Influence of insulin and testosterone on adrenocortical steroidogenesis in vitro: preliminary studies.

OBJECTIVE: The mechanisms underlying the adrenal androgen (AA) excess of polycystic ovary syndrome (PCOS) remain unclear, although it is possible that the adrenocortical dysfunction may be a response to other, extraadrenal factors. Consistent with the pathophysiology of PCOS and with in vivo data in normal and PCOS women, we have hypothesized that insulin inhibits and that T stimulates AA secretion in vitro. DESIGN: In vitro experimental study. SETTING: University medical center. PATIENT(S): Normal human adrenals (n = 4 women, ages 25-57 years) were obtained with consent at the time of organ donation. INTERVENTION(S): Fresh adrenal tissue minces were incubated in serum-free medium with 10-microM pregnenolone substrate and 1-microM ACTH-(1-24). Challenge doses of 0.2, 1, 5, 20, and 100 nM of insulin and 1, 10, 100, 1,000, and 10,000 nM of T were added, and the media were sampled after 8 hours of incubation at 37 degrees C, 4% CO2. Dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEAS), and cortisol (F) were measured by radioimmunoassay (significant effects compared with the case of zero-dose control). MAIN OUTCOME MEASURE(S): The production of DHEA, DHEAS, and F in the media of the adrenal minces was compared between different subjects and at different concentrations of T and insulin. RESULT(S): Analysis of the combined data from all donors indicated that insulin stimulated DHEAS and suppressed DHEA production but had no consistent effect on F. Similar analyses of the combined data indicated that T had no significant predictable effect on the production of DHEAS, DHEA, or F. When examining donor data individually, insulin and T did elicit significant increases and/or decreases in steroid production within subjects, although no consistent trends were observed. CONCLUSION(S): On the basis of these data, it is clear that extra-adrenal factors such as insulin and T have some adrenal regulatory capacity. In general, insulin stimulated DHEAS and decreased DHEA production, suggesting that it increases adrenocortical sulfotransferase activity. However, although in the individual subjects studied, both insulin and T frequently altered the production of DHEAS, DHEA or F, these effects did not appear to be uniform or consistent from subject to subject. Expanded studies are required to confirm these results.

Altered autophosphorylation of the insulin receptor in the ovary of a woman with polycystic ovary syndrome.

OBJECTIVE: To determine whether the tyrosine autophosphorylation of the insulin receptor (IR) in the ovary of a woman with polycystic ovary syndrome (PCOS) was reduced compared to normal. DESIGN: Experimental study. SETTING: Tertiary care medical center. PATIENT(S): One woman with PCOS and one healthy control, both of whom underwent a hysterectomy and bilateral salpingo-oophorectomy. INTERVENTION(S): Plasma membrane fraction of ovarian tissue was isolated, and the IR was purified and concentrated. MAIN OUTCOME MEASURE(S): Western blots of the IR, which had been incubated with and without insulin, were prepared. Colorimetric and chemiluminescent methods were used to detect the presence of the IR beta-subunit and IR tyrosine autophosphorylation, respectively. RESULT(S): The presence of the beta-subunit of the IR was identified in both ovarian samples. The degree of insulin-stimulated IR tyrosine autophosphorylation, reflected by the mean (+/-SD) relative optical density of the 95 kd band, was 4.3-fold higher in the normal ovary compared to the PCOS ovary (0.56 +/- 0.18 optical density vs. 0.13 +/- 0.10 optical density, respectively). CONCLUSION(S): Tyrosine autophosphorylation of the IR may be decreased in the ovaries of women with PCOS, similar to the findings in other tissues. The mechanisms through which insulin acts to produce an excess in ovarian androgen production in the face of a decrease in ovarian IR autophosphorylation remain to be determined.

Levels of progesterone, testosterone, and estradiol, and androstenedione metabolism in the gonads of Lytechinus variegatus (Echinodermata:echinoidea).

Levels of progesterone (P4), testosterone (T) and estradiol (E2) indicated significant variation among individual echinoids during the annual cycle, reflecting generally the variation in gamete development that can be observed among individuals. Testosterone and E2 levels in both the ovaries and testes were higher during the period of gonadal growth. Levels of all steroids were greatly reduced compared to those levels reported for asteroids. Differences in the levels of P4, T, and estrogens between asteroids and Lytechinus variegatus may be related to differences in gonad morphology and nutrient storage capacity between asteroids and echinoids. It was hypothesized that the low levels of steroids detected in L. variegatus reflect paracrine-like mechanisms in cell signaling as compared to endocrine-like mechanisms proposed to be involved in regulating gonad function in asteroids. Both the ovaries and testes of L. variegatus had the capacity to synthesize T and a variety of 5alpha-reduced androgens including 5alpha-androstane-3beta,17beta-diol and 5alpha-androstane-3alpha,17beta-diol (5alpha-adiols) from androstenedione (AD) in 8 h. Estrogen synthesis was not detected. The sex-specific pattern of accumulation of 5alpha-adiols in the ovaries and testes suggests that the 5alpha-adiols may affect processes related to reproduction in L. variegatus.

Prevalence of 21-hydroxylase-deficient nonclassic adrenal hyperplasia and insulin resistance among hirsute women from Puerto Rico.

OBJECTIVE: To determine the prevalence of 21-hydroxylase (21-OH)-deficient nonclassic adrenal hyperplasia (NCAH) and insulin resistance in hirsute women from Puerto Rico. DESIGN: Cross-sectional prospective study. SETTING: Clinical research center. PATIENT(S): 100 consecutive untreated hirsute women. MAIN OUTCOME MEASURE(S): Fasting total T, free T, DHEAS, insulin, and glucose were measured, and a 60-minute acute ACTH-(1-24) stimulation for 17-hydroxyprogesterone (17-HP) was performed. A diagnosis of 21-OH-deficient NCAH was considered when the stimulated 17-HP level was >30.3 nmol/L. The glucose/insulin ratio was calculated as a measure of insulin resistance (normal value, > or =4.5). RESULT(S): Patients had a mean (+/-SD) age of 26.8+/-6.6 years; 82 were oligomenorrheic. Overall, 12%, 8%, and 60% of patients had elevated levels of DHEAS, total T, or free T, respectively. One patient was identified as having 21-OH-deficient NCAH. Eight women, none of whom had NCAH, were found to be hyperglycemic; four of these women had type 2 diabetes mellitus. Excluding hyperglycemic patients, a glucose/insulin ratio of <4.5, consistent with IR, was found in 51.7%. CONCLUSION(S): The prevalence of 21-OH-deficient NCAH among patients from Puerto Rico does not differ significantly from that reported for other non-Jewish, non-Hispanic white populations.

Effects of aging on adrenal function in the human: responsiveness and sensitivity of adrenal androgens and cortisol to adrenocorticotropin in premenopausal and postmenopausal women.

We sought to determine the effects of aging on several aspects of adrenal steroidogenesis in the hopes of characterizing the possible causes of adrenal androgen deficiency in elderly women. To this end, we quantified basal morning concentrations of cortisol (F), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DS), and androstenedione (A4) and then evaluated the effects of overnight dexamethasone (DEX) suppression followed by adrenal responses to graded hourly infusions of ACTH, ranging from 20-1280 ng/1.5 m2 x h. Finally, we performed a standard 0.25-mg ACTH bolus stimulation test, with sampling at 1 h thereafter. Basal serum levels of DHEA, DS, and A4 were significantly reduced (approximately 50% each) in a group of 35 healthy postmenopausal women, 55-68 yr old, compared to those in 30 healthy, regularly menstruating women, 20-25 yr old. Post-DEX levels of these C19 steroids also were significantly lower in the older women than in the younger women; the percent decrease after DEX for A4 was greater in the older women, whereas those in DHEA and DS were not age related. Basal and post-DEX levels of F were similar in both groups. Secretory responses of DS to ACTH were not informative due to its large plasma pool and slow clearance rate. The maximally stimulated levels of DHEA after ACTH bolus were significantly lower in the older women than in younger women; those of A4 were similar in both age groups, and the maximally achieved levels of F were higher in the older women than in the younger women. The sensitivity of adrenal DHEA, A4, and F to ACTH (defined as the minimal dose of ACTH required to significantly increase the steroid levels above basal post-DEX values) was similar in older and younger women. The responsiveness of the steroids of interest to ACTH (defined as the slope of the dose-response curve over the linear portion of the dose-response curve) also was similar among younger and older women. These data demonstrate that the deficiency in adrenal androgen production in women is restricted to the delta5-pathway steroid products (DHEA and DS), whereas there is no reduction in the capacity of the adrenal to produce A4 or cortisol. As DHEA and DS are likely to be produced mainly in the zona reticularis of the adrenal cortex, we propose that these data point to an alteration in that cortical zone as the cause of adrenal androgen deficiency in aging. The reductions in A4 in aging are probably due to reduced ovarian secretion after menopause.

Steroid levels and steroid metabolism in relation to early gonadal development in the tilapia Oreochromis niloticus (Teleostei: cyprinoidei).

Sex steroid levels and steroid metabolism were investigated in relation to early gonadal development in a mixed sex population of the tilapia Oreochromis niloticus. Androstenedione (AD), testosterone (T), 11-ketotestosterone (KT), and estradiol (E2) were quantified by radioimmunoassay (RIA) of whole body extracts. Androstenedione metabolism was assessed by incubations in vitro with 3H-AD and metabolites were identified by thin-layer chromatography coupled with radioisotope image analysis. Histology revealed the presence of gonadal structures at 15 days postfertilization (dpf) and ovaries at 36 dpf, with other individuals exhibiting undifferentiated gonads containing germinal cells, presumably eventual testes. Androgen levels were initially high in eggs then decreased severalfold prior to the emergence of gonads. A transient increase in the levels of T and KT occurred at 22 dpf. Levels of E2 were either low or undetectable except for a transient increase (43 dpf) after ovaries were present. Levels of T approached bimodality from 57 to 64 dpf. Steroid metabolism generally increased throughout development. Metabolites were generally similar, consisting of T predominantly as well as 5beta-reduced androgen derivatives and 11-oyxgenated derivatives. Estriol was tentatively identified. Conjugated steroids were not formed. Two types of steroid metabolic profiles occurred at 50 dpf. These results demonstrate that changes in the steroidogenic profile occur during early transitions of gonadal development. Notably, (1) steroid biosynthetic capacity preceeds gonadal differentiation, (2) evidence for estrogens occurs after ovarian development has begun, and (3) bimodality of levels of T and differential steroid metabolism later in development may reflect the onset of sexual divergence.

Ovulation after glucocorticoid suppression of adrenal androgens in the polycystic ovary syndrome is not predicted by the basal dehydroepiandrosterone sulfate level.

Adrenal androgen (AA) excess, primarily in the form of dehydroepiandrosterone sulfate (DHEAS), affects over 50% of women with the polycystic ovary syndrome (PCOS). Nonetheless, it is unclear what role AA excess plays in the PCOS-associated oligo-ovulation. We have hypothesized that AAs are important in the maintenance of the ovulatory dysfunction of women with PCOS and AA excess, which can be improved by glucocorticoid suppression. To test our hypothesis we prospectively studied 36 unselected women, ages 18-40 yr, with PCOS; i.e. oligomenorrhea (cycles > 35 days in length), and clinical/ biochemical evidence of hyperandrogenism (i.e. hirsutism and/or hyperandrogenemia), after the exclusion of related disorders. After informed consent, all patients underwent an acute ACTH-(1-24) stimulation test, measuring androstenedione, dehydroepiandrosterone (DHEA) and cortisol (F), and were then treated with dexamethasone 0.5 mg/day for four cycles. Ovulatory function was assessed before and during treatment using a basal body temperature calendar and day 22-24 progesterone (P4) levels. If patients were anovulatory (P4 < 4 ng/mL), a withdrawal bleed was induced by the administration of 100 mg P4 in oil i.m. Before and during treatment the levels of total and free testosterone (T), sex hormone-binding globulin, androstenedione, DHEA, DHEAS, cortisol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were monitored. With therapy, all patients demonstrated a significant decrease in all androgens (-40-60%), a 24% increase in sex hormone-binding globulin, and no change in LH/FSH. Mean body weight increased by over 4 kg (4.4%) during treatment. Of the 138 cycles monitored, 78% remained anovulatory. Twenty-five percent, 17%, 14%, and 20% of the first, second, third, and fourth treatment cycles, were ovulatory, respectively (P = 0.381). Of the 36 patients studied, 18 (50%) did not demonstrate a single ovulatory cycle (i.e. a day 22-24 P4 level > 4 ng/mL); and of the remaining, 10 (28%) had only one, five (14%) had two, and three (8%) had three ovulatory cycles. There were no significant differences either in physical features, basal hormones, adrenal response to ACTH stimulation, or hormonal levels at the end of treatment, between those women ovulating and those not. Finally, there were no differences in ovulatory response to dexamethasone therapy between women with (n = 14) and without (n = 22) DHEAS excess (i.e. DHEAS > 2750 ng/mL). In conclusion, the data from this prospective study do not suggest that continuous dexamethasone suppression results in consistent ovulation in any PCOS patient, regardless of basal DHEAS levels. Furthermore, this treatment is associated with significant side-effects, notably weight gain. Finally, these data suggest that, while AA may be an important risk factor for PCOS, once the syndrome is established, they play a limited role in the associated ovulatory dysfunction.

Impact of architectural disruption on adrenocortical steroidogenesis in vitro.

The adrenal cortex is an architecturally complex tissue, with cellular zonation thought to determine steroidogenesis. The impact that disruption of this tissue's architecture has on steroidogenesis in vitro, particularly adrenal androgen (AA) production, is unclear. We hypothesized that the extent of architectural disruption during tissue preparation would impact the study results. To test this hypothesis, we compared adrenocortical steroidogenesis in freshly prepared tissue slices, minces, and cell suspensions. Normal human adrenals (n = 5, three males and two females, age range 17-43 yr) were obtained at the time of organ donation. The three adrenal tissue preparations were incubated in serum-free medium with 10 microM pregnenolone substrate +/- 1 microM ACTH. The production of dehydroepiandrosterone, dehydroepiandrosterone sulfate, androstenedione, and cortisol in the media were measured by radioimmunoassay. Initial time course intubations using adrenals from a single donor generally demonstrated that minces and suspensions had a greater steroid production compared with slices. In another series of 6-hr incubations using adrenals from four donors, production of dehydroepiandrosterone sulfate was found to be quite sensitive to architectural disruption, i.e. slices less than minces less than suspensions (0.88 vs. 2.1 vs. 3.0 microg/gm tissue, respectively, P < 0.0001). Alternatively, cortisol and androstenedione production was higher in minces compared with slices or suspensions (25.6 vs. 37.7 vs. 18.7 ng/gm tissue, P < 0.0028, and 254 vs. 709 vs. 456 ng/gm tissue, P < 0.0042, respectively). Production of dehydroepiandrosterone was apparently not significantly affected by the type of tissue preparation (28.2 vs. 22.2 vs. 31.2 ng/gm tissue, P < 0.297, respectively). It is unlikely that generalized tissue disruption alone accounted for the observed differences, as the trends among tissue preparations were not consistent among steroids. We conclude that the type of tissue preparation of fresh adrenal tissue impacts significantly on steroidogenesis in vitro.

Synthesis of testosterone and 5alpha-androstanediols during nutritionally stimulated gonadal growth in Lytechinus variegatus lamarck (Echinodermata:Echinoidea).

Although sex steroids and steroid converting enzymes have been found in echinoids, the relationship between steroids and reproduction has not been demonstrated. On days 0, 4, 8, 16, 32, and 48 of feeding, the gonads of previously starved Lytechinus variegatus were excised and incubated with [3H]androstenedione for 0.5 h to determine if changes in steroidogenic capacity are correlated with gonadal growth. Total rates of androstenedione conversion in the testes and ovaries increased significantly during feeding. In addition, the types and relative quantities of metabolites synthesized varied, suggesting that androstenedione metabolism is influenced by nutritional status. Both testes and ovaries synthesized testosterone, 5alpha-androstane-3alpha,17beta-diol, and 5alpha-androstane-3beta, 17beta-diol (5alpha-adiols), 5alpha-androstanedione, epiandrosterone, and androsterone on all days of feeding. In the testes, the relative quantities of testosterone and 5alpha-adiols increased greatly on day 4 of feeding. In contrast, in the ovaries testosterone synthesis was not detectable on day 4, although the relative quantities of 5alpha-adiols increased threefold. The sex-specific changes in the synthesis of these metabolites reflect a shift in the metabolic pathway indicated by changes in the relative enzyme activity indices for 5alpha-reductase (5alpha-R) (necessary for the synthesis of 5alpha-reduced androgens) and 3alpha/beta-hydroxysteroid dehydrogenase (3alpha/beta-HSDs, necessary for the synthesis of 3alpha- or 3beta-hydroxylated androgens). In both testes and ovaries the relative activities of 5alpha-R and 3alpha/beta-HSD increased on day 4 of feeding. The physiological significance of changes in androstenedione metabolism may be associated with the initiation of biosynthetic processes associated with gametogenesis.

Adrenal androgen excess in the polycystic ovary syndrome: sensitivity and responsivity of the hypothalamic-pituitary-adrenal axis.

Over 50% of patients with the polycystic ovary syndrome (PCOS) demonstrate excess levels of adrenal androgens (AAs), particularly dehydroepiandrosterone sulfate (DHS). Nonetheless, the mechanism for the AA excess remains unclear. It has been noted that in PCOS the pituitary and ovarian responses to their respective trophic factors (i.e. GnRH and LH, respectively) are exaggerated. Similarly, we have postulated that excess AAs in PCOS arises from dysfunction of the hypothalamic-pituitary-adrenal axis, due to 1) exaggerated pituitary secretion of ACTH in response to hypothalamic CRH, 2) excess sensitivity/responsivity of AAs to ACTH stimulation, or 3) both. To test this hypothesis we studied 12 PCOS patients with AA excess (HI-DHS; DHS, > 8.1 mumol/L or 3000 ng/mL), 12 PCOS patients without AA excess (LO-DHS; DHS, < 7.5 mumol/L or 2750 ng/mL), and 11 controls (normal subjects). Each subject underwent an acute 90-min ovine CRH stimulation test (1 microgram/kg) and an 8-h incremental i.v. stimulation with ACTH-(1-24) at doses ranging from 20-2880 ng/1.5 m2.h) with a final bolus of 0.25 mg. All patient groups had similar mean body mass indexes and ages, and both tests were performed in the morning during the follicular phase (days 3-10) of the same menstrual cycle, separated by 48-96 h. During the acute ovine CRH stimulation test, no significant differences in the net maximal response (i.e. change from baseline to peak level) for ACTH, dehydroepiandrosterone (DHA), androstenedione (A4), or cortisol (F) or for the DHA/ACTH, A4/ACTH, or F/ACTH ratios was observed. Nonetheless, the net response of DHA/F and the areas under the curve (AUCs) for DHA and DHA/F indicated a greater response for HI-DHS vs. LO-DHS or normal subjects. The AUC for A4 and A4/F and the delta A4/delta F ratio (delta = net maximum change) indicated that HI-DHS and LO-DHS had similar responses, which were greater than that of the normal subjects, although the difference between LO-DHS patients and normal subjects reached significance only for the AUC of the A4 response. No difference in the sensitivity (i.e. threshold or minimal stimulatory dose) to ACTH was noted between the groups for any of the steroids measured. Nonetheless, the average dose of ACTH-(1-24) required for a threshold response was higher for DHA than for F and A4 in all groups. No difference in mean responsivity (slope of response to incremental ACTH stimulation) was observed for DHA and F between study groups, whereas the responsivity of A4 was higher in HI-DHS patients than in normal or LO-DHS women. The net maximal and the overall (i.e. AUC) responses of DHA were greater for HI-DHS than for normal or LO-DHS women. The response of A4 and the delta A4/delta F ratio were greater for HI-DHS patients than for LO-DHS patients or normal subjects. Alternatively, HI-DHS and LO-DHS patients had similar overall responses (i.e. AUC) for A4 or A4/F, although both were greater than those of normal subjects. The relative differences in response to incremental ACTH stimulation between steroids was consistent for all subject groups studied, i.e. A4 > F or DHA. In conclusion, our data suggest that AA excess in PCOS patients is related to an exaggerated secretory response of the adrenal cortex for DHA and A4, but not to an altered pituitary responsivity to CRH or to increased sensitivity of these AAs to ACTH stimulation. Whether the increased responsivity to ACTH for these steroids is secondary to increased zonae reticularis mass or to differences in P450c17 alpha activity, particularly of the delta 4 pathway, remains to be determined.

Sex steroid levels in the testes, ovaries, and pyloric caeca during gametogenesis in the sea star Asterias vulgaris.

The concentrations of progesterone, testosterone, and estradiol were determined via radioimmunoassay in testes, ovaries, and pyloric caeca of the sea star Asterias vulgaris during one complete and two partial gametogenic cycles. These compounds were found in all tissues examined and were present in quantities similar to those reported previously in other echinoderms and in vertebrates. Testes and ovaries exhibited annual growth cycles during which testicular and ovarian mass increased up to 100-fold as gametes were produced and stored until spawning. Pyloric caecal mass varied during the annual reproductive season; however, no seasonal trends were apparent. In the testes, sex steroid levels were highest at the onset of spermatogenesis. Transient increases in the levels of estradiol coincided with spermatogonial mitotic proliferation. Transient increases in the levels of testosterone and progesterone in the testes coincided with spermatogenic column formation and with spermiogenesis, respectively. In the ovaries, estradiol and testosterone levels were highest at the onset of oogenesis while progesterone levels did not change significantly throughout the annual gametogenic cycle. Male and female pyloric caeca exhibited similar seasonal variations in levels of sex steroids as compared with the gonads. It is hypothesized that transient increases in the levels of sex steroids during gametogenesis may serve as endogenous modulators of reproduction.

Androgen metabolism in somatic and germinal tissues of the sea star Asterias vulgaris.

1. Cell-free homogenates of male and female pyloric caeca, body wall, testis and ovary were incubated with radiolabeled 3H-androstenedione. 2. Pyloric caeca had highest rates of androstenedione conversion. The predominant metabolites in the pyloric caeca were testosterone, 5 alpha-androstane-3 beta, 17 beta-diol and 5 beta-androstane-3 beta, 17 beta-diol. 3. In body wall, testicular and ovarian homogenates, androstenedione was converted primarily to testosterone and also to 5 alpha-androstanedione and epiandrosterone. 4. Qualitative and quantitative differences in androgen metabolism in somatic and germinal tissues may be related to tissue-specific regulation of cellular metabolism.

Determination of polyamines in digestive and reproductive tissues of adult Asterias vulgaris (Echinodermata: Asteroidea).

1. The polyamines spermine, spermidine and putrescine were extracted from tissues of Asterias vulgaris and quantitated using thin layer chromatography. 2. In the pyloric caeca, mean (+/- SE) levels of spermine, spermidine and putrescine were 138(15), 86(24) and 415(77) nmol/g wet wt tissue, respectively. In the testes, levels were 95(12), 13(6) and less than 6 nmol/g wet wt. In the ovaries, levels were 105(9), 11(0.8) and 15(8) nmol/g wet wt. 3. High levels of polyamines in the pyloric caeca may be related to secretion or excretion in this tissue. 4. We hypothesize that polyamines will be important in the regulation of cellular activity in these tissues during the annual reproductive cycle.