy in patients with metastatic HR-negative breast cancer. Postmenopausal women with HR-negative disease were eligible if they had not received more than 3 chemotherapy regimens for metastatic disease. All patients were treated with MPA 1,000-1,500 mg/day orally; patients in cohort two also received low-dose oral cyclophosphamide and methotrexate (ldCM, 50 mg/day and 2.5 mg twice daily on Days 1 and 2 each week). Tissue and circulating biomarkers were assessed serially. The primary endpoint was clinical benefit response defined as objective response or stable disease >6 months. Thirty patients were enrolled (14 MPA monotherapy; 16 MPA + ldCM); median age was 55 (35-80); nearly all had visceral involvement. Despite dose escalation in 90 % of patients, only 17 (57 %) patients ever achieved MPA trough concentrations >50 ng/ml. One patient developed grade 4 renal failure in the setting of rapid disease progression and dehydration. There were no objective responses. One patient in each cohort (~7 %) had stable disease for > 6 months. Skin Nm23 expression increased after 4 weeks of MPA + ldCM, but there were no significant changes in TSP-1, PAI-1 antigen, or PAI-1 activity. MPA had limited activity and does not warrant further development in patients with HR-negative advanced breast cancer. Poor bioavailability limited exposure despite dose escalation.

Depot medroxyprogesterone acetate concentrations in patients with and without the use of antiseizure medications.

OBJECTIVES: To measure plasma concentrations of medroxyprogesterone acetate (MPA) in users with epilepsy treated with antiseizure medications and compare these to MPA concentrations in those without epilepsy. STUDY DESIGN: For this multisite cross-sectional study, we obtained a single blood sample from those with epilepsy treated with various antiseizure medications (n = 18) within the week before their next depot medroxyprogesterone injection. Among the participants without epilepsy (n = 20), 10 similarly were scheduled within the week prior to the next injection, and 10 were scheduled at earlier intervals to attempt to balance the time intervals between groups. MPA concentrations were determined by a validated assay. RESULTS: MPA concentrations were similar among those with epilepsy and controls and between groups with and without the use of enzyme-inducing medications. The lowest MPA concentrations, under 0.07 ng/mL, were observed among two of eight using enzyme-inducing antiseizure medications, one of 10 using noninducing medications, and one of 19 controls had concentrations below 0.2 ng/mL. CONCLUSIONS: In this exploratory study, lower MPA concentrations in some participants using enzyme-inducing antiseizure medications suggest a potential interaction that could reduce depot medroxyprogesterone efficacy.

Endometrial histopathology, ovarian changes and bleeding patterns among users of long-acting progestin-only contraceptives in Egypt.

OBJECTIVE: To evaluate endometrial and ovarian effects, and bleeding patterns, among users of Depo-Provera(®), Norplant(®), and Implanon(®). STUDY DESIGN: One-hundred and fifty women, who had been using one of these long-acting progestin-only contraceptives (LAPCs) for at least the previous six months, with fifty in each of the groups, were assessed. RESULTS: All results are mentioned in the following sequence: (1) Depo-Provera(®), (2) Norplant(®), and (3) Implanon(®). Normal bleeding was reported by 0%, 52%, and 8%; amenorrhoea or infrequent bleeding by 68%, 24%, and 72%; and abnormal bleeding by 32%, 24%, and 20%, respectively (p < 0.001). Histological evaluation revealed an atrophic endometrium in 84%, 32%, and 28%, respectively (p < 0.0001); a progestin effect in 16%, 28%, and 62%, respectively (p < 0.0001), and a proliferative pattern in 0%, 40%, and 10%, respectively (p < 0.0001). Endometrial thickness was 3 ± 0.41 mm, 3.62 ± 0.65 mm, and 5.2 ± 0.84 mm, respectively (p < 0.0001). Follicular growth in the ovaries was observed at ultrasound in 12%, 40%, and 72%, respectively (p < 0.001). CONCLUSION: Bleeding patterns, endometrial thickness, ovarian activity, and endometrial histology among Egyptian users of LAPCs differed significantly depending on the nature of the contraceptive.

The effect of depot medroxyprogesterone acetate on tenofovir alafenamide in rhesus macaques.

Prevention of HIV infection and unintended pregnancies are public health priorities. In sub-Saharan Africa, where HIV prevalence is highest, depot medroxyprogesterone acetate (DMPA) is widely used as contraception. Therefore, understanding potential interactions between DMPA and antiretrovirals is critical. Here, we use a macaque model to investigate the effect of DMPA on the pharmacology of the antiretroviral tenofovir alafenamide (TAF). Female rhesus macaques received 30 mg of DMPA (n = 9) or were untreated (n = 9). Macaques received a human equivalent dose of TAF (1.5 mg/kg) orally by gavage. Tenofovir (TFV) and TFV-diphosphate (TFV-DP) were measured in blood, secretions, and tissues over 72 h. The median area under the curve (AUC0-72h) values for TFV-DP in peripheral blood mononuclear cells were similar in DMPA-treated (6991 fmol*h/106 cells) and untreated controls (5256 fmol*h/106 cells) (P = 0.174). Rectal tissue TFV-DP concentrations from DMPA+ animals [median: 20.23 fmol/mg of tissue (range: 4.94-107.95)] were higher than the DMPA- group [median: below the limit of quantification (BLOQ-11.92)], (P = 0.019). TFV-DP was not detectable in vaginal tissue from either group. A high-dose DMPA treatment in macaques was associated with increased rectal TFV-DP levels, indicating a potential tissue-specific drug-drug interaction. The lack of detectable TFV-DP in the vaginal tissue warrants further investigation of PrEP efficacy with single-agent TAF products. DMPA did not affect systemic TAF metabolism, with similar PBMC TFV-DP in both groups, suggesting that DMPA use should not alter the antiviral activity of TAF.

HIV risk associated with serum medroxyprogesterone acetate levels among women in East and southern Africa.

BACKGROUND: Some observational studies have found increased HIV risk associated with self-reported use of injectable depot medroxyprogesterone acetate. Testing blood samples for medroxyprogesterone acetate (MPA), the progestin in depot medroxyprogesterone acetate, permits validation of self-reported data, and exploration of whether potential HIV risk is correlated with MPA levels, which are highest soon after injection. METHODS: We conducted a case-control study testing archived serum from women who participated in three longitudinal studies of HIV prevention in East and southern Africa. Case samples, from women who acquired HIV, were from visits that occurred at or immediately prior to the first evidence of HIV infection. Secondary analyses restricted to case samples collected within 15 and 30 days of the estimated date of HIV infection. Matched control samples were from women who remained HIV uninfected. We used multivariable conditional logistic regression to compare exogenous hormone levels, quantified through mass spectrometry, among cases and controls. RESULTS: When restricted to cases with samples collected within 15 days or less of estimated date of HIV infection, MPA detection was more frequent among women who acquired HIV (adjusted odds ratio = 2.75, 95% confidence interval 1.22-6.19). In this subset, the increase in HIV risk was only among samples with MPA detected at a low level of 0.02-0.50 ng/ml: 36.7% of cases and 9.4% of controls, adjusted odds ratio = 6.03, 95% confidence interval 2.50-14.54. CONCLUSION: Detection of MPA at low levels close to the estimated time of HIV acquisition was significantly more frequent among women who acquired HIV. Studies are needed that explore biological mechanisms elicited by any MPA level and HIV risk.

Discordance between self-reported contraceptive use and detection of exogenous hormones among Malawian women enrolling in a randomized clinical trial.

OBJECTIVE: The objective was to assess the extent of concordance between self-reported contraceptive use and the presence of contraceptive progestins in serum. STUDY DESIGN: We evaluated self-reported contraceptive use by using radioimmunoassay to examine baseline serum levels of medroxyprogesterone acetate (MPA) and levonorgestrel (LNG) among 97 Malawian women enrolling in a contraceptive trial. RESULTS: Twelve percent (12/97) of study participants who reported no hormonal contraceptive use in the previous 6months had either MPA or LNG detected in their serum. CONCLUSIONS: The observed discordance between self-report and detection of exogenous hormones in serum indicates that caution is warranted when drawing conclusions based on self-reported contraceptive use.

Progestins initiate a luminal to myoepithelial switch in estrogen-dependent human breast tumors without altering growth.

Although long-term clinical use of progestins is associated with an increased incidence of breast cancers, their role in established cancers is unclear. Estrogens are considered to be the main mitogens in the majority of breast cancers. Whether progesterone affects proliferation and/or differentiation is under debate. To assess the role of progesterone in established breast cancers, we used T47D human breast cancer cells that are estrogen receptor (ER) positive and either progesterone receptor (PR) negative or positive for PRA, PRB, or both. These cells were grown as strictly estrogen-dependent solid tumors in ovariectomized female nude mice. Progesterone or medroxyprogesterone acetate (MPA) alone did not support tumor growth, nor did progesterone or MPA given simultaneously with estrogen significantly alter estrogen-dependent tumor growth. However, treatment of mice bearing ER+PR+ but not ER+PR- tumors with either progesterone or MPA increased expression of the myoepithelial cytokeratins (CK) 5 and 6 in a subpopulation of tumor cells. These CK5+/CK6+ cells had decreased expression of luminal epithelial CK8, CK18, and CK19. We conclude that progestins exert differentiative effects on tumors characterized by transition of a cell subpopulation from luminal to myoepithelial. This may not be beneficial, however, because such a phenotype is associated with poor prognosis.

Allopregnanolone concentration and mood--a bimodal association in postmenopausal women treated with oral progesterone.

RATIONALE: Allopregnanolone effects on mood in postmenopausal women are unclear thus far. OBJECTIVES: Allopregnanolone is a neuroactive steroid with contradictory effects. Anaesthetic, sedative, and anxiolytic as well as aggressive and anxiogenic properties have been reported. The aim of this study is to compare severity of negative mood between women receiving different serum allopregnanolone concentrations during progesterone treatment. MATERIALS AND METHODS: A randomized, placebo-controlled, double-blind, crossover study of postmenopausal women (n=43) treated with 2 mg estradiol daily during four treatment cycles. Oral micronized progesterone at 30, 60, and 200 mg/day, and placebo were added sequentially to each cycle. Participants kept daily symptom ratings using a validated rating scale. Blood samples for progesterone and allopregnanolone analyses were collected during each treatment cycle. RESULTS: During progesterone treatment, women had significantly higher negative mood scores when allopregnanolone serum concentration was in the range of 1.5-2 nmol/l compared to lower and higher concentrations. In addition, women displayed a significant increase in negative mood during the progesterone treatment period, compared to the estradiol-only period when 30 mg progesterone daily was used. On the other hand, treatment with higher doses of progesterone had no influence on negative mood. CONCLUSIONS: Mood effects during progesterone treatment seem to be related to allopregnanolone concentration, and a bimodal association between allopregnanolone and adverse mood is evident.

Medroxyprogesterone acetate levels among Kenyan women using depot medroxyprogesterone acetate in the FEM-PrEP trial.

OBJECTIVE: To describe medroxyprogesterone acetate (MPA) levels among Kenyan depot medroxyprogesterone acetate (DMPA) users in the FEM-PrEP HIV prevention trial, and to compare MPA levels between ARV for HIV prevention (treatment) and placebo groups. STUDY DESIGN: We measured MPA in previously collected plasma samples from 63 Kenyan trial participants who used DMPA for one or two complete intervals. We separately assessed MPA levels among the nine DMPA users who became pregnant at this site. RESULTS: Mean MPA levels at the end of each 12week injection interval were 0.37ng/ml (95% CI: 0.25, 1.99) and 0.28ng/ml (95% CI: 0.19, 1.22) among participants assigned TDF/FTC and 0.49 (95% CI: 0.40, 1.27) and 0.39 (95% CI: 0.31, 1.17) among those assigned placebo. The difference between groups was not statistically significant overall, or in an analysis which adjusted for the observed low adherence to TDF/FTC. Unanticipated findings of this analysis were low 12-week MPA levels among DMPA users in both study arms. Of 61 women who contributed data for the first DMPA injection interval, 26.2% had MPA levels<0.1ng/ml and 9.8% had levels below the detection level (0.02ng/ml) at 12weeks post-injection. Levels were similar at the end of the second injection interval. Five of nine women who became pregnant had levels below 0.15ng/mL at the time of their last negative pregnancy test. CONCLUSIONS: Use of TDF/FTC did not appear to affect serum MPA levels, however we found lower than expected MPA concentrations at the end of the dosing interval among DMPA users in the FEM-PrEP trial, the cause of which are unknown. IMPLICATIONS: This study presents some of the few available data on MPA levels among DMPA users in Africa. The low levels among users described here, together with a number of pregnancies among DMPA users, are potentially concerning and require further investigation.

Oral medroxyprogesterone acetate in the treatment of advanced or recurrent endometrial carcinoma: a dose-response study by the Gynecologic Oncology Group.

PURPOSE: Progestins have definite activity against advanced or recurrent endometrial carcinoma. Both parenteral and oral progestins yield similar serum levels and response rates, which range from 18% to 34%. The one major study that used oral medroxyprogesterone acetate (MPA) noted a response rate at the lower end of the range (18%) and much poorer progression-free and overall survival times (4 and 10.5 months, respectively) than previously reported. The present study sought to confirm this earlier study of oral MPA, to assess the importance of prognostic factors such as histologic grade and receptor levels, and to determine whether a higher dose of MPA would yield a higher response rate. PATIENTS AND METHODS: Two hundred ninety-nine eligible women with advanced or recurrent endometrial carcinoma were randomized to receive oral MPA either 200 mg/d or 1, 000 mg/d until unacceptable toxicity intervened or their disease progressed. RESULTS: Among 145 patients receiving the low-dose regimen, there were 25 complete (17%) and 11 partial (8%) responses for an overall response rate of 25%. The 154 patients receiving the high-dose regimen experienced 14 (9%) complete and 10 (6%) partial responses for an overall response rate of 15%. Median durations of progression-free survival were 3.2 months and 2.5 months for the low-dose and high-dose regimens, respectively. Median survival durations were 11.1 months and 7.0 months, respectively. The adjusted relative odds of responding to the high-dose regimen compared with the low-dose regimen was 0.61 (90% confidence interval, 0.36 to 1.04). Prognostic factors having a significant impact on the probability of response included initial performance status, age, histologic grade, and progesterone receptor concentration. Compliance with oral therapy was documented with serum levels 1 month after starting therapy, when possible. MPA levels were commensurate with the assigned dose and schedule. CONCLUSION: Oral MPA is active against endometrial carcinoma. Response to progestin therapy is more frequent among patients with a well-differentiated histology and positive progesterone receptor status. This study provides no evidence to support the use of MPA 1,000 mg/d orally instead of MPA 200 mg/d orally. In fact, the trends suggest the opposite. The use of oral MPA 200 mg/d is a reasonable initial approach to the treatment of advanced or recurrent endometrial carcinoma, particularly those lesions that are well-differentiated and/or progesterone receptor-positive (> 50 fmol/mg cytosol protein). Patients with poorly differentiated and/or progesterone receptor levels less than 50 fmol/mg cytosol protein had only an 8% to 9% response rate.

High-performance liquid chromatography-tandem mass spectrometry validation of medroxyprogesterone acetate in products of pork origin and serum.

Different extraction and purification methods are described here to determine medroxyprogesterone acetate (MPA) in pork meat and serum. Spiked samples are investigated over the concentration range of MPA 0.5-20 ng/g. Pork meat tissues are subjected to extraction using organic solvent, and pork serum is simply diluted with acetate buffer. Clean-up is performed using solid-phase extraction on a C18 cartridge, and MPA is eluted with ethanol. Aliquots are injected into a high-performance liquid chromatography-mass spectrometry system. MPA content is determined on the basis of m/z 387-327 and 387-123 transitions.

Estrogen increases endothelial nitric oxide synthase via estrogen receptors in rat cerebral blood vessels: effect preserved after concurrent treatment with medroxyprogesterone acetate or progesterone.

BACKGROUND AND PURPOSE: In vivo and in vitro rat models of hormone therapy were used to test the following hypotheses: (1) estrogen acts directly on cerebrovascular estrogen receptors to increase endothelial nitric oxide synthase (eNOS); (2) increased protein correlates with higher NOS activity; and (3) effects of estrogen on eNOS are altered by concurrent treatment with either medroxyprogesterone acetate (MPA) or progesterone. METHODS: Blood vessels were isolated from brains of ovariectomized female rats; some were treated for 1 month with estrogen, estrogen and progesterone, or estrogen and MPA. Isolated cerebral vessels were also treated in vitro with estrogen in the absence and presence of progesterone, MPA, tamoxifen, and the estrogen receptor antagonist ICI 182 780. Levels of eNOS were measured by Western blot, and NOS activity was measured by [14C]arginine-[14C]citrulline conversion. RESULTS: Chronic hormone treatment in vivo resulted in plasma levels of 17beta-estradiol, progesterone, and MPA in the range of values found in humans. Estrogen treatment resulted in higher levels of cerebrovascular NOS activity that paralleled increases in eNOS protein. In vitro estrogen treatment for 18 hours also resulted in a concentration-dependent increase in eNOS protein (EC50 approximately 300 pmol/L) that was completely prevented by estrogen receptor antagonists tamoxifen or ICI 182 780. However, cotreatment with progesterone or MPA, either in vivo or in vitro, did not alter the effect of estrogen on eNOS protein. CONCLUSIONS: Estrogen receptor activation in cerebrovascular tissue results in increased eNOS activity and protein levels. The latter effect persists in the presence of either progesterone or MPA. Thus, increased NO production by eNOS may contribute to the neuroprotective effects of estrogen.

Predictive value of serum medroxyprogesterone acetate concentration for response in advanced or recurrent breast cancer.

Medroxyprogesterone acetate (MPA) is one of the most commonly prescribed drugs for endocrine therapy of metastatic breast cancer. In this study, the serum MPA concentration was measured by high-performance liquid chromatography (HPLC) and evaluated for its usefulness in predicting the response in 79 cases of advanced or recurrent breast cancers. Overall, 29 patients (37%) achieved an objective response. The response rate correlated significantly with the oestrogen receptor (ER) status (P = 0.03), proliferative activity determined by DNA polymerase alpha (P = 0.04), the disease-free interval (DFI) (P = 0.05) and the serum MPA concentration (P < 0.001). Patients with ER-positive tumours, lower proliferative activity, a longer (DFI) or a higher serum MPA concentration responded more frequently. The mean serum MPA concentration in the responders with ER-positive tumours (P = 0.01) or tumours with a lower proliferative activity (P = 0.008) were significantly lower than in cases with ER-negative tumours or tumours with a higher proliferative activity, respectively. Cases with soft tissue metastases showed responses at significantly lower MPA concentrations (P = 0.003) than those with bone or visceral metastases. Furthermore, there was a dramatic decrease in the MPA concentration when a responder with a high concentration became unresponsive to the therapy. Thus, the serum MPA concentration is a determining factor for the response to treatment.

Effects of two progestin-only contraceptives, Depo-Provera and Norplant-II, on the vaginal epithelium of rhesus monkeys.

The objective of this study was to determine whether progestin-only contraceptives induce thinning of the vaginal epithelium in nonhuman primates. Eight intact rhesus monkeys (four per group) were treated with either a single intramuscular injection of 30 mg of Depo-Provera or a subcutaneous insertion of Norplant-II (2 x 75 mg rods; day 0). Norplant-II rods were removed 90 days after insertion. Vaginal biopsies were obtained during a pretreatment menstrual cycle and following treatment on days 10, 30, 60, 118, and 146. Formalin-fixed vaginal biopsies were evaluated for epithelial thickness and the degree of keratinization. The circulating levels of estradiol, progesterone, medroxyprogesterone acetate (MPA), or levonorgestrel (LNG) were monitored throughout the study by specific radioimmunoassays. Circulating levels of estradiol and progesterone confirmed the stage of the menstrual cycle in which pretreatment biopsies were obtained. Following treatment with Depo-Provera, serum levels of MPA increased to 2.3 +/- 0.6 ng/ml (x +/- SE, n = 4) within 24 hr. Serum levels of MPA were maximal on day 14 (5.5 +/- 0.9 ng/ml), dropped below 1 ng/ml by day 50, and were nondetectable by day 70. Circulating levels of LNG were elevated 24 hr after insertion of Norplant-II (5.8 +/- 3.0 ng/ml), peaked on day 2 (7.6 +/- 4.2 ng/ml), remained between 1.4 and 6.2 ng/ml from days 14 to 90, and were nondetectable by day 118, the first serum sample after removal of Norplant-II. There were no significant differences (p > 0.05) in the epithelial thickness (microm), number of epithelial cell layers, or type of epithelium present in vaginal biopsies obtained during the follicular or luteal phases of the pretreatment menstrual cycle. Conversely, a pronounced effect of progestin treatment was observed on the vaginal epithelium. There were no significant differences (p > 0.05) between the two progestin treatment groups, but a significant effect (p < 0.05) over time was observed (two-way ANOVA). Compared with pretreatment menstrual cycle controls, the vaginal epithelial thickness was decreased (p < 0.05) by day 30 or 60 following Norplant-II insertion or Depo-Provera injection, respectively. The number of epithelial cell layers was also decreased (p < 0.05) on days 30 and/or 60 in progestin-treated monkeys compared with pretreatment control cycles. Following removal of Norplant-II or metabolic excretion of MPA, the vaginal epithellium regenerated and the thickness was no longer different (p > 0.05) from the pretreatment control cycle. These data demonstrate that progestin-only contraceptives induced thinning of the vaginal epithelium in rhesus monkeys, and this effect was rapidly reversible following physical or metabolic removal of the progestin.

Hormone replacement therapy for oxidative stress in postmenopausal women with hot flushes.

OBJECTIVE: To assess the association of hot flushes during postmenopause with oxidative stress and to determine whether hormone replacement therapy (HRT) affects the plasma redox status of postmenopausal women. METHODS: We conducted a prospective clinical study of 49 postmenopausal women who have (n = 29) or do not have (n = 20) hot flushes. Twelve of the postmenopausal women with hot flushes and six without were treated with HRT (estradiol patches and medroxyprogesterone acetate) for 4 months. Plasma level of estradiol, total antioxidant status, reduced sulfhydryl groups, lipoperoxides, total cholesterol, and triglycerides were measured at 4-month intervals in both groups, before and after treatment. RESULTS: Postmenopausal women who have hot flushes, had lower total basal antioxidant status in plasma (.9 +/-.01 compared with 1.14 +/-.01 mmol/L), lower concentration of reduced sulfhydryl groups (145 +/- 4 compared with 200 +/- 3 micromol/L), and higher concentration of lipoperoxides (2.88 +/-.04 compared with 2.61 +/-.04 micromol/L) than women without hot flushes. After HRT, total antioxidant status and reduced sulfhydryl groups increased, and lipoperoxides decreased similarly in both groups. Hormone replacement therapy decreased the frequency of hot flushes per day from 11.2 +/- 0.8 to 1.4 +/- 0.3. CONCLUSION: Hot flushes in postmenopausal women were associated with the oxidative process. Hormone replacement therapy decreases oxidative stress and the number of episodes of hot flushes. Because oxidative stress is associated with a high risk for cardiovascular diseases, HRT might protect women with hot flushes.

Pharmacokinetic study of low- versus high-dose medroxyprogesterone acetate (MPA) in women.

The present study was conducted to compare the pharmacokinetics (PK) of low-dose versus high-dose medroxyprogesterone (MPA) as a once-daily oral administration. Of 32 patients, all women, enrolled in this PK study, 18 received 600 mg MPA daily and 14 received 1200 mg daily. Detailed PK data were obtained on day 1 and after more than 4 weeks of MPA treatment. In addition, multiple data for the minimum steady-state concentration (Css min) were analyzed. The MPA serum concentrations were measured by high-performance liquid chromatography. Wide interpatient variability was found in the PK parameters obtained both on day 1 and after more than 4 weeks. There were no clear relationships between the oral dose and the MPA peak concentration (Cmax), area under the time versus concentration curve (AUC), or mean Css min. Weight gains of 10% or more were demonstrated more frequently in the high-dose group (P < 0.01). Liver dysfunction (n = 5) did not influence the PK of MPA. Five patients demonstrated extremely low AUC and Cmax (< 10 ng/ml) values on day 1. Phenobarbital, dexamethasone and betamethasone were being taken concomitantly with the MPA each by one patient. The serum MPA concentrations were markedly increased after the discontinuation of phenobarbital in that patient, suggesting a drug interaction. At present we cannot recommend the high dose of MPA, except in clinical studies, from a PK or a pharmacodynamic points of view.

Effect of short-term hormone replacement therapy on left ventricular mass and contractile function.

OBJECTIVE: To determine the effect of hormone replacement therapy (HRT) on cardiac structure and function and whether these changes are related to changes in blood volume. DESIGN: Open-label pilot study. SETTING: Academic medical center. PATIENT(S): Eighteen healthy postmenopausal women. INTERVENTION(S): We administered medroxyprogesterone acetate orally, 5 mg/d for 2 months followed by 2 months of oral sequential 17beta-estradiol, 1 mg/d plus medroxyprogesterone acetate, 10 mg/d for the last 12 days of each month. MAIN OUTCOME MEASURE(S): Cardiac output, stroke volume, heart rate, end diastolic volume, end systolic volume, ejection fraction, and left ventricular mass were measured by echocardiography; blood and plasma volumes were measured using 125I-albumin dilution. RESULT(S): Cardiac output, stroke volume, left ventricular mass, end diastolic volume, and ejection fraction increased by 12.8%, 11.7%, 9.4%, 7.2%, and 10.9%, respectively, by 16 weeks. End systolic volume decreased, whereas heart rate was unaffected. There was a significant increase in blood volume (5.2%) and plasma volume (4.8%) from baseline during treatment, which could explain the increased cardiac output but not the increased ejection fraction. CONCLUSION(S): Hormone replacement therapy causes modest but significant increases in cardiac output, ejection fraction, and left ventricular mass. These pilot data suggest a direct myocardial effect of HRT that is preload independent.