Intracrinology and menopause: the science describing the cell-specific intracellular formation of estrogens and androgens from DHEA and their strictly local action and inactivation in peripheral tissues.

The secretion of estrogens by the ovaries stops at menopause. Afterward, dehydroepiandrosterone (DHEA) becomes the only source of both estrogens and androgens during all the postmenopausal years. To maintain very low and biologically inactive concentrations of estrogens and androgens in the circulation, DHEA is transformed intracellularly into cell-specific small amounts of estrogens and androgens (except in the endometrium) which then act and are inactivated locally in the same cells, thus avoiding biologically significant systemic exposure to active sex steroids. The secretion of DHEA, however, mainly of adrenal origin, has already decreased by an average of 60% at the time of menopause and it continues to decrease thereafter with a parallel lowering in available intracellular estrogens and androgens. Consequently, after the arrest of estrogen secretion by the ovaries, the loss of DHEA becomes practically responsible for the symptoms and signs of menopause. Replacing what is missing, namely DHEA, at the right place, at the right time, and in the right amount, seems to be the logical and physiological approach for the treatment of menopausal symptoms and signs, as recently demonstrated for pain at sexual activity (dyspareunia), the most bothersome symptom of vulvovaginal atrophy due to menopause.

Androgen Receptor Targeted Treatments of Prostate Cancer: 35 Years of Progress with Antiandrogens.

PURPOSE: Antiandrogens inhibit the androgen receptor and have an important role in the treatment of prostate cancer. This review provides a historical perspective on the development and clinical benefit of antiandrogens in the treatment of prostate cancer. MATERIALS AND METHODS: We searched PubMed® for clinical trials with the search terms antiandrogens and prostate cancer combined with drug names for antiandrogens. This article represents a collaboration of clinical investigators who have made critical scientific contributions leading to the approval of antiandrogens for treating patients with prostate cancer. RESULTS: Antiandrogens differ in chemical structure and exert varying efficacy and safety profiles. The unfavorable therapeutic index of steroidal antiandrogens led to replacement by safer nonsteroidal agents. Flutamide, nilutamide and bicalutamide, which were designed to target the androgen receptor, were developed primarily for use in combination with castration to provide combined androgen blockade. Modest clinical benefits were observed with the combination of first generation antiandrogens and castration vs castration alone. With increased knowledge of androgen receptor structure and its biological functions a new generation of antiandrogens without agonist activity was designed to provide more potent inhibition of the androgen receptor. Randomized clinical trials in patients with metastatic, castration resistant prostate cancer showed significant survival benefits, which led to the approval of enzalutamide in August 2012. Apalutamide was recently approved while darolutamide is not yet approved in the United States. These next generation antiandrogens are being actively tested in earlier disease states such as nonmetastatic prostate cancer. Evolving knowledge of resistance mechanisms to androgen receptor targeted treatments will stimulate research and drug discovery for additional compounds. Further testing in nonmetastatic castration resistant prostate cancer as well as castration sensitive disease states will hopefully augment our ability to treat a broader spectrum of patients with prostate cancer. CONCLUSIONS: Antiandrogens have already provided important benefits for prostate cancer treatment. Greater knowledge about the structural and functional biology of the androgen receptor in prostate cancer will facilitate further discovery and development of further improved antiandrogens with enhanced clinical activity in patients with advanced metastatic disease. Testing these new agents earlier in the course of prostate cancer may further improve the survival and quality of life of patients with current local and/or systemic treatment modalities.

Increased body fat mass explains the positive association between circulating estradiol and insulin resistance in postmenopausal women.

The relationship between circulating estrogen levels and cardiometabolic risk factors such as insulin resistance is unclear in postmenopausal women. High estradiol (E2) levels have been reported to predict increased risk of type 2 diabetes in this population. We aimed to examine associations among estrogen levels, adiposity measurements, and cardiometabolic risk variables including insulin resistance in postmenopausal women. One hundred-one healthy participants (mean ± SD: age 57 ± 4 yr, BMI 27.9 ± 4.8 kg/m2) were included in the analysis. Fifteen plasma steroids or metabolites were measured by liquid chromatography-tandem mass spectrometry. Insulin sensitivity was assessed with a hyperinsulinemic-euglycemic clamp. Body composition and fat distribution were determined with hydrostatic weighing and computed tomography, respectively. Blood lipids and circulating cytokines were also measured. Circulating E2 was positively correlated with all adiposity indexes ( r = 0.62 to 0.42, P < 0.0001) except waist-to-hip ratio. E2 was positively correlated with VLDL-cholesterol, plasma-, VLDL-, and HDL-triglyceride levels ( r = 0.31 to 0.24, P < 0.02) as well as with hs-CRP and IL-6 ( r = 0.52 and 0.29, P < 0.005) and negatively with HDL-cholesterol, adiponectin, and insulin sensitivity ( r = -0.36 to -0.20, P < 0.02). With adjustments for percent body fat, correlations between E2 and metabolic risk variables were no longer significant. Similar results were observed for circulating estrone (E1) and estrone-sulfate (E1-S) levels. In conclusion, circulating estrogen concentrations are proportional to adipose mass in postmenopausal women, although they remain in the low range. Insulin resistance as well as altered blood lipids and cytokines are observed when circulating estrogen levels are high within that range, but these differences are explained by concomitant variation in total adiposity.

The effect of androgen excess on maternal metabolism, placental function and fetal growth in obese dams.

Pregnant women with polycystic ovary syndrome (PCOS) are often overweight or obese. To study the effects of maternal androgen excess in obese dams on metabolism, placental function and fetal growth, female C57Bl6J mice were fed a control (CD) or a high fat/high sucrose (HF/HS) diet for 4-10 weeks, and then mated. On gestational day (GD) 15.5-17.5, dams were injected with dihydrotestosterone (CD-DHT, HF/HS-DHT) or a vehicle (CD-Veh, HF/HS-Veh). HF/HS dams had higher fat content, both before mating and on GD18.5, with no difference in glucose homeostasis, whereas the insulin sensitivity was higher in DHT-exposed dams. Compared to the CD groups, the livers from HF/HS dams weighed more on GD18.5, the triglyceride content was higher, and there was a dysregulation of liver enzymes related to lipogenesis and higher mRNA expression of Fitm1. Fetuses from HF/HS-Veh dams had lower liver triglyceride content and mRNA expression of Srebf1c. Maternal DHT exposure, regardless of diet, decreased fetal liver Pparg mRNA expression and increased placental androgen receptor protein expression. Maternal diet-induced obesity, together with androgen excess, affects maternal and fetal liver function as demonstrated by increased triglyceride content and dysfunctional expression of enzymes and transcription factors involved in de novo lipogenesis and fat storage.

Impact of sample extraction on the accurate measurement of progesterone in human serum by liquid chromatography tandem mass spectrometry.

In the present study, the impact of the extraction solvent on the accuracy of endogenous progesterone assay in human serum has been investigated using two selective reaction monitoring (SRM) transitions (315>97 & 315>109). Higher levels of noise and more interference were observed when more polar solvents were used for extraction, thus resulting in serious bias of the measured values of progesterone in serum. This is confirmed by monitoring the ion ratio of 315>97-315>109. This issue could not be easily resolved by changes in MS/MS transitions or chromatography conditions. More bias was observed with the SRM transition 315>109 for the polar solvent extraction. Hexane and 1-chlorobutane (polarity index of 0 and 1, respectively) did provide the cleanest samples with a lower noise level in the chromatograms. Moreover, the measured values of progesterone were not changed with different SRM transitions or longer retention time in search of an improved separation. Recovery tests of progesterone have been performed with 1-chlorobutane in matrices with phosphate buffered saline (PBS) 1x, PBS 1×3% bovine serum albumin (BSA), stripped serum/H2O (1:1) and unstripped serum. The recovery (70%∼80%) consistency is observed not only at different levels but also in different matrices. The equivalent recovery between PBS 1x, PBS 1×3% BSA and unstripped serum shows that the impact of progesterone binding to serum proteins on the measurement accuracy can be avoided with this sample preparation procedure. No significant matrix effect on the determination of progesterone was observed with 1-chlorobutane. Within the range of 12.5-2000pg/mL, a good linearity is observed with R>0.99 and weighting factor 1/X. Bias and covariance efficiency of QCs are within 10%. With 1-chlorobutane as the extraction solvent, the concentration of progesterone was measured where the range for postmenopausal serum is 5.74∼91.7pg/mL, which is well below the reported concentrations of 314 pg/mL∼942pg/mL in postmenopausal serum by immunoassay-based techniques, while the range in premenopausal serum is 12.8 pg/mL∼18.6ng/mL.

Comparison of intravaginal 6.5mg (0.50%) prasterone, 0.3mg conjugated estrogens and 10µg estradiol on symptoms of vulvovaginal atrophy.

The objective is to compare the effect of intravaginal dehydroepiandrosterone (DHEA, prasterone), conjugated equine estrogens (CEE) and estradiol (E2) on moderate to severe dyspareunia and/or vaginal dryness. In a review of available data, independent prospective, randomized, double-blind and placebo-controlled Phase III 12-week clinical trials involved daily administration of 6.5mg (0.50%) prasterone, daily (21days on/7days off) 0.3mg CEE, twice weekly 0.3mg CEE or 10µg E2 daily for 2 weeks followed by twice weekly for 10 weeks. Vulvovaginal atrophy (VVA) symptoms were evaluated by questionnaires. The total severity score of dyspareunia decreased from baseline by 1.27 to 1.63 units with prasterone treatment, 1.4 with CEE and 1.23 in one statistically significant study with E2 (combined symptoms). Decreases over placebo ranged from 0.35 to 1.21 with prasterone, 0.7 to 1.0 with CEE and 0.33 for the E2 study. The total decreases in vaginal dryness severity ranged from 1.44 to 1.58 units for prasterone, 1.1 unit for CEE and 1.23 unit for E2. The decreases over placebo of vaginal dryness intensity ranged from 0.30 to 0.43 unit for prasterone, 0.40 unit for CEE and 0.33 for the E2 study with combined symptoms. Daily 6.5mg (0.50%) prasterone appears to be at least as efficacious as 0.3mg CEE or 10µg E2 for treatment of the VVA symptoms. In summary, the beneficial effects on the VVA symptomatology can be obtained by the addition of a small amount of intravaginal prasterone to compensate for the low serum concentration of prasterone observed in the majority of women after menopause without concerns about systemic effects.

Androgens in women are essentially made from DHEA in each peripheral tissue according to intracrinology.

The objective is to review how the cell-specific amounts of intracellular androgens are all made in women from circulating dehydroepiandrosterone (DHEA) in each peripheral tissue, independently from the rest of the body. Following 500 million years of evolution, approximately three dozen cell-specific intracrine enzymes have been engineered in human peripheral tissues whereby the inactive sex steroid precursor DHEA mainly of adrenal origin is transformed into the appropriate minute intracellular amounts of androgens. These intracellular androgens are inactivated in the same cells, with no biologically significant release of active androgens in the circulation. The best estimate is that approximately 50% as much androgens are synthesized in women, compared to men of the same age. The problem with DHEA, however, the exclusive source of androgens in women of all ages, is that DHEA secretion has already decreased by an average of 60% at time of menopause and continues to decrease thereafter. The human-specific and highly sophisticated mechanisms of intracrinology permit each cell to control androgen availability according to its own needs independently from the remaining of the body. Such a mechanism is completely different from classical endocrinology well understood in men where testosterone of testicular origin is transported through the blood and has indiscriminate access to the androgen receptor (AR) in all AR-containing cells of the body. In men, both the endocrine and intracrine mechanisms are in operation while, in women, only the intracrine mechanisms responsible for intracellular formation from DHEA provide androgens.

Science of intracrinology in postmenopausal women.

OBJECTIVE: To illustrate the marked differences between classical endocrinology that distributes hormones to all tissues of the body through the bloodstream and the science of intracrinology, whereby each cell of each peripheral tissue makes a small and appropriate amount of estrogens and androgens from the inactive precursor dehydroepiandrosterone (DHEA), DHEA being mainly of adrenal origin. Because only the inactivated sex steroids are released in the blood, influence in the other tissues is avoided. METHODS: Molecular biology has been used for the identification/characterization of the steroid-forming and steroid-inactivating enzymes, whereas steroids have been measured by mass spectrometry-based assays validated according to the US Food and Drug Administration guidelines. RESULTS: Evolution over 500 million years has engineered the expression of about 30 steroid-forming enzymes specific for each peripheral tissue. These tissue-specific enzymes transform DHEA into the appropriate small amounts of estrogens and androgens for a strictly intracellular and local action. Humans, contrary to species below primates, also possess intracellular steroid-inactivating enzymes, especially glucuronyl transferases and sulfotransferases, which inactivate the estrogens and androgens at their local site of formation, thus preventing the release of a biologically significant amount of estradiol (E2) and testosterone in the circulation. Since DHEA becomes the unique source of sex steroids after menopause, serum E2 and testosterone are thus maintained at low biologically inactive concentrations with no activity outside the cells of origin. DHEA secretion, unfortunately, starts decreasing at about the age of 30 at various rates in different women. Moreover, there is no feedback mechanism to increase DHEA secretion when the concentration of serum DHEA decreases. Considering this mechanism is unique to the human, it seems logical to replace DHEA locally in women suffering from vulvovaginal atrophy (genitourinary syndrome of menopause). The clinical data obtained using a small dose of intravaginal DHEA (prasterone) confirm the mechanisms of intracrinology mentioned above which avoid biologically significant changes in serum E2 and testosterone. CONCLUSIONS: The symptoms and signs of vulvovaginal atrophy (genitourinary syndrome of menopause) can be successfully treated by the intravaginal administration of DHEA without safety concerns. This strategy exclusively replaces in the vagina the missing cell-specific intracellular estrogens and androgens. This approach avoids systemic exposure and the potential risks of estrogen exposure for the tissues other than the vagina.

A low dose (6.5 mg) of intravaginal DHEA permits a strictly local action while maintaining all serum estrogens or androgens as well as their metabolites within normal values.

OBJECTIVE: Serum concentrations of estradiol (E2) and testosterone (testo) measured by mass spectrometry-based assays should remain below the 95th centile measured at 9.3 pg/mL for E2 and 0.26 ng/mL for testo in normal postmenopausal women in order to avoid the risk of non-physiological systemic exposure to elevated serum concentrations of these two sex steroids. METHODS: Serum E2 and testo, as well as dehydroepiandrosterone (DHEA) and nine of its other metabolites, were measured at 10 time intervals over 24 h on the first and seventh days of daily intravaginal administration of 0.50% (6.5 mg) DHEA by validated mass spectrometry-based assays. RESULTS: No biologically significant change in the individual serum concentrations of E2, testo or DHEA was observed. Most importantly, estrone sulfate (E1-S) and the glucuronidated androgen metabolites also remained within normal values, thus confirming the absence of biologically significant systemic exposure in line with intracrinology. Using data from the literature, comparison is made with serum E2 above normal postmenopausal values following administration of 10-µg E2 tablets. CONCLUSION: While the clinical program on vulvovaginal atrophy has shown the efficacy and safety of intravaginal 6.5 mg of DHEA (prasterone), the present data illustrate in detail the serum levels of the individual sex steroids and their metabolites derived from DHEA. The data obtained are in line with the physiology of intracrinology and confirm an action limited to the vagina as the serum concentrations of all sex steroids are maintained within the normal values of menopause, thus protecting the uterus and most likely other tissues.

Is vulvovaginal atrophy due to a lack of both estrogens and androgens?

OBJECTIVE: The aim of this study was to review the preclinical data showing the role of both estrogens and androgens in the physiology of the vagina, and, most likely, in vulvovaginal atrophy of menopause. METHODS: Mass spectrometry-based assays (validated according to the FDA guidelines) for the measurement of sex steroids, their precursors, and metabolites were used. In addition to fixation of the vagina for morphological examination, histomorphometry, immunocytochemistry, immunofluorescence, and quantitative reverse transcription polymerase chain reaction were performed. RESULTS: The vaginal epithelium of the animals receiving dehydroepiandrosterone (DHEA) was made of large multilayered columnar mucous cells showing distended cytoplasmic vacuoles representative of an androgenic effect. DHEA also stimulates collagen fiber compactness of the lamina propria (second layer)-an effect essentially due to an androgenic effect, whereas stimulation by DHEA of the muscularis in the third vaginal layer is approximately 70% due to the androgenic conversion of DHEA. Stimulation of the surface area of the nerve endings, on the contrary, is exclusively androgenic. Vaginal weight stimulation by DHEA is about 50% androgenic and 50% estrogenic. CONCLUSIONS: Practically all studies on the influence of steroid hormones in the vagina have focused on luminal epithelial cells. Since all estrogens and androgens in postmenopausal women are made intracellularly and derive from the conversion of circulating DHEA, it is of interest to observe from these preclinical data that DHEA exerts both estrogenic and androgenic activity in the three layers of the vagina, the stimulatory effect on nerve density being 100% androgenic. Taking vaginal weight as a global parameter, the stimulatory effect of DHEA in the rat vagina is about equally estrogenic and androgenic, thus illustrating the importance of androgens in vaginal morphology and function, and the likely importance of androgens in vulvovaginal atrophy of menopause.

Human 3α-hydroxysteroid dehydrogenase type 3: structural clues of 5α-DHT reverse binding and enzyme down-regulation decreasing MCF7 cell growth.

Human 3α-HSD3 (3α-hydroxysteroid dehydrogenase type 3) plays an essential role in the inactivation of the most potent androgen 5α-DHT (5α-dihydrotestosterone). The present study attempts to obtain the important structure of 3α-HSD3 in complex with 5α-DHT and to investigate the role of 3α-HSD3 in breast cancer cells. We report the crystal structure of human 3α-HSD3·NADP(+)·A-dione (5α-androstane-3,17-dione)/epi-ADT (epiandrosterone) complex, which was obtained by co-crystallization with 5α-DHT in the presence of NADP(+) Although 5α-DHT was introduced during the crystallization, oxidoreduction of 5α-DHT occurred. The locations of A-dione and epi-ADT were identified in the steroid-binding sites of two 3α-HSD3 molecules per crystal asymmetric unit. An overlay showed that A-dione and epi-ADT were oriented upside-down and flipped relative to each other, providing structural clues for 5α-DHT reverse binding in the enzyme with the generation of different products. Moreover, we report the crystal structure of the 3α-HSD3·NADP(+)·4-dione (4-androstene-3,17-dione) complex. When a specific siRNA (100 nM) was used to suppress 3α-HSD3 expression without interfering with 3α-HSD4, which shares a highly homologous active site, the 5α-DHT concentration increased, whereas MCF7 cell growth was suppressed. The present study provides structural clues for 5α-DHT reverse binding within 3α-HSD3, and demonstrates for the first time that down-regulation of 3α-HSD3 decreases MCF7 breast cancer cell growth.

Serum steroid concentrations remain within normal postmenopausal values in women receiving daily 6.5mg intravaginal prasterone for 12 weeks.

This study integrates all data obtained in women aged 40-80years enrolled with moderate to severe symptoms of vulvovaginal atrophy (VVA) who received daily intravaginal administration of 0.50% (6.5mg) dehydroepiandrosterone (DHEA; prasterone) for 12weeks (n=723; ITT-S population) as compared with placebo (n=266; ITT-S population). To this end, serum steroid levels (DHEA, DHEA-sulfate (DHEA-S), androst-5-ene-3ß, 17ß-diol (5-diol), testosterone, dihydrotestosterone (DHT), androstenedione (4-dione), estrone (E1), estradiol (E2), estrone sulfate (E1-S), androsterone glucuronide (ADT-G), and androstane-3α, 17ß-diol 17-glucuronide (3α-diol-17G)) were measured at Day 1 and Week 12 by liquid chromatography-tandem mass spectrometry (LC-MS/MS) following validation performed according to the FDA guidelines [1-6]. In agreement with the mechanisms of intracrinology where DHEA is exclusively transformed intracellularly into active sex steroids which act and are inactivated locally before being released as glucuronided or sulfated metabolites for elimination by the kidneys and liver, all sex steroids remained well within normal postmenopausal values following administration of intravaginal DHEA. Serum estradiol, the most relevant sex steroid, was measured after 12weeks of treatment at 3.36pg/ml (cITT-S population) or 19% below the normal postmenopausal value of 4.17pg/ml. On the other hand, serum E1-S, the best recognized marker of global estrogenic activity, shows an average value of 209pg/ml at 12 weeks compared to 220pg/ml in normal postmenopausal women. Moreover, serum ADT-G, the main metabolite of androgens, also remains well within normal postmenopausal values. The present data shows that a low daily intravaginal dose (6.5mg) of DHEA (prasterone) which is efficacious on the symptoms and signs of VVA, permits to achieve the desired local efficacy without systemic exposure, in agreement with the stringent mechanisms of menopause established after 500 million years of evolution where each cell in each tissue is the master of its sex steroid exposure.

Serum steroids remain within the same normal postmenopausal values during 12-month intravaginal 0.50% DHEA.

OBJECTIVE: Analyze the serum levels of DHEA (prasterone) and its metabolites after daily intravaginal 0.50% (6.5 mg) DHEA in postmenopausal women with vulvovaginal atrophy (VVA). METHODS: Serum samples were obtained at baseline and after 12, 26 and 52 weeks of treatment. The serum levels of DHEA, DHEA-sulfate (DHEA-S), androstene-3ß, 17ß-diol (5-diol), androstenedione (4-dione), testosterone, dihydrotestosterone (DHT), estrone (E1), estradiol (E2), E1-sulfate (E1-S), androsterone glucuronide (ADT-G) and androstane-3α,17ß-diol 17-glucuronide (3α-diol-17G) were measured by validated liquid chromatography-tandem mass spectrometry. RESULTS: A total of 435 women were exposed for 52 weeks. All serum steroids remained within normal values with no significant differences between lengths of treatment. For the most relevant estrogen-related compounds, namely E1, E2, and E1-S, a reliable marker of total estrogen exposure, the values in the DHEA-treated group at 52 weeks were -3.4%, -9.1% and +1.8%, respectively, compared to the normal postmenopausal values, thus clearly confirming the absence of significant systemic estrogen exposure. CONCLUSION: While confirming that all serum sex steroids originating exclusively from DHEA after menopause are maintained within the normal postmenopausal values, the present data show that the dose of intravaginal DHEA used is free from systemic exposure with no detectable change in metabolism up to 52 weeks of treatment.

Lack of effect of intravaginal dehydroepiandrosterone (DHEA, prasterone) on the endometrium in postmenopausal women.

OBJECTIVE: This study aims to evaluate the effects of intravaginal dehydroepiandrosterone (DHEA, prasterone) on the endometrium in postmenopausal women. METHODS: Intravaginal DHEA (6.5 mg) was administered daily for 52 weeks to 422 women who had endometrial biopsy at baseline and end of study, whereas 15 women were similarly treated for 26 to 52 weeks. Participants in three other studies received 3.25 mg (n = 126), 6.5 mg (n = 129), or 13 mg (n = 30) of DHEA for 12 weeks; women similarly had baseline and end-of-study biopsies. Endometrial biopsy samples were available for 668 women at baseline and end of study, with sufficient material for analysis. RESULTS: Endometrial atrophy or inactive endometrium (668 women) was found in all women treated with intravaginal DHEA. Similar atrophy was observed in 119 of 121 participants with sufficient material for analysis who received placebo. CONCLUSIONS: After cessation of estradiol secretion by the ovaries at menopause, the estrogens made by mechanisms of intracrinology are inactivated intracellularly at their site of formation and action, thus maintaining serum estradiol at biologically inactive concentrations to avoid stimulation of the endometrium. The absence of enzymes that are able to transform DHEA into estrogens in the endometrium explains the typical endometrial atrophy in all normal postmenopausal women in the presence of variable concentrations of circulating endogenous DHEA. According to these mechanisms, the inactive sex steroid precursor DHEA administered intravaginally acts exclusively in the vagina, whereas all serum sex steroids remain well within the biologically inactive postmenopausal reference range, thus avoiding any stimulation of the already atrophic endometrium.

Circulating gonadotropins and ovarian adiponectin system are modulated by acupuncture independently of sex steroid or ß-adrenergic action in a female hyperandrogenic rat model of polycystic ovary syndrome.

Acupuncture with combined manual and low-frequency electrical stimulation, or electroacupuncture (EA), reduces endocrine and reproductive dysfunction in women with polycystic ovary syndrome (PCOS), likely by modulating sympathetic nerve activity or sex steroid synthesis. To test this hypothesis, we induced PCOS in rats by prepubertal implantation of continuous-release letrozole pellets (200 µg/day) or vehicle. Six weeks later, rats were treated for 5-6 weeks with low-frequency EA 5 days/week, subcutaneous injection of 17ß-estradiol (2.0 µg) every fourth day, or a ß-adrenergic blocker (propranolol hydrochloride, 0.1 mg/kg) 5 days/week. Letrozole controls were handled without needle insertion or injected with sesame oil every fourth day. Estrous cyclicity, ovarian morphology, sex steroids, gonadotropins, insulin-like growth factor I, bone mineral density, and gene and protein expression in ovarian tissue were measured. Low-frequency EA induced estrous-cycle changes, decreased high levels of circulating luteinizing hormone (LH) and the LH/follicle-stimulating hormone (FSH) ratio, decreased high ovarian gene expression of adiponectin receptor 2, and increased expression of adiponectin receptor 2 protein and phosphorylation of ERK1/2. EA also increased cortical bone mineral density. Propranolol decreased ovarian expression of Foxo3, Srd5a1, and Hif1a. Estradiol decreased circulating LH, induced estrous cycle changes, and decreased ovarian expression of Adipor1, Foxo3, and Pik3r1. Further, total bone mineral density was higher in the letrozole-estradiol group. Thus, EA modulates the circulating gonadotropin levels independently of sex steroids or ß-adrenergic action and affects the expression of ovarian adiponectin system.

Weight loss increases follicle stimulating hormone in overweight postmenopausal women [corrected].

OBJECTIVES: To examine the impact of a weight loss intervention upon follicle stimulating hormone (FSH) levels in postmenopause. METHODS: Participants were postmenopausal, overweight, glucose-intolerant women not using exogenous estrogen (n = 382) in the Diabetes Prevention Program. Women were randomized to intensive lifestyle change (ILS) with the goals of weight reduction of at least 7% of initial weight and 150 min per week of moderate-intensity exercise, metformin 850 mg twice a day, or placebo administered twice a day. RESULTS: Randomization to ILS led to small increases in FSH between baseline and 1-year follow-up vs. placebo (2.3 IU/l vs. -0.81 IU/l, P < 0.01). Increases in FSH were correlated with decreases in weight (r = -0.165, P < 0.01) and estradiol (E2) (r = -0.464, P < 0.0001) after adjustment for age, race/ethnicity, and randomization arm. Changes in FSH were still significantly associated with changes in weight even after adjustment for E2 levels. Metformin users had reductions in weight but non-significant changes in FSH and E2 levels vs. placebo. CONCLUSIONS: Weight loss leads to small increases in FSH among overweight, postmenopausal women, potentially through pathways mediated by endogenous estrogen as well as other pathways.

All sex steroids are made intracellularly in peripheral tissues by the mechanisms of intracrinology after menopause.

Following the arrest of estradiol secretion by the ovaries at menopause, all estrogens and all androgens in postmenopausal women are made locally in peripheral target tissues according to the physiological mechanisms of intracrinology. The locally made sex steroids exert their action and are inactivated intracellularly without biologically significant release of the active sex steroids in the circulation. The level of expression of the steroid-forming and steroid-inactivating enzymes is specific to each cell type in each tissue, thus permitting to each cell/tissue to synthesize a small amount of androgens and/or estrogens in order to meet the local physiological needs without affecting the other tissues of the organism. Achieved after 500 million years of evolution, combination of the arrest of ovarian estrogen secretion, the availability of high circulating levels of DHEA and the expression of the peripheral sex steroid-forming enzymes have permitted the appearance of menopause with a continuing access to intratissular sex steroids for the individual cells/tissues without systemic exposure to circulating estradiol. In fact, one essential condition of menopause is to maintain serum estradiol at biologically inactive (substhreshold) concentrations, thus avoiding stimulation of the endometrium and risk of endometrial cancer. Measurement of the low levels of serum estrogens and androgens in postmenopausal women absolutely requires the use of MS/MS-based technology in order to obtain reliable accurate, specific and precise assays. While the activity of the series of steroidogenic enzymes can vary, the serum levels of DHEA show large individual variations going from barely detectable to practically normal "premenopausal" values, thus explaining the absence of menopausal symptoms in about 25% of women. It should be added that the intracrine system has no feedback elements to adjust the serum levels of DHEA, thus meaning that women with low DHEA activity will not be improved without external supplementation. Exogenous DHEA, however, follows the same intracrine rules as described for endogenous DHEA, thus maintaining serum estrogen levels at substhreshold or biologically inactive concentrations. Such blood concentrations are not different from those observed in normal postmenopausal women having high serum DHEA concentrations. Androgens, on the other hand, are practically all made intracellularly from DHEA by the mechanisms of intracrinology and are always maintained at very low levels in the blood in both pre- and postmenopausal women. Proof of the importance of intracrinology is also provided, among others, by the well-recognized benefits of aromatase inhibitors and antiestrogens used successfully for the treatment of breast cancer in postmenopausal women where all estrogens are made locally. Each medical indication for the use of DHEA, however, requires clinical trials performed according to the FDA guidelines and the best rules of clinical medicine.