Cortisol Metabolite Concentrations Research Articles

Profiling endogenous adrenal function during veno-venous ECMO support in COVID-19 ARDS: a descriptive analysis.

Prolonged critical illness is often accompanied by an impairment of adrenal function, which has been frequently related to conditions complicating patient management. The presumed connection between hypoxia and the pathogenesis of this critical- illness- related corticosteroid insufficiency (CIRCI) might play an important role in patients with severe acute respiratory distress syndrome (ARDS). Since extracorporeal membrane oxygenation (ECMO) is frequently used in ARDS, but data on CIRCI during this condition are scarce, this study reports the behaviour of adrenal function parameters during oxygenation support with veno-venous (vv)ECMO in coronavirus disease 2019 (COVID-19) ARDS. A total of 11 patients undergoing vvECMO due to COVID-19 ARDS at the Medical University of Vienna, who received no concurrent corticosteroid therapy, were retrospectively included in this study. We analysed the concentrations of cortisol, aldosterone, and angiotensin (Ang) metabolites (Ang I-IV, Ang 1-7, and Ang 1-5) in serum via liquid chromatography/tandem mass spectrometry before, after 1 day, 1 week, and 2 weeks during vvECMO support and conducted correlation analyses between cortisol and parameters of disease severity. Cortisol concentrations appeared to be lowest after initiation of ECMO and progressively increased throughout the study period. Higher concentrations were related to disease severity and correlated markedly with interleukin-6, procalcitonin, pH, base excess, and albumin during the first day of ECMO. Fair correlations during the first day could be observed with calcium, duration of critical illness, and ECMO gas flow. Angiotensin metabolite concentrations were available in a subset of patients and indicated a more homogenous aldosterone response to plasma renin activity after 1 week of ECMO support. Oxygenation support through vvECMO may lead to a partial recovery of adrenal function over time. In homogenous patient collectives, this novel approach might help to further determine the importance of adrenal stress response in ECMO and the influence of oxygenation support on CIRCI.

Comprehensive assessment of cortisol and cortisol metabolites provides insight into the complex relationship between HPA axis function and BMI

Aims/objectivesAlthough considerable effort, both experimental and theoretical, has been directed towards understanding the relationship between the HPA axis and weight regulation, no true consensus exists in the literature as to the nature of the relationship. The aim of this study was to explore potential correlations between BMI and measures of cortisol and cortisol metabolites using dried urine and saliva sampling in a large sample of individuals with BMIs ranging from underweight to obese. Materials and methodsA cohort of patients with data available from urinary and/or salivary measures of cortisol and cortisol metabolites who met inclusion criteria was extracted from the database of a commercial clinical laboratory. Pearson correlation coefficients were used to determine associations between variables; Student's t-test and one-way ANOVA were used to examine differences between groups, and the Jonckheere-Terpstra trend test was used to assess for trends by BMI category. A multivariable linear regression model was created to determine which variables explained the largest amounts of variance in BMI. ResultsA significant correlation was observed between the urinary cortisol metabolites and BMI (P < 0.0001). In addition, cortisol metabolites were associated with changes in BMI over time. No significant correlation was observed between urinary free cortisol and BMI, and correlations observed between BMI and other variables, with the exception of age, were either weak or not statistically significant. ConclusionsThe data presented in this study suggest that cortisol metabolism is a key component of weight regulation and that cortisol metabolite concentrations may potentially serve as informative biomarkers to characterize the relationship between the HPA axis and changes in BMI. The implications of this affect both clinical practice and the research and development of both prevention and treatment strategies aimed at either decreasing or increasing BMI.

Identification of cortisol metabolites with LC-MS/MS in plasma, skin mucus, bile and faeces for stress evaluation of farmed Atlantic salmon

As a stress hormone, cortisol and more recently its metabolites are analysed when assessing fish stress and welfare status, although the exact identity of these metabolites is not clearly defined for the Atlantic salmon. LC-MS/MS techniques, owing to their specificity, sensitivity and ability to simultaneously identify and measure several relevant compounds, can be useful tools for this purpose. Using the guidelines provided by the European Decision no. 657/2002/EC for validation, the LC-MS/MS method presented here, can reliably identify and quantify cortisol and five of its metabolites (5β-THF, cortisone, 5β-DHE, 5β-THE and β-cortolone) in bile and faeces, and cortisol and cortisone in skin mucus and blood plasma of farmed Atlantic salmon within 15 min. Identified as the most predominant compound in faeces and bile, 5β-THE is proposed as a candidate stress biomarker when using these matrices. A decision limit (CCα) below 5 ng/mL, a detection capability (CCβ) and a limit of detection (LOD) below 10 ng/mL and a limit of quantitation (LOQ) below 30 ng/mL were typically obtained for most of the compounds. The concentrations of these compounds measured in either non-stressed or stressed fish were all above the CCα, CCβ, LOD and the LOQ of the method. The latter consequently demonstrated significant difference in cortisol metabolites concentrations between the two groups of fish. The present study further demonstrates that pooling of samples from several individuals could provide reliable results for farmed fish stress evaluation, when sample materials are insufficient in terms of quantity.

Housing relocation does not have to induce a significant stress response in captive Japanese macaques (Macaca fuscata).

Previous studies suggest that housing relocation may be stressful for captive non-human primates. Our study investigated the stress levels of Japanese macaques during a housing relocation by measuring their daily fecal cortisol metabolites, which are often used as an indicator of stress. Ten adult Japanese macaques, single-housed for research purposes, were relocated to a new facility. Fecal samples were collected daily for 7 days. Cortisol metabolite concentrations were determined via enzyme immunoassay. No significant differences in cortisol metabolite levels were found in 7 days, but concentration levels showed that the highest median was associated to the relocation day. The minimal cortisol metabolite increase suggests that there was a slight activity increase in the hypothalamic-pituitary-adrenal axis. Techniques encouraging cooperation of the monkeys, the short time duration of the relocation, and consistency in the environment may have contributed to the minimal stress levels observed.

Welfare impacts associated with using aversive geofencing devices on captive Asian elephants

Animal-borne aversive geofencing devices (AGDs, or satellite-linked shock collars) are commercially available and used on livestock to restrict their movement within a virtual boundary. This technology has potential application as a human-wildlife conflict mitigation tool, where problem animals might be conditioned to avoid human-dominated habitats by associating an audio warning with a subsequent electric shock, which is delivered if the audio warning is ignored. Ensuring that high standards of animal welfare are maintained when implementing such tools is important for acquiring manager and community acceptance of such approaches. We conducted two pilot experiments with eight captive Asian elephants using mild electric shocks from a modified dog-training collar fitted around the neck, as part of an ongoing effort to develop AGDs suitable for mitigating human-elephant conflict. As part of these experiments, we assessed elephants' behavioural and physiological stress before, during and after the experiments. During the experiments elephants wore collars for up to nine consecutive days and received a small number of electric shocks on 1–3 consecutive days. Bootstrapped principal component analysis showed that daily activity budgets of individual elephants on experiment days were not different from the pre-experiment days. Generalised linear mixed-effects model (GLMM) showed that anxiety/stress behaviours increased on the first day of acclimatising to the collar and on testing days (i.e. days they received shocks) of the first experiment, but not during the second experiment relative to pre-experiment days. Analysis of faecal cortisol metabolite (FCM) concentrations using GLMM showed that FCM concentrations were higher in samples collected ∼24 hrs and ∼48 hrs after testing days compared to baseline levels as expected given the lag time for excretion of cortisol metabolites. These elevated anxiety/stress behaviours and FCM concentrations returned to baseline levels shortly after the experiment. Therefore, we conclude that AGDs did not produce lasting behavioural or physiological stress effects in elephants during this short-term study but recommend further studies with a larger sample of elephants to confirm the transferability of these findings.

Effects of OmniGen AF feed supplementation on glucocorticoids, blood leukocyte messenger RNA abundance, and energy metabolism in overstocked Holstein dairy cows

The physiological consequences of overstocking require more investigation, and no research has explored whether dietary supplements could mitigate the anticipated negative physiological effects. OmniGen AF (OG, Phibro Animal Health Corporation, Teaneck, NJ, USA) is a nutritional supplement that has been shown to support the immune system of cattle following internal and environmental stressors. This study aimed to determine if a 45-day period of OG feed supplementation would influence whole blood leukocyte messenger RNA abundance, energy metabolism and glucocorticoid concentration, during a two-week period of overstocking. Two stocking density treatments (control: one headlock and lying stall per cow; overstocked: 0.5 headlocks and 0.5 lying stalls per cow) and two diet treatments (control: no added supplement; and OG: 56 g/cow per day) were investigated. Four pens of 15 cows were fed their assigned diet (two pens per diet; control stocking density) for 45 days after which each stocking density treatment was applied for a 14-day period using a cross-over design; this study design was replicated twice. During each 14-day period, blood was collected on day four to measure whole blood leukocyte messenger RNA abundance (cluster of differentiation 80, interleukin 8 receptor-beta, interleukin 10 receptor-beta and L-selectin) and fecal samples were collected every two days to measure fecal cortisol metabolite concentration (11,17-dioxoandrostanes). At the end of each 14-day period, eight cows from each pen were selected for an intravenous glucose tolerance test; glucose, insulin and non-esterified fatty acids were measured. There were no effects of diet or stocking density on leukocyte messenger RNA abundance. Fecal cortisol metabolite concentrations were highest for overstocked cows on the control diet on day four of the stocking density treatment; however, by day 10, overstocked cows fed OG had the highest fecal cortisol metabolite concentrations. Overstocked cows, regardless of diet, had an attenuated insulin response during the glucose tolerance test, represented by a lower area under the curve estimate. Cows fed OG but not overstocked, had a lower non-esterified fatty acid nadir during the glucose challenge, compared to all the other treatments. In conclusion, overstocking prompts a physiological stress response and alters energy metabolism by decreasing the insulin response to an intravenous glucose challenge. Feeding OG during overstocking delayed the increase in fecal cortisol metabolites by several days; however, it is unclear if this altered glucocorticoid response benefited the cow, as OG had no effect on insulin responses or immune parameters.

Metabotypes of congenital adrenal hyperplasia in infants determined by gas chromatography-mass spectrometry in spot urine

Biochemical monitoring of treatment in infants with classic congenital adrenal hyperplasia (CAH) is not yet well defined. The aim of this study was to perform a cluster analysis of the urinary steroid metabolome for treatment monitoring of infants with classic salt-wasting CAH. We analyzed spot urine samples obtained from 60 young children ≤ 4 years of age (29 females) with classic CAH due to 21-hydroxylase deficiency treated with hydrocortisone and fludrocortisone by targeted gas chromatography-mass spectrometry (GC-MS). Patients were classified into different groups according to their metabolic patterns (metabotypes) using unsupervised k-means clustering algorithms. Three metabotypes could be discovered. Metabotype #1 (N = 15 (25%)) showed high concentrations of androgen and 17-hydroxyprogesterone (17OHP) precursor steroids, metabotype #2 (N = 28 (47%)) revealed balanced metabolic control, and metabotype #3 (N = 17; 28%) demonstrated severe adrenal suppression with low concentrations of androgen and 17OHP precursor steroids. Daily hydrocortisone doses and urinary concentrations of cortisol and cortisone metabolites did not differ between all three metabotypes. Metabotype #2 had highest daily dose of fludrocortisone (p = 0.006). Receiver operating characteristic curve analysis showed that 11-ketopregnanetriol (area under the curve [AUC] 0.967) and pregnanetriol (AUC 0.936) were most suitable of separating metabotype #1 from #2. For separation between metabotypes #2 vs. #3, the 11-oxygenated androgen metabolite 11-hydroxyandrosterone (AUC 0.983) and the ratio of 11-hydroxyandrosterone to tetrahydrocortisone (AUC 0.970) were most suitable. In conclusion, GC-MS-based urinary steroid metabotyping is a new method to help monitor the treatment of infants with CAH. This method allows classification of under-, over- and adequately treated young children.

Laissez-Faire Stallions? Males' Fecal Cortisol Metabolite Concentrations Do Not Vary with Increased Female Turnover in Feral Horses (Equus caballus).

Stress responses can be triggered by several physical and social factors, prompting physiological reactions including increases in glucocorticoid concentrations. In a population of feral horses (Equus caballus) on Shackleford Banks, North Carolina, females previously immunized with the immunocontraceptive agent porcine zona pellucida (PZP) change social groups (bands) more often than unimmunized females, disrupting the social stability within the population. We assessed the effects of increased female group changing behavior (or female turnover) on individual male stress by comparing fecal cortisol metabolite (FCM) concentrations among stallions experiencing varying amounts of female group changing behavior. FCM concentrations did not significantly correlate with female turnover. Similarly, FCM concentrations were not dependent upon the timing of female group changing behavior. These findings suggest that female turnover rate has little influence on physiological measures of stress in associated stallions. That said, Shackleford stallions experiencing increased female turnover do engage in behaviors typically associated with stress (increased vigilance, highly escalated male-male conflicts). Future work should compare FCM concentrations across time within populations and among populations managed under different strategies to better isolate factors influencing stallion stress physiology. Such studies are especially important if we are to determine how changes in female behavior related to immunocontraception impact physiological and behavioral indicators of stress for non-target animals. Finally, our study highlights the importance of considering both physiological and behavioral measures when investigating animal responses to potentially challenging situations.

Resident wild koalas show resilience to large-scale translocation of bushfire-rescued koalas.

Wildlife translocation is increasingly utilized as a conservation management action, to mitigate the immediate negative effects of habitat loss and fragmentation (e.g. from land clearing or bushfires). Previous research has shown that stress responses can help or hinder survival in translocated wildlife and determine the efficacy of translocation as a conservation action. Yet these translocated animals are only one side of the equation, with translocation also potentially impacting the animals in the recipient population. We measured physiological markers of stress (faecal cortisol metabolite concentrations and neutrophil-lymphocyte ratios) and assessed health condition in a wild koala population one year after a major translocation of bushfire-rescued koalas on Kangaroo Island. We expected to find a high population density at the site (>0.75 koalas per hectare) and that resident koalas would show signs of chronic stress and ill health as a result of territorial conflict over food trees and reproductive opportunities. In contrast, we found that only one-fifth of the population remaining at the site were translocated koalas. The overall population density was also much lower (0.21 koalas per hectare) than anticipated. With no evidence of mass mortality at the site, we suggest that the majority of translocated koalas dispersed away from the site. Our stress marker measurements did not differ between the wild koalas and a sample of captive (non-display) koalas at the nearby Kangaroo Island Wildlife Park and were generally low compared to other studies. Veterinary examinations found that most koalas were in good body condition with very few diagnostic indicators of systemic ill health. Overall, our results suggest that, if there is adequate landscape-scale habitat connectivity and opportunity for dispersal, translocated koalas are likely to disperse from the site of release, with limited impacts on recipient koala populations at translocation release sites.

Covariation between glucocorticoids, behaviour and immunity supports the pace-of-life syndrome hypothesis: an experimental approach.

The biomedical literature has consistently highlighted that long-term elevation of glucocorticoids might impair immune functions. However, patterns are less clear in wild animals. Here, we re-explored the stress-immunity relationship considering the potential effects of behavioural profiles. Thirteen captive roe deer (Capreolus capreolus) were monitored over an eight-week period encompassing two capture events. We assessed how changes in baseline faecal cortisol metabolite (FCM) concentrations following a standardized capture protocol and an immune challenge using anti-rabies vaccination affected changes in 13 immune parameters of innate and adaptive immunity, and whether these changes in baseline FCM levels and immune parameters related to behavioural profiles. We found that individuals with increased baseline FCM levels also exhibited increased immunity and were characterized by more reactive behavioural profiles (low activity levels, docility to manipulation and neophilia). Our results suggest that the immunity of large mammals may be influenced by glucocorticoids, but also behavioural profiles, as it is predicted by the pace-of-life syndrome hypothesis. Our results highlight the need to consider covariations between behaviour, immunity and glucocorticoids in order to improve our understanding of the among-individual variability in the stress-immunity relationships observed in wildlife, as they may be underpinned by different life-history strategies.

The Adrenal Cortisol Response to Increasing Ambient Temperature in Polar Bears (Ursus maritimus).

Simple SummaryHuman-caused climate change is proceeding rapidly and providing challenges to wildlife species, especially those adapted to colder temperatures. We investigated the cortisol response of polar bears to increasing ambient temperatures to improve our knowledge of the physiology of this Arctic species with the goal of informing management in zoos and in the wild. In adult polar bears temperatures above 20 °C were associated with an increase in the hormone cortisol to accommodate increased thermoregulatory demands. This temperature threshold was surprisingly high for an Arctic-adapted species. Zoos can provide sufficient housing options to prevent overheating in polar bears exposed to warmer temperatures but our results are concerning for wild polar bears. The number of days reaching 20 °C in the Arctic has increased significantly over the past 30 years and the associated increase in thermoregulatory costs add to the physiological burden many wild polar bears are already facing with the loss of sea ice hunting opportunities. We recommend that the management of polar bears in the wild and under human care be adapted to reflect the increased cortisol concentrations associated with thermoregulatory challenges in warmer temperatures.Our objective was to identify the upper ambient temperature threshold that triggers an increase in cortisol in response to increased thermoregulatory demands in polar bears. The results reported here include endocrine data collected over two years from 25 polar bears housed in 11 accredited zoological institutions across North America. The effects of ambient temperature, sex, age group (juvenile, adult, elderly), breeding season and humidity on fecal cortisol metabolite (FCM) concentrations (N = 8439 samples) were evaluated using linear mixed models. Ambient temperatures were placed into five different categories: <5 °C, 6–10 °C, 11–15 °C, 16–20 °C, and >20 °C. Ambient temperature and humidity had a significant (p < 0.05) effect on FCM concentrations with significant (p < 0.05) interactions of sex, age and breeding season. Once biotic factors were accounted for, there was a significant (p < 0.05) increase in FCM concentrations associated with ambient temperatures above 20 °C in adult polar bears. The implications of these findings for the management of both zoo and wild polar bears are discussed.

Comparison of lidocaine alone or in combination with a local nerve block of ethanol, bupivacaine liposome suspension, or oral meloxicam to extend analgesia after scoop dehorning in Holstein calves

The American Veterinary Medical Association recommends the use of practices that reduce or eliminate pain and discomfort associated with dehorning. Identification of an effective, long-acting local anesthetic that is practical for producers to implement and reduces pain from dehorning would benefit animal welfare. Thirty-two Holstein bulls and heifers were enrolled. The objective of this study was to compare the efficacy and duration of activity of bupivacaine liposome suspension (BUP; n = 8), ethanol (ETH; n = 8), or meloxicam (LID + MEL; n = 8) co-administered with lidocaine compared with lidocaine only (LID; n = 8), and to quantify their effect on pain biomarkers and behaviors after scoop dehorning with cauterization in approximately 20-wk-old calves. Outcome variables collected included infrared thermography (IRT), mechanical nociceptive threshold (MNT), visual analog scale (VAS) scoring, and blood sampling for serum cortisol and prostaglandin E2 metabolites (PGEM). There was evidence of a sex effect for MNT, with bulls demonstrating a higher threshold (13.74 kgf) compared with heifers (12.12 kgf). There was a treatment by time interaction for cortisol concentrations (ng/mL). At 2 h, the BUP group had higher cortisol values (17.32 ng/mL) than the LID + MEL group (3.10 ng/mL). Heifers also had higher mean cortisol values (13.88 ng/mL) compared with bulls (6.96 ng/mL). There was a treatment by time interaction for PGEM concentration. Calves in the LID + MEL group had lower PGEM values at 4 and 8 h (10.23 and 9.12 pg/mL) than at −24, 0, and 0.5 h (20.38, 27.27, and 22.59 pg/mL, respectively). At 4 h, the LID + MEL group had lower PGEM concentrations (10.23 pg/mL) than the ETH group (27.08 pg/mL). At 8 h, the LID + MEL group had lower PGEM concentrations (9.12 pg/mL) than both the ETH and BUP groups (24.80 and 20.52 pg/mL). Thus, LID + MEL reduced cortisol and prostaglandin metabolite concentrations more effectively than ETH + LID or BUP + LID administered as a local infiltration and cornual block, respectively, before scoop dehorning followed by cauterization. The treatments administered in the present study did not seem to extend the duration of analgesia beyond the currently recommended multimodal approach, including local anesthesia and systemic analgesia such as lidocaine and meloxicam. Evidence from the current study suggests that sex influences pain biomarkers such as nociceptive threshold and cortisol concentration, with males having a higher nociceptive threshold and lower cortisol responses.

Insect-repelling behaviour in horses in relation to insect prevalence and access to shelters

Pasture access is key to horse welfare, but during summer biting insects can cause discomfort and lead to health issues related to transmission of diseases and allergies. To measure the level of discomfort and whether access to shelters or other indoor areas may help prevent biting insect nuisance, we studied 39 horses: n = 21 with free indoor access (five groups) and n = 18 without indoor access (four groups) and recorded horse position (e.g., inside or outside), insect-repelling behaviour (e.g., tail swishing and head tossing), faeces cortisol metabolites, weather conditions, and insect prevalence through trap catches (e.g., tabanids which are known to attack horses). Data were collected one day per week per group for eight weeks during midsummer. Tail swishing (mean occurrence: 29.4 ± 1.1 per min) and skin shivering (mean occurrence: 13.8 ± 0.6 per min) were the most frequently recorded behaviours. The total frequency of insect-repelling behaviour was affected by treatment (indoor access vs. no access) and tabanid trap catches in interaction (F1281 = 8.08, P = 0.005), as more repelling behaviour was shown by horses without indoor access with increasing tabanid prevalence. Horses with indoor access were inside on 69% of recordings on days with a high tabanid prevalence vs. 14% on days with low tabanid prevalence. Concentrations of faeces cortisol metabolites did not differ between days with low vs. high tabanid prevalence. The following year, we conducted a small follow-up study on 13 horses (6 with free indoor access and 7 without) and recorded behaviour and saliva cortisol on four selected summer days with either low or high insect prevalence (2 ‘low’ and 2 ‘high’ days). On ‘high’ insect days, saliva cortisol increased significantly in horses without indoor access, suggesting that biting insect nuisance is reflected in saliva cortisol concentrations. We conclude that free access to shelters or other indoor areas during summer reduce nuisance by biting insects and thereby can improve horse welfare.

Kortisolkonzentrationen bei Schafen vor, während und nach der simulierten Klauenbehandlung im Kippstand – Eignung verschiedener Matrices

Matrices that can be collected non-invasively for quantification of a stress response in sheep have received little attention in the veterinary literature. This study examines the suitability of blood, tears and saliva for determining a stress response in sheep undergoing sham foot trimming on a tilt table. The cortisol concentration of blood, tears and saliva and the concentration of cortisol metabolites in faeces were measured in 13healthy Meat Merino ewes once a day for six days. Sham foot trimming on a tilt table was used as the stressor and was done during a one-hour period on day4; cortisol concentrations of blood and tears were measured at 0,10,20,30,40 and 60minutes. Cortisol concentrations of blood (maximum at 30minutes) and tears (maximum at 40minutes) increased during the procedure and then decreased. There were significant correlations between cortisol concentrations of blood and tears (p=0,04) during sham foot trimming (area under the curve, 0to60minutes). Over the entire 6-day study period, significant correlations were seen between the cortisol concentrations of blood and tears (r=0,55; p.

Evaluation of Fecal Glucocorticoid Metabolite Levels in Response to a Change in Social and Handling Conditions in African Lions (Panthera leo bleyenberghi).

Simple SummaryNon-invasive determination of cortisol metabolite concentrations in feces is widely used to evaluate the influence of housing and handling conditions on the stress physiology of wildlife in captivity. The present study aimed to assess the physiological response of a lion pride to a change in management and social conditions after the death of the dominant male of the pride. Before the dominant male died, weekly management routines between the indoor and outdoor enclosures were conducted to avoid cohabitation problems between the two males of the pride. After the death of the dominant male, these weekly management dynamics ceased, leading to a decrease in the daily management routine of the lion pride. An individualized sampling of the animals through the utilization of indigestive markers was conducted, and fecal samples were collected before and after the death of the dominant male. Significant lower cortisol metabolite concentrations in feces were detected after the death of the dominant male, suggesting a positive impact of a decrease in daily management routines, together with a more stable social environment. In addition, assessment of individualized hormone concentrations throughout the study revealed variable physiological responses among lions, providing evidence of the importance of monitoring hormonal profiles individually.Monitoring the hypothalamic–pituitary–adrenal (HPA) axis through determination of fecal cortisol metabolite (FCM) levels is a non-invasive method useful for understanding how handling and social conditions may affect the physiological status of zoo animals. The present study used FCM analysis to evaluate whether the HPA axis activity of a lion pride was modified by a change in social and handling conditions after the death of the dominant male. Five African lions (Panthera leo bleyenberghi), two males and three females, were included in the study. Fecal samples were collected before and after the death of the dominant male. To avoid cohabitation conflicts between males before the dominant male died, subgroups were established and subjected to weekly changes between indoor and outdoor facilities. After the death of the dominant male, these management dynamics ceased, and the remaining four lions were kept together outdoors. Significant lower group FCM concentrations (p < 0.001) were detected after the decease of the dominant male, probably associated with a decrease in daily handling, together with a more stable social environment. Overall, the present study indicates the effect of different management scenarios on the HPA axis activity and differentiated physiological responses to the same situation between individuals.

Non-invasive measurement of cortisol metabolites in feces as an indicator of stress and its relationship with the number and arrival frequency of visitors in captive sambar deer (Cervus unicolor)

Nowadays, the non-invasive measurement of cortisol in feces is a popular method used as an indicator of stress in wild and captive animals. This study was conducted to examine the feasibility of a non-invasive method for cortisol metabolites measurements in feces and investigate its relationship with the number and arrival frequency of visitors in captive Sambar deer. In total 64 fecal samples were collected together with the observation of the number and arrival frequency of visitors from 7 Sambar deers (3 adult males, 4 adult females) rearing in zoos of Taman Rusa Lamtanjong, Aceh Besar, Indonesia. Subsequently, fecal samples were extracted and the concentration of cortisol was measured by using 3α, 11β-dihydroxy-etiocholanolone assay. Data were analyzed using a t-test and Pearson correlation. Results showed that cortisol metabolites concentration in adult males of Sambar deer (276.20 ± 52.74 ng/g dry feces) was higher compared to adult females (181.56 ± 25.87 ng/g dry feces). The concentration of cortisol metabolites was significantly correlated with the number of visitors ( r = 0.482, p < 0.05 ) and the arrival frequency of visitors ( r = 0.398, p < 0.05 ) in which the higher number and arrival frequency of visitors increased the cortisol metabolites concentration. In conclusion, the concentration of cortisol metabolites in Sambar deer can be measured non-invasively from feces and associated with the number and arrival frequency of visitors.

Altered glucocorticoid metabolism in girls with central obesity

BackgroundDysregulation of glucocorticoid metabolism is known to be a causative factor of obesity. However, only a few studies have evaluated the enzymatic activities involved in glucocorticoid metabolism in the pediatric population. ObjectiveTo examine whether circulating glucocorticoid metabolites and their ratios reflecting the activities of metabolic enzyme are associated with obesity and body composition in girls. MethodsA total of 227 girls aged 7–13 years (131 control, 45 overweight, 51 obese) were enrolled in this study. Serum concentrations of glucocorticoids (11-deoxycortisol, cortisol, tetrahydrocortisol [THF], allo-THF, allo-dihydrocortisol [allo-DHF], and cortisone) were evaluated by gas chromatography-mass spectrometry. Enzyme activities corresponding to the ratios of cortisol and cortisone to their respective precursors and metabolites were also assessed. ResultsSerum levels of allo-THF were significantly higher in obese girls compared with those in overweight and control girls (P = 0.018); however, concentrations of other cortisol metabolites were not significantly different between the groups studied. According to the severity of obesity, increasing trends in the metabolic ratios reflecting the activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) [(cortisol + allo-DHF + allo-THF + THF)/cortisone], relative 5α/5β-reductase [allo-THF/THF] activity, and 3α-HSD [allo-THF/allo-DHF] activity, were noted (P-for-trend <0.05). Body fat percentage and waist-to-height ratio positively correlated with the activities of 11β-HSD1 and 3α-HSD (P < 0.05). Following covariate control, girls with central obesity demonstrated significantly higher metabolic ratios reflecting 11β-HSD1, relative 5α/5β-reductase, and 3α-HSD activities (P < 0.05). ConclusionsWe found an altered glucocorticoid metabolism suggesting increased production of cortisol by 11β-HSD1 and increased metabolic clearance of cortisol catalyzed by 3α-HSD in girls with central obesity.

Endocrine changes related to dog domestication: Comparing urinary cortisol and oxytocin in hand-raised, pack-living dogs and wolves

Dogs are exceptionally well adapted to life close to humans, and alterations in their endocrine system during the domestication process may be an underlying mechanism. In particular, it has been suggested that low circulating cortisol concentrations in conjunction with simultaneously high oxytocin concentrations may have resulted in dogs' increased docility (‘selection for tameness’ hypothesis) and heightened propensity to interact and form relationships with humans (‘hypersociability’ hypothesis) compared to wolves. To investigate this, we analyzed cortisol and oxytocin metabolite concentrations from urine samples of hand-raised, pack-living domestic dogs and their non-domestic relatives, grey wolves. Based on the hypotheses outlined above, we predicted lower cortisol but higher oxytocin concentrations in dogs than wolves. In contrast to our prediction, we found higher cortisol concentrations in dogs than wolves. However, oxytocin concentrations were higher in dogs compared to wolves although the effect was relatively small. Indeed, male dogs had the highest oxytocin concentrations while female dogs' oxytocin concentrations were comparable to wolves'. Feeding status, reproductive phase, and conspecific social interactions also significantly affected cortisol and oxytocin concentrations. Furthermore, we compared two methods of correcting for variable water content of urine samples. We discuss our results in light of physiological and behavioral changes during domestication and highlight the importance of accounting for confounding variables in future studies.

Resident European ground squirrels exhibit higher stress levels than translocated individuals after conservation reinforcement

The European ground squirrel (Spermophilus citellus) is a rodent inhabiting the open grasslands of central and southeastern Europe. The species is endangered, and various conservation activities are being conducted to preserve and improve the populations’ status, especially during the recent years including translocations of individuals. The success of these measures has varied and is potentially strongly influenced by the chronic and acute stress associated with the translocation process itself. This stress load, however, has rarely been investigated in the framework of such conservation projects, neither in translocated nor in resident individuals. To fill this gap, we investigated glucocorticoid metabolite concentrations in translocated ground squirrels and compared these with concentrations in resident animals of a reinforced colony in southeastern Bulgaria. Between 2017 and 2019, we sampled a total of 252 individuals for faecal cortisol metabolite concentrations (FCM). The results showed that FCM decreased after the release in translocated individuals and that the time span after the translocation event was the key variable explaining the decrease. Surprisingly, the FCM levels were higher in the resident ground squirrels than in the translocated individuals throughout the active season and in the following spring. Furthermore, we found no effect of FCM concentrations on dispersal distances or body mass gain in translocated individuals.

Fecal Cortisol Metabolites in Dairy Cows: A Cross-Sectional Exploration of Associations with Animal, Stockperson, and Farm Characteristics.

Simple SummaryDairy cows are exposed to various potentially stressful situations in the daily farm routine, which might considerably impair their welfare and performance. On 25 German organic dairy farms, we explored associations of cows’ physiological stress levels by means of cortisol metabolite concentrations in feces (1) with different potentially influencing farm factors including human–animal contact, (2) cows’ fear behaviors towards humans, and (3) milk production and udder health. Cortisol metabolite levels were decreased on farms that did not separate diseased cows, possibly reflecting less regrouping stress. Levels were also lower on farms with straw yards compared to raised cubicles, and on farms with generous compared to suboptimal lying space, underlining the importance of resting comfort for cattle. Increased human–animal contact was associated with decreased cortisol metabolite levels. However, against expectations, levels were higher, when the farm provided concentrate feed by hand and habituated young cows to milking, requiring specific experimental investigations to draw conclusions on causal associations.To date, little is known about influences on cows’ physiological stress levels on farms. The present study explored associations of fecal cortisol metabolite concentrations (FCM) with (1) farm factors including human–animal contact, (2) cows’ fear behaviors towards humans, and (3) milk production and udder health, involving 25 dairy farms and repeated fecal samples (n = 2625) from 674 focal cows. Farm factors via interviews and observations, avoidance distance (AD) and qualitative behavior assessment (QBA) during a human–animal interaction were recorded. Milk yield and somatic cell scores (SCS) were calculated from milk recordings. Levels of FCMs were in general relatively low. No associations with AD and milk yield could be detected. Correlations between FCMs and QBA and SCS were significant, but on a low level. Against expectations, FCMs were higher, when the farm provided concentrates by hand and habituated heifers to milking, in part possibly due to reversed cause–effect relations. Decreased FCM levels were found on farms that did not separate diseased cows, possibly due to the avoidance of social stress following changes in group structure. Additionally, straw yards compared to raised cubicles and generous compared to suboptimal lying space were associated with decreased levels, underlining the importance of comfort around resting. Moreover, FCMs were decreased with increased human contact time per cow. The different associations detected in this study provide a basis for further experimental investigations that moreover might provide insights into causal relationships.