Chemiluminescence enzyme immunoassay of dehydroepiandrosterone and its sulfate using peroxidase as label

We report a highly sensitive enzyme immunoassay for dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) using horseradish peroxidase as the label enzyme. Separation of free and bound DHEA-peroxidase conjugate was by insolubilized antibody, prepared by coupling purified IgG of goat anti-rabbit IgG serum with Sepharose 4B or a polystyrene tube. The enzyme activity was measured by the chemiluminescence reaction using luminol and hydrogen peroxide as substrate. The faint chemiluminescence was measured by a photon counter. The sensitivity was 25 pg/assay tube for DHEA and 100 pg/assay tube for DHEA-S. Upon comparison, results obtained by radioimmunoassay and this method showed good agreement; r = 0.86 for free DHEA, r = 0.92 for acid-hydrolyzed DHEA-S and r = 0.91 for solvolyzed DHEA-S. The present method is applicable in the routine determination of DHEA and DHEA-S in biological fluid.     

Serum and saliva adrenocortical hormones in obese diabetic men during submaximal exercise

The aim of this study was to evaluate serum and saliva adrenocortical hormones and their relationships at rest and during submaximal exercise and recovery in 9 obese diabetic middle-aged men (BMI: 35.2 ± 1.6 kg/m (2)). Blood and saliva samples were taken at rest, every 10 min of a 30-min cycling exercise at 70% of maximal heart rate, and after 10 min of recovery in order to analyze cortisol, dehydroepiandrosterone sulfate (DHEA-S) and dehydroepiandrosterone (DHEA). Serum and saliva cortisol increased significantly during recovery (p<0.05), but no significant difference was observed between the rest, exercise, and recovery DHEA-S and DHEA concentrations. A strong correlation was found at rest between both serum and saliva cortisol (r=0.72, p<0.001) and DHEA-S and DHEA (r=0.93, p<0.001). Serum DHEA-S and saliva DHEA remained strongly correlated during and after the submaximal exercise (r=0.81, p<0.001), whereas a weaker but still significant relationship was observed between serum and saliva cortisol during and after the exercise (r=0.52, p<0.001). In conclusion, these results suggest that saliva adrenocortical hormones, and especially saliva DHEA, may offer a practical surrogate for serum concentrations during both rest and exercise in obese diabetic men.     

Regulation of steroid hormone biosynthesis enzymes and organic anion transporters by forskolin and DHEA-S treatment in adrenocortical cells

Several important physiological functions are regulated by cortisol. Previously, we demonstrated the involvement of human organic anion transporter 3 (hOAT3) in cortisol release. In the present study, we investigated the influence of dehydroepiandrosterone sulfate (DHEA-S) and estrone sulfate on cortisol release in a human adrenocortical cell line (NCI-H295R) compared with forskolin stimulation. Additionally, we examined the impact of forskolin and DHEA-S on the expression of key enzymes in steroid biosynthesis and expression of hOAT3 and -4 in NCI-H295R cells. The cortisol release was increased 10-fold after 24-h incubation with DHEA-S, but incubation with estrone sulfate did not show any significant change in cortisol release. When cells were incubated with DHEA-S in the presence of forskolin, an additive influence of DHEA-S stimulation of cortisol was recorded over forskolin alone. The 24-h stimulation of NCI-H295R cells with forskolin increased the expression of steroidogenic acute regulatory protein (StAR), CYP17, CYP21A2, and CYP11A1, whereas only StAR mRNA expression was increased significantly by incubation with DHEA-S. Immunofluorescence analyses revealed strongly elevated expression of hOAT3 by forskolin as well as by DHEA-S stimulation. We conclude that the increased cortisol release of adrenocortical cells by DHEA-S and forskolin stimulation is probably due to high expression of the key enzymes of steroid biosynthesis and hOAT3.     

Quantification of hair cortisol concentration in common marmosets (Callithrix jacchus) and tufted capuchins (Cebus apella)

Quantifying cortisol concentration in hair is a non‐invasive biomarker of long‐term hypothalamic‐pituitary‐adrenal (HPA) activation, and thus can provide important information on laboratory animal health. Marmosets (Callithrix jacchus) and capuchins (Cebus apella) are New World primates increasingly used in biomedical and neuroscience research, yet published hair cortisol concentrations for these species are limited. Review of the existing published hair cortisol values from marmosets reveals highly discrepant values and the use of variable techniques for hair collection, processing, and cortisol extraction. In this investigation we utilized a well‐established, standardized protocol to extract and quantify cortisol from marmoset (n = 12) and capuchin (n = 4) hair. Shaved hair samples were collected from the upper thigh during scheduled exams and analyzed via methanol extraction and enzyme immunoassay. In marmosets, hair cortisol concentration ranged from 2,710 to 6,267 pg/mg and averaged 4,070 ± 304 pg/mg. In capuchins, hair cortisol concentration ranged from 621 to 2,089 pg/mg and averaged 1,092 ± 338 pg/mg. Hair cortisol concentration was significantly different between marmosets and capuchins, with marmosets having higher concentrations than capuchins. The incorporation of hair cortisol analysis into research protocols provides a non‐invasive measure of HPA axis activity over time, which offers insight into animal health. Utilization of standard protocols across laboratories is essential to obtaining valid measurements and allowing for valuable future cross‐species comparisons.     

Effect of resistance exercise on dehydroepiandrosterone sulfate concentrations during a 72-h recovery: relation to glucose tolerance and insulin response

Serum dehydroepiandrosterone sulfate (DHEA-S) concentration is known to be associated with the whole-body insulin sensitivity. The main purpose of the study was to investigate the effect of resistance exercise on DHEA-S concentration during a 72 h post-exercise recovery, and its relation to glucose tolerance and insulin sensitivity. Morning fasted serum samples was obtained from 19 male volunteers (aged 21.1+/-0.4 years) 24 h before the onset of exercise and 24 h, 48 h, and 72 h following exercise for measurements of DHEA-S, cortisol, and TNF-alpha. Oral glucose tolerance test (OGTT) and insulin response were determined 24 h before and 48 h after exercise. We found that resistance exercise causes a delayed suppression in serum DHEA-S levels during recovery (48 h and 72 h). This exercise challenge did not affect glucose tolerance, but insulin response during OGTT was significantly elevated. The increased insulin level was not associated with serum levels of cortisol and TNF-alpha. In conclusion, the present study found that resistance exercise has a DHEA-S lowering effect that persisted for 72 h. This change could be related to the elevated insulin concentrations during OGTT.     

Mechanism of dissociation of cortisol and adrenal androgen secretion after removal of adrenocortical adenoma in patients with Cushing's syndrome

We investigated the mechanism of dissociation of cortisol and dehydroepiandrosterone sulfate (DHEA-S) secretion by the adrenal glands after the removal of an adrenal gland containing an adrenocortical adenoma in a patient with Cushing's syndrome. After removal of the adrenocortical adenoma, the serum cortisol rapidly decreased from 24.6 +/- 6.4 micrograms/dl (mean +/- SD, n = 6) to 0.7 +/- 0.5 micrograms/dl. Serum DHEA-S levels were 15 +/- 14 micrograms/dl and 6 +/- 9 micrograms/dl before and after surgery, respectively, and significantly lower than the control values. Serum cortisol levels reverted to normal levels 1.5 to 3 years after the surgery. On the other hand, DHEA-S levels reverted to normal 5 to 7 years after the serum cortisol levels had normalized. Monolayer cultures of normal human adrenal cells obtained at adrenalectomy in patients with advanced breast cancer and atrophic adrenal cells adjacent to the adrenocortical adenoma in patients with Cushing's syndrome were used to study the mechanism of the dissociation of cortisol and DHEA-S secretion. ACTH caused significant increases in the productions of pregnenolone (P5), progesterone (P4), 17-hydroxypregnenolone (17-OH-P5), 17-hydroxyprogesterone (17-OH-P4), DHEA, DHEA-S, androstenedione (delta 4-A), and cortisol. The amounts of 17-OH-P5 and 17-OH-P4 produced by ACTH in atrophic adrenal cells were significantly greater than those in normal adrenal cells. The amounts of DHEA, DHEA-S and delta 4-A produced by ACTH in atrophic adrenal cells were significantly smaller than those of normal adrenal cells. The conversion rate of 17-OH-[3H]P5 to 17-OH-[3H]P4 and 11-deoxy-[3H] cortisol was higher in atrophic adrenal cells than in normal adrenal cells, but the conversion rate to [3H]DHEA, [3H]DHEA-S and [3H]delta 4-A was significantly lower in atrophic adrenal cells than in normal adrenal cells. These results suggest that the dissociation of cortisol from DHEA-S after the removal of adrenocortical adenoma is a probably due to diminished C17,20-lyase activity in the remaining atrophic adrenal gland.     

Basal level of prostaglandin D2 in rat brain by a solid-phase enzyme immunoassay

A solid-phase enzyme immunoassay for prostaglandin D2 (PGD2) was developed in which PGD2 was labeled with horseradish peroxidase. After competitive binding to the immobilized antibody between enzyme-labeled and free PGD2, the activity of the enzyme bound to the antibody was assayed fluorometrically using 3-(p-hydroxyphenyl)-propionic acid and hydrogen peroxide as substrates. The procedure allowed determinations of 3-100 pg for PGD2. The IC50 value for PGD2 in the solid-phase enzyme immunoassay was about 25 pg and the sensitivity was improved about 10 times compared to those in radioimmunoassay and in solution-phase enzyme immunoassay. The solid-phase enzyme immunoassay was applied to the measurement of PGD2 content in rat brain and thereby an octadecylsilyl silica cartridge and a reversed-phase HPLC were sequentially used for sample preparations. Heads were immediately frozen in liquid nitrogen after decapitation to avoid a postmortem formation of PGD2. PGD2 contents measured by solid-phase enzyme immunoassay correlated well with the values obtained by radioimmunoassay (r = 0.966) after raising its contents by intravenous administration of PGD2. The in vivo level of PGD2 in rat brain was extremely low but determined to be 0.11 +/- 0.03 ng/g tissue (mean +/- S.E.M.) with this enzyme immunoassay. The result was equal to the value extrapolated to zero time from the postmortem change.     

The within-pair resemblance in serum levels of androgens, sex-hormone binding globulin and cortisol in female obese identical twins - effect of negative energy balance induced by very low-calorie diet.

The first aim of the present study was to evaluate the changes in serum levels of cortisol, testosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEA-S) and sex hormone-binding globulin (SHBG) in response to weight loss induced by one month of treatment with a very low-calorie diet (VLCD) in twelve pairs of female obese monozygotic twins. The second aim of the study was to investigate any within-pair resemblance in serum levels of steroids and SHBG before and after a negative balance protocol, as well as the resemblance in changes in response to therapeutic weight loss. VLCD-induced weight loss of 8.7+2.9 kg was associated with significant increases in serum testosterone (p<0.05) and SHBG (p<0.001) levels, whereas no significant changes in serum levels of cortisol, DHEA and DHEA-S were observed. Significant within-pair resemblances for both pre-treatment and post-treatment concentrations were revealed for DHEA-S (pre-treatment ICC = 0.795, p < 0.01, post-treatment ICC = 0.712, p < 0.01) and for testosterone (pre-treatment ICC = 0.594, p <0.05, post-treatment ICC = 0.735, p < 0.01). The baseline within-twin-pair resemblance in serum cortisol level at 7 a.m. (ICC=0.747, p < 0.05) was lost with VLCD treatment, while its concentration at 9 p.m. developed a within-pair similarity with weight loss (ICC = 0.824, p < 0.001). Similarly, VLCD treatment led to a significant within-pair resemblance in post-treatment level of DHEA (ICC = 0.755, p < 0.01), while no within-twin-pair resemblance was shown for either pre-treatment or post-treatment SHBG levels. None of the hormones measured exhibited any within-pair resemblance in response to VLCD-induced energy deficit, except for serum cortisol levels. A significant within-twin-pair resemblance in the changes in serum cortisol levels at 7 a. m. (ICC = 0.789, F = 8.5, p < 0.001), at 1 p.m. (ICC = 0.660, F = 4.9, p <0.01) and at 9 p.m. (ICC = 0.795, F = 8.8, p <0.001) were demonstrated even after adjustment for fat mass loss. An absence of any within-pair similarity was observed in both pretreatment and post-treatment levels of SHBG, while a significant within-pair resemblance in SHBG response to VLCD treatment (ICC = 0.658, p < 0.05) was recorded. We conclude that the significant within-twin-pair resemblance demonstrated for androgens and cortisol might suggest an important role for genetic factors in the regulation of their serum levels. Our results also suggest that the mechanisms controlling baseline levels of cortisol and SHBG differ from those influencing their responses to energy deficit induced by VLCD.     

Hormonal status of cortisol and dehydroepiandrosterone sulfate in an elderly Tunisian population

Adrenal function and aging have been the object of intense interest recently, especially as regards dehydroepiandrosterone sulfate (DHEA-S), which is of major importance, since it is distinct from cortisol and aldosterone in declining with age. In a group of healthy old Tunisians, we investigated the association between cortisol and DHEA-S, on the one hand, and age, sex, lifestyle, physical health, including the body mass index (BMI), physical activity, and smoking indicators, on the other hand. We observed that cortisol concentrations did not change with aging, while DHEA-S concentrations decrease with age in both sexes. Cortisol/DHEA-S ratio, however, increases with aging. Our results revealed that DHEA-S levels are affected neither by physical activity nor by weight. It appears also that current smoking could not affect the level of DHEA-S. Relationships were found between DHEA-S concentrations and BMI, then between DHEA-S levels and serum cholesterol, triglycerides and calcium. No modification in the morning serum cortisol was found to be associated with aging. Decrease in DHEA-S levels is, however, clearly associated with this phenomenon. High cortisol/DHEA-S ratio accelerates the occurrence of some adult diseases, such as diabetes mellitus, atherosclerosis, dementia, and osteoporosis. Generally, the adrenal insufficiency marked by a cognitive impairment, immune disorders, sexual dysfunction, and scores for depression and anxiety can be corrected by a replacement of deficient DHEA-S.     

A sensitive solid phase enzymeimmunoassay for testosterone in plasma and saliva.

A sensitive, solid phase enzymeimmunoassay suitable for determining testosterone concentrations in samll aliquots of plasma (20 microliter) and saliva (200 microliter) has been developed. A solid phase antiserum raised against a testosterone-11 alpha-hemisuccinate/bovine serum albumin conjugate was prepared by coupling to cyanogen bromide activated cellulose. The "enzyme label" was a covalently linked testosterone/horseradish peroxidase conjugate. The assay had a lower limit of sensitivity of 4pg/assay tube and satisfied accepted criteria of specificity and precision. Testosterone concentrations determined by enzyme-immunoassay were in excellent agreement not only with a gas liquid chromatography/mass spectrometry procedure (r=0.96, n=12) but also with the radioimmunoassay in routine use (r=0.95, n=12). The EIA can therefore replace RIA in both the small clinical laboratory and high throughput service centres for determining plasma and salivary testosterone concentrations. In normal males salivary testosterone concentrations reflected circulating steroid levels and indicated the possibility of assaying saliva rather than plasma in clinical studies.     

Circulating progesterone and obesity in men.

Progesterone can be detected in male plasma and has been considered to originate mainly from the adrenals. We have examined the association between circulating progesterone and obesity in a sample of thirty-eight lean to morbidly obese men aged 44.5 +/- 9.9 years (BMI: 44.3 +/- 12.8 kg/m (2)). Plasma concentrations of progesterone, 17-OH-progesterone as well as androstenedione, testosterone, DHT and DHEA-S were determined. Negative correlations were observed between plasma progesterone levels and body weight (r = - 0.47, p < 0.05), BMI (r = - 0.56, p < 0.001), waist circumference (r = - 0.58, p < 0.001), as well as subcutaneous adipocyte diameter (r = - 0.50, p < 0.05). Plasma levels of 17-OH-progesterone, DHEA-S, androstenedione, testosterone and DHT were also negatively associated with body weight, BMI and waist circumference. However, the ratio of 17-OH-progesterone-to-progesterone and androstenedione-to-17-OH-progesterone were not related to these variables. A positive correlation was found between circulating progesterone and DHEA-S levels (r = 0.50, p < 0.002 after adjustment for age). Accordingly, using multivariate regression analyses, the best steroid predictor of progesterone level was plasma DHEA-S. Waist circumference was the best predictor of progesterone levels in a multivariate model including steroid concentrations as well as waist circumference, BMI and subcutaneous adipocyte diameter. In conclusion, plasma progesterone was negatively associated with markers of obesity such as BMI, waist circumference and subcutaneous adipocyte diameter in this sample of men. Circulating DHEA-S level was the best steroid correlate of plasma progesterone. We suggest that the low progesterone levels observed in obese men may reflect decreased adrenal C(19) steroid production in the adrenal cortex. Further research is needed to confirm this hypothesis.     

A sensitive solid phase enzymeimmunoassay for norethisterone (norethindrone) in saliva and plasma

A sensitive, solid phase enzymeimmunoassay suitable for determining norethisterone in small aliquots of plasma (10 μl) and saliva (100 μ1) has been developed. A solid phase antiserum raised against a norethisterone-llα-hemi-succinyl/bovine serum albumin conjugate was prepared by coupling to cyanogen bromide activated cellulose. A norethisterone/horseradish peroxidase conjugate was used as enzyme label, o?-phenylenediamine/hydrogen peroxide being the substrate for colour development. The assay had a lower limit of sensitivity of 3 pg/assay tube and satisfied accepted validation criteria. Norethisterone concentrations determined by enzymeimmunoassay and by a well established radioimmunoassay were in excellent agreement in both plasma (r = 0.993, n = 20) and saliva (r = 0.989, n = 15). Plasma and salivary norethisterone concentrations determined in healthy volunteers reached peak values at about 1 hour after administering a norethisterone-containing oral contraceptive preparation. The maximum values achieved in saliva (775–1430 pmol/l) were only approximately 3% of those observed in plasma. Since salivary norethisterone concentrations reflected those in plasma, they may be useful in fertility control programmes and pharmacokinetic studies.     

Effect of prolactin on the secretion of dehydroepiandrosterone (DHEA), its sulfate (DHEA-S), and cortisol by the human fetal adrenal in vitro

The effect of prolactin on the secretions of dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) as well as that of cortisol were studied in vitro in order to investigate the possible regulatory role of prolactin on steroidogenesis of the human fetal adrenal at mid-gestational age. The addition of 0.5 microgram/ml of human prolactin to the incubation medium produced a significant (P less than 0.05) increase in DHEA, DHEA-S, and cortisol secretion. These results indicate that prolactin has a regulatory role in steroidogenesis in the human fetal adrenal at mid-gestation.     

Validation and application of a highly specific and sensitive ELISA for the estimation of cortisone in saliva, urine and in vitro cell-culture media by using a novel antibody

It is generally acknowledged that local tissue concentrations of cortisol and cortisone are modulated by site-specific actions of 11β-hydroxysteroid dehydrogenase (11β-HSD) isoenzymes 1 and 2. Cortisone, the inactive metabolite of cortisol is produced by 11βHSD type 2. To assess 11β-HSD types 1 and 2 activities, the cortisol/cortisone ratio has to be accurately determined. Immunoassays to measure cortisone levels are not widely available and tend to lack specificity. The aim of this project was to develop a highly specific and sensitive ELISA method for the estimation of free cortisone levels in urine, saliva and in vitro media samples without chromatographic separation. Antibodies against cortisone were raised in rabbits using cortisone-3-CMO-KLH as immunogen. HRP-goat anti-rabbit IgG conjugate was used as enzyme tracer. Cross-reactivities of the untreated cortisone antiserum with major interfering steroids were minimal except for cortisol (3.15%). However, following an immune-affinity purification of the antibodies using CNBr-activated sepharose-cortisol-3-CMO-BSA, cross-reactivity of the purified cortisone antibody with cortisol was reduced to 0.27%. The minimum detection limit of cortisone ELISA was 28 pg/mL (77.7 pM). The validity of the cortisone ELISA was confirmed by the excellent correlation obtained before and after an HPLC fractionation step (Y=1.09X-0.21, R2=0.98). Intra-assay and inter-assay imprecision were 5.5-11.7% and 8.7-12.8% CV, respectively. Using this assay, salivary cortisone levels showed a circadian rhythm in men and women (11.2±7.3 nM at 08.00 h and 5.1±3.6 nM at 18.00 h), and the levels were reduced following liquorice ingestion. In media of adrenocortical H295 cell line incubations, basal cortisone levels were 4.24±0.22 nM that increased to 8.6±1.2 nM post forskolin treatment. Urinary free cortisone excretion levels in healthy subjects were 56.66±36.9 nmol/day. In human volunteers following ingestion of green coffee bean extract for 2 weeks, urinary free cortisol excretion reduced significantly from 66.67±22.3 to 42.66±17.5 nmol/day (p=0.02) and the cortisol/cortisone ratio from 2.04±1.33 to 1.49±1.13, p=0.05. In conclusion, a simple and highly specific and sensitive ELISA has been developed and applied to estimate cortisone levels in biological fluids and culture media.     

Effect of a two-month detraining on glucose tolerance and insulin sensitivity in athletes--link to adrenal steroid hormones

Reduction in physical activity has been demonstrated to associate with the increased risk in insulin resistance and type 2 diabetes. To determine whether alteration in insulinemia, due to abstention from regular exercise training, is associated with changes in serum dehydroepiandrosterone sulfate (DHEA-S) and cortisol, 18 highly trained badminton players (21.2 +/- 0.3 years) were enrolled into a 2-month detraining study. Fasting serum insulin, glucose, DHEA-S, and cortisol were determined at trained state and at day 60 of detraining. Glucose tolerance and insulin sensitivity were assessed by an oral glucose tolerance test (OGTT). The 2-month detraining increased fasting glucose and insulin concentrations and body weight slightly, but did not significantly affect glucose tolerance and insulin response curve, in which 10 subjects had increased and 8 subjects had slightly decreased in the area under curve for insulin (IAUC). In the subjects with increased IAUC, serum cortisol was also elevated (from 0.44 +/- 0.07 to 0.83 +/- 0.26 U/l, P < 0.05) in parallel, and serum creatine kinase (CK) was unaltered during detraining. Whereas in the subjects with decreased IAUC, serum cortisol (from 0.51 +/- 0.19 to 0.54 +/- 0.14 U/l, no significance) was not changed and serum creatine kinase (from 461 +/- 179 to 151 +/- 21 U/l) was decreased during detraining. Two groups of detrained subjects exhibited a similar reduction in serum DHEA-S levels and slight elevation in body weight. The novel finding of the study is that the changes in serum cortisol, but not DHEA-S, were associated with the change in insulin sensitivity during early phase of lifestyle change from physically active to sedentary, and this response appears to be varied individually among athletes.     

Comparison of quantity of thyroxine in thyroglobulin and the peptide hormones derived from chromatography and immunoenzyme assay

An evaluation of the thyroxine content in thyroglobulin and different derived thyroxine-containing peptides by enzyme immunoassay is presented. Results correlate very well with those obtained by ion-exchange chromatography which served as a reference method: r = 0.997, p less than 10(-6). Enzyme immunoassay is more rapid and sensitive than ion-exchange chromatography and then suitable for routine use. Furthermore, this paper shows, for the first time, that enzyme immunoassay can be used to perform direct thyroxine estimation in small peptide (Mr less than 2,500) without previous total enzymatic hydrolysis.     

The role of salivary cortisol and DHEA-S in response to sexual, humorous, and anxiety-inducing stimuli

Stress and anxiety are commonly thought to be detrimental to sexual function. Several studies in both the human and animal literature, however, have found that inducing anxiety can enhance sexual function in women. The mechanisms that explain a negative relationship between physical and psychological stress and sexual functioning are well documented, but little is known about how stress or anxiety might have a facilitatory effect on sexual arousal. As an initial step in exploring the relationship between anxiety and sexual arousal, the present study examined the role of the autonomic nervous system, and the adrenal hormones cortisol and dehydroepiandrosterone-sulfate (DHEA-S) in response to a sexual film, an anxiety-inducing film, and a humorous film. Nineteen premenopausal women (mean age 24.4 years) who were free from sexual difficulties came into the lab on three separate days. At each session they were shown an anxiety-inducing, sexually arousing, or humorous (control) film while their physiological arousal was measured. They also provided saliva samples before and after each film. Cortisol significantly decreased, while DHEA-S increased in the sexual and humorous conditions. Neither hormone changed significantly in the anxiety-inducing condition. Autonomic nervous system activity measured by heart rate and heart rate variability did not change in response to the sexual or anxiety-inducing films, but heart rate variability increased significantly in response to the humorous film. The cortisol/DHEA-S ratio at the post-sexual film time point was significantly negatively correlated with genital arousal (measured by vaginal pulse amplitude). Anxiety-inducing films did not result in a physiological stress response, which can explain why they do not impair sexual function.     

Cortisol as a marker of stress

The review considers the roles cortisol (Crt), dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEA-S) play in the stress response. Age-related, sex-related, and circadian fluctuations in normal conditions and in acute or chronic stress are described for Crt, DHEA, and DHEA-S. The main techniques used to estimate the Crt level in the blood, urine, and saliva are described, and approaches to the interpretation of the results discussed. Special attention is paid to Crt assays in anthropological and psychological studies.     

Dehydroepiandrosterone sulfate linked to physiologic response against hot spring immersion

The steroid dehydroepiandrosterone sulfate (DHEA-S) is associated with longevity and adaptation against external stress in humans. The aim of the study was to investigate the acute effect of a 30-min hot spring immersion at 41 °C on insulin resistance measures of 16 male subjects, in relation to DHEA-S level. To elucidate the role of DHEA-S in the coping against the heat stress, all subjects were evenly divided into lower and upper halves according to their baseline DHEA-S concentrations. The levels of glucose, insulin, blood pressure, and stress hormones (growth hormone, testosterone, and cortisol) in both groups were compared before and after hot spring immersion. The result shows that hot spring immersion significantly increased heart rate and reduced diastolic blood pressure, both of which were paralleled with a drop of DHEA-S concentration. Homeostasis model assessment for insulin resistance (HOMA-IR) and area under curve of glucose (GAUC) of oral glucose tolerance test were significantly increased by the hot spring immersion only in the Low DHEA-S group. Likewise, hot spring immersion caused an opposing effect on cortisol changes for the Low and High DHEA-S groups (+95% vs. −33%, p < 0.05), respectively. In conclusion, hot spring bathing induced insulin resistance confined only to those Low DHEA-S individuals. This response may be associated with a stress response such as increased cortisol levels.     

Circadian rhythm parameters of endocrine functions in elderly subjects during the seventh to the ninth decade of life

The circadian rhythm of 17 endocrine parameters (ACTH, aldosterone, cortisol, C-peptide, DHEA-S, FSH, growth hormone, insulin, LH, 17-OH progesterone, prolactin, testosterone, total T3, total T4 and TSH and estradiol and progesterone in women only) were studied in 63 clinically apparently healthy men (124 profiles) and 86 women (154 profiles) during the 7th to 9th decade of life. The subjects lived under very uniform conditions in a home for the aged with their daily schedule standardized by institutional routine with rest at night on the average from 21:30 to 06:30 local time and 3 daily meals at 08:30, 13:00 and 18:30. Blood was drawn over a 24-h span at 4-h intervals. Circadian periodicity was ascertained and the rhythm parameters quantified by cosinor analysis. In clinically healthy elderly subjects, circadian periodicity persisted in most parameters studied well into the 9th decade of life. The timing of the circadian rhythm was comparable between subjects in their 7th decade and 9th decade of life with the exception of cortisol and DHEA-S, which showed a phase advance with advancing age. A decrease in circadian amplitude is limited during this part of the human life span to only a few of the functions investigated and with the exception of prolactin in the women, a decrease in amplitude did accompany a decrease in MESOR.