Plasma levels of estrogens, androgens and progesterone during normal and dexamethasone-treated cycles

Cholesterol Deprivation Drives DHEA Biosynthesis in Human Adrenals

Adrenarche is an early event in sexual maturation in prepubertal children and corresponds to the postnatal development of the adrenocortical zona reticularis (zR). However, the molecular mechanisms that govern the onset and maturation of zR remain unknown. Using tissue laser microdissection combined with transcript quantification and immunodetection, we showed that the human zR receives low levels of cholesterol in comparison with other adrenal layers. To model this metabolic condition, we challenged adrenal cells in vitro using cholesterol deprivation. This resulted in reprogramming the steroidogenic pathway toward inactivation of 3-beta-hydroxysteroid dehydrogenase type 2 (HSD3B2), increased CYB5A expression, and increased biosynthesis of dehydroepiandrosterone (DHEA), 3 key features of zR maturation during adrenarche. Finally, we found that cholesterol deprivation leads to decreased transcriptional activity of POU3F2, which normally stimulates the expression of HSD3B2 by directly binding to its promoter. These findings demonstrate that cholesterol deprivation can account, at least in part, for the acquisition of a zR-like androgenic program in humans.

Mutual Shaping of Circadian Body-Wide Synchronization by the Suprachiasmatic Nucleus and Circulating Steroids

Background

Steroids are lipid hormones that reach bodily tissues through the systemic circulation, and play a major role in reproduction, metabolism, and homeostasis. All of these functions and steroids themselves are under the regulation of the circadian timing system (CTS) and its cellular/molecular underpinnings. In health, cells throughout the body coordinate their daily activities to optimize responses to signals from the CTS and steroids. Misalignment of responses to these signals produces dysfunction and underlies many pathologies.

Questions Addressed

To explore relationships between the CTS and circulating steroids, we examine the brain clock located in the suprachiasmatic nucleus (SCN), the daily fluctuations in plasma steroids, the mechanisms producing regularly recurring fluctuations, and the actions of steroids on their receptors within the SCN. The goal is to understand the relationship between temporal control of steroid secretion and how rhythmic changes in steroids impact the SCN, which in turn modulate behavior and physiology.

Evidence Surveyed

The CTS is a multi-level organization producing recurrent feedback loops that operate on several time scales. We review the evidence showing that the CTS modulates the timing of secretions from the level of the hypothalamus to the steroidogenic gonadal and adrenal glands, and at specific sites within steroidogenic pathways. The SCN determines the timing of steroid hormones that then act on their cognate receptors within the brain clock. In addition, some compartments of the body-wide CTS are impacted by signals derived from food, stress, exercise etc. These in turn act on steroidogenesis to either align or misalign CTS oscillators. Finally this review provides a comprehensive exploration of the broad contribution of steroid receptors in the SCN and how these receptors in turn impact peripheral responses.

Conclusion

The hypothesis emerging from the recognition of steroid receptors in the SCN is that mutual shaping of responses occurs between the brain clock and fluctuating plasma steroid levels.

PKA signaling drives reticularis differentiation and sexually dimorphic adrenal cortex renewal

The adrenal cortex undergoes remodeling during fetal and postnatal life. How zona reticularis emerges in the postnatal gland to support adrenarche, a process whereby higher primates increase prepubertal androgen secretion, is unknown. Using cell-fate mapping and gene deletion studies in mice, we show that activation of PKA has no effect on the fetal cortex, while it accelerates regeneration of the adult cortex, triggers zona fasciculata differentiation that is subsequently converted into a functional reticularis-like zone, and drives hypersecretion syndromes. Remarkably, PKA effects are influenced by sex. Indeed, testicular androgens increase WNT signaling that antagonizes PKA, leading to slower adrenocortical cell turnover and delayed phenotype whereas gonadectomy sensitizes males to hypercorticism and reticularis-like formation. Thus, reticularis results from ultimate centripetal conversion of adult cortex under the combined effects of PKA and cell turnover that dictate organ size. We show that PKA-induced progenitor recruitment is sexually dimorphic and may provide a paradigm for overrepresentation of women in adrenal diseases.

The steroid metabolome of adrenarche

Adrenarche is an endocrine developmental process whereby humans and select nonhuman primates increase adrenal output of a series of steroids, especially DHEA and DHEAS. The timing of adrenarche varies among primates, but in humans serum levels of DHEAS are seen to increase at around 6 years of age. This phenomenon corresponds with the development and expansion of the zona reticularis of the adrenal gland. The physiological phenomena that trigger the onset of adrenarche are still unknown; however, the biochemical pathways leading to this event have been elucidated in detail. There are numerous reviews examining the process of adrenarche, most of which have focused on the changes within the adrenal as well as the phenotypic results of adrenarche. This article reviews the recent and past studies that show the breadth of changes in the circulating steroid metabolome that occur during the process of adrenarche.

Adrenal suppression and sexual initiation in group-living female rhesus monkeys

Eight female rhesus monkeys living in an outdoor social group were studied for two menstrual cycles during the breeding season. During one cycle, adrenal steroids were suppressed for an average of 24 days using dexamethasone (0.6 mg/day) administered via subcutaneous osmotic minipumps. During the other cycle females were implanted with control pumps containing sterile water. Observers were blind to the treatments and treatment order was counterbalanced. Female sexual behavior was observed daily with each of two adult rhesus males. During dexamethasone treatment, cortisol levels were suppressed to less than 10% of control levels, and testosterone and androstenedione levels were suppressed to less than 50% of control, suggesting nearly total elimination of adrenal contribution to circulating androgen. All females showed hormonal evidence of ovulation. Adrenal suppression had no significant effect on female behavior, including approaches to the male and sexual solicits. In addition, no differences in any male behavior, including number of ejaculations, were seen between the two treatments. The continued cyclic copulation during adrenal suppression demonstrates that ovarian hormones are sufficient to modulate female rhesus sexual behavior and that adrenal androgens have little effect on the sexual behavior of intact, group-living rhesus females.

Hirsutism

Hirsutism is a common clinical problem. The pathogenesis of hirsutism in most women is not clearly defined. In this review, the characteristic endocrinologic findings in women with hirsutism are described, and the disorder's evaluation and treatment are discussed.

Plasma androgens during the luteal phase in a case of true hermaphroditism with bilateral ovotestis

A true hermaphrodite with a bilateral ovotestis and a 46 XX karyotype was studied. This 14-year old subject developed ambiguous puberty with bilateral gynecomastia and stage IV public hair. Relatively high level of testosterone (T) (2.80 ng/ml), was found. The 5 alpha-reductase activity for T in the pubic skin was similar to that observed in normal adult males. A hemorrhagic corpus luteum in the left ovotestis was observed at laparotomy. The luteal phase immediately after dexamethasone administration (1 mg/day for 7 days) was characterized by a significant decrease of plasma androgens, T and androstenedione (A). The constantly low level of T (0.30 ng/ml) during the luteal phase in this subject did not appear to be due to the previously administered dexamethasone. This decrease of T production in the luteal phase might be secondary either to the increase of the estradiol-17 beta (E2) secreted by the corpus luteum or to the decrease of LH levels. Both mechanisms might act concomitantly.

Hirsutism: evaluation and treatment

Hirsutism, a troublesome cosmetic problem, may also be a sign of serious systemic disease that can be screened for by means of the patient's history, physical examination, and certain basic blood tests. Most patients with functional hirsutism have elevated production rates of testosterone, elevated metabolic clearance rates of testosterone, depressed levels of sex hormone-binding globulin, and elevated levels of serum-free testosterone and hair follicle sensitivity. Once a neoplastic source is ruled out and hirsutism established as functional, essentially empiric treatment, including low-dose dexamethasone, oral contraceptives, and spironolactone, has proved to be effective.

Ovarian and adrenal vein steroids in healthy women with ovulatory cycles--selective catheterization findings

Bilateral ovarian-adrenal vein catheterization and androgen measurements in the efferent samples were utilized to directly assess glandular steroid release in 8 healthy volunteers with proven ovulatory cycles during the early follicular phase. Side effects did not occur in any of the women. Hormone levels were as follows (mean +/- SD; ng/ml) T: peripheral vein (PV) 0.36 +/- 0.16, ovarian veins (OV) 0.39 +/- 0.13, adrenal veins (AV) 0.85 +/- 0.63; dihydro-T (DHT): PV 0.25 +/- 0.09, OV 0.29 +/- 0.10, AV 0.93 +/- 0.65; delta 4-androstendione (A): PV 0.88 +/- 0.34, OV 1.82 +/- 1.04, AV 9.22 +/- 8.04; DHEA; PV 5.13 +/- 1.96, OV 6.73 +/- 2.69, AV 146.79 +/- 217.24; DS PV 1860 +/- 850, OV 1937 +/- 1039, AV 2567 +/- 1201; 17 alpha-hydroxyprogesterone (17P): PV 0.60 +/- 0.19, OV 1.46 +/- 1.64, AV 6.94 +/- 6.20; F: PV 170 +/- 50, OV 130 +/- 21, AV 788 +/- 1320; the bilateral differences of effluent levels were not significant. Glandular-peripheral vein steroid gradients served as semiquantitative estimates of momentary secretory activity; they were as follows (mean +/- SD; ng/ml) T: ovarian-peripheral vein gradient (OPG) 0.03 +/- 0.09, adrenal-peripheral vein gradient (APG) 0.48 +/- 0.57; DHT: OPG 0.05 +/- 0.05, APG 0.69 +/- 0.60; A: OPG 0.97 +/- 1.13, APG 8.33 +/- 7.86; DHEA: OPG 1.70 +/- 1.80, APG 141.80 +/- 216.60; DS: OPG 191 +/- 72, APG 706 +/- 824; 17P: OPG 0.87 +/- 1.67, APG 6.30 +/- 6.10; F: OPG 38 +/- 11, APG 610 +/- 1329. Gradient, analysis revealed that the ovaries produced significant quantities of A, DHEA and 17P, but no T, DHT or F between day 3-7 of the cycle; direct gonadal DS output was detected in 2 individuals. A significant OPG for DS was detected in two individuals possibly indicating its partially gonadal origin. The adrenals released larger amounts of A, DHEA and 17P than the ovaries at this stage (P less than 0.05); also, they consistently secreted T, DHT, DS and F.

Studies on ovarian and adrenal studies at different phases of the menstrual cycle. IV. The effect of dexamethasone suppression and subsequent ACTH stimulation at different phases of the menstrual cycle and following the administration of 150 mg of depot-medroxy-progesterone acetate (DMPA)

In an attempt to assess the effect of depot-medroxyprogesterone acetate (DMPA) on adrenal function, to peripheral levels of a variety of steroids were estimated after dexamethasone suppression and subsequent ACTH stimulation in 5 subjects. The steroid responses observed 16 and 54 days after a single injection of 150 mg of DMPA were compared with those obtained in the same women before DMPA treatment or with those found at different phases of the cycle in another group of 6 normally menstruating women. The levels of cortisol, pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone, androstenedione and dihydrotestosterone were significantly suppressed by dexamethasone and stimulated by ACTH in all phases of the cycle, and before and after DMPA administration. The extent of suppression or stimulation (expressed as a percentage) was different in case of different steroids, but was rather constant with regard to the same steroid. Hence, the functional capacity of the adrenal as reflected by the levels of these steroids. Dexamethasone administration did not exert any influence on the levels of progesterone and 17-hydroxyprogesterone during the different phases of the cycle; however, ACTH administration increased the levels of these two steroids in the follicular phase and also after DMPA treatment. The levels of estradiol and lutropin were not influenced by dexamethasone or ACTH at any of the occasions studied. It is concluded that the functional capacity of the adrenal cortex is constant during the various cycle phases and is not affected by the administration of a single dose of 150 mg of DMPA.

Effect of short dexamethasone suppression on plasma steroids in prepubertal and pubertal girls

In 40 girls aged from 2 to 14 years, subdivided into groups according to age and pubertal development, and in 6 adult female volunteers, plasma cortisol (F), pregnenolone (delta 5), dehydroepiandrosterone (DHA) progesterone (P), 17-hydroxyprogesterone (17P), androstenedione (A), testosterone (T) and estradiol (E2) were measured before and after short dexamethasone (DXM) suppression. The results confirmed the capacity of DXM to inhibit plasma steroids in all age groups, except T in 2-9 year old and P1 Tanner's stage girls. The percentage suppression of each given steroid was constant over the age groups from 6-9 years to P4-5 Tanner's stage, while lower suppression was found in 17P, P and DHA in 2-5 year old girls and in 17P, DHA and E2 in adult women. These results emphasize the fundamental role of ACTH as the overall stimulating factor of adrenal steroidogenesis but do not negate the possibility of another factor responsible for the development of the adrenal androgen secreting cells throughout prepuberty and puberty.

The relation between plasma testosterone levels and the lengths of phases of the menstrual cycle

Plasma testosterone levels were measured in 331 women of reproductive age. The incidence of clinical signs of hyperandrogenism (hirsutism, acne) was recorded. Ovulatory activity was evaluated clinically by basal body temperature and frequent observation of changes in the appearance of the cervical os and cervical mucus. Plasma testosterone levels were abnormally elevated in patients with clinical signs of hyperandrogenism. The highest mean testosterone levels were noted in the group of hyperandrogenic women with amenorrhea. Significant prolongation of the follicular phase and shortening of the luteal phase were demonstrated to be associated with clinical signs of hyperandrogenism and elevated plasma testosterone levels. Statistically significant correlations between plasma testosterone levels and duration of phases of the menstrual cycle were observed. Testosterone levels were directly related to the length of the follicular phase and inversely related to the length of the luteal phase. A significant inverse correlation between the lengths of the two phases of the menstrual cycle was also demonstrated. These results suggest an association between hyperandrogenism and prolongation of the follicular phase and shortening of the luteal phase of the menstrual cycle, possibly related to the high incidence of infertility and menstrual irregularity reported for hyperandrogenic women.

Ovarian hyperandrogenism with normal and abnormal histologic findings of the ovaries

Thirty-one patients with clinical features of polycystic ovary syndrome (PCO) were studied to determine the correlation between biochemical and histologic findings. The biochemical features investigated were the effects of adrenocortical and ovarian suppression by dexamethasone and oral contraceptives (Ovulen) on plasma free androgens. Four patients showed a histologic picture consistent with PCO (Group A), and five had histologically normal ovaries (Group B). The remaining 22 patients had no tissue available for histologic examination (Group C). The baseline values of plasma free testosterone (FTel) were higher and those of testosterone-binding globulin (TeBG) were lower (p less than 0.05) in Group A than in Group B, although plasma total testosterone (T) and the free 17beta-hydroxysteroid androgen index (FHSl) were similar in the two groups. During dexamethasone administration in all study groups, T and FTel fell slightly (17.7% to 33.8%), and FHSl levels decreased moderately (36% to 46.6%); in no case did both indices of free androgen levels fall to the normal range for dexamethasone-suppressed women. However, no change was noted in TeBG in all three groups. On the other hand, Ovulen treatment suppressed T and free androgens to normal in all groups, and raised TeBG more than 350% from the baseline. These data suggest a decrease in androgen production. The effects of dexamethasone and Ovulen on all three groups were similar in percent changes. As Group B patients resemble those of Group A biochemically and clinically, except for possibly being less hyperandrogenic, the concept of ovarian hyperandrogenism should be expanded to include patients with no anatomic ovarian abnormality, particularly in milder cases.

Concentration of circulating hormones and metabolism of androgens by human gingiva

The present study evaluates the relationship between periodontal status, concentration of circulating hormones and metabolism of androgens by human male and female gingiva in vitro. In both male and female patients with healthy gingiva the plasma concentration of gonadotropins (LH and FSH) and steroid hormones (testosterone, androstenedione, estradiol-17 beta, progesterone and cortisol) were in a normal range. However, an alteration in the plasma concentration of progesterone was found in both male and female patients with periodontal pathosis. Both androgens (testosterone and androstenedione) were readily metabolized by human gingiva tissue in vitro. The major pathway of the metabolism of testosterone was via the formation of 17 beta-hydroxy-5 alpha-A-ring reduced androgens (5 alpha-dihydrotestosterone and 3 alpha-, 3 beta-androstanediol). In contrast, androstenedione was metabolized mainly to 17-keto-5 alpha-A-ring reduced (5 alpha-androstanedione, androsterone and epiandrosterone) and 17 beta-oxidoreduced (testosterone) compounds. In addition both substrates were metabolized to 5 beta-A-ring reduced androgens (5 beta-dihydrotestosterone, 5 beta-androstanediol and 5 beta-androstanedione). A significant feature of the metabolism of testosterone and androstenedione by inflamed gingiva was an increase of 5 alpha-A-ring reductase activity (mainly the formation of 5 alpha-dihydrotestosterone and 5 alpha-androstanedione) and 17 beta-oxidoreductase activity (mainly the formation of testosterone from androstenedione). The increase in 5 alpha-reductase activity also showed a significant correlation with the plasma progesterone concentration.

Concentrations of circulating steroids in normal prepubertal and adult male and female humans, chimpanzees, rhesus monkeys, rats, mice, and hamsters: a literature survey

Radioimmunoassay (RIA) data on concentrations of circulating steroids in normal prepubertal and adult male and female humans, chimpanzees, rhesus monkeys, rats, mice, and hamsters have been collated from the literature. Few reports include data for both sexes, for age groups, or for more than one species. In selecting references for inclusion in the tables, efforts were made to choose data only from RIA procedures that were adequately validated. A number of similarities can be found by reviewing the tables. Levels of estradiol appear somewhat similar for humans, chimpanzees, and rhesus monkeys of both sexes. Among the notable differences are the levels of estradiol and progesterone in primates and rodents, the apparently high level of aldosterone in mice, and the patterns of progesterone secretion in mice and rats. All values in the tables have been converted to picograms for easy comparison between steroids and species. Data for humans are fairly complete, but there is a significant lack of information for several other species.

Effect of cortisol treatment on hormonal relationships in congenital adrenal hyperplasia

The temporal relationship between administration of cortisol and serum 17alpha-hydroxyprogesterone was investigated in five patients aged 9-19 years with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. There was marked variability in the 17alpha-hydroxyprogesterone response (determined hourly for 24 h) of individual patients to administration of cortisol. Mean concentration was less than 0.030 micronmol/l in one patient but 0.519 micronmol/l in another. Levels were higher in all patients while off treatment, and were greatest in those with salt-losing adrenal hyperplasia. Growth hormone secretion was not suppressed by treatment with cortisol. Withdrawal of cortisol for 3 days resulted in a significant decrease in the mean serum FSH/LH ratio and a rise in serum testosterone in all subjects. Episodic release of gonadotrophins persisted in the adolescent patients.

The effects of dexamethasone on plasma free androgens during the normal menstrual cycle

In order to evaluate the ovarian and adrenal contribution to peripheral plasma concentrations of total testosterone (TTe), indixes of the plasma concentrations of free testosterone (FTeI), free 17 beta-hydroxysteroid androgens (FHSI), and testosterone-binding globulin (TeBG) during the menstrual cycle, women were examined during three normal cycles and three other cycles under dexamethasone (0.5 mg., four times a day) suppression. All study cycles were apparently ovulatory. The mean TTe and FTeI during the midcycle period were significantly higher than during the early follicular (P less than 0.005) and the midluteal periods (P less than 0.01 and P less than 0.001, respectively). During the menstrual cycles under dexamethasone suppression only the difference in TTe and FTeI between the midcycle (37 +/- 12.4 (S.D.) ng. per 100 ml. and 10.5 +/- 4.0 (S.D.), respectively) and the midluteal (26.0 +/- 10.1 (S.D.) ng. per 100 ml and 7.2 +/- 3.2 (S.D.), respectively) periods was significant statistically (P less than 0.05). No significant differences in the mean levels of FHSI and TeBG between three periods within the cycle were noted in either the control or the dexamethasone-treated cycle. When each phase was compared, the mean levels of TTe, FTel, and FSHI were significantly lower in the dexamethasone-treated cycles than in the normal cycles. The data suggest that the level of TeBG is not perceptibly affected by physiologic fluctuation of estrogen levels during the menstrual cycle, and the FHSI levels are stable throughout the ovulatory cycle. Decrease in levels of TTe, FTeI, and FHSI during dexamethasone suppression seems to be due to reduction of androgen production as TeBG, a major determinant of the metabolic clearance rate of androgens, was not affected by dexamethasone.

Plasma sex steroid and gonadotropin levels in control and silastic vaginal medroxyprogesterone acetate-impregnated ring cycles

The concentrations of sex steroid hormones in plasma were determined daily in 14 young adult women, during both a control cycle and a treatment cycle. During the latter a Silastic ring into which 100 or 200 mg of medroxyprogesterone acetate (Provera) had been incorporated was worn intravaginally. During the treatment cycles, plasma levels of estradiol, progesterone, and 17-hydroxyprogesterone remained within the range observed during the early follicular phase. Testosterone and androstenedione levels did not show any cyclic variation during the treatment cycle; however, the mean levels were decreased by about 25% compared with the over-all plasma levels of the control cycle, whereas dehydroepiandrosterone levels were decreased by about 15%. It is concluded that these Provera-containing Silastic intravaginal rings inhibit ovulation and decrease androgen secretion by the ovaries significantly.

Plasma androgen levels during the menstrual cycle

Utilizing RIA methods, T, DHT, delta 4, and DHEA levels were determined daily during a complete cycle in 15 normal young women with apparently normal ovulatory cycles. T, DHT, and delta 4 levels showed statistically significant cyclical variations, with highest values in the periovulatory period and lowest values in early follicular and late luteal phase. DHEA levels showed random variations during the cycle. The failure to detect these variations by some authors may be related to the relatively large interindividual variation in plasma levels.

Estriol concentrations in plasma of normal, non-pregnant women

Using a rabbit antisera directed against estriol-3-0-carboxy methyl ether complexed to BSA, an immunoassay for estriol (1) was developed. The mean plus or minus SE concentration of estriol in 18 women in days 5-7 of their cycle was 7.9 plus or minus 0.6 pg/ml which was significantly (P less than 0.01) less than the mean value of 11.1 plus or minus 0.8 pg/ml in 15 women in days 20-22 of the cycle. In 3 of 6 women in whom plasma samples were drawn frequently during their cycle, an estriol peak occurred coincident with the estradiol peak. In 3 women from whom plasma was obtained several times during the course of a day estriol levels did not appear to vary significantly. In 8 women who were on oral contraceptives the mean level of estriol was 7.6 plus or minus 1.5 pg/ml. In 8 post-menopausal women the mean level was 6.0 plus or minus 1.2 pg/ml which is significantly (P less than 0.01) less than the mean luteal phase value but not less (P greater than 0.1) than the follicular phase or oral contraceptive user values. We conclude that some of the circulating estriol is directly secreted by the ovary of normal women.