OBJECTIVE

To evaluate the association between androstenedione, testosterone, and free testosterone and metabolic disturbances in polycystic ovary syndrome.

METHODS

We analyzed the association between androstenedione, testosterone, and free testosterone and metabolic parameters in a cross-sectional study including 706 polycystic ovary syndrome and 140 BMI-matched healthy women. Polycystic ovary syndrome women were categorized into 4 groups: normal androstenedione and normal free testosterone (NA/NFT), elevated androstenedione and normal free testosterone (HA/NFT), normal androstenedione and elevated free testosterone (NA/HFT), elevated androstenedione and free testosterone (HA/HFT).

RESULTS

Polycystic ovary syndrome women with elevated free testosterone levels (HA/HFT and NA/HFT) have an adverse metabolic profile including 2 h glucose, HbA1c, fasting and 2 h insulin, area under the insulin response curve, insulin resistance, insulin sensitivity index (Matsuda), triglycerides, total and high density lipoprotein cholesterol levels compared to NA/NFT (p<0.05 for all age- and BMI-adjusted analyses). In binary logistic regression analysis adjusted for age and BMI, odds ratio for insulin resistance was 2.78 (1.34-5.75, p = 0.006) for polycystic ovary syndrome women with HA/HFT compared to NA/NFT. We found no significantly increased risk of metabolic disorders in polycystic ovary syndrome women with HA/NFT. In multiple linear regression analyses (age- and BMI-adjusted), we found a significant negative association between androstenedione/free testosterone-ratio and area under the insulin response curve, insulin resistance, and total cholesterol/high density lipoprotein cholesterol-ratio and a positive association with Matsuda-index, and high density lipoprotein cholesterol (p<0.05 for all).

CONCLUSIONS

Polycystic ovary syndrome women with elevated free testosterone levels but not with isolated androstenedione elevation have an adverse metabolic phenotype. Further, a higher androstenedione/free testosterone-ratio was independently associated with a beneficial metabolic profile.

A combination of accelerator mass spectrometry (AMS) and liquid chromatography-tandem mass spectrometry has been used to clarify some new aspects of testosterone metabolism. The main pathway of testosterone oxidative metabolism by human liver microsomes is the formation of 1beta-, 2alpha-/beta-, 6beta-, 15beta-, and 16beta-hydroxytestosterones, mainly catalyzed by cytochromes P<em>4</em>50 2C9, 2C19, and 3A<em>4</em>. We now report the first determination that 11beta-hydroxytestosterone (11beta-OHT) can also be formed by human liver microsomal fractions. The structures of five hydroxylated metabolites of testosterone (2beta-, 6beta-, 11beta-, 15beta-, and 16beta-OHT) and the C-17 oxidative metabolite <em>androstenedione</em> were determined by liquid chromatography with UV detection at 2<em>4</em>0 nm and liquid chromatography-tandem mass spectrometry. Corresponding results were obtained by high-performance liquid chromatography-AMS analysis of incubations of [<em>4</em>-1<em>4</em>C]testosterone with human liver microsomes. 6beta-Hydroxylation was always the dominant metabolic pathway, but 2beta-, 15beta-, and 16beta-OHT, and <em>androstenedione</em> were also formed. The previously undetected hydroxytestosterone, 11beta-OHT, was found to be a minor metabolite formed by human liver microsomal enzymes. It was formed more readily by CYP3A<em>4</em> than by either CYP2C9 or CYP2C19. 11beta-Hydroxylation was inhibited by ketoconazole (IC50 = 30 nM) at concentrations similar to the IC50 (36 nM) for 6beta-hydroxylation Therefore, CYP3A<em>4</em> could be mainly responsible for testosterone 11beta-hydroxylation in the human liver. These findings identify human hepatic biotransformation of testosterone to 11beta-OHT as a previously unrecognized extra-adrenal metabolic pathway.

The effects of insulin on porcine thecal steroidogenesis were examined in long-term cultures of hyaluronidase-collagenase dispersed thecal cells. The thecal cultures made significant amounts of progesterone (P) and <em>androstenedione</em> (delta <em>4</em> A). Testosterone, dihydrotestosterone, estrone, and estradiol could not be detected in the media. Luteinizing hormone (LH) alone significantly increased P and delta <em>4</em> A accumulation. Insulin alone increased P accumulation on days 2 to <em>4</em> of culture. Insulin alone did not stimulate delta <em>4</em> A accumulation. Insulin plus LH resulted in a significantly greater accumulation of P and delta <em>4</em> A than LH alone. These results suggest that insulin may be a regulator of ovarian thecal steroidogenesis.

In girls, but not in boys, pronounced adrenarche and precocious pubarche along with ovarian hyperandrogenism have been related to insulin resistance and reduced fetal growth. However, insulin secretion is increased during puberty in normal boys. The aim of this study was to analyze the possible implication of changes in the GH/IGF-I axis and in insulin sensitivity for the regulation of adrenal androgen secretion of normal prepubertal and adolescent boys. Fifty-six normal boys were divided into the following groups (Gr): Gr1, prepuberty (testicular volume, (<em>4</em> cc; n = 33); and Gr3, puberty (testicular volume, <em>4</em>-25 cc; n = 23). Gr1 was subdivided according to age into: Gr1A, early prepuberty (boys younger than 5.9 yr old; n = 16); and Gr1B, late prepuberty (prepubertal boys, 5.9 yr old or older; n = 17). Gr3 was subdivided according to testicular volume into: Gr3A, early puberty (testicular volume, <em>4</em>-8 cc; n = 13); and Gr3B, late puberty (testicular volume, 10--25 cc; n = 10). To study hormonal changes during the transition between prepuberty and puberty, an additional group, Gr2 (n = 30), was defined by mixing Gr1B and Gr3A. Serum dehydroepiandrosterone sulfate (DHEAS), <em>androstenedione</em> (Delta(<em>4</em>)A), insulin, IGF-I, and glucose were determined after overnight fasting. Insulin sensitivity was estimated by the fasting glucose/insulin (G/I) ratio. There was a close correlation between fasting G/I ratio and QUICKI, a quantitative insulin sensitivity check index. Mean values for Gr1 and Gr3 as well as their subgroups were compared using t test. In Gr1, the mean fasting G/I ratio was significantly higher, and the mean serum IGF-I, serum DHEAS, and serum Delta(<em>4</em>)A levels were significantly lower than in Gr3 (P < 0.001). Mean fasting G/I ratios in Gr1A and Gr3A were not significantly different from those in Gr1B and Gr3B, respectively, but the fasting G/I ratio in Gr3A was significantly lower than that in Gr1B (P < 0006). Moreover, body mass index (BMI) in Gr3A was significantly higher than that in Gr1B (P < 0.01). On the other hand, mean serum IGF-I levels in Gr1A and Gr3A were significantly lower than those in Gr1B and Gr3B, respectively (P < 0.0001). The mean serum DHEAS level in Gr1A was significantly lower than that in Gr1B (P < 0.01), but no difference was found between Gr3A and Gr3B. The mean serum Delta(<em>4</em>)A in Gr1A was similar to that in Gr1B, but the mean serum Delta(<em>4</em>)A in Gr3A was significantly lower than that in Gr3B (P = 0.0001). Correlation studies within Gr1, Gr2, and Gr3 were also carried out. There was a significant positive correlation between serum DHEAS and age in Gr1 and Gr2, but not in Gr3. In Gr1, no significant correlation was found between serum DHEAS and fasting G/I ratio or between serum DHEAS and serum IGF-I, suggesting that adrenal steroidogenesis in male prepuberty is independent of insulin sensitivity or peripheral IGF-I. In Gr2, a significant negative correlation (P = 0.01) between serum DHEAS and the fasting G/I ratio was found, but not between serum DHEAS and serum IGF-I. Furthermore, a significant negative correlation between BMI and the fasting G/I ratio was also found. Therefore, changes in insulin sensitivity might be involved in adrenal androgen synthesis during the transition from prepuberty to puberty. Finally, in Gr3, DHEAS was not significantly correlated with the fasting G/I ratio or serum IGF-I. A significant negative correlation between serum Delta(<em>4</em>)A and the fasting G/I ratio was found in Gr2. In Gr2, but not in Gr3, there was a significant negative correlation between the fasting G/I ratio and age (P = 0.03) and between the fasting G/I ratio and serum IGF-I (P = 0.03). In conclusion, our data support the hypothesis that the GH/IGF-I axis and insulin sensitivity are not involved in the mechanism of adrenarche in boys. Insulin sensitivity and BMI, however, decrease at early puberty rather than at late puberty, and this change could be involved in modulating adrenal androgen steroidogenesis during the transition between late prepuberty and early puberty.

Recently, laparoscopic ovarian cautery has been described as a method of ovulation induction in women with polycystic ovarian disease. In an attempt to determine the mechanism of action, serum levels of <em>androstenedione</em>, testosterone, luteinizing hormone, follicle-stimulating hormone, and estradiol were determined before and after the laparoscopic ovarian cautery in six women with polycystic ovarian disease who had failed to ovulate with clomiphene citrate and human chorionic gonadotropin. Six regularly cycling women undergoing laparoscopy for investigation of infertility or tubal ligation served as controls. In patients with polycystic ovarian disease but not in controls, serum <em>androstenedione</em>, testosterone, estradiol, and luteinizing hormone significantly decreased to nadir levels on postoperative days 3 and <em>4</em>. In contrast follicle-stimulating hormone levels rose after operation. These results resemble those reported after ovarian wedge resection. Of the six treated women, five ovulated postoperatively and four conceived. Laparoscopic ovarian cautery appears to be a promising alternative treatment for patients with polycystic ovarian disease in whom initial medical management fails.

BACKGROUND

Ovarian and adrenal hyperandrogenism characterize premenopausal women with polycystic ovary syndrome (PCOS). Androgens decline with age in healthy and PCOS women.

OBJECTIVE

The objective of the study was to investigate hyperandrogenism in PCOS after menopause.

METHODS

This was a case-control, cross-sectional study.

METHODS

The study was conducted at a university hospital endocrinology unit.

METHODS

Twenty postmenopausal women with PCOS and 20 age- and body mass index-matched controls participated in the study.

METHODS

Serum cortisol, 17-hydroxyprogesterone (17-OHP), Δ(<em>4</em>)-<em>androstenedione</em> (Δ(<em>4</em>)A), dehydroepiandrosterone sulfate (DHEAS), total testosterone (T), and free androgen index (FAI) levels were measured at baseline, after ACTH stimulation, and after 3-d dexamethasone suppression. The ACTH and cortisol levels were measured during the CRH test.

METHODS

Androgen profile at baseline, after ACTH stimulation, and 3-d dexamethasone suppression tests were the main outcome measures.

RESULTS

Postmenopausal PCOS women had higher 17-OHP, Δ(<em>4</em>)A, DHEAS, total T, FAI (P < 0.05) and lower SHBG (P < 0.05) baseline levels than control women. ACTH and cortisol responses during the CRH test were similar in the two groups. After ACTH stimulation, Δ(<em>4</em>)A, DHEAS, and total T levels were equally increased in both groups. After dexamethasone suppression, LH levels did not change in either group; 17-OHP-, Δ(<em>4</em>)A-, and FAI-suppressed levels remained higher in PCOS than in control women (P < 0.05), whereas total T and DHEAS levels were suppressed to similar values in both groups.

CONCLUSIONS

In postmenopausal PCOS women, ACTH and cortisol responses to CRH are normal. Androgen levels at baseline are higher in PCOS than control women and remain increased after ACTH stimulation. The dexamethasone suppression results in postmenopausal PCOS women suggest that DHEAS and total T are partially of adrenal origin. Although the ovarian contribution was not fully assessed, increased Δ(<em>4</em>)A production suggests that the ovary also contributes to hyperandrogenism in postmenopausal PCOS women. In conclusion, postmenopausal PCOS women are exposed to higher adrenal and ovarian androgen levels than non-PCOS women.

Estrogen action is regulated at the receptor level by regulation of expression of estrogen receptors, and at the pre-receptor level by interconversions between the active hormone (estradiol) and its inactive counterparts (estrone, estrone-sulfate). In peripheral tissues, estrogens can be produced via the aromatase or the sulfatase pathways. Aromatase converts <em>androstenedione</em> and testosterone to estrone and estradiol, respectively, and sulfatase releases estrogens from inactive sulfates, while sulfotransferase catalyzes the reverse reaction. In both pathways, 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) are of paramount importance as they catalyze activation of estrone to estradiol and inactivation of estradiol to estrone. These enzymes belong to either the short-chain dehydrogenase/reductase (SDR) or the aldo-keto reductase (AKR) protein superfamilies. Differential expression of these pre-receptor regulatory enzymes can lead to high estradiol concentrations, which have been implicated in the development of different diseases. Here, we have examined gene expression levels of estrogen-metabolizing enzymes, as six SDRs (17beta-HSD types 1, 2, <em>4</em>, 7, 8, 12) and one AKR (17beta-HSD type 5; AKR1C3), of aromatase, steroid sulfatase (STS) and estrogen sulfotransferase (SULT1E1), and of the alpha and beta estrogen receptors (ERs), in breast cancer (MCF-7), endometrial cancer (Ishikawa), choriocarcinoma (JEG3) and liver cancer (HepG2) cell lines. After RNA isolation and cDNA synthesis, real-time PCR analyses were performed. The expression of AKR1C3 was examined also at the protein level. Our data show that in all four cancer cell lines, estradiol can be synthesized from estrone by the action of 17beta-HSD type 12, or from estrone-sulfate by sulfatase. In JEG3 and HepG2 cells, estradiol can be formed from androgens by aromatase and 17beta-HSD type 1. Also in HepG2 cells, AKR1C3, which converts <em>androstenedione</em> to testosterone, in concert with aromatase might be responsible for estradiol formation. In MCF7 and Ishikawa cells, estradiol exerts its actions through ERalpha, while in JEG3 and HepG2 cells, it may act through non-ER-mediated pathways.

Twelve persons with sexual ambiguity were identified in an isolated village in southern Turkey. Eleven were examined and had pseudovaginal perineoscrotal hypospadias; eight were studied. Serum and urine samples from five affected males and urine samples from three affected children were analyzed. Urine samples from another 26 villagers, mostly parents and siblings, were also analyzed. In all but one of the affected adult subjects, serum testosterone levels were either normal or increased, and in all adults, the dihydrotestosterone levels were low (8 to 20 ng/dl) and the testosterone/dihydrotestosterone ratios were elevated (to 36 or more); the levels of <em>4</em>-<em>androstenedione</em> were normal. Thirty-four urine samples were analyzed for etiocholanolone/androsterone, 11-beta-hydroxyetiocholanolone/11-beta-hydroxyandrosterone, tetrahydrocorticosterone/5-alpha-tetrahydrocorticosterone and tetrahydrocortisol/5-alpha-tetrahydrocortisol ratios. In affected persons, all 5-beta/5-alpha urinary C19 and C21 steroid metabolite ratios measured were elevated. These findings are compatible with the diagnosis of male pseudohermaphroditism due to 5-alpha-reductase deficiency. In parents and some of the siblings of the affected subjects, the 5-beta/5-alpha urinary ratios were between affected and normal levels. The intermediate 5-beta/5-alpha ratios of the parents who were phenotypically normal, together with documented consanguinity, confirm an autosomal recessive mode of inheritance and are useful in identification of the carrier state. The urinary tetrahydrocortisol/5-alpha-tetrahydrocortisol ratios provided the highest index of discrimination between homozygotes (mean +/- SD, adults: 35.80 +/- 20.10; children: 15.<em>4</em>8 +/- 7.91), heterozygotes (parents: <em>4</em>.56 +/- 1.61; siblings and other relatives: 5.97 +/- 3.68), and normal subjects (1.07 +/- 0.36). Thus, this study identified a second community with inherited male pseudohermaphroditism due to 5-alpha-reductase deficiency, confirming the autosomal recessive inheritance of this condition and the generalized abnormality in both C19 and C21 steroid 5-alpha metabolism.

NO synthase is present in human ovarian granulosa-luteal cells and NO inhibits estradiol secretion by granulosa cells in culture. These findings suggest that NO is an autocrine regulator of ovarian steroidogenesis. The purpose of this investigation was to explore the mechanisms through which NO exerts an inhibitory effect on cytochrome P<em>4</em>50 aromatase activity. To examine the effect of NO on aromatase mRNA levels, human granulosa-luteal cells were cultured in the presence or absence of the NO donor SNAP for 16 h. Using a probe for human aromatase, Northern blots revealed a 26% decrease in aromatase mRNA in cells exposed to SNAP. Because this modest decrease in mRNA is unlikely to explain a rapid and profound reduction in estradiol secretion that we have observed, we looked for direct effects of NO on cytochrome P<em>4</em>50 aromatase activity. Aromatase activity was assayed in placental microsomes and granulosa-luteal cells by measuring the release of 3H2O from [1 beta-3H] <em>androstenedione</em>. NO (10(-<em>4</em>)-10(-3)M), added as a saturated saline solution, reduced aromatase activity by as much as 90% in a concentration-dependent, non-competitive manner. In contrast, carbon monoxide (CO), a gas known to bind to the heme iron in aromatase, had no effect on aromatase activity when added alone nor could CO reverse the NO-induced inhibition of aromatase. These data suggest that NO binding to the heme is insufficient to inhibit aromatase activity. NO has been reported to alter protein function by reacting with the sulfhydryl group of cysteines, forming a nitrosothiol group. Because a cysteine sulfhydryl group is thought to participate in the catalytic mechanism of all P<em>4</em>50 enzymes, experiments were designed to test whether NO might inhibit aromatase via such a mechanism. Addition of increasing amounts of mercaptoethanol, a chemical with free sulfhydryl groups, blocked the NO-induced inhibition of aromatase in microsomes. N-Ethylmaleimide, a chemical which covalently modifies sulfhydryl groups, reduced aromatase activity in a concentration-dependent manner. We conclude that NO inhibits aromatase both by decreasing mRNA for the enzyme and by an acute, direct inhibition of enzyme activity. We hypothesize that the direct inhibition occurs as a result of the formation of a nitrosothiol on the cysteine residue adjacent to the heme in aromatase.

Several synthetic flavones were found to inhibit the aromatization of <em>androstenedione</em> to estrone catalyzed by human placental microsomes. Twenty-one compounds were tested and the IC50 of the most active were: flavone, 10 microM; 7-hydroxyflavone, 0.5 microM; 7,<em>4</em>'-dihydroxyflavone, 2.0 microM; flavanone, 8.0 microM; and <em>4</em>'-hydroxyflavanone, 10 microM. Most of the others had IC50 values ranging from 80 to greater than 200 microM. These findings show that <em>4</em>'-hydroxylation results in either no change or very little change in IC50 for flavanone, isoflavone and isoflavanone as well as other ring A hydroxylated flavones. Derivatives of flavone with a hydroxyl substituent at position 5, 6 and 7 were also screened. 7-Hydroxyflavone (11) was the most effective competitive inhibitor (IC50 = 0.5 microM) with an apparent Ki value of 0.25 microM. Compound 11 also induced a change in the absorption spectrum of the aromatase cytochrome P-<em>4</em>50 which is indicative of substrate displacement. The relative binding affinities of the flavonoid analogs were determined and only ring A adn ring B dihydroxylated analogs were found to bind to the estrogen receptor.

To characterize thyroid hormone action on the ovary, the direct effects of T<em>4</em> or T3 were investigated in vitro using a monolayer culture system of porcine granulosa cells. Monolayer cultures were maintained for 6 days in <em>4</em>% serum-supplemented medium in the absence or presence of porcine FSH (20 ng/ml), with or without graded doses of T<em>4</em> or T3. Combined treatment with FSH and T<em>4</em> (10(-7) M) induced morphological alternation resembling epithelioid cells, while FSH alone or T<em>4</em> alone failed to bring about the epithelioid morphology. Concomitant treatment with FSH and T<em>4</em> (10(-7) M) markedly increased FSH-stimulated induction of [125I]iodo-human CG binding to cultured granulosa cells obtained from small follicles. The combined treatment with FSH and T<em>4</em> (10(-7) M) also resulted in a significant increase in progesterone and estrogen secretion by the cultured cells relative to treatment with FSH alone. Increases in progesterone, 17 beta-estradiol, and estrone secretion caused by the combined treatment with FSH and T<em>4</em> (10(-7) M) were further augmented in response to the addition of exogenously provided substrate pregnenolone, testosterone, and <em>androstenedione</em>, respectively. Furthermore, aromatase activity assessed by the release of [3H]water from [1 beta-3H, <em>4</em>-1<em>4</em>C]<em>androstenedione</em> was significantly higher in cells treated concomitantly with FSH and T<em>4</em> (10(-7) M) than that in cells treated with FSH alone. All the stimulatory effects of T<em>4</em> (10(-7) M) on the morphological and functional differentiation of cultured granulosa cells were also found in combined treatment with FSH and T3 (10(-9) M). Either treatment with higher or lower concentrations of T<em>4</em> or T3 gave attenuated effects, and T<em>4</em> or T3 alone without FSH was incapable of exhibiting these stimulatory effects. These findings suggest that thyroid hormones synergize with FSH to exert direct stimulatory effects on granulosa cell functions, including morphological differentiation, LH/human CG receptor formation and steroidogenic enzyme (3 beta-hydroxysteroid dehydrogenase and aromatase) induction. Hence, decreases in ovarian functions during the states of hypo- or hyperthyroidism may account for diminished responsiveness of the granulosa cells to FSH.

<em>4</em>-Hydroxy<em>androstenedione</em> (<em>4</em>-OHA) is a specific inhibitor of aromatase activity used for the treatment of breast cancer in post-menopausal women. Treatment with <em>4</em>-OHA has been shown to inhibit the peripheral conversion of <em>androstenedione</em> to oestrone and reduce plasma oestrogen concentrations, but the effect of treatment on breast-tissue oestrone concentrations is not known. We have therefore examined the effect of treatment with <em>4</em>-OHA on oestrone concentrations in normal and malignant breast tissues and also measured plasma and tissue <em>4</em>-OHA concentrations. Changes in tumour oestrone concentrations were related to DNA polymerase alpha activity, a marker of cellular proliferation. Blood and breast-tissue samples were obtained before and 36 hr after treatment with <em>4</em>-OHA. The mean plasma concentration of <em>4</em>-OHA was 27.9 +/- 19.3 ng/ml, compared with levels of 33.7 +/- 25.6 ng/g for breast tumour and 13.5 +/- 11.5 ng/g for normal breast tissue. There was a significant correlation between <em>4</em>-OHA concentrations in plasma and normal breast tissue (r = 0.91, p less than 0.001). Treatment with <em>4</em>-OHA resulted in a significant (p less than 0.02) decrease in breast-tissue oestrone concentrations. For 3/<em>4</em> tumour samples, a marked decrease in the concentration of oestrone (78 +/- <em>4</em>%) was associated with a similar decrease (6<em>4</em> +/- 16%) in DNA polymerase alpha activity. It is concluded that treatment with <em>4</em>-OHA effectively reduces breast-tissue exposure to oestrogen.

BACKGROUND

Radiotherapy (RT) is considered a standard treatment option after surgery for breast cancer. Letrozole, an aromatase inhibitor, is being evaluated in the adjuvant setting. We determined the effects of the combination of RT and letrozole in the aromatase-expressing breast tumour cell line MCF-7CA, stably transfected with the CYP19 gene.

METHODS

Irradiations were performed using a cobalt-60 source with doses ranging from 0 to <em>4</em> Gy. Cells were incubated with <em>androstenedione</em> in the presence or absence of letrozole. Effects of treatment were evaluated using clonogenic assays, tetrazolium salt colorimetric (MTT) assays, and cell number determinations. Cell-cycle analyses were conducted using flow cytometry.

RESULTS

The survival fraction at 2 Gy was 0.66 for RT alone and was 0.<em>4</em><em>4</em> for RT plus letrozole (P = 0.02). Growth of MCF-7CA cells as measured by the cell number 6 days after radiotherapy (2 and <em>4</em> Gy) was decreased by 76% in those cells treated additionally with letrozole (0.7 microM) compared with those receiving radiotherapy alone (P = 0.009). Growth inhibition, assessed either by cell number (P = 0.009) or by the MTT assay (P = 0.02), was increased after 12 days of the combination treatment. Compared with radiation alone, the combination of radiation and letrozole produced a significant decrease in radiation-induced G2 phase arrest and a decrease of cells in the S phase, with cell redistribution in the G1 phase.

CONCLUSIONS

These radiobiological results may form the basis for concurrent use of letrozole and radiation as postsurgical adjuvant therapy for breast cancer.

Transforming growth factor type beta (TGF-beta) suppresses basal as well as corticotropin (ACTH)-stimulated steroid formation by bovine adrenocortical cells in culture. The effect is dose dependent and is not accompanied by any change in adrenocortical cell growth. The minimum effective dose of TGF-beta is <em>4</em> X 10(-13) M (10 pg/ml), and maximal inhibition is observed at a concentration of <em>4</em> X 10(-11) M (1 ng/ml). A 16- to 20-hr incubation with TGF-beta is required to decrease steroidogenesis, and 12-18 hr are required before cells treated with TGF-beta recover complete responsiveness to corticotropin. Increases in cAMP mediated by corticotropin, forskolin, and isobutylmethylxanthine are not modified by the addition of TGF-beta; thus adenylate cyclase activity is unaffected by TGF-beta. Although TGF-beta inhibits the formation of all of the delta <em>4</em>-steroids measured (including cortisol, corticosterone, aldosterone, and <em>androstenedione</em>), its effect can be completely reversed by the addition of 25-hydroxycholesterol, pregnenolone, or progesterone to the cells. In contrast, the addition of low density lipoprotein has no effect suggesting that TGF-beta targets the conversion of cholesterol precursors to cholesterol. The results demonstrate a highly potent effect of TGF-beta on the differentiated function of the adrenocortical cell. The inhibition of steroidogenesis can be dissociated from any effect on cell proliferation, and it occurs distal to the formation of cAMP but proximal to the formation of cholesterol. The results suggest that in the adrenal, TGF-beta or TGF-beta-like proteins may be playing an important role in modifying the differentiated state of the adrenocortical cell.

The anti-parkinsonian agent orphenadrine has been shown to form an in vitro metabolic intermediate (MI) complex in hepatic microsomes isolated from phenobarbital (PB)-treated rats. The present study was undertaken to assess the cytochrome P-<em>4</em>50 isozyme specificity of inhibition and MI complexation. Spectral studies with untreated and PB-induced rat hepatic microsomes confirmed earlier reports on the selectivity of P-<em>4</em>50 complexation by orphenadrine; MI complex formation was only observed with PB-induced microsomes. Inhibition studies with the P-<em>4</em>50 substrates androst-<em>4</em>-ene-3,17-dione (<em>androstenedione</em>) and 7-pentoxyresorufin revealed selective inhibition of P-<em>4</em>50 PB-B/D-associated monooxygenase activity. Thus, in microsomes from untreated male rats, orphenadrine failed to significantly inhibit (less than 50% inhibition up to a concentration of 300 microM) any of the major pathways of P-<em>4</em>50-associated <em>androstenedione</em> metabolism. Preincubation of these microsomal fractions with orphenadrine and NADPH was not associated with increased inhibition of <em>androstenedione</em> metabolism. However, in PB-induced microsomes, P-<em>4</em>50 PB-B/D-specific <em>androstenedione</em> 16 beta-hydroxylase activity was significantly and selectively inhibited (IC50 = 90 microM). Preincubation of orphenadrine with NADPH-supplemented PB-induced microsomes for 2, <em>4</em>, or 8 min before <em>androstenedione</em> addition resulted in increased inhibition toward 16 beta-hydroxylase activity, lowering the observed IC50 to 6.6, 0.<em>4</em>7, and 0.06 microM), respectively. Preincubation did not affect the selectivity of inhibition. In the absence of preincubation, orphenadrine appeared to be a potent mixed (competitive/noncompetitive)-type inhibitor of P-<em>4</em>50 PB-B/D-associated pentoxyresorufin O-depentylation (Ki = 3.8 microM). Preincubation of orphenadrine with NADPH-supplemented microsomal fractions for <em>4</em> min resulted in a 30-fold lowering of the apparent inhibitor constant (Ki = 0.13 microM) and a change in the apparent inhibition kinetics to noncompetitive. Treatment of rats with orphenadrine (75 mg/kg/day intraperitoneally for 3 days) was associated with a 2-fold induction of total hepatic P-<em>4</em>50, a 5- and 2.<em>4</em>-fold induction of <em>androstenedione</em> 16 beta- and 6 beta-hydroxylase activity, respectively, and formation of an orphenadrine-P-<em>4</em>50 MI complex. Western blots of orphenadrine-induced microsomes revealed a 20-fold increase in P-<em>4</em>50 PB-B/D-immunoreactive protein.(ABSTRACT TRUNCATED AT <em>4</em>00 WORDS)

This study was designed to determine the effects of FSH and LH on ovarian follicular development in adult hypophysectomized (HX) mice. Twelve days after HX, the animals received s.c. injections of ovine FSH (oFSH; <em>4</em> micrograms/day) or oFSH (<em>4</em> micrograms/day) plus ovine LH (oLH; 2 micrograms/day) twice a day for 1 to <em>4</em> days. After <em>4</em> days of treatment with FSH alone, the number of preantral follicles (stages 1-3) increased significantly compared to that in HX controls and reached cyclic numbers; however, incorporation of [3H]thymidine into these preantral follicles as compared to HX controls did not increase. The number of healthy antral follicles (stages <em>4</em>-5) and incorporation of [3H]thymidine into stage 5 follicles started to increase after only 1 day of treatment with FSH, and the number of atretic follicles concomitantly decreased. Treatment with both FSH and LH for 1 to <em>4</em> days increased the number of healthy follicles and restored DNA synthesis at all stages (1-5) to normal levels. Two days of replacement with FSH or FSH plus LH was required for follicles to attain preovulatory size (stage 6). FSH alone induced FSH and hCG receptors in granulosa cells, but without the induction of thecal LH/hCG receptors; FSH induced production of progesterone and <em>androstenedione</em> by stage 6 follicles, but not estradiol (E2) accumulation in the incubation medium or in the serum. Combined FSH and LH induced hCG receptors in the theca and interstitium, and also restored follicular E2 production to proestrous values. LH alone increased only the number of stage 2-3 follicles. Unexpectedly, LH alone also induced thecal hCG receptors as well as FSH receptors in granulosa cells of preantral and antral follicles. The present results demonstrate that FSH is essential for follicular growth at all stages and for prevention of atretic antral follicles. Both FSH and LH are necessary for regulation of follicular development and differentiation from the earliest preantral to preovulatory stages.

The aims of the present studies were to determine the number, size range, health, and steroidogenic activities of antral follicles in normal human ovaries during the luteal phase of the menstrual cycle. Steroidogenic activity was assessed from the levels of <em>androstenedione</em>, testosterone, and estradiol in follicular fluid and the levels of extant and FSH-stimulable aromatase activity and FSH-stimulable progestin synthesis in the granulosa cells. Data for luteal phase ovaries were compared to those obtained for ovaries from the late follicular phase. On average, 9<em>4</em>% (range, 70-100%) of the luteal phase follicles (greater than or equal to 1 mm diameter) were atretic as assessed by oocyte viability and granulosa cell number. The largest healthy follicles during the mid- to late luteal phase were <em>4</em>-<em>4</em>.5 mm in diameter; these contained high levels of aromatizable androgen (500-2000 ng/ml), low levels of estradiol (less than 10 ng/ml), and granulosa cells with an extant level of aromatase activity 200 times lower than that in a preovulatory follicle. Based on these biochemical criteria, healthy (luteal phase) follicles were not distinguishable from atretic follicles. Granulosa cells from the luteal phase follicles were responsive to FSH with respect to progesterone and estradiol biosynthetic activity; the aromatase system in the cells from the mid- to late luteal phase follicles was significantly more responsive to FSH than that in cells from late follicular or early luteal phase follicles (P less than 0.05). These data suggest that the number of healthy luteal phase follicles (greater than or equal to 1 mm diameter) available for subsequent preovulatory development is limited.

Brain aromatase (ARO) activity in the quail is markedly enhanced by testosterone (T). This effect only becomes detectable after several hours and reaches its maximum within a few days, which suggests enzymatic induction at the genomic level. This idea is reinforced by the fact that T also increases the ARO protein, as observed by immunocytochemistry (ICC) and the ARO mRNA, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR). These changes can be mimicked by the administration of estrogens and therefore presumably require T aromatization. In our first test, injection of the non-steroidal ARO inhibitor, R76713 (racemic vorozole), unexpectedly revealed an increase in ARO immunoreactivity in the preoptic area (POA) of treated birds. This property of R76713 was shared by another non-steroidal inhibitor, fadrozole, but not by two steroidal inhibitors, androstatrienedione (ATD) and <em>4</em>-hydroxy-<em>androstenedione</em> (OHA). These last two compounds markedly decreased the concentration of brain ARO as estimated by ICC. In parallel, ATD and OHA decreased ARO mRNA concentration measured by RT-PCR but vorozole and fadrozole had no effect on these concentrations in the POA, and only caused them to decrease slightly in the posterior hypothalamus. Together, these data indicate that the removal of estrogens caused by steroidal inhibitors decreases the synthesis of ARO, presumably at the transcriptional level. Additional regulatory mechanisms apparently take place after the injection of non-steroidal inhibitors and probably include increased half-life of the protein. The induction of ARO activity by steroids appears to be greater in males than in females, but this difference has been difficult to localize and confirm by assay methods. We therefore analysed by ICC the tridimensional distribution of ARO-ir neurons in the POA of males and females that were sexually mature or gonadectomized and treated with T-filled or control empty implants. Localized sex differences and effects of T were detected in this way. In particular, males had more ARO-ir cells than females in the lateral POA but a difference in the opposite direction was evident in the medial part of this area. These sex differences are largely activational (i.e. caused by the higher T levels in males) but they may also reflect organizational effects of neonatal steroids. Castration decreased ARO-ir cell numbers in the lateral POA, but increased it in the periventricular region. This anatomically specialized control by T may be mediated by three potential mechanisms that are discussed and comparatively evaluated: a migration of ARO neurons towards the ventricle after castration; a differential colocalization of ARO with estrogen receptors or a differential modulation of ARO neurons by catecholaminergic inputs.

OBJECTIVE

The aim of this study to evaluate during normal pregnancy plasma bioavailable testosterone and androstanediol glucuronide levels.

METHODS

Bioavailable testosterone, androstanediol glucuronide and SHBG levels were evaluated every <em>4</em> weeks from week 6 to week 38 in 10 normal pregnant women. We also measured plasma oestradiol, oestriol, delta <em>4</em>-<em>androstenedione</em>, 17-hydroxyprogesterone, progesterone and testosterone.

RESULTS

The mean bioavailable testosterone levels were within the range of non-pregnant women but with an increasing trend until delivery. Androstanediol glucuronide had increased at weeks 6 and 8, decreased at week 1<em>4</em>, remained low at week 30, and increased again at week 3<em>4</em>. SHBG was significantly correlated with testosterone, oestradiol and oestriol. No correlation could be established between androstanediol glucuronide and any other parameter.

CONCLUSIONS

Bioavailable testosterone (non-SHBG bound testosterone) represents the sum of free testosterone plus albumin bound testosterone. The increase in testosterone concentrations with decreased albumin levels during pregnancy, could suggest reduced metabolic clearance of testosterone throughout pregnancy. No correlation was established between the decrease in androstanediol glucuronide and increase in progesterone, suggesting that the decrease in androstanediol glucuronide is not a consequence of the inhibitory effect of progesterone on 5 alpha-reductase activity.

BACKGROUND

Concentrations of estrogen and progesterone within the breast could provide a better reflection of breast cancer risk than levels in the circulation. We developed highly sensitive immunoassays for multiple steroid hormones and proteins in the nipple aspirate fluid (NAF), which can be obtained noninvasively with a simple suction device. Previous studies showed that NAF hormone levels are strongly correlated between breasts and within a single breast over time and are predictably related to hormone replacement therapy or use of oral contraceptives. This study evaluates the relationship of NAF estrogen and progesterone levels to those in serum and saliva, the relationship of NAF estradiol to androgenic and estrogenic precursors in NAF, and the relationship of NAF hormone levels to those of response proteins such as cathepsin D and epidermal growth factor (EGF).

METHODS

Normal premenopausal women collected saliva daily and donated blood and NAF in the midluteal phases of menstrual cycles at intervals of 0, <em>4</em>, 12, and 15 months. Analytes were measured by immunoassays after solvent fractionation. Log-transformed values were fit to repeated measures analysis of covariance models to ascertain associations between analytes.

RESULTS

Small nonsignificant associations were found between NAF and serum or salivary estradiol. However, progesterone in NAF was significantly associated with progesterone in serum and saliva (R=0.18 and 0.32, respectively). Within NAF, the estradiol precursors estrone sulfate, androstenedione, and dehydroepiandrosterone were significantly associated with estradiol concentration (P<0.06), and a multiprecursor model explained the majority of variance in NAF estradiol (model R(2)=0.83). Cathepsin D and EGF in NAF could not be predicted from serum or salivary steroid measurements; however, both could be predicted from estradiol and its precursors in NAF (model R(2)=0.70 and 0.93, respectively).

CONCLUSIONS

By showing consistent associations between estradiol and its precursors and response proteins, these data provide support for the biological validity of NAF hormone measurements and for the importance of steroid interconversion by aromatase and sulfatase within the breast. The low correlation between estrogen levels in NAF and those in serum or saliva suggests that the degree of association between estrogen or its androgen precursor levels and risk of breast cancer observed in epidemiologic studies using serum estimates might be highly attenuated.

Ten male pseudohermaphrodites with 17 beta-hydroxysteroid dehydrogenase 3 (17 beta-HSD3) deficiency were evaluated in 1 clinic with an average follow-up of 10.1 years. The diagnoses were made by demonstrating low to normal serum testosterone levels, high <em>androstenedione</em> levels, and high ratios of serum <em>androstenedione</em> to testosterone in the basal state or after treatment with human chorionic gonadotropin. The molecular features of the underlying mutations were identified in all 7 families. Two additional males in the same families are believed to be affected on the basis of history obtained from family members. All of the <em>4</em>6,XY individuals in these families were registered at birth and raised as females (despite the presence of ambiguous genitalia in all or most), and all virilized after the time of expected puberty due to a rise in serum testosterone to or toward the normal male range. The age at diagnosis varied from <em>4</em> to 37 years. Ten individuals were studied by the same psychologist, and change of gender role (social sex) from female to male occurred in 3 subjects and in the 2 presumed affected subjects not studied. The individual with the highest serum testosterone level maintained female sexual identity, and in 2 families some of the affected males changed gender role and others did not. Thus, while androgen action plays a role in the process, additional undefined psychological, social, and/or biologic factors must be determinants of gender identity/role behavior. Management of the 7 individuals who chose to maintain female sex roles included castration, clitoroplasty, vaginal enlargement procedures when appropriate, treatment of hirsutism, cricoid cartilage reduction, and estrogen replacement. Three of the 7 are married (2 twice), 1 is involved in a long-term heterosexual relationship, 1 is engaged to be married, and the other 2 are not married and not believed to be sexually active. The 3 subjects who changed gender role behavior to male underwent hypospadias repair, and 1 was given supplemental testosterone therapy. One of these men is divorced, and the other 2 (aged 29 and 35 years) are unmarried. The diagnosis in 8 of these subjects was made after the time of expected puberty; it is unclear whether the functional and social outcomes would have been different if the diagnosis had been made and therapy begun earlier in life.

Castrated male primates, unlike castrated male rodents, respond to exogenous estrogen by releasing gonadotropin. Although this disparity is unexplained, it may occur because the amount of testicular androgen secreted during a critical period for sexual differentiation is not sufficient to completely androgenize the anlagen of the central nervous system (CNS) in male primates. Therefore, male primates might be incompletely masculinized, and if fetal males were exposed to additional androgen during sexual development, they would no longer display the positive feedback to estrogen that usually characterizes females. Besides the development of mechanisms mediating the release of gonadotropins, questions about relationships between adult male sexual behaviors and the intensity of the androgen stimulus upon developing neural structures are of interest. We tested some of these possibilities by injecting androgen into 8 pregnant rhesus macaques from Days <em>4</em>0 through 50 of gestation, and we compared serum levels of testosterone (T), dihydrotestosterone (DHT), and <em>androstenedione</em> (delta <em>4</em>) in the fetal circulation with that of 5 untreated control males. Fetal sera (both male and female) from treated pregnancies did not contain significantly greater quantities of T and DHT than sera of intact control males from untreated mothers. The maternal sera, however, contained large amounts of T (125.05 +/- 27.<em>4</em>0 [SEM] ng/ml, n = 8) and significant elevations of DHT and delta <em>4</em> after treatment. The concentrations of delta <em>4</em> in the fetal circulation were significantly elevated (p less than 0.01) in treated fetuses compared to intact control males, probably due to the actions of the 17 beta-hydroxysteroid dehydrogenases in the placenta, the fetus, or both.(ABSTRACT TRUNCATED AT 250 WORDS)

The somatotropic axis, GH, and IGF-I interact with the hypothalamic-pituitary-gonadal axis in health and disease. GH-resistant GH receptor-disrupted knockout (GHRKO) male mice are fertile but exhibit delayed puberty and decreases in plasma FSH levels, testicular content of LH, and prolactin (PRL) receptors, whereas PRL levels are elevated. Because the lifespan of GHRKO mice is much greater than the lifespan of their normal siblings, it was of interest to compare age-related changes in the hypothalamic-pituitary-gonadal axis in GHRKO and normal animals. Plasma IGF-I, insulin, PRL, LH, FSH, <em>androstenedione</em> and testosterone levels, and acute responses to GnRH and LH were measured in young (2-<em>4</em> and 5-6 months of age) and old (18-19 and 23-26 months of age) male GHRKO mice and their normal siblings. Plasma IGF-I was not detectable in GHRKO mice. Plasma PRL levels increased with age in normal mice but declined in GHRKO males, and did not differ in old GHRKO and normal animals. Plasma LH responses to acute GnRH stimulation were attenuated in GHRKO mice but increased with age only in normal mice. Plasma FSH levels were decreased in GHRKO mice regardless of age. Plasma testosterone responses to LH stimulation were attenuated in old mice regardless of genotype, whereas plasma <em>androstenedione</em> responses were reduced with age only in GHRKO mice. Testicular IGF-I mRNA levels were normal in young and increased in old GHRKO mice, whereas testicular concentrations and total IGF-I levels were decreased in these animals. These findings indicate that GH resistance due to targeted disruption of the GH receptor gene in mice leads to suppression of testicular IGF-I levels, and modifies the effects of aging on plasma PRL levels and responses of the pituitary and testes to GnRH and LH stimulation. Plasma testosterone levels declined during aging in normal but not in GHRKO mice, and the age-related increase in the LH responses to exogenous GnRH was absent in GHRKO mice, perhaps reflecting a delay of aging in these remarkably long-lived animals.