Higher Plasma Cortisol Research Articles

Effect of hospitalization on equine local intestinal immunoglobulin A (IgA) concentration measured in feces

During hospitalization horses may develop gastrointestinal conditions triggered by a stress-associated weak local immune system. The prospective, clinical trial was conducted to find out whether fecal immunoglobulin A (IgA) concentrations could be determined in hospitalized horses and how they changed during hospitalization and in response to various stressors. Samples were obtained from 110 horses and a control group (n = 14). At arrival in the hospital, horses were categorized into pain grades (1-5), and elective versus strenuous surgery (> 2 hours, traumatic and emergency procedures). Feces were collected on day 1, day 2, day 3, and day 7 in all horses. Blood samples were obtained at the same intervals, but additionally after general anaesthesia in horses undergoing surgery (day 2). IgA concentration in feces was determined by ELISA and measured in optical density at 450nm. The control group showed constant IgA concentrations on all days (mean value 0.30 OD450 ±SD 0.11, 1.26 mg/g; n = 11). After general anaesthesia fecal IgA concentrations decreased considerably independent of duration and type of surgery (P < 0.001 for elective and P = 0.043 for traumatic surgeries). High plasma cortisol concentrations were weakly correlated with low fecal IgA on the day after surgery (P = 0.012, day 3, correlation coefficient r = 0.113). Equine fecal IgA concentrations showed a decline associated with transport, surgery, and hospitalization in general, indicating that stress has an impact on the local intestinal immune function and may predispose horses for developing gastrointestinal diseases such as enterocolitis.

Pro-opiomelanocortin and ACTH-cortisol dissociation during pediatric cardiac surgery.

In critically ill adults, high plasma cortisol in face of low ACTH coincides with high pro-opiomelanocortin (POMC) levels. Glucocorticoids further lower ACTH without affecting POMC. We hypothesized that in pediatric cardiac surgery-induced critical illness, plasma POMC is elevated, plasma ACTH transiently rises intraoperatively but becomes suppressed post-operatively, and glucocorticoid administration amplifies this phenotype. From 53 patients (0-36 months), plasma was obtained pre-operatively, intraoperatively and on post-operative day 1 and 2. Plasma was also collected from 24 healthy children. In patients, POMC was supra-normal pre-operatively (p<0.0001) but no longer thereafter (p<0.05). ACTH was never high in patients. While in glucocorticoid-naive patients ACTH became suppressed by post-operative day 1 (p<0.0001), glucocorticoid-treated patients had suppressed ACTH already intraoperatively (p≤0.0001). Pre-operatively high POMC, not accompanied by increased plasma ACTH, suggests a centrally-activated HPA-axis with reduced pituitary processing of POMC into ACTH. Increasing systemic glucocorticoid availability with glucocorticoid treatment accelerated the suppression of plasma ACTH.

High replacement of soybean meal by different types of rapeseed meal is detrimental to rainbow trout (Oncorhynchus mykiss) growth, antioxidant capacity, non-specific immunity and Aeromonas hydrophila tolerance.

A 12-week feeding trial was conducted to evaluate the effects of replacing soybean meal with different types of rapeseed meal (RSM; Chinese 95-type (oil press model) rapeseed meal [C95RM], Chinese 200-type rapeseed meal [C200RM], cold pressed rapeseed cake [CPRC], Indian rapeseed meal [IRM] and Canadian rapeseed meal [CRM]) on growth, antioxidant capacity, non-specific immunity and Aeromonas hydrophila infection tolerance in 990 fingering (average weight 12.77 ± 0.01 g) rainbow trout (Oncorhynchus mykiss). A basal diet was prepared using fishmeal and soybean meal as the main protein sources, the other 10 diets were formulated with five types of RSM at 20% (C95RM20, C200RM20, CPRC20, IRM20, CRM20) or 35% (C95RM35, C200RM35, CPRC35, IRM35, CRM35) inclusion levels to replace iso-nitrogenous soybean meal. Regardless of the RSM source, dietary inclusion of 20% RSM significantly reduced the weight gain rate (WGR) and digestive enzymes activities (except C200RM20) of fish, but increased the blood urea nitrogen (BUN) and hepatic malondialdehyde (MDA) content (except CRM20). Fish fed with CPRC20 and IRM20 exhibited relatively higher plasma cortisol and MDA content, but lower content/activities of triiodothyronine (T3), thyroxine (T4) and glutathione peroxidase (GPx) in plasma, lysozyme (LZM) and complement 3 (C3) in serum, catalase (CAT) in liver, and respiratory burst activity (RBA) of head kidney macrophages. The intestinal and hepatic tissues fed with 20% RSM were damaged to some extent, with the CPRC20 and IRM20 groups being the most severely affected. Regardless of the RSM source, dietary inclusion of 35% RSM significantly decreased WGR and digestive enzymes activities, but significantly increased plasma BUN and MDA content. The fish fed with CPRC35 and IRM35 exhibited relatively higher plasma cortisol, MDA, serum triglyceride, BUN content, but lower content/activities of T3, T4, C3, and LZM in serum, CAT, peroxidase and GPx in plasma, CAT in liver, RBA and phagocytic activity of head kidney macrophage. The hepatic and intestinal tissues damage was the worst in the IRM35 group among the 35% RSM inclusion groups. These results indicate that including ≥20% RSM in the diet, regardless of the source, reduced the growth, antioxidant capacity, immunity, and survival to Aeromonas hydrophila infection in rainbow trout.

O-03 Adrenalectomy for Cushing's syndrome during pregnancy

Abstract Introduction Cushing's syndrome (CS) is rare in pregnancy because CS itself is a cause of anovulatory infertility due to excess cortisol secretion. Moreover it is also difficult to diagnose CS in pregnancy because placental production of corticotropin releasing and adrenocorticotropic hormone (ACTH), increased maternal production of estrogen induced corticosteroid binding globulin leads to physiological hypercortisolism during pregnancy. So physicians face a clinical overlap in many features of CS such as weight gain, fatigue, edema, hypertension, hyperglycemia, stretch marks, mood changes that can also be attributed to pregnancy. Thus their coexistence represents a diagnostic challenge. Herein we report a case of CS that was diagnosed and successfully treated during pregnancy. Clinical Case A 43-year-old gravida 3 female was consulted at the 21st week of gestation with persistent high blood pressure and hyperglycemia for a month. She had an obstetric history of 2 spontaneous first term abortion, 2 healthy labor 18 years ago and she was healthy after. She was in such a depressive mood that she was consulted with psychiatry many times. On physical examination edema, proximal weakness of lower extremities and hirsutism (modified Ferriman–Gallwey score of 9) was detected. Initial laboratory tests were all within normal range except potassium level (2.7 mmol/L), the results were not consistent with preeclampsia and there was a suspicious adrenal mass detected on ultrasound. She was currently receiving high dose antihypertensive treatment with methyldopa, calcium channel blockers, rapid acting and detemir insulin for diabetes and i.v. potassium replacement. We ruled out conns syndrome with normal plasma aldosterone renin ratio and found catecholamine levels normal. Hormonal analyses revealed with high plasma cortisol levels, increased nocturnal cortisolemia, a suppressed plasma ACTH and dehydroepiandrosterone sulfate level and distinctly elevated 24-hour urinary cortisol greater than 3-fold the upper normal reference range. Non contrast magnetic resonance imaging demonstrated a 47×32 mm left adrenal mass. Laparoscopic adrenalectomy was performed in the 26th week of gestation and the following histopathology revealed an adrenocortical adenoma. Antihypertensive medication was progressively reduced, glycemic control and hypokalemia reversal were achieved. She was followed up with appropriate glucocorticoid replacement. At 34 weeks of gestation, after sudden labor pain and regular uterine contractions a 2586 g male infant with Apgar scores of 8 was born by cesarean section. They were discharged in good health. Conclusion CS should be kept in mind especially in the case of hypertension and diabetes that started before the 20th gestational age. Analysis of the urinary free cortisol level and circadian rhythm of cortisol is necessary to diagnose. Despite the diagnostic challenge we can achieve better maternal and fetal outcomes with proper management.Figure 1.Non-contrast magnetic resonance imaging of the patient Table 1.Patient's laboratuary test results Table 2.Patient's laboratory test results

Association between levels of serotonin, melatonin, cortisol and the clinical condition of patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic connective tissue disease of autoimmune basis. It is characterized by inflammation of joints and systemic complications. The etiopathogenesis is still unknown. Predisposing factors for the disease include genetic, immunological and environmental. Chronic disease and the stress experienced by patients disrupt the body’s homeostatic state and weaken the human immune system. Reduced immunity and endocrine disruption may influence the development of autoimmune diseases and exacerbate their course. The aim of the study was to investigate whether there is a relationship between the blood levels of hormones such as cortisol, serotonin, melatonin and the clinical status of RA patients as determined by the DAS28 index and CRP protein. A total of 165 people participated in the study of these 84 subjects had RA and the rest were the control group. All participants completed a questionnaire and had their blood drawn to determine hormones. Patients with RA had higher plasma cortisol (324.6 ng/ml vs. 292.9 ng/ml) and serotonin concentrations (67.9 ng/ml vs. 22.1 ng/ml) and lower plasma melatonin (116.8 pg/ml vs. 330.2 pg/ml) compared to controls. Patients whose CRP concentration were above normal also had elevated plasma cortisol concentration. No significant association was observed in RA patients between plasma melatonin, serotonin and DAS28 values. However, it can be concluded that those with high disease activity had lower melatonin levels as compared to patients with low and moderate DAS28 values. Significant differences were found between RA patients not using steroids and plasma cortisol (p = 0.035). In RA patients, it was observed that as plasma cortisol concentration increased, the chance of having an elevated DAS28 score, indicating high disease activity, increased.

In sea trout, the physiological response to salmon louse is stronger in female than in males.

The aims of this study were to compare male and female sea trout (Salmo trutta) with respect to their hypo-osmoregulatory ability over a simulated migration to seawater and their clinical and physiological response to salmon louse (Lepeophtheirus salmonis) infection in seawater and over a simulated pre-mature return to freshwater. For this purpose, 2-year-old hatchery-reared male and female brown trout (F1 offspring of wild caught anadromous fish) were infected with salmon lice and measured for changes in plasma ions, glucose, lactate and osmolality and relative heart, liver and gonad sizes during a simulated seawater migration and thereafter a premature return to freshwater after 4weeks in seawater (pre-adult louse). Un-infected trout served as control. Male trout used longer time to develop full hypo-osmoregulatory ability in seawater and showed a stronger response in plasma glucose and lactate following simulated premature return to freshwater, compared to female trout. Response to salmon louse was stronger in female trout, shown by stronger osmotic stress by chalimus (plasma Cl-) and pre-adult louse (plasma osmolality) and elevated relative liver size (hepatosomatic index) by pre-adult louse in female compared to male trout. Moreover, high plasma cortisol in infected female and low plasma cortisol in infected male trout produced a significant treatment-sex interaction on plasma cortisol. Lice infection intensity was initially higher in male (0.18 lice g-1) compared to female trout (0.11 lice g-1) at the chalimus stage, but equal between sexes at the pre-adult stage (male 0.15 and female 0.17 lice g-1). This study showed that female trout were better adapted for changes in water salinity, while male trout were more robust against salmon louse infection. These results suggests that the elevated salmon louse infection pressure generated by salmon farming have strong and unexplored negative effects on wild sea trout populations. Further research on this topic is vital for the conservation of wild sea trout populations.

PS-R03-3: INTERMITTENTLY SCANNED CONTINUOUS GLUCOSE MONITORING IN A DIFFICULT PATIENT WITH GESTATIONAL DIABETES MELLITUS AND SUBCLINICAL CUSHING'S SYNDROME: A CASE REPORT

A 41-year-old woman was admitted to the obstetrics department because of epigastric pain, nausea, and fatigue at 31 weeks of gestation. She was suspected of subclinical Cushing's syndrome based on high plasma cortisol and low ACTH levels along with an incidentally discovered tumor in the left adrenal gland 4 years prior to conception. 3 months before admission, 75 g oral glucose tolerance test yielded one point positive (81–169–174 mg/dL) and diagnosis of gestational diabetes mellitus was made. Diet and exercise therapy was started on an outpatient basis. While blood glucose control had been favorable, she discontinued visits to outpatient clinics due to difficulty in physical activity. At the time of admission, blood glucose level was running more than 200 mg/dl, and self-monitoring of blood glucose (SMBG) and insulin self-injection therapy were proposed for immediate blood glucose control accordingly. However, the patient had psychiatric symptoms that were presumably associated with delusional disorder and subclinical Cushing's syndrome. As such, she refused to implement both procedures on account of a strong fear against puncture, which caused blood glucose management difficult. Despite understanding the necessity of SMBG and potential risks to the fetus, the patient frequently expressed anxiety and could not perform SMBG. Given the difficult circumstance, intermittently scanned continuous glucose monitoring was installed to reduce invasive procedures. As a result, blood glucose levels were under good control with 0.43 U/kg of insulin per day until the delivery by cesarean section at 34 weeks of gestation. A healthy infant weighing 2442 g was delivered without complications. Here we highlight utility and efficacy of intermittently scanned continuous glucose monitoring in a difficult patient with gestational diabetes mellitus and subclinical Cushing's syndrome.

Iron supplementation in aquaculture wastewater and its effect on the growth of spinach and pangasius in nutrient film technique based aquaponics

A 105-day experiment was carried out to optimize the iron dose and investigate its effect on the spinach (Spinacia oleracea) and growth of pangasius (Pangasianodon hypophthalmus) in nutrient film technique (NFT) based aquaponics using aquaculture wastewater. The experimental setup consisted 15 individual and identical aquaponics units, with each unit containing a fish tank, NFT hydroponic, and a filtration system. Four different iron dosages T1 (1.0 mg/L), T2 (1.5 mg/L), T3 (2.0 mg/L), and T4 (2.5 mg/L) were assigned as treatments and compared with unsupplemented (control). The pangasius (3.13 ± 0.03 g) and spinach were stocked at 2.8 kg/m3 and 28 plants/m2, respectively in each aquaponic unit. During the experimental period, the spinach was harvested six times. During the fifth harvest (90th day), the highest yield was observed in T2 (881.74 ± 17.16 g) followed by T1 > T3 > T4 > C (563.67 ± 57.85 g). The nutrient analysis of plants revealed that the iron interacted with essential macronutrients and micronutrients and had a beneficial impact on their uptake, which in turn affected the plant growth and the yield of crops. A significant (P < 0.05) difference was found in the fish body weight among the treatments and control. The highest fish body weight was observed in T2 (16.34 ± 0.63 g) followed by T3 > T4 > T1 > C (11.72 ± 0.38 g). Higher plasma cortisol and glucose values were recorded in T4 and T3. Based on water quality parameters, spinach yield, proximate analysis, growth of fish, physiological responses, and nutrient analysis, an iron dose of 1.5 mg/L per fortnight can be optimum for pangasius-spinach nutrient film technique based aquaponics.

Atypical thymic carcinoid associated with rapidly progressive symptoms of Cushing's syndrome in a child

Atypical thymic carcinoid in children is rare and its prognosis principally depends on the completeness of the surgical resection. We report a case of atypical thymic carcinoid with lymph node metastasis that had not been identified prior to surgery. An 8-year-old boy was referred because of Cushing's syndrome and a worsening of his symptom, which included facial edema, fatigue, and headache, over 3 weeks. Blood testing revealed high plasma cortisol and adrenocorticotropic hormone (ACTH), and chest computed tomography demonstrated two tumors in his anterior mediastinum, but no findings suggestive of lymph node metastasis. We suspected the presence of an ACTH-producing thymic carcinoid tumor; therefore, the patient underwent total thymectomy and dissection of his anterior mediastinal and bilateral deep cervical lymph nodes. Histopathological examination revealed an atypical carcinoid tumor and left cervical lymph node metastasis. The patients' plasma cortisol and ACTH concentrations decreased after surgery, and he was further treated with radiotherapy and combination chemotherapy. Thus, it is possible that the development of symptoms may indicate more rapid progression of atypical thymic carcinoid, and deep cervical lymphadenectomy is necessary for its complete resection.

Association of Plasma Cortisol Levels with Gestational Age and Anthropometric Values at Birth in Preterm Infants.

There are no study reports to clarify the association between gestational age (GA) or anthropometric values at birth, and plasma cortisol levels in the blood of preterm infants at birth and at one month of age. This hospital-based retrospective cohort study included infants born at <37 weeks’ gestation between 2019 and 2021. First, the association between plasma cortisol level and GA or anthropometric values at birth (birth weight standard deviation score [SDS], birth length SDS, and birth head circumference SDS) was identified by regression and multiple regression analyses. Second, plasma cortisol levels in the umbilical cord at birth and at one month of age were compared between small-for-gestational age (SGA) and non-SGA infants. Sixty-one preterm infants were enrolled (SGA: 24 and non-SGA: 37). Plasma cortisol levels at birth were significantly associated with GA. Plasma cortisol levels at one month of age were associated with GA and birth head circumference SDS. Plasma cortisol levels at birth were significantly higher in SGA than non-SGA (p = 0.010). GA was an independent determinant of plasma cortisol levels at birth. SGA infants had a high plasma cortisol level at birth; resulting in speculation that a high plasma cortisol level at birth may predict abnormal neurological outcomes.

Metabolic scope, performance and tolerance of juvenile European sea bass Dicentrarchus labrax upon acclimation to high temperatures.

European sea bass is a species of great commercial value for fisheries and aquaculture. Rising temperatures may jeopardize the performance and survival of the species across its distribution and farming range, making the investigation of its thermal responses highly relevant. In this article, the metabolic scope, performance, and tolerance of juvenile E. sea bass reared under three high water temperatures (24, 28, 33°C), for a period of three months was evaluated via analysis of selected growth performance and physiological indicators. Effects on molecular, hormonal, and biochemical variables were analyzed along with effects of acclimation temperature on the metabolic rate and Critical Thermal maximum (CTmax). Despite signs of thermal stress at 28°C indicated by high plasma cortisol and lactate levels as well as the upregulation of genes coding for Heat Shock Proteins (HSP), E. sea bass can maintain high performance at that temperature which is encouraging for the species culture in the context of a warming ocean. Critical survivability thresholds appear sharply close to 33°C, where the aerobic capacity declines and the overall performance diminishes. European sea bass demonstrates appreciable capacity to cope with acute thermal stress exhibiting CTmax as high as 40°C for fish acclimated at high temperatures, which may indicate resilience to future heatwaves events.

Swimming energetics of Atlantic salmon in relation to extended fasting at different temperatures.

Predicted future warming of aquatic environments could make fish vulnerable to naturally occurring fasting periods during migration between feeding and spawning sites, as these endeavours become energetically more expensive. In this study, Atlantic salmon (Salmo salar) acclimated to midrange (9°C) or elevated suboptimal (18°C) temperatures were subjected to critical (Ucrit) and sustained (4hours at 80% Ucrit) swimming trials before and after 4weeks of fasting. Fasting caused weight losses of 7.3% and 8.3% at 9°C and 18°C, respectively. The Ucrit was unaffected by fasting, but higher at 18°C. Fatigue was associated with higher plasma cortisol, osmolality, Na+ and Cl- at 18°C, and ionic disturbances were higher in fasted fish. All fish completed the sustained swim trials while maintaining constant oxygen uptake rates (ṀO2), indicating strictly aerobic swimming efforts. At low swimming speeds ṀO2 was downregulated in fasted fish by 23.8% and 15.6% at 9°C and 18°C, respectively, likely as an adaptation to preserve resources. However, at higher speeds ṀO2 became similar to fed fish showing that maximum metabolic rates were maintained. The changes in ṀO2 lowered costs of transport and optimal swimming speeds in fasted fish at both temperatures, but these energetic alterations were smaller at 18°C while routine ṀO2 was 57% higher than at 9°C. As such, this study shows that Atlantic salmon maintain both glycolytic and aerobic swimming capacities after extended fasting, even at elevated suboptimal temperatures, and adaptive metabolic downregulation provides increased swimming efficiency in fasted fish. Although, improved swimming energetics were smaller when fasting at the higher temperature while metabolism becomes elevated. This could affect migration success in warming climates, especially when considering interactions with other costly activities such as coping with parasites obtained when passing aquaculture sites during seaward travel or gonad development while being voluntarily anorexic during upriver travel to spawning grounds.

Changes in the pituitary-adrenal system for extracorporal membrane oxygenation: prospective study

INTRODUCTION. At the moment, assessing adrenal dysfunction in critical patients and ways to correct this function with hormone replacement therapy are extremely difficult. OBJECTIVES. Analysis of changes in the dynamics of ACTH and cortisol levels in blood plasma during ECMO. MATERIALS AND METHODS. The prospective study was performed in intensive care unit (47 patients on ECMO). After connecting ECMO (D0), (D1–D3–D5–D7–D9), and until the completion of ECMO, assessment of cortisol and ACTH levels was carried out. RESULTS. The median level of cortisol in blood plasma was higher in the non-survivors patients on the third day (D3) (p = 0.05), D7 (p = 0.03); D13 (p = 0.05) and the last day of observation (p = 0.001), respectively. The level of ACTH in the blood of non-survivors patients was higher immediately on the day of ECMO initiation (D0) and on day 3 (D3) of observation: D0 (p = 0.018); D3 (p = 0.04), respectively. Analysis of the ROC curve showed that cortisol levels show a sensitivity of 71 % and a specificity of 89 % to an adverse outcome during ECMO. DISCUSSION. The life-saving ECMO technique, in critical conditions, is associated with a high risk of increasing of complications, including potentially lethal ones. Critical illness-related corticosteroid insufficiency (CIRCI) clinically manifests itself as inadequate adrenal activity, taking into account the augmentation of the disease severity. This activity is expressed in the form of a decrease in production and/or resistance to endogenous cortisol, as confirmed by the study. Consideration of CIRCI during the usage of ECMO reflects more objectively the violation of the pituitary-adrenal system. CONCLUSIONS. 1. CIRCI is detected in patients during ECMO. 2. High plasma cortisol levels are the predictor of an adverse outcome. 3. The level of ACTH in blood plasma is higher in patients with adverse outcomes. 4. High levels of cortisol in plasma are not a criterion for making the decision to initiate hydrocortisone therapy.

Associations between psychophysiological stress responses, inflammatory markers, and CSF biomarkers in the spectrum of Alzheimer’s disease

AbstractBackgroundAlthough genetic factors associated with the aggregation of misfolded proteins clearly play a role in Alzheimer’s disease (AD), several individual difference factors have been seen to confer an increased risk for the clinical manifestation of AD as well as the development of AD pathology. One of the key factors is an individual’s susceptibility to psychological stress. The goal of this study was to examine the relationships between psychophysiological stress responses measured by plasma stress hormones and neuropsychiatric symptoms, inflammatory markers, and AD pathology along the spectrum of AD.MethodAlzheimer’s Disease Neuroimaging Initiative (ADNI) consists of 819 adult subjects— 229 cognitively normal older adults (CNs), 398 participants with mild cognitive impairment (MCIs), and 192 patients with AD. Of these subjects, we included 58 CNs, 396 MCIs, and 112 AD patients whose plasma stress measures were available. Plasma cortisol and cytokines and CSF Aβ1‐42, t‐tau, and p‐tau181 data were downloaded from ADNI. Neuropsychiatric Inventory (NPI‐Q) total scores were used to indicate a psychological stress level.ResultAD stages were significantly related to the level of plasma cortisol and NPI‐Q total scores showing that AD patients exhibit the highest level of cortisol and greater severity of psychological symptoms followed by MCIs and CNs. AD stages were also significantly related to the level of inflammatory markers measured by cytokines, although the level of inflammatory markers in relation to the diagnostic groups varied across different types of cytokines. Plasma cortisol levels did not relate to concurrent levels of CSF Aβ1‐42 either across diagnostic groups or within diagnostic groups. Higher plasma cortisol, however, corresponded to higher CSF p‐tau among CNs, but not in MCIs and ADs.ConclusionPsychophysiological stress responses and inflammatory markers are significantly associated with the disease severity. A positive relationship between plasma cortisol level and CSF p‐tau in CNs may indicate a role of individuals’ susceptibility to stress in neuronal hyperexcitability in the early stage of AD and confer a risk of neurodegeneration and the development of AD. Alleviating stress and regulating stress responses may be important modifiable factors that help prevent AD.

The role of pro-opiomelanocortin in the ACTH\u2013cortisol dissociation of sepsis

BackgroundSepsis is typically hallmarked by high plasma (free) cortisol and suppressed cortisol breakdown, while plasma adrenocorticotropic hormone (ACTH) is not increased, referred to as ‘ACTH–cortisol dissociation.’ We hypothesized that sepsis acutely activates the hypothalamus to generate, via corticotropin-releasing hormone (CRH) and vasopressin (AVP), ACTH-induced hypercortisolemia. Thereafter, via increased availability of free cortisol, of which breakdown is reduced, feedback inhibition at the pituitary level interferes with normal processing of pro-opiomelanocortin (POMC) into ACTH, explaining the ACTH–cortisol dissociation. We further hypothesized that, in this constellation, POMC leaches into the circulation and can contribute to adrenocortical steroidogenesis.MethodsIn two human studies of acute (ICU admission to day 7, N = 71) and prolonged (from ICU day 7 until recovery; N = 65) sepsis-induced critical illness, POMC plasma concentrations were quantified in relation to plasma ACTH and cortisol. In a mouse study of acute (1 day), subacute (3 and 5 days) and prolonged (7 days) fluid-resuscitated, antibiotic-treated sepsis (N = 123), we further documented alterations in hypothalamic CRH and AVP, plasma and pituitary POMC and its glucocorticoid-receptor-regulated processing into ACTH, as well as adrenal cortex integrity and steroidogenesis markers.ResultsThe two human studies revealed several-fold elevated plasma concentrations of the ACTH precursor POMC from the acute to the prolonged phase of sepsis and upon recovery (all p < 0.0001), coinciding with the known ACTH–cortisol dissociation. Elevated plasma POMC and ACTH–corticosterone dissociation were confirmed in the mouse model. In mice, sepsis acutely increased hypothalamic mRNA of CRH (p = 0.04) and AVP (p = 0.03) which subsequently normalized. From 3 days onward, pituitary expression of CRH receptor and AVP receptor was increased. From acute throughout prolonged sepsis, pituitary POMC mRNA was always elevated (all p < 0.05). In contrast, markers of POMC processing into ACTH and of ACTH secretion, negatively regulated by glucocorticoid receptor ligand binding, were suppressed at all time points (all p ≤ 0.05). Distorted adrenocortical structure (p < 0.05) and lipid depletion (p < 0.05) were present, while most markers of adrenocortical steroidogenic activity were increased at all time points (all p < 0.05).ConclusionTogether, these findings suggest that increased circulating POMC, through CRH/AVP-driven POMC expression and impaired processing into ACTH, could represent a new piece in the puzzling ACTH–cortisol dissociation.

Sex-specific differences in physiological recovery and short-term behaviour following fisheries capture in adult sockeye salmon (Oncorhynchus nerka)

Numerous laboratory and field studies have found that female Pacific salmon have higher mortality than males during their once-in-a-lifetime upriver spawning migration. However, the proximate cause(s) of this increased mortality are poorly understood. This study exposed sockeye salmon (Oncorhynchus nerka) to a mild capture and tagging stressor and evaluated physiological recovery and movement behaviour at 1 and 4 h postrelease. Female sockeye salmon did not expend more anaerobic energy in response to the stressor but did have higher plasma lactate levels 4 h after the stressor, indicating that females took longer to physiologically recover compared with males. In addition, female salmon had lower plasma glucose but higher plasma cortisol, plasma K+, and cardiac lactate levels compared with males. Male and female salmon had markedly different postrelease behaviours within the first hour of release; males were more likely to hold position within the staging area. Two potential mechanisms leading to increased mortality in female salmon were identified in this study: (a) prolonged recovery duration (possibly mediated by elevated plasma cortisol levels) and (b) insufficient oxygen delivery to the heart.

1872-P: Metabolomic Profiling during Diabetic Ketoacidosis (DKA) Demonstrates Unique Defects Underlying the Pathophysiology of Ketosis-Prone Diabetes

Obese patients with ketosis-prone type 2 diabetes (“A-β+ KPD”) have increased catabolism of the ketogenic amino acids leucine/isoleucine (Leu/Ile) and impaired ketone oxidation when stable and normoglycemic (Patel et al, Diabetes 2013). We performed comparative serum metabolomics on patients at presentation with hyperglycemic crisis without (N = 29) or with (N = 73) DKA compared to healthy controls (N = 17). The diabetic groups included normal weight and overweight/obese subgroups. DKA patients had higher plasma cortisol and catecholamines and lower C-peptide than the other groups. Three metabolite patterns distinguished the DKA patients from the other groups: 1) Elevated levels of Leu/Ile and of their respective ketoacids, no difference in isovaleryl carnitine (C5) but markedly lower ratio of C5 to C2 (acetyl carnitine) - implying accelerated shunting of Leu/Ile into their catabolic pathways but impaired oxidation because defective TCA cycle activity restrains acetyl CoA entry and metabolism. These changes were most pronounced in obese DKA patients, recapitulating the pattern of A-β+ KPD patients when stable; 2) Markedly decreased levels of glutamate, ammonia and many non-essential amino acids including citrulline, in the presence of increased glutamine, suggesting a defect in glutaminase activity; 3) Low levels of 3-methyl histidine, suggesting a surprising decrease in muscle protein breakdown. The pattern of amino acids and their metabolites among the DKA (especially obese) patients indicate that both increased ketone production from Leu/Ile and their blunted oxidation contribute to the proclivity to develop DKA; elevated leucine and low citrulline could contribute to beta cell dysfunction via mTOR hyperactivity and diminished intracellular arginine availability. Thus serum metabolomic profiling during an acute DKA episode helps define a unique pathophysiology underlying the phenotype of obese ketosis-prone T2D. Disclosure J.W. Hsu: None. P. Mehta: None. K.R. Keene: None. S.N. Mulukutla: None. E.I. Caducoy: None. W. Peacock: None. A. Balasubramanyam: None. F. Jahoor: None. Funding National Institutes of Health (R01DK101411)

OR19-06 Sepsis-Induced Critical Illness in Mice Alters Key Regulators of ACTH Production and Secretion Within the Anterior Pituitary Gland

IntroductionCritical illness is hallmarked by high plasma cortisol without elevated ACTH. This is partly explained by low cortisol-binding proteins and reduced binding affinity and by suppressed cortisol metabolism, 3 peripheral drivers of increased free cortisol (corticosterone (CORT) in rodents).1 We hypothesized that lack of elevated plasma ACTH is explained by CORT-induced feed-back inhibition either due to suppressed CRH or AVP pituitary signaling or to direct glucocorticoid receptor (GR)-mediated action within corticotrophs. To test this hypothesis, we documented alterations in ACTH precursors and key enzymes controlling ACTH maturation and secretion in a mouse model of sepsis-induced critical illness.MethodsC57Bl/6 mice were randomly allocated to a healthy control group or to 4 critically ill groups sacrificed after increasing illness duration (30 hours (H), 3 days (D), 5D or 7D). Critical illness was induced by sepsis brought about by cecal-ligation and puncture followed by fluid-resuscitation and antibiotics treatment. The study was continued until 15 surviving animals per time cohort were reached (n=120).We quantified pituitary pro-opiomelanocortin (POMC) gene/protein expression and POMC plasma concentrations, pituitary POMC intracellular trafficking and cleavage via intracellular POMC sorting/trafficking receptor Carboxypeptidase E (CPE) and prohormone convertase 1 (PC1/3) gene/protein expression. Gene expression of Annexin A1, an inhibitor of mature ACTH secretion, was quantified as marker of GR-mediated CORT-induced feedback inhibition at corticotroph level.ResultsPlasma CORT concentrations were median 3-fold increased during critical illness (p<0.001 for all time cohorts) in the face of normal (for 30H, 3D and 5D cohorts) to low (7D time cohort; p=0.01) plasma ACTH concentrations. Plasma POMC concentrations were higher in critically ill than in control mice (p=0.05). POMC gene expression (but not protein, P=0.8) was a median 55% higher in critically ill mice than in controls (p<0.05 for all time cohorts). In contrast, pituitary mature ACTH protein concentration was median 61% lower in critically ill than in control mice (p<0.01). CPE gene expression was only increased in 30H time cohort (p<0.001). PC1/3 gene and protein expression were positively correlated (R2 0.1; p=0.001) and were reduced (by 37% and 43%, respectively) during the entire course of critical illness (p<0.01). Annexin A1 gene expression was increased during critical illness (p<0.05 for all time cohorts).ConclusionSuppressed CRH or AVP signaling and GR-mediated action within corticotrophs explained lack of elevated plasma ACTH in critical illness, as indicated by impaired POMC processing and ACTH maturation. However, increased POMC gene expression suggests ongoing corticotroph activation, the driver of which needs to be identified. 1. Teblick A et al. Nat Rev Endocrinol 2019

Steroidal regulation of the aromatase gene and dominant behavior in the false clown anemonefish Amphiprion ocellaris

The interaction between cortisol and aromatase may be a critical factor in sex determination or sex changes in teleost species. High cortisol concentrations inhibit transcription of the aromatase gene, resulting in masculinization. Anemonefish (Amphiprion spp.) are socially controlled, protandrous sex-changing fish, with a monogamous mating system. Females are the largest and most dominant members of social groups, second-ranking individuals become males, and other individuals remain nonreproductive. Individuals that change from male to female display high plasma cortisol concentrations, contrary to a previously established mechanism of masculinization. We investigated the effects of exogenous steroids on gene expression in the brain and gonads and on the occurrence of dominant behavior in the sexually immature ambisexual false clown anemonefish Amphiprion ocellaris. Transcription of the cyp19a1a aromatase gene increased in the gonads of estradiol pellet-fed fish but decreased in cortisol pellet-fed fish. Dominant behavior intensity significantly increased in estradiol pellet-fed fish, but decreased in cortisol pellet-fed fish. Methyltestosterone had no apparent effect on gene transcription or behavior. These results suggest that the masculinization mechanism induced by cortisol is common among teleost species, including protandrous sex-changing fish, and that behavioral changes induced by steroid supplements reflect social status in A. ocellaris.

Involvement of purinergic signaling in the Amazon fish Pterygoplichthys pardalis subjected to handling stress: Relationship with immune response

Stress has a considerable impact on the welfare and productivity of fish, and stress caused by transport and handling can result in mortality rates of up to 73%. Cortisol is the major corticosteroid produced by the hypothalamic-pituitary-interrenal axis (HPI) in several stressful conditions, and high plasma cortisol levels impair immune and inflammatory responses. However, the involvement of purinergic signaling, a system that might contribute to the fine tuning of inflammatory and immune responses caused by the stress response, remains unknown in fish subjected to handling stress. Thus, the aim of this study was to evaluate the involvement of purinergic signaling with the immune response of the Amazon fish bodó (Pterygoplichthys pardalis) to acute handling stress. Plasma cortisol levels were higher 240 min post-stress in fish subjected to handling than in the control group. Plasma triphosphate diphosphohydrolase (NTPDase) activity, using adenosine triphosphate (ATP) as a substrate, was upregulated 30 min post-stress in fish subjected to handling, whereas splenic NTPDase activity was downregulated 240 min post-stress compared to the control group. No significant difference was observed between the groups regarding plasma and spleen NTPDase (using adenosine diphosphate as substrate) and 5′-nucleotidase and adenosine deaminase (ADA) activities. The levels of nitric oxide metabolites (NOx) and ATP in the spleen were higher 240 min post-stress in fish subjected to handling, although no significant difference was observed in the plasma levels. Based on these results, purinergic signaling via regulation of extracellular ATP catabolism could be involved in the immunophysiological responses of bodó subjected to acute handling stress, exerting two different profiles. In plasma, this signaling contributes to a reduction in the systemic inflammatory response, however, inhibition of ATP hydrolysis in the spleen displayed a pro-inflammatory profile due to the excessive ATP levels in the extracellular milieu, which induced the release of pro-inflammatory mediators. Thus, NTPDase activity could be a pathway associated with the immunophysiological responses of bodó to acute handling stress.