Contraceptive applications of estrogen

Chronic exposure to gestodene impairs reproductive system in adult female zebrafish (Daniarerio)

Gestodene (GES) is widely used in human therapy and animal husbandry and is frequently detected in aquatic environments. Although GES adversely affects aquatic organisms at trace levels, its effects on the reproductive biology of fish remain inconclusive. In this study, female zebrafish (Danio rerio) were exposed to environmentally relevant levels of GES for the evaluation of the effects of GES on the reproductive system by using endpoints including gene expression, plasma steroid concentrations, histological and morphological analyses, copulatory behavior, and reproductive output. Adult female zebrafish exposed to environmentally relevant concentrations of GES (4.0, 40.2, and 372.7 ng/L) for 60 d demonstrated stagnant ovarian oocyte development, evidenced by an increase in the percentage of perinuclear and atretic oocytes and a decrease in the percentage of late vitellogenic oocytes. GES-exposed females were less attractive to males and had lower copulatory intimacy than females in control. Consequently, spawning (44.3-49.2 %) and egg fertilization rates (27.9-32.0 %) were decreased. The decreased survival of fertilized eggs and hatching rates were accompanied by increased malformations. These negative effects were associated with abnormal transcriptional levels of gonadal steroid hormones, which were regulated by genes (Hsd17β3, Hsd11β2, Hsd20β, Cyp19a1a, and Cyp11b). Overall, our findings suggest that GES impairs the reproductive system of zebrafish, which may threaten population stability.

The reproductive inhibitory effects of levonorgestrel, quinestrol, and EP-1 in Brandt's vole (Lasiopodomys brandtii)

Background

Rodent pests can inflict devastating impacts on agriculture and the environment, leading to significant economic damage associated with their high species diversity, reproductive rates and adaptability. Fertility control methods could indirectly control rodent pest populations as well as limit ecological consequences and environmental concerns caused by lethal chemical poisons. Brandt’s voles, which are common rodent pests found in the grasslands of middle-eastern Inner Mongolia, eastern regions of Mongolia, and some regions of southern Russia, were assessed in the present study.

Methods

We evaluated the effects of a 2-mg/kg dose of levonorgestrel and quinestrol and a 1:1 mixture of the two (EP-1) on reproductive behavior as well as changes in the reproductive system, reproductive hormone levels, and toxicity in Brandt’s voles.

Results

Our results revealed that all three fertility control agents can cause reproductive inhibition at a dosage of 2 mg/kg. However, quinestrol caused a greater degree of toxicity, as determined by visible liver damage and reduced expression of the detoxifying molecule CYP1A2. Of the remaining two fertility control agents, EP-1 was superior to levonorgestrel in inhibiting the secretion of follicle-stimulating hormone and causing reproductive inhibition. We believe that these findings could help promote the use of these fertility control agents and, in turn, reduce the use of chemical poisons and limit their detrimental ecological and environmental impacts.

Cortisol effects on fear memory reconsolidation in women

RATIONALE

Previous work from our group has shown that cortisol enhances fear reconsolidation in men. Whether similar effects can be observed in women remains an open question.

OBJECTIVES

The effects of cortisol on the reconsolidation of fear memories were investigated in women. Based on results in men, we expected a specific enhancing effect of cortisol administration on the reactivated fear memory. In addition, possible interactions with oral contraceptive use were tested.

METHODS

We incorporated a differential fear conditioning paradigm in a 3-day reconsolidation design. A fear memory, which was created on the first day, was reactivated on the second day following cortisol administration in the target group. One control group was given cortisol without reactivation, and the other participated in the reactivation session following placebo intake. On the third day, the return of fear for all stimuli following reinstatement was tested. Skin conductance response served as measure of conditioned response.

RESULTS

In contrast to the hypothesis, cortisol in combination with reactivation did not enhance fear reconsolidation. No differences between the three experimental groups were apparent. In addition, hormonal contraceptive use had no effect on any of the learning phases and did not interact with the cortisol manipulation.

CONCLUSIONS

The lack of an effect in women might be the result of alternating concentrations of sex hormones during different phases of the menstrual cycle or following oral contraceptive use. Considering the higher vulnerability of women to stress-related mental disorders, further investigations in women are of great importance for both theory and treatment.

Permeation measurement of gestodene for some biodegradable materials using Franz diffusion cells

Biodegradable poly(d,l-lactide) (PDLLA), Poly(trimethylene carbonate) (PTMC), polycaprolactone (PCL), poly(caprolactone-co-d,l-lactide) (PCDLLA) and poly(trimethylene carbonate-co-caprolactone) (PTCL) are recently used for clinical drug delivery system such as subcutaneous contraceptive implant capsule due to their biodegradable properties that they could possess long-term stable performance in vivo without removal, however their permeation rate is unknown. In the work, biodegradable material membranes were prepared by solvent evaporation using chloroform, and commercial silicone rubber membrane served as a control. Gestodene was used as a model drug. Gestodene has high biologic progestational activity which allows for high contraceptive reliability at very low-dose levels. The permeation rate of gestodene for several biodegradable materials was evaluated. In vitro diffusion studies were done using Franz diffusion cells with a diffusion area of 1.33 cm². Phosphate buffer solution (PBS, pH 7.4), 10% methanol solution and distilled water were taken in donor and receiver chambers at temperature of 37 °C respectively. The in vitro experiments were conducted over a period of 24 h during which samples were collected at regular intervals. The withdrawn samples were appropriately diluted and measured on UV–vis spectrophotometer at 247 nm. Conclusion data from our study showed that permeation rate of PCDLLA with CL ratio more than 70% could be more excellent than commercial silicone rubber membrane. They may be suitable as a candidate carrier for gestodene subcutaneous contraceptive implants in contraceptive fields.

Combined effects of levonorgestrel and quinestrol on reproductive hormone levels and receptor expression in females of the Mongolian gerbil (Meriones unguiculatus)

The effects of treatment with a combination of levonorgestrel and quinestrol (EP-1; ratio of 2:1) on reproductive hormone levels and the expression of their receptors in female Mongolian gerbils were examined. We show that serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) decreased, whereas serum estradiol (E2) and progesterone (P4) increased after EP-1 treatment. EP1 down-regulated mRNA expression of the follicle-stimulating hormone receptor (FSHR) and the estrogen receptor (ER) βin the ovary. EP-1 up-regulated the mRNA expression of the luteinizing hormone receptor (LHR) and the progesterone receptor (PR) in the ovary as well as ERα and PR in the uterus of Mongolian gerbils. The effects were time-dependent and dose-dependent. EP-1 had no obvious effects on ERα mRNA expression in the ovary. The current study demonstrates that the effect of EP-1 on the expression of ER subtypes is tissue-specific in Mongolian gerbils. EP-1 disrupted the reproductive endocrinology of the Mongolian gerbil. These findings suggest that the effects of EP-1 on reproductive hormone levels and their receptor expression in Mongolian gerbils may be the result of synergistic actions of levonorgestrel and quinestrol, with quinestrol playing the major role.

Symptom-specific associations between low cortisol responses and functional somatic symptoms: the TRAILS study

BACKGROUND

Functional somatic symptoms (FSS), like chronic pain and overtiredness, are often assumed to be stress-related. Altered levels of the stress hormone cortisol could explain the association between stress and somatic complaints. We hypothesized that low cortisol levels after awakening and low cortisol levels during stress are differentially associated with specific FSS.

METHODS

This study is performed in a subsample of TRAILS (Tracking Adolescents' Individual Lives Survey) consisting of 715 adolescents (mean age: 16.1 years, SD=0.6, 51.3% girls). Adolescents' cortisol levels after awakening and during a social stress task were assessed. The area under the curve with respect to the ground (AUCg) and the area under the curve above the baseline (AUCab) were calculated for these cortisol levels. FSS were measured using the Youth Self-Report and pain questions. Based upon a factor analysis, FSS were divided into two clusters, one consisting of headache and gastrointestinal symptoms and the other consisting of overtiredness, dizziness and musculoskeletal pain.

RESULTS

Regression analyses revealed that the cluster of headache and gastrointestinal symptoms was associated with a low AUCg of cortisol levels during stress (β=-.09, p=.03) and the cluster of overtiredness, dizziness and musculoskeletal pain with a low AUCg of cortisol levels after awakening (β=-.15, p=.008). All these analyses were adjusted for the potential confounders smoking, physical activity level, depression, corticosteroid use, oral contraceptive use, gender, body mass index and, if applicable, awakening time.

CONCLUSION

Two clusters of FSS are differentially associated with the stress hormone cortisol.

Adolescents' cortisol responses to awakening and social stress; effects of gender, menstrual phase and oral contraceptives. The TRAILS study

Studies on the influence of sex hormones on cortisol responses to awakening and stress have mainly been conducted in adults, while reports on adolescents are scarce. We studied the effects of gender, menstrual cycle phase and oral contraceptive (OC) use on cortisol responses in a large sample of adolescents. Data come from TRAILS (TRacking Adolescents' Individual Lives Survey), a prospective population study of Dutch adolescents. This study uses data of 644 adolescents (age 15-17 years, 54.7% boys) who participated in a laboratory session including a performance-related social stress task (public speaking and mental arithmetic). Free cortisol levels were assessed by multiple saliva samples, both after awakening and during the laboratory session. No significant effects of gender and menstrual phase on cortisol responses to awakening were found, while girls using OC displayed a slightly blunted response (F(1, 244)=5.30, p=.02). Cortisol responses to social stress were different for boys and free-cycling girls (F(3, 494)=9.73, p<.001), and OC users and free-cycling girls (F(3, 279)=15.12, p<.001). Unexpectedly, OC users showed no response at all but displayed linearly decreasing levels F(1, 279)=19.03, p<.001) of cortisol during the social stress test. We found no effect of menstrual cycle phase on cortisol responses to social stress (F(3, 157)=0.58, p=.55). The absence of a gender difference in the adolescents' cortisol awakening response found in this study is consistent with previous reports. Our results further suggest that adolescent OC users display slightly blunted cortisol responses after awakening, and that gender differences in cortisol responses to social stress during adolescence are comparable to those described for adult populations, that is, stronger responses in men than in women. Whereas previous work in adults suggested blunted stress responses in OC users compared to men and free-cycling women, adolescent OC users showed no cortisol response. Effects of type of OC could not be studied because of low numbers of OC that were only progestin based.

Oral contraceptive and IUD use and endometrial cancer: a population-based case-control study in Shanghai, China

Oral contraceptive (OC) and intrauterine device (IUD) use have been shown to be protective factors for endometrial cancer in several epidemiological studies; however, few studies have been conducted in Chinese populations. We evaluated the association between OC and IUD use and endometrial cancer risk in a population-based case-control study among Chinese women in Shanghai, China. The study included 1,204 newly diagnosed endometrial cancer cases and 1,212 age frequency-matched healthy controls. Logistic regression models were used to estimate adjusted odds ratios (OR) and their 95% confidence intervals (95% CI). In our study population, 18.5% cases and 24.9% controls reported having ever used OCs with an OR of 0.75 (95% CI, 0.60-0.93), after adjusting for known risk or protective factors for endometrial cancer. The risk of endometrial cancer decreased with long-term use of OCs with the OR for more than 72 months of use being 0.50 (95% CI, 0.30-0.85). The effect of OC use remained 25 or more years after cessation of use; the associated OR was 0.57 (95% CI = 0.42-0.78) as compared to nonusers. Similarly, fewer cases than controls had ever used IUD, with the multivariable adjusted OR being 0.53 (95% CI = 0.43-0.65). A reduction in risk was observed regardless the duration of use or age at first and last use. These results suggest that OC and IUD use may confer long-term protection against endometrial cancer.

The impact of antiepileptic drug therapy on steroidal contraceptive efficacy

Women with epilepsy face unique challenges in maintaining steroidal contraceptive efficacy because some antiepileptic drugs (AEDs) increase the rate of hepatic metabolism of contraceptive steroids, leading to higher potential for contraceptive failure in this population. Planned pregnancy is of great clinical and social importance for women with epilepsy because of the increased risk of birth defects from fetal exposure to AEDs. Current clinical guidelines for contraceptive management in women with epilepsy provide misleading information by focusing on the estrogen content of the formulation, which regulates the menstrual cycle, rather than on the progestin content of the formulation, which provides contraceptive efficacy. This article reviews studies of AED-contraceptive interaction and misconceptions about maintaining contraceptive efficacy and makes recommendations for contraceptive management in women with epilepsy who receive concomitant AED therapy.

Metal complex SERMs (selective oestrogen receptor modulators). The influence of different metal units on breast cancer cell antiproliferative effects

The selective oestrogen receptor modulator tamoxifen is a leading agent in the adjuvant treatment of breast cancer. Several organometallic moieties have been vectorised with tamoxifen, in order to improve on the latter's antiproliferative properties by the addition of a potentially cytotoxic moiety, and have been evaluated versus both oestrogen receptor positive (MCF7) and oestrogen receptor negative (MDA-MB231) breast cancer cells. For tamoxifen analogues with ((R,R)-trans-1,2-diaminocyclohexane)platinum(II), cyclopentadienyl rhenium tricarbonyl, and ruthenocene tethers, there was no enhancement of the antiproliferative effect on oestrogen receptor positive cells, nor any cytotoxic effect on oestrogen receptor negative cells, while those containing cyclopentadienyl titanium dichloride showed an oestrogenic effect. However, compounds where ferrocene replaces tamoxifen's phenyl ring were strongly cytotoxic against both cell lines. The synthesis and biological results of these compounds is reviewed and placed in the historic context of inorganic compounds in therapy.

Cortisol and memory retrieval in women: influence of menstrual cycle and oral contraceptives

RATIONALE

Studies in rodents observed that the effects of stress on memory are modulated by gonadal hormones. In animals and humans, stress and cortisol treatment impairs memory retrieval.

OBJECTIVES

To investigate if the acute impairing effect of cortisol on memory retrieval in women is influenced by endogenous or exogenous gonadal steroids.

METHODS

Three groups of women were studied: women during mensis (n=13), women in the luteal phase (n=14), and women using oral contraceptives (OCs; n=20). In a double-blind crossover fashion, they received cortisol (30 mg) or placebo 1 h prior to memory retrieval testing.

RESULTS

Overall cortisol led to a significant impairment of memory retrieval. Further exploratory analysis using t tests showed that both groups of naturally cycling women were significantly impaired (p<0.05), while no effect was apparent in the OC users (p=0.29).

CONCLUSIONS

The current results could suggest that OC use is associated with a reduced sensitivity of the brain to acute cortisol elevations. In contrast, menstrual-cycle-associated changes in estradiol and progesterone concentrations appear to have no strong influence on this acute cortisol effect. The underlying neurobiological mechanisms of these behavioral findings remain to be elucidated.

Estrogen: physiology, pharmacology, and formulations for replacement therapy

Estrogen is the central component in 6 of the 100 most widely prescribed medications in the United States today. This steroid has several therapeutic uses including contraceptive applications, treatment of menopausal symptoms, and the prevention of osteoporosis. A wide variety of estrogen replacement therapy (ERT) and estrogen plus progestational hormonal replacement therapy (HRT) preparations are available. In addition, there are an increasing number of products with estrogenic properties that are being promoted as alternatives to drugs containing estrogen, such as phytoestrogens and selective estrogen receptor modifiers (SERMs). This article reviews the physiology of estrogenic effects, estrogen metabolism, and the pharmacokinetics of marketed preparations.