Cortisol Release Research Articles

Salivary cortisol levels in horses and their junior riders during show jumping

The group of 22 warm-blooded half-breed horses 6 stallions, 6 mares, and 10 geldings and their riders 12 women and 10 men who ended jumping competition for juniors, were selected for a study. The horses were aged from 7 to 17 years, while the riders were 15 to 18 years old. The saliva samples were collected before and after each jumping round. The cortisol concentration was determined by using an immunoassay method. The following factors were considered: horses' sex, age, and breeds, riders' sex and age as well. In riders, significant correlation was found in the group of younger juniors 15-16 years old between the level of cortisol concentration before and after jumping round. High significant correlation coefficient was found due to influence of sex and age of horses on salivary cortisol concentration, but only for stallions and mares. Individual horses? intensity of cortisol release in response to participation in jumping competition is found to vary greatly. Therefore, the salivary cortisol test seems to be a useful and efficient method to evaluate the horses' responses to competitions including the influence of the rider.

Internal clock and the surgical ICU patient

The alteration of circadian rhythms in the postoperative period has been demonstrated to influence the outcomes. With this narrative review we would revise how anesthesia, surgery and intensive care can interfere with the circadian clock, how this could impact on the postsurgical period and how to limit the disruption of the internal clock. Anesthesia affects the clock in relation to the day-time administration and the type of anesthetics, N-methyl-D-aspartate receptor antagonists or gamma-aminobutyric acid receptors agonists. Surgery causes stress and trauma with consequent alteration in the circadian release of cortisol, cytokines and melatonin. ICU represents a further challenge for the patient internal clock because of sedation, immobility, mechanical ventilation and alarms noise. The synergic effect of anesthesia, surgery and postoperative intensive care on circadian rhythms require a careful approach to the patient considering a role for therapies and interventions aimed to re-establish the normal circadian rhythms. Over time, approach like the Awakening and Breathing Coordination, Delirium Monitoring and Management, Early Mobility and Family engagement and empowerment bundle can implement the clinical practice.

Acute hypercortisolemia inhibits innate immune parameters in Piaractus mesopotamicus experimentally infected with Aeromonas hydrophila

Cortisol is a key modulator of the immune response in fish, and considered an essential molecule for adaptation of animals to stress and overcoming the stressor. Antagonist effects, pro and anti-inflammatory have been associated to acute increases in cortisol levels, however knowledge about the mechanisms of this regulation in tropical teleosts is scarce. The effects of pharmacological inhibition of cortisol release with metyrapone (MTP) on innate immune response were investigated for the freshwater teleost, Piaractus mesopotamicus, using Aeromonas hydrophila to induce an inflammatory-immune response. Pacus were randomly distributed into four experimental groups. T1: basal control, without any previous handling. T2: without MTP treatment, inoculated via swim bladder with lethal concentration 50%-96 h (LC50- 96h) of A. hydrophila. T3: supplemented with 30mgkg−1 MTP in the diet for five days, injected on the sixth day with 50mgkg−1 live weight (LW) MTP and immediately inoculated with the bacteria. T4: supplemented with MTP, without bacterial inoculation. Blood samples were taken at 1, 3, 6 and 9 h post infection (hpi), for assessment of cortisolemia, glycemia, hematological and innate immunity parameters. The results revealed that high cortisol concentrations, during the initial phase of A. hydrophila infection, inhibited the immune-inflammatory response. Fish treated with MTP and inoculated with the bacterium showed significant higher total blood leukocytes and lymphocytes numbers, blood phagocyte respiratory activity and plasma lytic activity when compare to infected fish that did not receive MTP. It was concluded that the inhibition of cortisol release favored the immune-inflammatory response during the initial phase of bacterial infection.

Racial exclusion causes acute cortisol release among emerging-adult African Americans: The role of reduced perceived control

ABSTRACT Racial discrimination contributes to stress-related health disparities among African Americans, but less is known about the acute effects of racial exclusion on the hypo-pituitary-adrenocortical response and psychological mediators. Participants were 276 Black/African American emerging-adults (54% female; M age = 21.74, SD = 2.21) who were randomly assigned to be excluded or included by White peers via the game Cyberball. Racial exclusion (vs. inclusion) predicted: greater negative affect (F(1, 276) = 104.885, p < .0001), lower perceived control (F(1, 276) = 205.523, p < .0001), and greater cortisol release (F(1, 274) = 4.575, p = .033). Racial exclusion’s impact on cortisol release was mediated by lower perceived control (95% CI: .027, .112), but not negative affect (−.041, .013). These findings suggest that racial exclusion contributes to acute cortisol release, and that reduced perceived control is a consequence of racial discrimination that has important implications for the health of those who experience discrimination.

Cortisol reactivity to a psychosocial stressor significantly increases the risk of developing Cognitive Impairment no Dementia five years later

Alzheimer’s disease (AD) patients show high cortisol levels suggesting that biological mediators of stress may play a role in the neurodegenerative process of cognitive disorders. However, there is no consensus as to whether cortisol concentrations represent a risk factor for the development of cognitive impairment. We analyzed the potential association between the incidence of cognitive impairment and cortisol concentrations under basal and acute stress conditions in 129 individuals aged 50 years or older, with preserved cognitive and functional abilities. All participants were recruited in 2011 for assessment of cognitive performance and cortisol levels. Cortisol was analyzed in saliva samples collected during two typical and consecutive days, in the morning, afternoon, and night, and also during exposure to an acute psychosocial stressor (Trier Social Stress Test – TSST). After a five-year follow-up, 69 of these volunteers were reassessed for cognitive performance, functional evaluation, memory complaints, and depression. The incidence of cognitive impairment not dementia (CIND) was 26.1 %, and was positively associated with greater TSST-induced cortisol release (responsiveness) [(95 % CI = 1.001–1.011; B = 0.006), p = 0.023]. Moreover, five years before diagnosis, participants who later developed CIND had greater responsiveness to TSST (p = 0.019) and lower cortisol awakening response (CAR: p = 0.018), as compared to those who did not develop CIND. These findings suggest that higher psychosocial stress responsiveness profiles may represent a preclinical sign of cognitive impairment.

Influence of organic chromium supplementation on the performance of beef calves undergoing weaning-related stress

ABSTRACT: Dietary chromium supplementation before, during, and after weaning was conducted to evaluate the hypothesis that chromium supplementation could reduce weaning-induced cortisol release in beef calves. We examined the effects of chromium supplementation in 150 crossbred calves (male and female) between five and six months of age. The calves were randomly divided by sex and breed into two equal homogeneous groups (n=75). One group was used as the control, and the other experimental group received supplementation with 0.9mg of chromium carbon-amino-phospho-chelate per 100kg BW. The chromium supplement was mixed with mineral salt for the consumption of 0.1% of BW, and the supplement was administered via creep feeding 60 days before and 60 days after forced weaning. Calves were weighed, and their blood and urine samples were obtained at four time-points: T0 (60 days before weaning), T1 (at weaning), T2 (48 hours after weaning), and T3 (60 days after weaning). Blood samples were used to determine chromium, cortisol, total protein, and albumin concentrations, and urine samples were used to determine urinary creatinine and chromium levels. Cumulative weight gain was higher in calves supplemented with chromium before weaning and during the experiment (P&lt;0.05). In addition, weaning-related stress caused an increase in chromium excretion in the urine, and chromium supplementation reduced stress, which resulted in lower cortisol and total protein levels during weaning.

Relationship between Cortisol Changes during the Night and Subjective and Objective Sleep Quality in Healthy Older People.

The aim of this study was to investigate whether the nighttime cortisol release was associated with subjective and objective sleep quality and the discrepancy between them. Forty-five healthy older adults (age range from 56 to 75 years) collected salivary samples immediately before sleep and immediately after awakening on two consecutive nights. Actigraphy was used to assess objective sleep quality and quantity. A sleep diary was used to assess subjective sleep quality. Linear mixed models were performed using subjective and objective sleep quality data from 76 nights to investigate between-subject associations. We observed that larger changes in cortisol levels between sleep onset and awakening, reflecting a healthier circadian rhythm of the Hypothalamic-Pituitary-Adrenal (HPA) axis, were associated with better subjective sleep quality, but not with objective sleep quality. Moreover, smaller changes in nighttime cortisol were associated with lower subjective sleep quality relative to objective sleep quality. All these results were observed even after controlling for important confounders such as sleep quantity, age, sex, subjective socioeconomic status, stress perception, depression, physical activity, and adherence to the salivary sampling protocol. This study demonstrates that subjective sleep quality in older people may be explained, to some extent, by the activity of the HPA axis.

Cognitive Distortions in Relation to Plasma Cortisol and Oxytocin Levels in Major Depressive Disorder.

Negative thinking is prominent in major depressive disorder (MDD). Cognitive models propose that negative thinking influences the hypothalamus-pituitary-adrenal axis and cortisol release. Oxytocin is also linked to MDD, social and affective processing, and stress buffering. Little research has examined direct relationships between negative cognitions, cortisol, and oxytocin.MethodsSixty-one unmedicated participants meeting DSM-5 criteria for MDD and 60 healthy controls completed measures of psychopathology, stress, and cognitions. Plasma samples were analyzed for cortisol and oxytocin. Between-group analyses of variance were conducted along with correlational, regression and mediation analyses.ResultsDepressed participants reported greater frequency and believability of negative thoughts than controls. Cortisol levels were positively, and oxytocin inversely, correlated with negative thinking. Cortisol and negative thinking accounted for unique variance in depression, and the relationship between stress and cortisol depended on the extent of negative cognitions.ConclusionsThe results support long-standing cognitive models which propose that negative thoughts are important in the relationship between stress and cortisol levels.

Sensitized corticosterone responses do not mediate the enhanced fear memories in chronically stressed rats

Following a stressful event, the hypothalamus-pituitary-adrenal axis mediates the release of the stress hormone cortisol (corticosterone in rodents; CORT). Elevated CORT binds to glucocorticoid receptors to mediate physiological responses including facilitating memory formation. Previous work from our laboratory demonstrated that male rats exposed to chronic stress demonstrate enhanced contextual fear memories and sensitized CORT responses to subsequent stress exposure; however, this is unknown in female rats. The experiments here tested whether chronic stress enhances fear memory formation in female rats and whether the sensitized CORT response in chronic stress rats contributes to their enhanced fear memory. Studies first examined CORT responses to contextual fear conditioning in male and female rats and examined whether chronic stress enhanced the formation of contextual fear memories 24 h later. Studies then used metyrapone, a CORT synthesis inhibitor, to investigate whether blockade of plasma CORT would eliminate the chronic stress-induced enhancement in contextual fear memory. Results show that female rats have greater CORT responses than males, and chronic stress sensitizes the CORT response to fear conditioning in both sexes. However, female rats do not show enhanced contextual fear memory following chronic stress. Chronically stressed male rats show greater memory acquisition and show greater contextual fear memory 24 h later following fear conditioning. Metyrapone dampens contextual fear memory in all rats but does not eliminate the enhancement in freezing behavior in chronic stress rats. Collectively, these studies indicate sensitized CORT responses in chronically stressed rats is likely not the mechanism by which chronic stress facilitates memory formation.

Possible evidence of gluconeogenesis in Plasmodium- Infected children in relationship with the parasite density

Background: Gluconeogenesis is stimulated by low blood glucose to maintain the glucose level; it involves lipolysis (breaking down of triglycerides), release of cortisol, and production of glycerol which can be converted into glucose. Hypoglycemia is associated with Plasmodium infection in children. Glucose homeostasis also involves glycogenolysis. This work was designed to determine the possible evidence of gluconeogenesis in Plasmodium-infected children in relationship with the parasite density to provide the information for useful direction in the management of Plasmodium infection in children. Methods: Thirty-five (2–5 years; female – 14, male – 11) Plasmodium-infected children were recruited as test patients, while fifty (n = 50; female – 25, male – 23) age-matched children (Plasmodium-noninfected children) were recruited from the same environment as controls. Plasma cortisol and cortisol-binding globulin were measured by the ELISA; total bile acid, glycerol by spectrophotometry, glucose, and total triglycerides were measured using Cobas C111, while Plasmodium identification and density were carried out by Leishman's thin blood film technique. Results: The results obtained showed a significant increase in plasma cortisol, cortisol-binding globulin, total bile acid, and glycerol with increase in parasite density and in children with the parasite densities of 512 ± 4.0 and 1014 ± 6.0 than the control children (P

An Association between Work Stress and Serum Cortisol with the development of Type 2 Diabetes Mellitus among Industrial Workers

Objective: The main purpose of this study was to find out the interrelationship between stress and development of Type 2 DM using stress hormone Serum Cortisol as a marker among the industrial workers as work related stress was found to be an analogue between the environment and the individual. Method: A total of 250 Non diabetic Industrial workers have been chosen to conduct this cohort study in relation to their perceived stress which was measured through perceived stress scale PSS 10 and GHQ 12 questionnaire and their stress hormone, Serum cortisol level was assessed using Architect CLIA method as serum Cortisol will be secreted in higher levels during the body’s fight or flight response to stress and is also responsible for several stress related changes in the body mainly metabolic path way. The altered blood glucose levels were estimated using blood plasma by regular Glucose Oxidase method using fully automated chemistry analyser. Result: Study among 250 Industrial workers of age group ranging from 25-55yrs with the number of years of service ranging from 2- 30 years revealed a positive association between stress score and cortisol levels varying with work experience. the work group with 0-10 years of work experience had a cortisol value of 27+2.1µg/dl with fasting blood sugar 108 + 2.6 mg/dl and PPBS being 135+1.7 mg/dl and their perceived stress score 20+1 however for the work group with 11 to 20 years of experience their cortisol level was 22+1.3 which is almost little lesser in comparison to the first work group with fasting and post prandial values almost showing an average of 109 + 3.8 and PPBS 135 + 2.6 with a less degree of stress score of 16+2 and the work group with the work experience of 21 to 30 years showed a cortisol value of 24+3.1 with fasting blood sugar 109 +4.2 and Post prandial 135 +3.6 with a significant correlation to the stress score of 21+2 . Existence of correlation between parameters using Pearson’s correlation revealed statistically significant low correlation with age of workers and their fasting blood sugars. Their fasting blood glucose and post prandial blood glucose levels were statistically significant ( p<0.05) and highly correlated and the increase in cortisol levels could be correlated with increased fasting blood glucose and post prandial blood glucose levels with the correlation being ( p<0.01). Conclusion: From this cohort study it is evidently proven that work stress plays a major role in the development of Type 2 diabetes among industrial workers apart from other factors that could cause diabetes. And it is also evident from this study that release of high Cortisol by the body in relationship to its stress mechanism can influence the regulation of blood glucose resulting in an increased risk of Type 2 DM.

Environmental enrichment strategies for nursery piglets and efficacy for maintaining interest

Context Animals in situations of stress and constant fear exhibit unwanted behaviours for production. Pigs that are afraid of humans tend to associate any management as stressful. The use of environment enrichment for pigs may help to alleviate anxiety and fear, and hence reduce unwanted behaviours during handling. However, provision of appropriate enrichment presents challenges such as the rapid loss of interest in objects by animals. Aims The present study evaluated the effects of different environmental enrichment strategies on the behaviour of pigs at the nursery stage, maintenance of animal interest in the enrichment objects, and their reflexes when faced with emotionally negative situations. Methods Piglets (n = 425) were assigned in a completely randomised design with five treatments and five replicates per treatment (17 animal per replicate). The treatments employed were: control, no enriching objects in the environment; WB, wooden box with popcorn and wood shavings; PT, objects made of plastic tubing; WB and PT concurrently; and WB or PT on alternate days. Behavioural observations were made over 10 days for 8 h each day, divided into four periods of 2 h. Piglets from enriched (n = 10) and non-enriched (n = 10) environments were subjected to three fear tests (human approach, novel object and novel arena). Key results No significant (P &amp;gt; 0.05) effect was found for the type of enrichment provided or strategy adopted (concurrent vs alternating) on the time piglets interacted with the enrichment objects. Animals kept in an environment with no stimulus had higher frequency (P &amp;lt; 0.05) of undesirable behaviours than those with enrichment, regardless of enrichment type or strategy adopted. Piglets reared without enrichment, when isolated in a new environment, had higher frequency of behaviours such as defecating, urinating and attempting escape, as well as more and longer vocalisation events (P &amp;lt; 0.05). Piglets reared in an enriched environment had higher frequency and duration of interaction with a new object, as well as shorter latency time for the first contact with the object (P &amp;lt; 0.05). Conclusions The use of enrichment objects in the rearing environment of piglets at the nursery stage reduced undesirable behaviours, suggesting reduced fear and anxiety, and may therefore improve their psychological wellbeing. Implications Use of enrichment objects during rearing may have implications for alleviation of chronic stress, which leads to constant release of cortisol, an immune suppressor hormone that reduces the health status of the batch and hence production indices.

Corrigendum to: Environmental enrichment strategies for nursery piglets and efficacy for maintaining interest

Context Animals in situations of stress and constant fear exhibit unwanted behaviours for production. Pigs that are afraid of humans tend to associate any management as stressful. The use of environment enrichment for pigs may help to alleviate anxiety and fear, and hence reduce unwanted behaviours during handling. However, provision of appropriate enrichment presents challenges such as the rapid loss of interest in objects by animals. Aims The present study evaluated the effects of different environmental enrichment strategies on the behaviour of pigs at the nursery stage, maintenance of animal interest in the enrichment objects, and their reflexes when faced with emotionally negative situations. Methods Piglets (n = 425) were assigned in a completely randomised design with five treatments and five replicates per treatment (17 animal per replicate). The treatments employed were: control, no enriching objects in the environment; WB, wooden box with popcorn and wood shavings; PT, objects made of plastic tubing; WB and PT concurrently; and WB or PT on alternate days. Behavioural observations were made over 10 days for 8 h each day, divided into four periods of 2 h. Piglets from enriched (n = 10) and non-enriched (n = 10) environments were subjected to three fear tests (human approach, novel object and novel arena). Key results No significant (P &amp;gt; 0.05) effect was found for the type of enrichment provided or strategy adopted (concurrent vs alternating) on the time piglets interacted with the enrichment objects. Animals kept in an environment with no stimulus had higher frequency (P P P Conclusions The use of enrichment objects in the rearing environment of piglets at the nursery stage reduced undesirable behaviours, suggesting reduced fear and anxiety, and may therefore improve their psychological wellbeing. Implications Use of enrichment objects during rearing may have implications for alleviation of chronic stress, which leads to constant release of cortisol, an immune suppressor hormone that reduces the health status of the batch and hence production indices.

Does Stress Trigger Seizures? Evidence from Experimental Models.

This chapter describes the experimental evidence of stress modulation of epileptic seizures and the potential role of corticosteroids and neurosteroids in regulating stress-linked seizure vulnerability. Epilepsy is a chronic neurological disorder that is characterized by repeated seizures. There are many potential causes for epilepsy, including genetic predispositions, infections, brain injury, and neurotoxicity. Stress is a known precipitating factor for seizures in individuals suffering from epilepsy. Severe acute stress and persistent exposure to stress may increase susceptibility to seizures, thereby resulting in a higher frequency of seizures. This occurs through the stress-mediated release of cortisol, which has both excitatory and proconvulsant properties. Stress also causes the release of endogenous neurosteroids from central and adrenal sources. Neurosteroids such as allopregnanolone and THDOC, which are allosteric modulators of GABA-A receptors, are powerful anticonvulsants and neuroprotectants. Acute stress increases the release of neurosteroids, while chronic stress is associated with severe neurosteroid depletion and reduced inhibition in the brain. This diminished inhibition occurs largely as a result of neurosteroid deficiencies. Thus, exogenous administration of neurosteroids (neurosteroid replacement therapy) may offer neuroprotection in epilepsy. Synthetic neurosteroid could offer a rational approach to control neurosteroid-sensitive, stress-related epileptic seizures.

Conditions for assessing cortisol in sheep: the total form in blood v. the free form in saliva

Cortisol is often used as a stress indicator in animal behaviour research. Cortisol is commonly measured in plasma and can also be measured in saliva. Saliva contains only the free form of cortisol, which is biologically active, and saliva sampling is not invasive and may therefore be less stressful. Our study aims to guide the choice between the measurements of cortisol in plasma v. saliva depending on experimental conditions. We analysed the effect of the level of cortisol in plasma on the concentration of cortisol in saliva compared to plasma and the effect of saliva sampling v. jugular venepuncture on the cortisol response. In Experiment 1, blood and saliva were collected simultaneously under conditions in which the expected cortisol release in blood varied: in an undisturbed situation or after the isolation of lambs from their pens or the administration of exogenous ACTH (six animals per treatment). In Experiment 2, we subjected lambs to saliva sampling, venepuncture or neither of these for 8 days to evaluate how stressful the sampling method was and whether the animals habituated to it by comparing the responses between the first and last days (four animals per treatment). All animals were equipped with jugular catheters to allow regular blood sampling without disturbance. Samples were collected 15 min before any treatment was applied, then at various time points up to 135 min in Experiment 1 and 45 min in Experiment 2. In Experiment 1, we observed a strong correlation between salivary and plasma cortisol concentrations (r = 0.81, P < 0.001). The ratio between salivary and plasma cortisol concentrations was 0.106 on average. This ratio was higher and more variable when the cortisol concentration in plasma was below 55 nmol/l. In Experiment 2, venepuncture induced a larger cortisol response than saliva sampling or no intervention on day 1 (P < 0.02); this difference was not observed on day 8, suggesting that sheep habituated to venepuncture. We recommend the measurement of cortisol in saliva to avoid stressing animals. However, when the expected concentration in plasma is below 55 nmol/l, the cortisol in saliva will reflect only the free fraction of the cortisol, which may be a limitation if the focus of the experiment is on total cortisol. In addition, if cortisol is measured in plasma and blood is collected by venepuncture, we recommend that sheep be habituated to venepuncture, at least to the handling required for a venepuncture.

The glucagon test in diagnosis of secondary adrenal insufficiency after craniospinal irradiation: the feasibility of application, the features of performing the test, and its diagnostic informativity

The glucagon test (GT) is a promising alternative to the insulin hypoglycemia test (IHT) in diagnosis of secondary adrenal insufficiency (SAI). To study the feasibility of using the GT in patients after craniospinal irradiation and to determine the cut-off value to rule out SAI. A total of 28 patients (14 males and 14 females) with the median age of 19 years (17; 23) who had undergone combination treatment (surgery, craniospinal irradiation (35 Gy) with boost to the tumor bed, and polychemotherapy) of extrapituitary brain tumors no later than 2 years before study initiation and 10 healthy volunteers of matching sex and age were examined. All the subjects underwent the GT and IHT with an interval of at least 57 days. The cortisol, ACTH, and glucose levels were measured. Twelve out of 28 patients were diagnosed with SAI according to the IHT results. ROC analysis revealed that cortisol release during the GT 499 nmol/L ruled out SAI [100% sensitivity (Se); 62% specificity (Sp)], while the absence of a rise 340 nmol/l verified SAI (Sp 100%; 55% Se). For GT, the area under a curve (AUC) was 93.6%, which corresponds to a very good diagnostic informativity. In 19 patients, the IHT and GT results were concordant (in ten patients, the release of cortisol occurred above the cut-off value in both tests; no release was detected in nine patients). In nine cases, the results were discordant: the maximum cortisol level detected in the GT was 500 nmol/l, but the IHT results ruled out SAI (the GT yielded a false positive outcome). Contrariwise, in three (10.7%) patients the release of cortisol detected in the GT was adequate, while being insufficient in the IHT test. Adverse events (nausea) were reported during the GT test in 9 (25%) subjects; one patient had hypoglycemia (1.8 mmol/l). GT is highly informative and can be used as a first-level stimulation test for ruling out SAI in patients exposed to craniospinal irradiation performed to manage brain tumors. The cortisol level of 500 nmol/L is the best cut-off value for ruling out SAI according to the GT results. The insulin hypoglycemia test is used as the second-level supporting test in patients with positive GT results.

Hydrangeae Dulcis Folium Attenuates Physical Stress by Supressing ACTH-Induced Cortisol in Zebrafish.

To determine the effects of Hydrangeae Dulcis Folium (EHDF) on physical stress, changes in the whole-body cortisol level and behaviour in zebrafish (Danio rerio). One hundred and seventy-four fish were randomly divided into 4 [adrenocorticotropin hormone (ACTH) challenge test: 4 fish per group] or 6 groups (behavioural test: 10-12 fish per group, whole-body cortisol: 4 fish per group). Net handling stress (NHS) was used to induce physical stress. Fish were treated with vehicle or EHDF (5-20 mg/L) for 6 min before they were exposed to stress. And then, fish were sacrificed for collecting body fluid from whole-body or conducted behavioural tests, including novel tank test and open field test, and were evaluated to observe anxiety-like behaviours and locomotion. In addition, to elucidate the mode of action of the anti-stress effects of EHDF, ACTH (0.2 IU/g, i.p.) challenge test was performed. The increased anxiety-like behaviours in novel tank test and open field test under stress were prevented by treatment with EHDF at 5-20 mg/L (P <0.05). Moreover, compared with the unstressed group, which was not treated with NHS, the whole-body cortisol level was significantly increased by treatment with NHS (P <0.05). Compared with the NHS-treated stressed control group, pre-treatment with EHDF at concentrations of 5-20 mg/L for 6 min significantly prevented the NHS-increased whole-body cortisol level (<0.05). In addition, ACTH challenge test showed that EHDF completely blocked the effects of ACTH on cortisol secretion (P <0.05). EHDF may be a good antistress candidate and its mechanism of action may be related to its positive effects on cortisol release.

Road Transport of Late-Pregnant Mares Advances the Onset of Foaling

Cortisol is involved in the initiation of parturition and we hypothesized that increased maternal cortisol release advances the onset of foaling. Transport is a stressor for horses and induces an increase in cortisol release. To determine stress effects on the time of foaling, late-pregnant mares were transported by road for 3 hours (n = 12) or remained in their stable as controls (n = 4). Starting on day 325 of gestation, saliva and blood samples were taken for cortisol and progestin analysis, respectively. Fetomaternal electrocardiograms were recorded repeatedly. Mares were checked for impending parturition and changes in precolostrum pH. When pH decreased to 6.5, mares were either transported or left untreated. After birth, saliva was collected repeatedly from mares and their foals and heart rate (HR) was recorded. Foals were checked for maturity and health. Gestation length was 337 ± 2 days in stressed and 336 ± 2 days in control mares. Cortisol concentration increased from 3.3 ± 0.9 to 8.4 ± 0.8 ng/mL in transported mares (P < .001) and remained constant in controls. Maternal HR and heart rate variability (HRV) did not differ between groups and neither fetal HR nor HRV changed in response to transport. In transported mares, time from precolostrum decrease to parturition was shorter (40 ± 10 hours) than the respective time in controls (134 ± 49 hours, P < .01). Neither duration of foaling nor times to first standing and suckling of foals or the postnatum increase in HR and decrease in HRV differed between groups. In conclusion, transport-induced maternal cortisol release may have advanced the onset of foaling.

Hair Cortisol Concentration in Healthy Children and Adolescents Is Related to Puberty, Age, Gender, and Body Mass Index

Introduction: Hair cortisol concentrations (HCC) have been found to be related to various common childhood diseases, like otitis media, conjunctivitis, respiratory viral infections, and asthma. However, the confounding effects of age, gender, body mass index (BMI), pubertal stage (Tanner stages), socioeconomic status (SES) as well as of some hair maintenance procedures on HCC are still not well examined. Methods: A population-based cohort of 434 children aged between 5 and 18 years was examined for HCC between January 2012 and February 2015 in the context of the Leipzig Research Centre for Civilization Diseases (LIFE) Child study. Thereby, anthropometric data, gender, BMI, SES and pubertal status were assessed. HCC was measured by liquid chromatography mass spectrometry. Results: In the total cohort, HCC levels ranged between 0.95 and 29.86 pg/mg. In prepuberty, boys showed significantly higher HCC than girls (6.54 vs. 3.73 pg/mg, p < 0.05). During puberty HCC values in both genders converged. Higher BMI was significantly associated with higher HCC in both genders. In girls, HCC did not differ depending on Tanner stages. In boys, HCC was significantly higher in Tanner stage 1 than in stages 2–5. Conclusion: Measuring cortisol concentration in hair gives information about long-term release of cortisol. We have found that puberty, gender, and BMI had a profound effect on HCC. As a result, further research should take into account the potentially confounding role of puberty, gender and BMI and may use the results of our study as a reference at determining values of HCC in healthy children.

Analgesia mediated by stress: Possible antalgic mechanism of the dry needling technique

Abstract Introduction and Aim One of the possible mechanisms of action of dry needling is stress-induced analgesia, produced by the activation of the sympathetic nervous system (SNS). Cortisol is a steroid hormone, which is considered to be the most representative indicator of physiological states that are altered after a stressful stimulus. Although studies of other invasive techniques exist which measure the cortisol levels, no studies on dry needling have been found which gather this stress indicator. Thus, the aim of this study was to determine the changes produced in the levels of cortisol concentration in saliva after the application of the dry needling technique. Material and Methods Sixty-two healthy volunteer subjects participated in this randomized controlled single blinded trial performed at the University of Alcalá. Participants were randomly distributed into two intervention groups: deep dry needling (n = 33) and placebo needling (control) (n = 32). The saliva samples were gathered prior to the intervention and 3 minutes after finalization of the same. The level of cortisol in saliva was determined in a laboratory by performing a solid phase enzyme immunoassay using the ELISA® kit. Statistical significance was set at p &lt; 0.05. The differences between both groups were compared based on the percentage of change between the initial level and at three minutes via the Student's t-test for independent samples, estimating the effect size via the Cohen's d test. Results An increase of the levels of cortisol in saliva of 11.27% ± 4.76 was observed after the deep dry needling; in the group of placebo needling, an increase of 1.51% ± 3.08 was observed. However, when comparing both groups, no statistically significant differences were obtained (p = 0.920), with an effect size of d = 0.42. Conclusions The dry needling technique leads to an increase in the release of cortisol, one of the hormones involved in the sympathetic-excitatory relationship. This could be related to one of the possible effects of this invasive procedure with mechanisms of stress-induced analgesia. However, further studies are required to deepen our knowledge on the plausible physiological effects which support the application of the dry needling technique.