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PubMed1985

Development of a salivary cortisol method for detecting changes in plasma "free" cortisol arising from acute stress in sheep.

A simple device for collecting saliva (mainly parotid) from sheep is described. The collection of saliva, and the assay of "free" cortisol in saliva appears to offer certain advantages over the collection of blood, and the assay of serum cortisol, for the assessment of stress in sheep. With a little experience, it is easier to collect saliva than take blood samples when sheep are passing through a race. The "free" cortisol can be measured directly in saliva, whereas in serum, it is first necessary to separate "free" from protein-bound cortisol. Basal levels of "free" cortisol of less than 10 nmol/l were recorded in saliva and blood plasma or serum in unstressed sheep which had previous experience of being handled in a race, Significant increases in salivary cortisol and "free" and total ("free" plus protein-bound) cortisol in serum were found in sheep following adrenal stimulation with synacthen, or after 30 min of stressful transport. This indicates that the salivary cortisol technique is applicable to studies of stress in sheep, and should also be useful for other ruminants.

Acute Disease↗

PubMed1983

Salivary cortisol: a better measure of adrenal cortical function than serum cortisol.

Salivary cortisol concentration was found to be directly proportional to the serum unbound cortisol concentration both in normal men and women and in women with elevated cortisol-binding globulin (CBG). The correlation was excellent in dynamic tests of adrenal function (dexamethasone suppression, ACTH stimulation), in normals and patients with adrenal insufficiency, in tests of circadian variation and randomly collected samples. Women in the third trimester of normal pregnancy exhibited elevated salivary cortisol throughout the day. The relationship between salivary and serum total cortisol concentration was markedly non-linear with a more rapid increase in salivary concentration once the serum CBG was saturated. The rate of equilibrium of cortisol between blood and saliva was very fast, being much less than 5 minutes. These data, combined with a simple, stress-free, non-invasive collection procedure, lead us to suggest that salivary cortisol is a more appropriate measure for the clinical assessment of adrenocortical function than is serum cortisol.

Adrenal Cortex↗

PubMed1992

Inhibition of the morning cortisol peak abolishes the expected morning decrease in serum osteocalcin in normal males: evidence of a controlling effect of serum cortisol on the circadian rhythm in serum osteocalcin.

Osteocalcin (OC) in serum varies in a remarkably constant circadian rhythm with zenith at night and nadir in the morning. The factors controlling this rhythm are unknown, but several studies indicate that serum cortisol could be of major importance. We tested this hypothesis in a double-blind, placebo-controlled, cross-over study comprising 10 normal male volunteers (aged 23-31 yr) by measuring the response in serum OC and cortisol rhythms to a single dose of metyrapone (30 mg/kg body weight) administered at midnight. During placebo, serum cortisol consistently peaked early in the morning before 0730 h. Ingestion of metyrapone at 2400 h significantly postponed and flattened this peak (P less than 0.01). On both occasions, serum OC increased towards peak levels around 0300 h (P less than 0.01) with no overall differences in the OC profiles. However, when the serum OC time series were synchronized according to the individual cortisol nadirs, we found a significant (P less than 0.01) decrease in serum OC on the placebo day approximately 4 h after the cortisol nadir, whereas no significant changes (P greater than 0.50) were seen on the metyrapone day. Moreover, the mean serum OC level tended to be higher (P less than 0.10 in the interval 0-12 h, and P = 0.06 in the interval 4-8 h) on the metyrapone day compared with the placebo day. On the placebo day, the mean level of serum cortisol during the interval 0-4 h correlated inversely with the mean level of serum OC in the interval 4-8 h (r = 0.77, P less than 0.05). This relation was not found on the metyrapone day. In conclusion, administration of metyrapone, which reduced and postponed the early morning cortisol peak, abolished the normal morning decrease in serum OC. This strongly supports that changes in endogenous serum cortisol are of major importance for the circadian rhythm in serum OC.

Adult↗

PubMed1988

The changes in plasma cortisol and urinary free cortisol by an overnight dexamethasone suppression test in patients with Cushing's disease.

We studied the suppressibility of cortisol secretion in 15 patients with Cushing's disease by measuring morning plasma cortisol level as well as the 24-hour urinary free corisol (UFC) excretion following single doses of increasing amounts of dexamethasone (ranging from 0.5 to 32 mg) given at 11 p.m. The mean plasma cortisol level in patients with Cushing's disease was twice as high as in normal subjects, whereas the mean UFC in these patients was 6 times as high. Plasma cortisol in seven patients were suppressed by less than 4 mg of dexamethasone (in 2 cases, less than 0.5 mg; in 3 cases, less than 2 mg; and in 2 cases less than 4 mg). In these cases, basal plasma cortisol and UFC were less than 25 micrograms/dl and 350 micrograms/day, respectively. Among the other eight patients, plasma cortisol was partially suppressed in 5 cases and not suppressed in 3 cases by high doses of dexamethasone (16-32 mg). In these cases the basal plasma cortisol and UFC were more than 25 micrograms/dl and 350 micrograms/day, respectively. There was a significant correlation between the basal plasma cortisol and UFC (r = 0.687, p less than 0.01). These data suggest that the suppression by increasing amounts of dexamethasone in most cases with Cushing's disease was related to the severity of hypercortisolism.

Cushing Syndrome↗

PubMed1997

One microgram is the lowest ACTH dose to cause a maximal cortisol response. There is no diurnal variation of cortisol response to submaximal ACTH stimulation.

There are many suggestions in the literature that the adrenal gland is more sensitive to ACTH in the evening than in the morning. However, all these studies in humans were conducted when the basal cortisol level was not suppressed, and were based on the observation that, after stimulation, the increases in cortisol differed, though the peak values were the same. To examine this, we established the lowest ACTH dose that caused a maximal cortisol stimulation even when the basal cortisol was suppressed, and used a smaller dose of ACTH for morning and evening stimulation. The lowest ACTH dose to achieve maximal stimulation was found to be 1.0 microgram, with which dose cortisol concentration increased to 607.2 +/- 182 nmol/l, compared with 612.7 +/- 140.8 nmol/l with the 250 micrograms test (P > 0.3). The use of smaller doses of ACTH (0.8 and 0.6 microgram) achieved significantly lower cortisol responses (312 +/- 179.4 and 323 +/- 157.3 nmol/l respectively; both P < 0.01 compared with the 1 microgram test). When a submaximal ACTH dose (0.6 microgram) was used to stimulate the adrenal at 0800 and 1600 h, after pretreatment with dexamethasone, no difference in response was noted at either 15 min (372.6 +/- 116 compared with 394.7 +/- 129.7 nmol/l) or 30 min (397.4 +/- 176.6 compared with 403 +/- 226.3 nmol/l; P > 0.3 for both times). These results show that 1.0 microgram ACTH, used latterly as a low-dose test, is very potent in stimulating the adrenal, even when baseline cortisol is suppressed; smaller doses cause reduction of this potency. Our data show that there is probably no diurnal variation in the response of the adrenal to ACTH, if one eliminates the influence of the basal cortisol level and uses physiologic rather than superphysiologic stimuli.

Adrenocorticotropic Hormone↗

PubMed2000

Interactions of CRH, AVP and cortisol in the secretion of ACTH from perifused equine anterior pituitary cells: "permissive" roles for cortisol and CRH.

To further elucidate the interaction of CRH, AVP and cortisol in the control of ACTH secretion, we used an in vitro perifusion model with dispersed equine anterior pituitary cells. To approximate the in vivo milieu in the horse, CRH was perifused continuously (at 0, 2 and 20 pmol/L) and 5-min pulses of AVP (0, 1, 3 and 10 nmol/L) were given every 30 min in the presence of 0 or 100 nmol/L cortisol. Total (baseline + incremental) ACTH secretion increased as both the CRH (p<0.001) and the AVP (p<0.001) concentration increased and interaction between CRH and AVP was significant (p=0.042). Cortisol reduced total ACTH secretion in the presence of 2 pmol CRH/L (p=0.001) but not 0 or 20 pmol CRH/L. For incremental ACTH there was interaction between CRH and AVP (p<0.0001), with increased secretion at higher concentrations, and no significant main effect of cortisol. There was significant (p=0.001) interaction between cortisol and CRH, with cortisol attenuating ACTH release at 0 pmol CRH/L (p=0.008), having no effect at 2 pmol CRH/L and potentiating it at 20 pmol CRH/L (p=0.026). We conclude that (1) CRH at high physiological levels has a "permissive" role in preventing the cortisol inhibition of the ACTH response to AVP, and (2) basal cortisol levels have a "permissive" action in priming the HPA axis for maximal responsiveness to stimulated levels of CRH and AVP.

Adrenocorticotropic Hormone↗

PubMed1978

[Relationship between cortisol metabolic clearance rate and cortisol concentrations in adult male dexamethasone treated guinea-pigs (author's transl)].

Continuous infusion of increasing unlabelled cortisol concentrations and tritiated cortisol was used to state precisely the relation between metabolic clearance rate of cortisol (MCR) and blood cortisol levels, on conscious male adult guinea-pigs under chronic cannulation and treated by dexamethasone. The MCR of cortisol depends on blood cortisol levels : constant for low values of cortisol concentrations (5 and 20 micrograms/100 ml), it rises 50 % between 20 and 50 micrograms/100 ml : from cortisol levels of 50 to 300 micrograms/100 ml, it reaches a maximala and constant value.

Animals↗

PubMed2002

Salivary cortisol levels and the cortisol response to dexamethasone before and after EMDR: a case report.

Trauma survivors with posttraumatic stress disorder (PTSD) have been shown to have lower basal cortisol levels in the urine, plasma, and saliva than in trauma survivors without PTSD, nontraumatized mentally ill, or healthy subjects. We report on a case study in which we measured pre- and post-Eye Movement Desensitization and Reprocessing (EMDR) treatment salivary cortisol levels and salivary cortisol response to 0.50 mg of dexamethasone in a 41-year-old female with chronic PTSD symptoms. Our goal was to determine whether symptom improvement following trauma-focused treatment (EMDR) is associated with changes in basal salivary cortisol or in the cortisol response to dexamethasone administration. Our findings show moderate symptom improvement, an increase in basal cortisol levels, and a more attenuated cortisol hypersuppression in response to the dexamethasone suppression test following EMDR treatment. These results suggest the potential utility of including neuroendocrine measures in the assessment of treatment outcome in PTSD.

Adult↗

PubMed2002

Ultrasound measures of bone and the diurnal free cortisol cycle: a positive association with the awakening cortisol response in healthy premenopausal women.

In this study we examined the relationship between characteristics of the diurnal pattern of salivary free cortisol concentration and ultrasound (US) measures of bone in premenopausal women. Subjects were 36 healthy, eumenorrhoeic, nonsmoking women mean age (SE) 30.9 (1.3) years. Saliva samples were collected on awakening and 10, 20, 30, 120, 240, and 600 minutes thereafter. Calcaneal broadband ultrasonic attenuation (BUA) and speed of sound (SOS) were determined. Mean (SE) salivary cortisol concentration was 4.7 (0.5) nmol/l on awakening, peaked at 8.6 (0.9) nmol/l 30 min later, and declined to a trough of 2.3 (0.2) nmol/l 600 min after awakening. BUA and SOS were significantly associated with cortisol 0 and 30 min after awakening (r = 0.40 and 0.40 for BUA and 0.33 and 0.37 for SOS, respectively, with body mass included as covariate). Cortisol levels 240 and 600 min after awakening were not significantly associated with bone variables. Women above the median for peak (30 min after awakening) cortisol had significantly higher BUA and SOS than those below the median [BUA 51.8 (1.0) vs 47.4 (1.5) dB/MHz, P = 0.017; SOS 1554.0 (2.5) vs 1546.4 (1.5) m/sec, P = 0.008]. A high peak in cortisol following awakening was associated with higher US measures of bone in healthy premenopausal women. This finding suggests the possibility that diurnal variation in cortisol may have a role in bone metabolism.

Adult↗

PubMed1977

Maternal and fetal serum levels of total cortisol and cortisone, unbound cortisol, and corticosteroid-binding globulin in vaginal delivery and cesarean section.

The levels of corticosteroid-binding globulin (CBG, transcortin), total cortisol, and unbound cortisol were measured in maternal and fetal serum at the time of cesarean section or vaginal delivery. While the total cortisol levels in maternal serum do not differ significantly in vaginal delivery as compared to cesarean section, cord serum cortisol levels are significantly higher after vaginal delivery. There are no differences associated with the route of delivery between the mean levels of CBG in cord and maternal blood. However, after the vaginal delivery the unbound cortisol level in maternal serum is more than twice as high as that at cesarean section and in cord serum it is seven times as high. These changes reflect changes in total cortisol and may represent a prelabor surge of fetal cortisol production, or a stress response associated with labor, or a combination of both.

Cesarean Section↗

PubMedDate not supplied

Enzyme immunoassay for cortisol in serum using cortisol 21-amine.

Cortisol 21-amine (21-amino-11beta,17-dihydroxy-4-pregnene-3,20-dione) was prepared and an enzyme immunoassay for cortisol in serum was established using cortisol 21-amine conjugated with alkaline phosphatase. The minimal amount of cortisol detected was 1ng/tube and the measurable range was from 1 to 80 microgram/d1, using 10 mu 1 of serum sample. This enzyme immunoassay satisfied the standard criteria of dilution, accuracy and precision. The values correlated well with those obtained by radioimmunoassay. This enzyme immunoassay is applicable to the routine determination of serum cortisol in any clinical laboratory. Cortisol 21-amine was found to be a useful derivative for preparing cortisol-enzyme conjugate in enzyme immunoassay.

Amines↗

PubMed1986

Evaluation of oral administration of cortisol and metyrapone: the effects on serum cortisol in rainbow trout (Salmo gairdneri).

The effect of manipulating dietary levels of cortisol and metyrapone on peripheral concentrations of serum cortisol was examined in rainbow trout, Salmo gairdneri. Fish were fed 0, 10, 20, 30, 40 or 50 mg/kg body weight/day of metyrapone or cortisol for 7 days. All levels of cortisol tested increased peripheral levels of serum cortisol. Feeding a level of 30-40 mg/kg body weight/day of metyrapone depressed serum cortisol. We describe, herein, a noninvasive technique for suppression or stimulation of serum cortisol in rainbow trout.

Animals↗

PubMed1996

Elevated basal cortisol levels and attenuated ACTH and cortisol responses to a behavioral challenge in women with metastatic breast cancer.

Hormones of the hypothalamic-pituitary-adrenal system were studied in 31 patients with early stage breast cancer and patients with metastatic breast cancer. Both groups received tamoxifen as first-line treatment. As a control group 15 age-matched healthy women participated in the study. The results showed that breast cancer patients had significant elevations in basal cortisol levels compared to controls. Metastatic breast cancer patients had higher cortisol levels than early stage breast cancer patients. No significant differences between breast cancer patients and controls were found in basal plasma ACTH and prolactin levels. These data provide evidence that breast cancer is associated with a hyperactive adrenal gland, which may be due to the physiological stress associated with the presence of (micro)metastases or tumor cells in the circulation, in combination with administration of tamoxifen. In response to a behavioral challenge increases were observed in plasma ACTH and prolactin. Metastatic breast cancer patients had a faster prolactin response to acute stress than healthy women. However, metastatic breast cancer patients showed a blunted ACTH response compared to healthy women. Stress-induced ACTH responses and basal cortisol levels were negatively correlated in the metastatic group only. Thus, the blunted ACTH response to the behavioral challenge might be related to hypercortisolemia suggesting that the pituitary corticotroph cell in metastatic cancer is appropriately restrained possibly by the negative feedback effects of chronic cortisol elevations. Interestingly, the behavioral challenge induced decreases in cortisol levels in all three groups. However, metastatic breast cancer patients had a faster cortisol decline compared to healthy women. We hypothesize that this is caused by increased metabolic clearance of cortisol due to increased utilization of metabolic substrates often observed in the presence of a tumor.

Adrenocorticotropic Hormone↗

PubMed2006

Effects of Cu on plasma cortisol and cortisol secretion by adrenocortical cells of rainbow trout (Oncorhynchus mykiss).

Fish are exposed to multiple stressors, often acting concurrently, in their environment. To evaluate the potential of Cu to act as a chemical stressor, rainbow trout (Oncorhynchus mykiss) were exposed to Cu (30 or 80 microg/l) for 30 days in the laboratory and they were subjected to a physical stressor (1 min air exposure) before sampling. Physiological stress indicators in the whole fish as well as cortisol secretion by adrenocortical cells in vitro were measured. Fish exposed to Cu had a lower condition factor, hepatosomatic index, plasma glucose, hepatic glycogen and gill Na(+)/K(+)-ATPase activity compared to controls. Exposure to Cu did not have an effect on basal plasma cortisol (fish sampled without air exposure stress) however, the air exposure-induced increase in plasma cortisol was lower in fish exposed to Cu. Cortisol secretion stimulated by ACTH in vitro was greater in adrenocortical cells isolated from fish exposed to Cu in vivo but in vitro exposure to Cu consistently impaired cortisol secretion. Our results indicate that Cu at high concentrations disrupts cortisol secretion through a direct toxic effect on adrenocortical cells while low concentrations resulting from a 30-day exposure to environmentally relevant Cu concentrations enhances cortisol secretion in response to ACTH in vitro.

Adrenal Cortex↗

PubMed1999

Cortisol metabolism, cortisol sensitivity and the pathogenesis of leprosy reactions.

The concentration of cortisol in a tissue is regulated by a reversible enzyme 'shuttle' that can deactivate cortisol by converting it to cortisone, or activate cortisone by converting it to cortisol. The activity of this shuttle, and the direction in which it operates, is regulated by numerous factors including cytokines. This results in large swings in the effective cortisol concentration in sites of inflammation at different phases of an inflammatory response. Thus changes in local cortisol concentration can be largely independent of circulating cortisol levels. The relevant shuttle enzymes are present in skin, blood vessels and nervous tissue, and inhibition of the enzymes in skin enhances the local anti-inflammatory effect of cortisol. We therefore suggest that changes in the activity or direction of action of the shuttle in leprosy lesions may predispose to reactions, requiring exogenous steroid supplements to regain control of the inflammation.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed1984

Cortisol binding in uremic plasma. II. Decreased cortisol binding to albumin.

We measured cortisol binding to albumin in uremic plasma during a study to see if increased morning plasma free cortisol values, reported previously in chronic renal failure patients, could be explained by binding abnormalities of plasma proteins. Cortisol binding was measured in plasma from chronic renal failure patients and compared to values in normal controls. The unbound and albumin-bound fractions of plasma cortisol were determined using an isocolloidosmolar equilibrium dialysis method and heat inactivation of corticosteroid-binding globulin. A lower ratio of albumin-bound cortisol to unbound cortisol was seen in uremic than in nonuremic plasma (p less than 0.05). This difference was eliminated when uremic plasma was treated with dextran-activated charcoal. These studies suggest that cortisol binding to albumin is decreased in uremic plasma because of a heat-stable substance which is removed from plasma by charcoal treatment.

Humans↗

PubMed1975

Free cortisol index: a rapid and simple estimation of free cortisol in human plasma.

A rapid and simple method for the estimation of free (nonprotein-bound) cortisol in human plasma is described. Total plasma cortisol (F) was determined by a competitive protein binding assay. An estimate of the saturation of Corticosteroid Binding Globulin was obtained by the use of "charcoal cortisol uptake" (CFU). "Charcoal cortisol uptake ratio" (CFUR) was defined as the ratio of the CFU of the unknown plasma to that of a reference serum pool. Free cortisol index (FFI) was calculated as (total plasma F) times (CFUR). Percent free cortisol and free cortisol concentration (FF) was determined by equilibrium dialysis at 37 C. 169 plasma samples with an F range of 0.8-61.2 mug/100 ml from 18 normal, 10 ACTH-stimulated, 17 estrogen-treated and 12 pregnant subjects were analyzed. A highly significant correlation between FFI and FF was found (r = 0.952). Inter-assay coefficients of variation were 7% for total plasma F and 3.5% for CFU. The method allows the rapid processing of large numbers of samples and can be performed on 0.2 ml of plasma.

Adrenocorticotropic Hormone↗

PubMed2006

Relationship between cortisol increment and basal cortisol: implications for the low-dose short adrenocorticotropic hormone stimulation test.

BACKGROUND: We analyzed the low-dose (1 microg) rapid adrenocorticotropic hormone test (LDST) in 17 patients with a normal hypothalamic-pituitary-adrenal axis to determine reference intervals for the LDST on the basis of poststimulation cortisol increments. METHODS: We analyzed test results for 17 patients (14 females and 3 males; age range, 18-46 years) who had received a 2-mL aliquot of low-dose (1 microg) adrenocorticotropic hormone prepared from one 250-microg vial of Synacthen diluted in 500 mL of sterile normal saline solution. Sampling took place at 0, 20, 30, and 60 min post stimulation. The cortisol increment was plotted against basal cortisol. RESULTS: We observed a marked interdependence of the basal cortisol concentration with the increase in cortisol concentration. The relationship was inverse and linear with the best fit observed at 30 min post stimulation. The lower 95% prediction limit for basal cortisol at the zero increment was 400 nmol/L with a mean concentration of 600 nmol/L. CONCLUSIONS: We propose that a peak cortisol concentration <400 nmol/L is a sufficient single criterion for abnormal adrenal function as assessed by the LDST. Concentrations of 400-600 nmol/L are in the gray area, and those >600 nmol/L confirm normal adrenal function. Repeat analyses with larger sample sizes are warranted to confirm these observations.

Adolescent↗