Simultaneous Measurement of Plasma Progesterone, 17-Hydroxyprogesterone and Estradiol-17B by Radioimmunoassay

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.

Fully automated method for quantitative determination of steroids in serum: An approach to evaluate steroidogenesis

Steroidogenesis is a set of metabolic reactions where the enzymes play a key role to control the physiological levels of steroids. A deficiency in steroidogenesis induces an accumulation and/or insufficiency of steroids in human blood and can lead to different pathologies. This issue added to the low levels of steroids (pg mL^-1 to ng mL^-1) in this biofluid make of their determination an analytical challenge. In this research, we present a high-throughtput and fully automated method based on solid-phase extraction on-line coupled to liquid chromatography with tandem mass spectrometry detection (SPE-LC-MS/MS) to quantify estrogens (estrone and estradiol), androgens (testosterone, androstenedione, dihydrotestosterone and dehydroepiandrosterone), progestogens (progesterone, pregnenolone, 17-hydroxyprogesterone and 17-hydroxypregnenolone), glucocorticoids (21-hydroxyprogesterone, 11-deoxycortisol, cortisone, corticosterone and cortisol) and one mineralocorticoid (aldosterone) in human serum. The performance of the SPE step and the multiple reaction monitoring (MRM) mode allowed reaching a high sensitivity and selectivity levels without any derivatization reaction. The fragmentation mechanisms of the steroids were complementary studied by LC-MS/MS in high-resolution mode to confirm the MRM transitions. The method was characterized with two SPE sorbents with similar physico-chemical properties. Thus, limits of quantification were at pg mL^-1 levels, the variability was below 25% (except for pregnenolone and cortisone), and the accuracy, expressed as bias, was always within ±25%. The proposed method was tested in human serum from ten volunteers, who reported levels for the sixteen target steroids that were satisfactorily in agreement with the physiological ranges reported in the literature.

Mobile phone based ELISA (MELISA)

Enzyme-linked immunosorbent assay (ELISA) is one of the most important technologies for biochemical analysis critical for diagnosis and monitoring of many diseases. Traditional systems for ELISA incubation and reading are expensive and bulky, thus cannot be used at point-of-care or in the field. Here, we propose and demonstrate a new miniature mobile phone based system for ELISA (MELISA). This system can be used to complete all steps of the assay, including incubation and reading. It weighs just 1 pound, can be fabricated at low cost, portable, and can transfer test results via mobile phone. We successfully demonstrated how MELISA can be calibrated for accurate measurements of progesterone and demonstrated successful measurements with the calibrated system.

Effects of lactational level on reactivation of ovarian function, and interval from parturition to first visual oestrus and conception in high-producing holstein cows

Data were collected on 19 high-producing Holstein dairy cows from day 20 post partum until they were either determined pregnant or reached 150 days post partum. Blood metabolites (progesterone (P4), glucose, beta-hydroxybutyrate (BHBA) and free fatty acids (FFA)) were related to the interval from parturition to first luteal phase, first visual oestrus and conception. Prior to data analysis, cows were divided into two groups based on their 120-day milk production and designated as below herd average (BHA; no. = 9) or above herd average (AHA; no. = 10). Average 120-day milk productions for BHA, AHA and herdmates (no. = 56) were 3932 (s.e. 157), 4841 (s.e. 60) and 4353 (s.e. 96) kg, respectively. Days from parturition to first luteal phase were not different between the BHA and AHA groups (31·7 (s.e. 1·7) and 31·5 (s.e. 6·9), respectively). In contrast, days from parturition to first visual oestrus and to conception oestrus were less for the BHA group than for the AHA group (46·8 (s.e. 4·6) and 76·9 (s.e. 7·5) v. 67·7 (s.e. 5·2) and 102·5 (s.e. 9·2) days, respectively (P < 0·05)). Further, average glucose concentration from day 20 to first luteal phase was higher (P < 0·05) for the BHA group than for the AHA group (64·1 (s.e. 1·6) v. 58·4 (s.e. 1·6) mg/dl). From day 20 to first visual oestrus, plasma glucose concentration increased while BHBA and FFA declined; all three metabolites then remained relatively constant until conception. These data suggest that as the amount of milk a dairy cow produces increases, the interval from parturition to first visual oestrus and conception increases. These data are consistent with a suppression of oestrus behaviour rather than with a delayed interval to ovarian cyclicity.

Partial development of the steroidogenic ultrastructural features in degenerative corpora lutea after a single injection of pituitary extract in the Western painted turtle (Chrysemys picta)

Pituitary glands were removed from sexually mature female turtles (Chrysemys picta) and they were injected intraperitoneally (i.p.) into other mature females of the same species (experimental). In addition mature females of the same species received saline injection only (controls). Initially all the turtles used in this study were steroidogenically inactive with corpora lutea already undergoing luteolysis (degeneration) as these turtles had ovioposited their eggs approximately 2 weeks earlier. Forty-eight hour post injection the corpora lutea were removed from the control and experimental turtles. In the experimental turtles, the lutein granulosa cells developed ultrastructural features such as tubular and cisternal smooth endoplasmic reticulum (SER) and mitochondria with tubular cristae associated with lipid droplets. However, the controls maintained degenerative corpora lutea without steroidogenic ultrastructural features. The circulating progesterone (Pro) levels in the experimental turtles were significantly higher than the controls (P<0.049). Although the 48h development of steroidogenic ultrastructural features in the lutein granulosa cells was only partial in development, the effect of the pituitary taken from the inactive donor triggered an activating process within a short period, clear evidence of gonadotropic effect on the inactive corpora lutea. The present data offer interesting information on the short-term effect of gonadotropins during the non-reproductive period. This information may have useful implication under natural conditions particularly during the onset of a new reproductive cycle where the ovary is still inactive.

Sex hormones and the changes in adolescent male lipids: longitudinal studies in a biracial cohort

OBJECTIVE

To determine the role of increasing free testosterone and estradiol in pubertal changes in male lipids.

METHODS

We conducted a 3-year, longitudinal, observation study with biannual visits of 251 black and 285 white boys who were 10 to 15 years of age at enrollment. Sex hormones, lipid parameters, and body composition measures were obtained according to a standard protocol. The body mass index (kg/m(2)) was used to characterize obesity.

RESULTS

White boys had higher triglycerides, lower high-density lipoprotein cholesterol (HDL-C), lower apolipoprotein (apo)AI, and higher apoB than black boys. In boys of both races, increased body mass index was associated with increases in triglycerides, low-density lipoprotein cholesterol, apoB and decreases in HDL-C and apoAII. Within this framework, increased free testosterone was associated with increased apoB and decreased HDL-C and apoAI, whereas increased estradiol was associated with increased HDL-C and decreased triglycerides, low-density lipoprotein cholesterol, and apoB.

CONCLUSION

Changes in sex steroid hormones have significant effects on changes in lipid parameters-increasing free testosterone levels has atherogenic effects and increasing estradiol has antiatherogenic effects.

Sex hormones and lipoproteins in adolescent male offspring of parents with premature coronary heart disease and a control group

OBJECTIVE

To compare pubertal maturation, sex steroid hormones, and lipoproteins and their interrelationships in male offspring of parents with premature coronary heart disease (cases) and a control group.

DESIGN

This was a cross-sectional comparison of cases and members of a control group 10 to 15 years of age.

SUBJECTS AND METHODS

Offspring were recruited from patient lists of area physicians. Members of the control group were recruited from area schools. Body mass (kg/m2), serum lipids, lipoproteins, apolipoproteins, estradiol, and free testosterone were measured.

RESULTS

Differences in age were not significant, but offspring were taller, heavier, and more mature. Offspring had higher total and low density lipoprotein cholesterol. Offspring had lower estradiol levels in early puberty but higher levels in late puberty. With family history and body mass in the regression models for lipid parameters, free testosterone was a significant explanatory factor for total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein, and estradiol was a significant predictor for apolipoprotein B. The percent of the variance in the lipid parameters explained by testosterone and estradiol was small.

CONCLUSION

Sex hormone concentrations appear to be modest but significant predictors of lipoprotein and apolipoprotein concentrations in offspring and a control group in cross-sectional analysis. After controlling for pubertal maturation, hormone and lipid concentrations differed in offspring and the control group.

Changes in plasma lipoprotein concentrations and composition in response to a low-fat, high-fiber diet are associated with changes in serum estrogen concentrations in premenopausal women

We have investigated the effects of a low-fat, high-fiber diet on plasma lipid and lipoprotein levels and serum sex hormone concentrations in 22 normal premenopausal women (mean age, 25.8 +/- 3.8 years). Participants consumed a baseline diet for 4 weeks (40% of calories as fat, 16% as saturated fatty acids, 8% as polyunsaturated fatty acids, 400 mg/d cholesterol, and 12 g/d dietary fiber) and then a low-fat, high-fiber diet for 8 to 10 weeks (16% to 18% of calories as fat, 4% as saturated fatty acids, 4% as polyunsaturated fatty acids, 150 mg/d cholesterol, and 40 g/d fiber). Blood samples for determination of plasma lipids and serum hormones were obtained during the follicular and luteal phases of the menstrual cycle during both diets. Compared with the baseline diet, the low-fat, high-fiber diet resulted in significant decreases in total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations during both the follicular and luteal phases (TC, -14% and -16%; LDL cholesterol, -14% and -17%; and HDL cholesterol, -15% and -18%, respectively). During the follicular phase but not the luteal phase on the low-fat, high-fiber diet, women exhibited significant increases in plasma triglyceride ([TG] 22%) and very-low-density lipoprotein (VLDL)-TG (36%) concentrations. During the follicular phase, serum estrone sulfate concentrations decreased by 25% (P < .0001) when subjects were fed the low-fat, high-fiber diet.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of dietary fat and fiber on serum estrogen concentrations in premenopausal women under controlled dietary conditions

The effect of dietary fiber and fat on serum sex hormones was studied in premenopausal women. After an initial control period during which the diet was high in fat (40% of calories as fat) and low in fiber (12 g/day), the amounts of fat and fiber were varied in the setting of a metabolic kitchen and carefully monitored meals. Forty-eight women completed 58 protocols. When the diet was changed to low-fat (20-25% calories as fat) and high fiber (40 g/day), there were significant decreases in serum concentrations of estrone, estrone sulfate, testosterone, androstenedione, and sex hormone binding globulin (SHBG) and near significant decreases in estradiol and free estradiol. When independent effects were examined, high fiber alone caused a decrease in estradiol and SHBG, whereas fat and fiber caused the observed decrease in estrone sulfate. Dietary fat independently influenced the serum concentration of androstenedione. Increased dietary fiber caused a lengthening of the menstrual cycle by 0.72 day and a lengthening of the follicular phase by 0.85 day.

Elevated serum estradiol associated with increased androstenedione-testosterone ratio in adolescent males with varicocele and gynecomastia

OBJECTIVE

To investigate the testicular function in adolescents with pubertal gynecomastia associated with varicocele before and after varicocelectomy.

DESIGN AND PATIENTS

We have studied six male adolescents 15 to 19 years of age with bilateral gynecomastia. They were selected among other adolescents with gynecomastia because of the presence of visible varicoceles. All of them had normal physical examination and secondary sexual characteristics. This was prospective study of 3 months' duration. All the patients that were included finished the study.

SETTING

All the patients were evaluated in the Endocrine Clinic of Winthrop-University Hospital, a tertiary care unit.

INTERVENTION

Serum testosterone (T), androstenedione (A), and estradiol (E2) responses to the administration of human chorionic gonadotropin (hCG) 2,000 IU for 3 consecutive days before and 3 months after varicocelectomy were determined.

RESULTS

Varicocelectomy did not cause any significant changes in the basal (pre-hCG) levels of the steroid. However, the increase in T levels achieved with hCG was significantly (P less than 0.005) higher after varicocelectomy (before T, 925 +/- 212 ng%; after T, 1,649 +/- 406 ng%). Simultaneously, the stimulated levels of E2 and A were significantly lower (P less than 0.005) after varicocelectomy (E2, 62 +/- 12 pg/mL; A, 326 ng% +/- 80 ng%) than before (E2, 106 +/- 13 pg/mL; A, 580 ng% +/- 95 ng%).

CONCLUSION

The reciprocal effect on the levels of T and its immediate precursor, A, suggests an impairment of the 17-ketoreductase enzyme activity. The increased levels of E2 after hCG and its normalization after varicocelectomy suggests that varicoceles may play a pathogenetic role in the development of gynecomastia.

Comparison of maternal serum estradiol and progesterone levels in pregnancies after induced and spontaneous ovulation

Maternal serum estradiol and progesterone levels during the early 6th to 15th weeks of gestation, were measured by radioimmunoassay in 140 pregnancies following induction of ovulation with gonadotropins or clomiphene citrate. The levels were compared with those observed in 79 spontaneous pregnancies. Significantly higher levels were observed in gonadotropin and clomiphene citrate induced pregnancies (both P values less than 0.001) between the 6th to 9th week of gestation as compared to spontaneous pregnancies. Steroid levels were similar in the two groups from the 9th week onwards. No statistically significant differences in steroid hormone values were observed in aborted and successful pregnancies within each group studied. We conclude that ovulation induction is associated with higher estradiol and progesterone levels until placental steroidogenesis starts.

Plasma lipoprotein cholesterol and endogenous sex hormones in healthy young women

Relationships between plasma levels of lipoproteins and sex hormones were studied in 24 healthy premenopausal women with no risk factors for coronary heart disease. The women were carefully selected to remove the effects of other environmental factors, such as smoking, drugs, alcohol, and exercise, which are known to influence lipid metabolism. They all ate precisely the same Western-style diet for 1 to 2 weeks before blood samples were obtained in the follicular phase of their menstrual cycle. After adjusting for other hormones by multiple regression, significant positive partial correlations were seen between high density lipoprotein cholesterol (HDL-C) and protein bound estradiol (r = .57, P = .02), as well as between very low density lipoprotein cholesterol (VLDL-C) and protein bound estradiol (r = .63, p = .01). A significant negative partial correlation was seen between VLDL-C and free estradiol (r = -.65 P = .01). Conversely, low density lipoprotein cholesterol (LDL-C) levels were negatively correlated with protein bound estradiol (r = -.77, P less than .001) and positively correlated with free estradiol (r = .71, P less than .001). No associations between plasma lipoproteins and testosterone were seen; however, androstenedione was positively correlated with VLDL-C (r = .59, P = .01). These findings show a close link between plasma lipoproteins and sex hormones, and may help to explain the lower risk of coronary heart disease in women.

Serum 11-ketotestosterone and testosterone concentrations associated with reproduction in male bluegill (Lepomis macrochirus: Centrarchidae)

Male bluegill (Lepomis macrochirus) display a complex reproductive behavior involving two alternative life history pathways: delay of sexual maturation to become "parentals" or precocious maturation as "cuckolders." The purpose of our study was to investigate the association of two androgens, 11-ketotestosterone (11KT) and testosterone (T), with reproduction in these two types of males. Radioimmunoassay techniques were used to measure daily levels of the two androgens in the blood serum of parental male bluegill captured during the prespawning, spawning, and nesting periods throughout the reproductive season. Dramatic changes in the levels of 11KT and T were observed among parental males during these periods. Peaks occurred at the onset of spawning activity during each breeding bout. Compared to spawning parental males, spawning cuckolder males had significantly lower serum levels of 11KT. In contrast, the serum levels of T among parental and cuckolder males were not significantly different. These findings suggest that the elevated levels of 11KT are associated with the behaviors displayed by spawning parental males. The levels of T, however, seem to be associated with the occurrence of a phenomenon common to both parental and cuckolder males, such as development of gonads and/or spermiation.

Relative diagnostic value of serum non-SHBG-bound testosterone, free androgen index and free testosterone in the assessment of mild to moderate hirsutism

Recent evidence suggests that steroid hormone loosely bound to albumin is available for target-cell entry. Preliminary studies have suggested that a measure of this fraction, non-sex-hormone-binding globulin-bound testosterone (NSB-T), provides the best in vitro diagnostic test for idiopathic hirsutism. We compared the diagnostic value of NSB-T, total testosterone (T), free testosterone (fT), and the free androgen index (FAI) in supporting the clinical diagnosis in 22 pre-menopausal women with hirsutism. NSB-T supported the diagnosis in 50% of cases, compared with 23% for T, 55% for fT by analogue RIA, and 68% for FAI. We conclude that in mild to moderate hirsutism the measurement of NSB-T does not yield diagnostic information addition to that provided by the FAI.

Sex hormone imbalance in male alcoholic cirrhotic patients with and without hepatocellular carcinoma

To investigate the possible role of sex-hormone imbalance in hepatocellular carcinogenesis in male alcoholic cirrhotic patients, we determined plasma levels of testosterone (T), dihydrotestosterone (DHT), androstenedione (A), dehydroepiandrosterone (DHA), estrone (E1), estradiol (E2), and sex-hormone-binding globulin (SHBG) in 15 men with alcoholic cirrhosis alone and in 15 similar men with alcoholic cirrhosis and hepatocellular carcinoma (HCC). The groups were matched for age and severity of liver disease using Child-Pugh scoring. Patients of both groups had evidence of hypogonadism with a decrease in plasma T levels (P less than 0.02) and of hyperestrogenemia with an increase in E1 (P less than 0.001), E2 (P less than 0.01), and SHBG (P less than 0.01) plasma levels compared with ten healthy age-matched controls. Cirrhotic patients with HCC had significantly lower plasma concentrations of T (P less than 0.02), DHT (P less than 0.01), and DHA (P less than 0.001) than patients with cirrhosis alone. However, the plasma concentrations of A, E1, E2, and SHBG did not significantly differ between these two groups. These results suggest a possible alteration of the estrogen-to-androgen ratio during carcinogenesis of the cirrhotic liver. This is shown by a greater reduction of circulating androgens and a similar elevation of estrogens in the group of cirrhotics with HCC.

A controlled comparison of the efficacy of clomiphene citrate in male infertility

To determine whether clomiphene citrate (CC) improves fertility in oligospermic men, 23 men with sperm concentrations between 0.5 and 20 million sperm per milliliter; normal serum gonadotropins and testosterone; and a presumptively fertile partner were enrolled in the study. After a 3-month control period, patients were randomly prescribed CC, 25 mg/day; or placebo, 1 tablet/day, for 12 months. The pregnancy rates for the CC group and the placebo group were 9.09% and 44.44%, respectively (not significant). During the treatment phase, the CC group had significantly higher levels of luteinizing hormone (LH) serum, follicle-stimulating hormone (FSH), testosterone (T), and estradiol than the placebo group. CC treatment also resulted in greater LH, FSH, and T responses to gonadotropin-releasing hormone (GnRH). There were no differences between the placebo and CC groups for the sperm penetration assay or semen parameters. The authors conclude that CC is not a useful drug in the treatment of male infertility.

Androgenic and estrogenic metabolites in serum of mice fed dehydroepiandrosterone: relationship to antihyperglycemic effects

The steroid prehormone, dehydroepiandrosterone (DHEA) has potent antihyperglycemic effects when fed in the diet of genetically diabetic C57BL/KsJ-db/db mice. The purpose of this investigation was to analyze changes in sex steroid levels in serum of mice fed DHEA, and to compare the antihyperglycemic potencies of the various metabolites in order to clarify the mechanism of DHEA action. Steroid radioimmunoassays showed that dietary DHEA entered the blood in high concentrations and was actively metabolized to both androgens (testosterone, T; dihydrotestosterone, DHT) and estrogens (estrone, E1; 17 beta-estradiol, E2). This metabolism did not require intact adrenal glands or gonads. In C57BL/KsJ normal (+/+) males, conversion of DHEA to androgens was the prominent feature; in db/db males, DHEA feeding not only increased serum T and DHT, but also serum E1 and E2 levels. The db/db mice had increased amounts of adipose tissue that sequestered more intravenously injected 3H-E2; this additional body fat could account for increased aromatization of DHEA-derived estrogen precursors. Comparisons of the relative antihyperglycemic potencies of androgenic and estrogenic steroid metabolites of DHEA in db/db mice showed that the estrogens and metabolites with estrogenic properties (androstenediol) or those convertible to estrogens (DHEA sulfate) were the most potent. Although 17 beta-E2 was effective by injection or per os, DHEA was effective only when administered per os, implicating alimentary tract conversion of DHEA to more biologically active reactants. Based on the pivotal position of DHEA as a prehormone for androgens, estrogens, and etiocholanolones, an explanation of the seemingly paradoxical effects exerted by this compound in blocking autoimmune disease, hyperglycemia, obesity, and neoplasia was proposed.

Testosterone levels change with subsistence hunting effort in !Kung San men

Although little is known empirically of the physiology of human hunting, arguments for innate biological bases of gender-dimorphic behaviors such as aggression frequently point to the role of hunting in human evolution. Study of !Kung San hunter-gatherer men demonstrated that the diurnal pattern in serum testosterone was altered during a six-day hunt, compared to pre- and post-hunt levels, due mainly to elevation of evening values. Hunting success did not correlate with any testosterone measures. The pattern of changes observed is most consistent with the known concomitants of moderate prolonged exercise.

Hepatic uptake of sex steroids in men with alcoholic cirrhosis

We attempted to determine to what extent the degree of liver function impairment might affect the hepatic uptake and, as a consequence, alter the systemic plasma levels of endogenous sex steroids in male patients with alcoholic cirrhosis. The plasma levels and hepatic uptake of the steroids dehydroepiandrosterone, androstenedione, testosterone, dihydrotestosterone, estrone, estradiol, progesterone, and 17-hydroxyprogesterone were assessed. Systemic plasma levels of testosterone and dehydroepiandrosterone were significantly (p less than 0.05) reduced, whereas those of androstenedione, estrone, and estradiol were significantly (p less than 0.05) elevated in men with alcoholic cirrhosis when compared to controls. Sex hormone binding globulin levels were also significantly elevated (p less than 0.01). The hepatic uptake of sex steroids depended on the degree of liver function impairment as shown by the linear significant relationship between their hepatic extractions and that of indocyanine green (r = 0.74-0.92, p less than 0.05; except for dihydrotestosterone, r = 0.17, not significant). In addition, the hepatic uptake of sex steroids depended on the binding affinity to sex hormone binding globulin. The higher the affinity for sex hormone binding globulin, the lower the hepatic uptake influenced by liver function impairment. It was estimated that hepatic clearances accounted for only 20%-50% of the metabolic clearance of sex steroids. No significant relationship between plasma levels of sex steroids and their hepatic clearance was found. We show here that in alcoholic cirrhosis the extent of hepatic uptake of sex steroids depends partly on the degree of liver function impairment and partly on the degree to which they are bound to sex hormone binding globulin. Production rate or peripheral metabolism, or both, rather than hepatic uptake alone may account for the altered circulating levels of sex steroids.

Steroid and gonadotropin levels in women during the peri-menopausal years

We obtained blood samples from 88 women 45-58 yr old who were having cyclic menses every 1-2 mth (37 women, 133 samples) or were amenorrheic for greater than 3 mth (51 women, 310 samples). Samples were obtained at intervals of 3-4 mth and analyzed for estrogens, androgens and gonadotropins using radioimmunoassay techniques. There was a gradual decline in the concentrations of estrone (E1), estradiol (E2), estrone sulfate (E1SO4) and progesterone (P) as the time from the last menses increased. A relatively stable concentration was reached in 12 mth for E1, E2, and E1SO4 and in 2 mth for P. The concentrations of testosterone, dihydrotestosterone, androstenedione, dehydroepiandrosterone and dehydroepiandrosterone sulfate remained relatively constant as the time from the last menses increased. There was no apparent difference in the mean values of any of these hormones for any time interval from the last menses. The concentrations of both luteinizing hormone (LH) and follicle stimulating (FSH) were noted to increase initially but they appeared to become stable after 12 mth for FSH and after only 6 mth for LH. Using only the measurements made on the initial blood samples obtained in all patients, we found significant correlations between FSH concentrations and the concentrations of E1, E2 and E1SO4 for women who were less than 3 mth from a menses as well as those whose last menses had occurred 3 or more mth previously. The correlations were generally not significant for LH in either groups of women.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of an aldosterone radioimmunoassay: the renin-angiotensin-aldosterone axis as a function of sex and age

A highly specific radioimmunoassay for aldosterone in plasma has been developed utilising extraction from plasma into dichloromethane, an antiserum raised to aldosterone-3-carboxy-methyloxime-BSA and a radio-iodinated derivative of aldosterone. The plasma values obtained after only extraction correlated very well with the results following chromatography over celite. The within- and between-batch variations for plasma pools ranged between 5 and 15%. The range obtained, 100-1806 pmol/L for 96 random upright subjects, was comparable to others reported. Measurement of plasma aldosterone and plasma renin activity in these subjects showed that both these parameters are higher in subjects under 40 years of age than in those over 40. In addition, plasma aldosterone levels are higher in women than in men even though their plasma renin activity levels are similar. The plasma aldosterone/renin activity ratios which provide an index of adrenal sensitivity to stimulation, are lower in men than in women. The findings in this study suggest that higher aldosterone levels in younger subjects are associated with greater stimulation of the adrenals than in older subjects and that the adrenal is more sensitive in women than in men.

The relationship between sex steroids and sex-hormone-binding globulin in plasma in physiological and pathological conditions

Physiological and many pathological changes in plasma sex-hormone-binding globulin (SHBG) levels have been attributed to the opposing effects of androgens which lower, and oestrogens which elevate, levels. We examined four clinical situations in which changes in SHBG levels may not be explained by sex steroid alterations. (1) Dexamethasone caused an increase in SHBG levels in hyperandrogenaemic hirsute women whether or not androgens were suppressed. (2) In male patients with untreated isolated gonadotrophin deficiency there was a highly significant correlation between SHBG levels and age, but there was no relationship between the levels of SHBG and those of plasma testosterone, androstenedione or DHEAS. (3) Two 46-XY siblings, phenotypic female subjects with complete androgen insensitivity, demonstrated a marked decline in SHBG levels between the ages of 9-13 and 12-16 years. (4) SHBG was suppressed in obese oligomenorrhoeic women while plasma concentrations of testosterone, androstenedione and oestradiol were normal and that of oestrone was elevated; however, the testosterone:SHBG ratio, an index of free testosterone, was elevated. These observations indicate that the decline in SHBG levels which normally occurs in men during the second decade of life is independent of androgen activity and is under the influence of as yet unidentified factors. Glucocorticoids in small doses under the influence of as yet unidentified factors. Glucocorticoids in small doses increase SHBG levels independently of sex steroid alterations while elevated free testosterone concentration may contribute to suppression of SHBG in obesity.

Serum progesterone, estradiol-17 beta, and glucocorticoids in the collared peccary during gestation and lactation as influenced by dietary protein and energy

Sixteen pregnant collared peccaries were assigned to four experimental diets representing two levels of crude protein and two levels of digestible energy. Serum levels of progesterone, estradiol-17 beta (E2), and glucocorticoids were measured by radioimmunoassay. There was no significant dietary effect (P greater than 0.05) associated with any hormone during gestation. Progesterone did not differ between days 11 and 140 of gestation (X +/- SE = 36.48 +/- 1.11 ng/ml, N = 72), began to decline during the last week prepartum, and continued to decline within 24 hr of birth. Glucocorticoid concentrations remained level throughout gestation (X +/- SE = 6.57 +/- 0.45 microgram/dl, N = 74). E2 levels were low during the first 90 days of gestation, rose significantly (P less than 0.001) from 10.11 +/- 1.73 pg/ml (X +/- SE, N = 8) at Days 81-90 gestation to 49.07 +/- 12.87 pg/ml (N = 3) at 2-4 days prepartum (Days 141-147 of gestation), and declined rapidly to baseline levels within 24 hr of farrowing. Litter size had no effect on progesterone or E2 concentrations. There was no significant dietary effect on litter size or gestation length. During lactation, glucocorticoids and E2 remained stable and did not differ by diet, while progesterone concentrations appeared to be affected by diet. Individuals on the high energy-high protein diet returned to normal ovarian function before animals on the other three diets. Results indicated that the pregnant collared peccary can maintain a reproductive steroid environment that allows for fetal development in the face of moderate caloric or protein restriction and that the lactating peccary can undergo a postpartum ovulation in the presence of good nutrition.

Altered androstenedione and estrone dynamics associated with abnormal hormonal profiles in amenorrheic subjects with weight loss or obesity

The present study was designed for exploration of hormonal disturbances underlying common forms of amenorrhea. Polycystic ovary syndrome (PCO) patients and obese amenorrheic subjects had significantly elevated estrone (E1) levels, elevated luteinizing hormone/follicle-stimulating hormone ratios, and an exaggerated luteinizing hormone response to luteinizing hormone-releasing hormone. However, androstenedione (delta 4A), the precursor of E1, was elevated only in PCO. Thus, the E1/delta 4A ratio, which provides an indirect index of aromatase activity in extraglandular sites, was raised in obese subjects as a group but not in PCO subjects. These findings suggest that elevated E1 levels, which give rise to abnormal gonadotropin secretion, arise from increased available androgens in PCO but from an increased effect of aromatase (present in adipose tissue) in obese subjects. Measurement of androgens and the E1/delta 4A ratio provides insights into the relative contributions of hyperandrogenemia and enhanced aromatase activity to the genesis of amenorrhea in these groups. In patients with suppressed estradiol levels associated with hyperprolactinemia or weight loss, follicle-stimulating hormone levels were suppressed, while luteinizing hormone was not elevated. Prolactin excess explains these findings in hyperprolactinemia. Plasma E1 levels and the E1/delta 4A ratio were suppressed in patients with weight loss, possibly as a consequence of reduced adiposity. This finding suggests that hypothesis that a minimum level of E1, dependent upon adequate adiposity, is critical for the normal mature function of the hypothalamic-pituitary-ovarian axis. Abnormal E1/delta 4A ratios, high in obesity-associated amenorrhea and suppressed in weight loss-associated amenorrhea, may provide specific markers for these groups of patients.

Effect of the bovine viral diarrhea (BVD) virus on the endometrium of the rabbit

The objective of this study was to determine the effect of BVD virus on the rabbit's endometrium. Six New Zealand White does (3-4 kg bwt) were used. Blood samples were obtained before treatment and euthanasia for determination of estrogen and progesterone. Does were anesthetized and both uterine horns identified through a midventral incision. Each horn was doubly-ligated at both cervical and ovarian ends. The right uterine horn (control) was injected with 1 ml Eagle's MEM and the left (treated) with 1 ml BVD virus (Singer strain, 10(3) CCID50/ml). Two does each were euthanized at 48 h, 72 h and 144 h post-inoculation (PI) and uterine samples obtained for viral assay and light microscopic examination. Serum hormonal levels showed that all does were in the estrogenic phase before treatment and euthanasia. Viral isolation was negative for all samples taken. On each day examined, there were no histopathologic lesions in the control uterine horn. However, in the treated horn at 48 h PI there was evidence of a purulent endometritis. At 72 h and 144 h PI there was mononuclear cell infiltration of the stratum compactum, but no other obvious lesions. A common feature in both treated and control uterine horns was mitosis of both endometrial and glandular epithelia. Results of this study suggest that BVD virus can induce histopathologic lesions of the rabbit's endometrium, the most obvious effect being at 48 h PI.

Physiological responses of the adult male collared peccary, Tayassu tajacu (Tayassuidae), to severe dietary restriction

Metabolic and hormonal responses of eight adult male collared peccaries (Tayassu tajacu) to an ad libitum diet intake, or 25% of an ad libitum intake, were examined. Blood samples for hematological, serum-biochemical and hormonal profiles were collected at three week intervals during the nine week experiment starting 4 August 1983. Males fed on the restricted diet lost an average of 26% of their body weight during the trial, compared to a slight weight gain for those fed ad libitum. Characteristics of the red and white blood cell populations were not influenced by diet intake, with the exception of mean corpuscular volume, which was consistently lower amongst males fed on the restricted diet. Restricted food intake resulted in significantly elevated serum values for urea nitrogen, urea nitrogen:creatinine, urea index, alpha globulin:beta globulin, gamma globulin:albumin, nonesterified fatty acids, alkaline phosphatase and lactate dehydrogenase isozymes (LD1 and LD2). Restricted food intake resulted in significantly lowered serum values for total alpha globulin, alpha-1 globulin, total beta globulin, beta-1 globulin, beta-2 globulin, glucose, triglycerides, calcium, magnesium, sodium, chloride, copper and triiodothyronine. Serum levels of creatinine, total protein, albumin, alpha-2 globulin, uric acid, total bilirubin, cholesterol, aspartate aminotransferase, alanine aminotransferase, gamma glutamyltransferase, lactate dehydrogenase, phosphorus, calcium:phosphorus, potassium, iron, zinc and thyroxine were unaffected by diet intake level. Semen evaluation indicated spermatogenesis was not affected by dietary restriction despite reductions in scrotal circumference and ejaculate gel volume. Serum testosterone levels were significantly lower among males fed on the restricted diet after nine weeks. These data suggest male libido might be depressed during poor range conditions, while maintenance of spermatogenesis might permit them to take immediate advantage of improved range conditions. Blood analysis of metabolic and hormonal function can provide useful information for predicting the adult male's nutritional and reproductive condition.

Relationship between LH and cortisol in acutely stressed beef cows

The influence of handling stress on tonic LH secretion was evaluated in eight ovariectomized Hereford cows. Four cows (acclimated group) were previously acclimated to stanchions and procedures for blood collection, whereas the other four cows (unacclimated group) were stanchioned and handled for the first time 2 hr before the evaluation period. Blood samples (10 ml) for cortisol, luteinizing hormone (LH) and progesterone quantitation were collected at 10-min intervals for 4 hr via an indwelling cannula inserted into the jugular vein 1 hr before the evaluation period. Mean plasma concentration of cortisol was lower (5.7 vs 66.1 ng/ml; P<0.01) but LH was higher (8.1 vs 4.1 ng/ml; P<0.05) in acclimated cows than in unacclimated cows. Plasma cortisol and LH concentrations were correlated negatively among cows (r = -0.83; P<0.01). Two- to four-fold increases (10 to 20 ng/ml) in systemic cortisol concentrations did not appear to affect LH secretion, whereas 10-to 20-fold increases associated with intensive stress suppressed tonic LH secretion, especially pulsatile LH releases. Plasma progesterone concentrations did not differ between the two treatment groups. Results suggest that the influence of stress on gonadotropin secretion, and subsequent reproductive responses, is dependent on the magnitude of the adrenal steroidogenic response and the animal's adaptation to stress. These results indicate the necessity to minimize and monitor animal stress when studying LH secretion.

Variable clinical and hormonal manifestations of hyperandrogenemia

This study was undertaken to contrast the hormonal profiles in patients with various hyperandrogenemic states in an attempt to correlate clinical manifestations with specific hormonal abnormalities. Patients with idiopathic hirsutism, polycystic ovaries, and a syndrome recently described by us, amenorrhea with cryptic hyperandrogenemia, ie, without hirsutism, participated. Total testosterone, the testosterone: sex-hormone-binding globulin (SHBG) ratio, and androstenedione levels were elevated in each group of patients. SHBG levels were suppressed in patients with idiopathic hirsutism and in patients with polycystic ovaries. In patients with polycystic ovaries or cryptic hyperandrogenemia, plasma estrone levels were elevated and the luteinizing hormone (LH) responses to luteinizing-hormone-releasing hormone (LH-RH) were exaggerated. Estrone is derived from androstenedione under the influence of the enzyme, aromatase. While elevated androstenedione occurred in both patients with polycystic ovaries or idiopathic hirsutism, estrone levels were only elevated in patients with polycystic ovaries. Reduced aromatase activity may have protected patients with idiopathic hirsutism from elevated estrone values and, thereby, from menstrual disturbances. The hormonal profiles in polycystic ovary syndrome and in patients with amenorrhea with cryptic hyperandrogenemia were very similar, with the exception that SHBG levels were high normal in three of five patients with cryptic hyperandrogenemia while estrone values were markedly elevated in these patients. Elevated estrone levels may explain the normal SHBG values, which are usually suppressed in hyperandrogenemic states. While each of the hyperandrogenemic disorders studied has a characteristic hormonal profile, the various clinical manifestations cannot be accounted for solely by abnormalities in circulating hormonal levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of in vivo administration of steroids on release of 3H2O from [1 beta,2 beta-3H] and [1-3H]androstenedione by isolated rabbit ovarian follicles

In vivo administration of progesterone and testosterone propionate to immature rabbits for 3 days resulted in a decreased ability of isolated ovarian follicles to generate 3H2O from [1 beta,2 beta-3H]androstenedione. By contrast, follicles isolated from rabbits treated with estradiol benzoate generated 3 times more 3H2O from the same substrate. Similar results were obtained when follicles were incubated with [1-3H]androstenedione. A similar pattern of differences was found when follicles from each group were analysed for estrogen content and when incubated with [4-14C]androstenedione and 14C-labelled estrogens isolated. These data suggest that estrogen may be a stimulant for its own production by rabbit ovarian follicles.

Serum levels of luteinizing hormone (LH), prolactin, estradiol, and progesterone in laying and nonlaying canvasback ducks (Aythya valisineria)

Temporal changes in the levels of serum luteinizing hormone (LH), prolactin, estradiol, and progesterone associated with the reproductive patterns of 53 wild captive canvasback ducks were measured. The reproductive endocrinology of both laying and nonlaying females was compared in this 3-year study. Females that remained sexually inactive had ovaries with small, undeveloped follicles. Nonlaying ducks also had lower serum levels of LH (P less than 0.01), prolactin (P less than 0.05), estradiol, and progesterone than those of laying ducks in mid-April (during prelay), mid-May (on the fourth day of egg production), and mid-June (during postlay and incubation). Prolactin levels of both layers and nonlayers increased over this time interval (P less than 0.01) but levels of nonlayers were significantly lower than those of layers for the three blood-sampling dates. The low prolactin levels demonstrate that reproductive failure was not a result of inhibition by high serum prolactin levels. Intravenous injections of luteinizing hormone-releasing hormone (LHRH) in female canvasbacks resulted in significantly elevated (P less than 0.01) serum LH on the prelay blood sampling date. Lack of reproduction in nonbreeding canvasbacks was thus associated with low circulating serum LH levels but with LHRH-sensitive pituitary pools. These data suggest that lack of reproduction was a result of the failure of the hypothalamus to release releasing factors. The serum hormones of laying canvasbacks varied temporally with stages of the nesting cycle. LH levels increased prior to egg laying and fluctuated during the laying period. LH levels decreased at the onset of incubation but increased after loss of clutch, with renesting activity. Serum prolactin levels of layers were low prior to egg laying and increased gradually through laying of the first clutch, the renesting period, and laying of the second clutch. The highest prolactin levels occurred in ducks incubating their eggs. Prolactin levels decreased in ducks that failed to incubate their eggs. Serum estradiol levels increased sharply between 2 and 5 weeks prior to egg laying and remained high until the second day of egg production. Estradiol levels decreased when the fourth egg was produced, and remained low through the laying of the first clutch, the renesting period, and laying of the second clutch. Progesterone fluctuated widely through the nesting cycle, showing several major peaks before laying and another during incubation.

A Sertoli-Leydig cell tumor and pregnancy. Clinical, endocrine, radiologic, and electron microscopic findings

An extremely rare case of a conception occurring in a 26-year-old patient with a small virilizing Sertoli-Leydig cell tumor (diameter: 0.6 cm), bilateral polycystic ovaries and non-tumorous adrenal hyperandrogenism is presented. Prepregnancy findings included hirsutism, clitoromegaly, secondary amenorrhea, and elevated peripheral plasma testosterone (T; 5.7 ng/ml). Extensive basal steroid screening, dynamic function tests, conventional radiologic procedures, selective glandular vein catheterization, and laparoscopy failed to localize unequivocally the source of androgen excess, but suggested bilateral adrenal involvement. The patient conceived during the diagnostic work-up; peripheral T levels increased to 12.1 ng/ml within the first trimester. An exploratory laparotomy with left adrenalectomy, right adrenal biopsy and left ovarian wedge resection revealed an incompletely removed Sertoli-Leydig cell tumor, but normal adrenal histology. The pregnancy was terminated, a left oophorectomy and right ovarian wedge resection were performed at 14 weeks' gestation. Subsequently, peripheral androgens returned to normal, regular menses resumed, and hirsutism disappeared. Three years later the patient delivered a healthy female infant.

Adrenal abnormalities in idiopathic hirsutism

The possibility that abnormal adrenal androgen production may be present in patients with idiopathic hirsutism was examined. Plasma testosterone, dihydrotestosterone and androstenedione levels were elevated in hirsute patients. In response to exogenous alpha 1-24 ACTH the increments in plasma androstenedione, dehydroepiandrosterone (DHA) and cortisol were significantly greater in hirsute patients than in normal subjects. The testosterone response was exaggerated following endogenous stimulation induced by metyrapone. Treatment with dexamethasone, 0.5 mg each night for 3 months, corrected both the androgen excess and the exaggerated androgen responses but not the excessive cortisol response to stimulation. These observations indicate adrenal abnormalities in idiopathic hirsutism. The dissociation of cortisol and adrenal androgen responsiveness following dexamethasone suggests that the abnormalities observed may be due to excessive adrenal androgen production stimulated by a dexamethasone-suppressible factor other than ACTH. Excess adrenal androgen production may be the primary disorder leading to the development of idiopathic hirsutism.

Estradiol and progesterone receptor concentrations and 17 beta-hydroxysteroid-dehydrogenase activity in estrogen-progestin stimulated endometrium of women with gonadal dysgenesis

Four hypergonadotrophic women between 25 and 37 years of age with gonadal dysgenesis were treated sequentially with estrogens and a progestin. The hormonal environment induced by this therapy was similar to that of ovulating women, as demonstrated by serum levels of estradiol, endometrial histology and pituitary gonadotropin secretion before and after LH-RH double stimulation. The concentrations of estradiol and progesterone receptors (ER and PR) and the activity of the 17 beta-hydroxysteroid-dehydrogenase (17 beta-HSD) were determined in endometrial curettings obtained from the above patients at 5 different days of their 28-day artificial cycles. The results were correlated to the histology of the endometrium and the serum concentrations of estradiol at the corresponding days of the cycle. The cytoplasmic ER and PR concentrations in the endometrium were 3-6 times higher during the estrogen than progestin phase of the induced endometrial cycle. For the activity of the 17 beta-HSD, the contrary was the case, being 6-10 fold higher during the progestin phase. A 22-day administration of estrogens only did not lead to a rise in enzyme activity or decrease in receptor content as observed under progestin influence after day 14. Since ER and PR concentrations and 17 beta-HSD activities were similar to those in the endometrium of normally ovulating women, these results confirm experimentally the present concept concerning the dependence of the cytoplasmic ER and PR content and 17 beta-HSD activity on female sex hormone action.

Comparison of the kinetics of injectable testosterone in eugonadal and hypogonadal men

Serum reproductive hormone levels were measured serially after eugonadal and hypogonadal men had received either a 200-mg or a 100-mg intramuscular injection of testosterone enanthate. The calculated mean integrated testosterone and estradiol levels indicated that the 200-mg testosterone enanthate injection in the hypogonadal subjects maintained eugonadal levels of these hormones through day 11. The 100-mg dose maintained eugonadal levels of these hormones through day 11. The 100-mg dose maintained eugonadal testosterone levels through day 7. The testosterone:estradiol ratios in both groups following the 200-mg injection remained above or at the eugonadal baseline trough day 21. The authors recommend that replacement therapy for hypogonadal men should be 200 mg of testosterone enanthate every 10 to 14 days. A similar dosage would be recommended if testosterone enanthate were to be used as an experimental inhibitor of spermatogenesis (contraceptive agent).

Vaginal administration of ethinylestradiol: effects on ovulation and hepatic transcortin synthesis

Ethinylestradiol (EE) was given vaginally to circumvent the intestinal metabolism and initial liver passage which follow oral intake. This route of administration was chosen in an effort to enhance the antiovulatory potency of EE, while decreasing adverse hepatic reactions. Vaginal tablets containing 20-30 micrograms of EE were taken daily by 7 ovulating volunteers from day 5 to day 25 of the menstrual cycle. The regimen resulted in serum EE levels of 62 +/- 27 pg/ml (mean +/- S.D.) 8-10 hours after insertion. Ovulation was inhibited in 5 women (monophasic basal body temperature curves, serum progesterone levels of 0.9 +/- 1.1 ng/ml during the second half of the treatment cycle). The cortisol-binding capacity of transcortin was significantly elevated in all subjects (52.3 +/- 6.4 micrograms/100 ml; controls 25.7 +/- 2.2 micrograms/100 ml). These findings indicate that intravaginal EE is twice as potent as oral EE in regard to inhibition of ovulation as well as stimulation of the hepatic transcortin synthesis. Vaginal administration apparently increases the bioavailability of EE; it does not facilitate a selective reduction of estrogenic effects upon the liver.