Corticosterone Concentrations Research Articles

Effects of chronic exposure to a high fat diet, nutritive or non-nutritive sweeteners on hypothalamic-pituitary-adrenal (HPA) and -gonadal (HPG) axes of male Sprague-Dawley rats.

Diet-related factors are of great significance in the regulation of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonad (HPG) axes. In this study, we aimed to investigate the effects of chronic exposure to a high fat diet (HFD), fructose or sucralose on the endocrine functions. Male, Sprague-Dawley rats received a normal chow diet, HFD, 10% fructose or 0.02% sucralose for 10 weeks. Behavioral changes were assessed by open field (OFT) and elevated plus-maze (EPM) tests at week 8. H&E staining was used to observe pathological changes in adrenal cortex, testis and perirenal adipose tissue. Serum hormone concentrations were quantified via enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of genes along the HPA and HPG axes were determined using real-time PCR. All types of dietary interventions increased body weight and disturbed metabolic homeostasis, with anxiogenic phenotype in behavioral tests and damage to cell morphology of adrenal cortex and testis being observed. Along the HPA axis, significantly increased corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) concentrations were observed in the HFD or 0.02% sucralose group. For HPG axis, gonadotropin-releasing hormone (GnRH) and estradiol (E2) concentrations were significantly increased in all dietary intervention groups, while decreased concentrations of follicle-stimulating hormone (FSH) and testosterone (T) were also detected. Moreover, transcriptional profiles of genes involved in the synthesis of hormones and corresponding hormone receptors were significantly altered. Long-term consumption of HFD, fructose or sucralose manifested deleterious effects on endocrine system and resulted in the dysregulation of HPA and HPG axes.

Anti-inflammatory, anti-oxidant and anti-ulcer activities of aqueous lyophilizate of Markhamia lutea (Bignoniaceae)

Abstract Objectives This work was carried out with a view to determining the antioxidant, anti-inflammatory and anti-ulcer properties of the aqueous lyophilized extract of Markhamia lutea. Methods In vitro proteinases inhibition, albumin denaturation, hemolysis of red blood cells by heat, inhibition of the proton pump H+/K+ATPase, FRAP (Ferric reducing antioxidant power) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays were performed. In vivo, cold water immersion-induced ulceration and methylene blue-induced ulceration was used to determine the anti-ulcer properties of the lyophilizate (100, 200 and 300 mg/kg). Results In vitro, the lyophilizate (400 μg/mL) significantly inhibited protein denaturation (66.65 %), hemolysis of red blood cells (56.54 %), proteinase activity (69.22 %); then the IC50 was 26.31 μg/mL on proton pump activity. It has also developed a strong ferric reducing antioxidant power (EC50=52.96 mmol FeSO4/g) as well as free radicals scavenging activity (EC50=22.38 μg/mL). In vivo, the aqueous lyophilizate (200 and 300 mg/kg) protected the gastric mucosa (70.68 and 79.00 % protection respectively) and reduced (p<0.05) acetylcholine, calcium and corticosterone concentrations. A decrease in malondialdehyde level, an increased glutathione level and an increased in catalase and SOD activities were recorded. In the methylene blue test, it significantly increased gastric fluid pH, while reducing gastric volume and improving hematological parameters in ulcer animals. In addition, the histological sections show that the aqueous lyophilizate of M. lutea protected the gastric mucosa from the deleterious effects of stress. Conclusions The aqueous lyophilizate of M. lutea has anti-ulcer properties thanks to its anti-inflammatory, antioxidant and anti-secretory properties.

3 The impact of early-life cecal microbiota transplantation on injurious behaviors in egg-laying chickens

Abstract Injurious behaviors in laying hens are a critical issue facing the poultry egg industry. Recent studies have shown that the gut microbiota influences host brain function and behavioral characteristics in humans and various animals. In laying hens, it has been reported that injurious behaviors (such as aggression, feather pecking and cannibalism) are associated with dysregulation of the microbiota-gut-brain axis. To further interrogate the role of the microbiota-gut-brain axis on bird behavior, we used two inbred layer chicken lines, 63 and 72 (line 72 displays more aggressive behavior), and transferred pooled cecal contents from either line to day of hatch chicks. Cecal microbiota transplantation (CMT) from each line was conducted once daily, by gavage, from d 1 to 10, then boosted once weekly from wk 3 to 5. We hypothesized that the cecal microbiota composition and animal behavior in recipient birds would be similar to that of their donor animals because of the microbiota-gut-brain axis. Microbial communities were compared using 16S rRNA gene amplicon sequencing, behavior was recorded in home cages as well as in paired aggression tests, and physiological measurements were taken from brain tissue and blood to measure levels of neurotransmitters and immune function. When examining the differences in the donor birds, hypothalamic serotonin and tryptophan concentrations were greater for line 63 compared with line 72 birds (P < 0.05). Plasma corticosterone, heterophil/lymphocyte ratios, and central norepinephrine concentrations were less for line 63 birds (P < 0.05). Cecal microbial diversity was not statistically different between the lines, but many bacterial taxa were differentially abundant between the two lines. After cecal transplantation, 63-CMT (recipient) birds displayed less aggressive behavior with a greater hypothalamic serotonergic activity at wk 5, similar to donor birds. Correspondingly, two amplicon sequence variants (ASVs) belonging to Lachnospiraceae and one Ruminococcaceae UCG-005 ASV were positively correlated with the concentrations of brain tryptophan and serotonin, respectively. Along with greater aggression, 72-CMT birds seemed to have greater physical growth traits (increased body weight, ileal villus/crypt; P ≤ 0.05), but decreased concentrations of brain norepinephrine and dopamine, and the greatest ileal serotonin turnover in the ileum at wk 5 (P < 0.05). ASVs belonging to Mollicutes RF39 and GCA-900066225 in 72-CMT birds were negatively correlated with the brain 5-hydroxyindoleacetic acid (5-HIAA) at wk 5, and one Bacteroides ASV was negatively correlated with plasma serotonin at wk 16. Meanwhile, 63-CMT birds potentially had better gut health and immune function (greater concentrations of ileal mucosal secretory IgA, plasma IL-10; P < 0.05). These results suggest linkages among serotonergic activity, stress response, innate immunity, and gut microbiota populations and that CMT could be a novel strategy for reducing aggressive behavior through regulating signaling along the microbiota-gut-brain axis.

Alcohol exacerbates psychosocial stress-induced neuropsychiatric symptoms: Attenuation by geraniol

Adaptation to psychosocial stress is psychologically distressing, initiating/promoting comorbidity with alcohol use disorders. Emerging evidence moreover showed that ethanol (EtOH) exacerbates social-defeat stress (SDS)-induced behavioral impairments, neurobiological sequelae, and poor therapeutic outcomes. Hence, this study investigated the effects of geraniol, an isoprenoid monoterpenoid alcohol with neuroprotective functions on EtOH escalated SDS-induced behavioral impairments, and neurobiological sequelae in mice. Male mice chronically exposed to SDS for 14 days were repeatedly fed with EtOH (2 g/kg, p. o.) from days 8–14. From days 1–14, SDS-EtOH co-exposed mice were concurrently treated with geraniol (25 and 50 mg/kg) or fluoxetine (10 mg/kg) orally. After SDS-EtOH translational interactions, arrays of behavioral tasks were examined, followed by investigations of oxido-inflammatory, neurochemicals levels, monoamine oxidase-B and acetylcholinesterase activities in the striatum, prefrontal-cortex, and hippocampus. The glial fibrillary acid protein (GFAP) expression was also quantified in the prefrontal-cortex immunohistochemically. Adrenal weights, serum glucose and corticosterone concentrations were measured. EtOH exacerbated SDS-induced low-stress resilience, social impairment characterized by anxiety, depression, and memory deficits were attenuated by geraniol (50 and 100 mg/kg) and fluoxetine. In line with this, geraniol increased the levels of dopamine, serotonin, and glutamic-acid decarboxylase enzyme, accompanied by reduced monoamine oxidase-B and acetylcholinesterase activities in the prefrontal-cortex, hippocampus, and striatum. Geraniol inhibited SDS-EtOH-induced adrenal hypertrophy, corticosterone, TNF-α, IL-6 release, malondialdehyde and nitrite levels, with increased antioxidant activities. Immunohistochemical analyses revealed that geraniol enhanced GFAP immunoreactivity in the prefrontal-cortex relative to SDS-EtOH group. We concluded that geraniol ameliorates SDS-EtOH interaction-induced behavioral changes via normalization of neuroimmune-endocrine and neurochemical dysregulations in mice brains.

Anthropogenic and climatic factors interact to influence reproductive timing and effort.

Reproduction, although absolutely essential to a species' persistence, is in itself challenging. As anthropogenic change increasingly affects every landscape on Earth, it is critical to understand how specific pressures impact the reproductive efforts of individuals, which directly contribute to the success or failure of populations. However, organisms rarely encounter a single burden at a time, and the interactions of environmental challenges can have compounding effects. Understanding environmental and physiological pressures is difficult because they are often context-dependent and not generalizable, but long-term monitoring across variable landscapes and weather patterns can improve our understanding of these complex interactions. We tested the effects of urbanization, climate, and individual condition on the reproductive investment of wild side-blotched lizards (Uta stansburiana) by measuring physiological/reproductive metrics from six populations in urban and rural areas over six consecutive years of variable precipitation. We observed that reproductive stage affected body condition, corticosterone concentration, and oxidative stress. We also observed that reproductive patterns differed between urban and rural populations depending on rainfall, with rural animals increasing reproductive investment during rainier years compared to urban conspecifics, and that reproductive decisions appeared to occur early in the reproductive process. These results demonstrate the plastic nature of a generalist species optimizing lifetime fitness under varying conditions.

Increasing concentrations of dietary threonine, tryptophan, and glycine improve growth performance and intestinal health with decreasing stress responses in broiler chickens raised under multiple stress conditions

The current study aimed to compare the effects of increasing concentrations of dietary threonine (Thr), tryptophan (Trp), and glycine (Gly) on productive performance, stress biomarkers, and intestinal function in broiler chickens under multiple stress conditions. Five hundred sixty 21-d-old broiler chickens were randomly allotted to 5 treatments with 8 replicates. Birds in a positive control (PC) treatment were raised under low stock density (16.9 birds/m2) with recommended environmental conditions, whereas birds in 4 treatments were subjected to multiple stress conditions: a cyclic heat stress of 30 ± 0.3 °C for 10 h and 23 ± 0.2 °C for 14 h per day with high stock density (25.3 birds/m2). A basal diet was assigned to both PC and negative control (NC) treatments. Three additional diets were individually formulated to contain double concentrations of digestible Thr, Trp, or Gly + Ser compared with their concentrations in the basal diet. The experiment lasted for 14 d. Results showed that NC treatment had less growth performance (P < 0.001), goblet cell counts (P = 0.018), and trans-epithelial electrical resistance (TEER; P < 0.001), but greater (P = 0.026) feather corticosterone (CORT) concentrations than PC treatment. Thr treatment showed the least (P < 0.001) feed conversion ratio (FCR) among treatments under multiple stress conditions. Thr, Trp, and Gly treatments had less (P = 0.026) feather CORT concentrations, but had greater (P < 0.001) TEER than NC treatment. In conclusion, increasing concentrations of dietary Thr, Trp, or Gly improve the growth performance and intestinal health of broiler chickens with decreasing stress response under multiple stress conditions.

Endocrine data provide further evidence of physiologic derangement in sea turtles affected by the Deepwater Horizon oil spill

This study was conducted to characterize the adrenocortical and thyroid status of Kemp’s ridley sea turtles Lepidochelys kempii that were affected by the Deepwater Horizon oil spill. A plasma aldosterone assay was validated for L. kempii, and it was used along with previously validated assays for corticosterone and free thyroxine to assess hormone concentrations of 30 L. kempii that were hospitalized due to oil exposure, representing 2 severities of oiling (lightly or heavily oiled). Hormone concentrations were also assessed in relation to 8 clinical biochemical analytes. Analysis of paired samples indicated that oiled turtles had significantly higher initial aldosterone and corticosterone concentrations, which declined during convalescence (average 96 and 90% decrease, respectively). Thyroxine concentrations significantly increased between admission and convalescence (average 65% increase). Initial biochemical data indicated significantly higher plasma potassium, ionized magnesium, and lactate concentrations compared to convalescent values. Aldosterone concentrations were positively correlated with corticosterone, negatively correlated with free thyroxine, and variably correlated with several clinical biochemical analytes. Results of this study indicate that L. kempii had robust adrenocortical activity after oiling, capture, and transport to the hospital, regardless of the degree of oiling, resulting in very high plasma concentrations of aldosterone and corticosterone. This study also confirms that aldosterone can be reliably measured in sea turtle plasma samples, providing another diagnostic tool for the physiologic assessment of this Critically Endangered species.

Seasonal Hair Glucocorticoid Fluctuations in Wild Mice (Phyllotis darwini) within a Semi-Arid Landscape in North-Central Chile.

Mammals in drylands face environmental challenges exacerbated by climate change. Currently, human activity significantly impacts these environments, and its effects on the energy demands experienced by individuals have not yet been determined. Energy demand in organisms is managed through elevations in glucocorticoid levels, which also vary with developmental and health states. Here, we assessed how anthropization, individual characteristics, and seasonality influence hair glucocorticoid concentration in the Darwin's leaf-eared mouse (Phyllotis darwini) inhabiting two areas with contrasting anthropogenic intervention in a semi-arid ecosystem of northern Chile. Hair samples were collected (n = 199) to quantify hair corticosterone concentration (HCC) using enzyme immunoassays; additionally, sex, body condition, and ectoparasite load were recorded. There were no differences in HCC between anthropized areas and areas protected from human disturbance; however, higher concentrations were recorded in females, and seasonal fluctuations were experienced by males. The results indicate that animals inhabiting semi-arid ecosystems are differentially stressed depending on their sex. Additionally, sex and season have a greater impact on corticosterone concentration than anthropogenic perturbation, possibly including temporal factors, precipitation, and primary production. The influence of sex and seasonality on HCC in P. darwini make it necessary to include these variables in future stress assessments of this species.

The Effect of Anti-fatigue Decoction on the Behaviors and Serological Indicators in a Central Fatigue Rat Model.

This study aimed to assess the effects of Anti-fatigue Decoction (AFD) against central fatigue by observing the behaviors and serological indicators of rats modeled by the modified multiple platform method (MMPM) after drug intervention. Grip strength measurements were used to evaluate the muscle strength of rats. The open field test was utilized to assess anxiety-like behavior, while the Morris water maze test was conducted to evaluate the memory function of the rats. Following the behavioral assessments, rat serum samples were collected to measure the concentrations of corticosterone (CORT) and lactic acid (LAC). The concentration of LAC was determined using the colorimetric method, while the concentration of CORT was measured using the enzyme-linked immunosorbent assay (ELISA) method. Compared to the blank control group, following MMPM modeling, rats exhibited significant reductions in grip strength and impaired ability to memory. The serum analysis revealed increased levels of LAC and CORT in the model group rats. AFD can noticeably reverse these adverse changes to a certain extent. These findings highlight the positive effects of AFD and coenzymeQ10 on physical and cognitive abilities and alterations in serum biomarker levels of central fatigue rats.

Testicular dysfunction and “its recovery effect” after cadmium exposure

In recent years, with the acceleration of industrialization, the decline of male fertility caused by heavy metal pollution has attracted much attention. However, whether the inhibition of testicular function after cadmium exposure is reversible remains to be studied. In this study, we constructed rat models of cadmium exposure and dis-exposure, and collected relative samples to observe the changes of related indicators. The results showed that cadmium exposure could reduce the fertility, inhibit the hypothalamic-pituitary-testis axis and activate hypothalamic-pituitary-adrenal axis function, the testicular GR/PI3K-AKT/AMPK signal was abnormal, cell proliferation was inhibited and apoptosis was enhanced. Four weeks after the exposure was stopped, the fertility was still decreased, testicular testosterone synthesis and spermatogenesis were inhibited, cell proliferation was inhibited and apoptosis was enhanced, but all of them were reversed. After eight weeks of cadmium exposure, the above indicators were observed to return to normal. At the same time, by giving different concentrations of corticosterone to spermatogonium, we confirmed that corticosterone may regulate the proliferation and apoptosis of spermatogonium through GR/PI3K-AKT/AMPK signal. In this study, the reproductive toxicity of cadmium, a metal environmental pollutant, was analyzed in depth to provide a new theoretical and experimental basis for ensuring male reproductive health.

Chronic unpredictable mild stress increases serum aldosterone without affecting corticosterone levels and induces hepatic steatosis and renal injury in young adult male rats.

Stress is often associated with anxiety and depressive symptoms in adolescents. Stress is associated with components of metabolic syndrome and inflammation. The present study hypothesizes that aldosterone, more than corticosterone, promotes chronic stress-hepatic steatosis and fibrosis, as well as renal inflammation and fibrosis in young adult rats. Thirty-two young adult male Wistar rats of 51 days old were divided into four groups (n = 8 per group): Control (C), chronic unpredictable mild stress (CUMS), control plus vehicle (C plus veh), CUMS plus eplerenone, a selective aldosterone blocker (CUMS plus EP). On postnatal day 51, eplerenone was administered orally through a gastric tube two hours before the start of the stress test. The CUMS paradigm was administered once daily at different times, with no repetition of the stressor sequence for four weeks. Renal inflammation and fibrosis were measured, as well as liver glycogen, triacylglycerol, and fibrosis levels. The serum concentrations of corticosterone, aldosterone, sodium, and creatinine were measured in urine and serum. The CUMS group showed a high level of serum aldosterone without affecting the level of corticosterone, increased urinary sodium, tubular atrophy, glomerular sclerosis, the presence of inflammation, and fibrosis, without affecting creatinine, increased glycogen content, triacylglycerol, and moderate fibrosis in the liver, and treatment with eplerenone prevented the inflammation, fibrosis, glycogen, and triacylglycerol. Our results show that chronic stress-induced aldosterone promotes hepatic steatosis and renal injury more than corticosterone. The prevention by eplerenone supports our hypothesis.

Spinal bestrophin-1 and anoctamin-1 channels have a pronociceptive role in the tactile allodynia induced by REM sleep deprivation in rats

Bestrophin-1 and anoctamin-1 are members of the calcium-activated chloride channels (CaCCs) family and are involved in inflammatory and neuropathic pain. However, their role in pain hypersensitivity induced by REM sleep deprivation (REMSD) has not been studied. This study aimed to determine if anoctamin-1 and bestrophin-1 are involved in the pain hypersensitivity induced by REMSD. We used the multiple-platform method to induce REMSD. REM sleep deprivation for 48 h induced tactile allodynia and a transient increase in corticosterone concentration at the beginning of the protocol (12 h) in female and male rats. REMSD enhanced c-Fos and α2δ-1 protein expression but did not change activating transcription factor 3 (ATF3) and KCC2 expression in dorsal root ganglia and dorsal spinal cord. Intrathecal injection of CaCCinh-A01, a non-selective bestrophin-1 blocker, and T16Ainh-A01, a specific anoctamin-1 blocker, reverted REMSD-induced tactile allodynia. However, T16Ainh-A01 had a higher antiallodynic effect in male than female rats. In addition, REMSD increased bestrophin-1 protein expression in DRG but not in DSC in male and female rats. In marked contrast, REMSD decreased anoctamin-1 protein expression in DSC but not in DRG, only in female rats. Bestrophin-1 and anoctamin-1 promote pain and maintain tactile allodynia induced by REM sleep deprivation in both male and female rats, but their expression patterns differ between the sexes.

Research Note: Morphine influences circulating and tissue concentrations of met-enkephalin and proenkephalin (PENK) expression and plasma concentrations of corticosterone in chickens

The effects of the administration of the opioid agonist, morphine, on plasma and tissue concentrations of Met-enkephalin were determined in 14 wk old female chickens. In addition, effects of morphine on proenkephalin (PENK) expression were examined. Plasma concentrations of Met-enkephalin were reduced 10 minutes after morphine administration. Plasma concentrations of peptides that contain Met-enkephalin motifs were decreased 30 minutes after morphine administration. Tissue concentrations of Met-enkephalin tended to be depressed following morphine administration. Adrenal concentrations of PENK peptides containing Met-enkephalin motifs were decreased in chickens challenged with morphine. Expression of PENK in the anterior pituitary gland and adrenal glands were decreased in morphine treated compared to control pullets. In contrast, plasma concentrations of corticosterone were elevated 10 min after morphine treatment. Morphine also induced changes in mu (µ) opioid receptors and delta (δ) opioid receptors in both anterior pituitary tissue and adrenal tissues.

How does visible light flicker impact laying hen pullet behavior, fear, and stress levels?

Many characteristics of artificial light have been evaluated; however, light-flicker frequency (F) has not been assessed extensively in poultry. Pullets (1,344 per strain [S]; Lohmann Brown-Lite [LB] and LSL-Lite [LW]) were placed into 8 light-tight rooms, containing 6 floor pens (15 pen replicates per F × S for 30 and 250 Hz; 18 pen replicates per F x S for 90 Hz), and assigned 1 of 3 F treatments (30, 90, 250 Hz). The experiment took place over 2 trials (blocks). To evaluate long-term effects of F during rearing, birds were followed through the hen phase. Data were analyzed using Proc Mixed (SAS 9.4). Differences were considered significant when P ≤ 0.05, and behaviors are expressed as percentage of time. Pullets reared under 30 Hz spent more time performing nutritive behaviors (P < 0.01) and as "unidentified" (P = 0.02) than other treatments. Active behavior demonstrated an age x F interaction, with pullets being more active at 16 wk, regardless of F (P < 0.01). Comfort behaviors were higher at 16 wk compared to other ages, regardless of F (P < 0.01). Exploratory behaviors were lowest at 4 wk in pullets under 30 Hz (P < 0.01). Aggressive behaviors (12 wk) were higher in pullets reared under 250 Hz than those under 90 Hz (P < 0.01). Comb score was unaffected by F (P = 0.79) and all birds scored had a full plumage. Heterophil-to-lymphocyte ratio was unaffected by F at 7 or 15 wk (P = 0.85 and P = 0.54, respectively). In trial 1, pullets reared under 90 Hz had higher corticosterone concentrations than those reared under 250 Hz (P = 0.02) and trial 2 there were no effects of F (P = 0.97). For novel object test, LW pullets reared under 90 Hz had a higher latency to peck than LW pullets under 30 Hz or 250 Hz (P = 0.03). Hen behavior (wk 39) and fear tests (36 wk; novel object test (P = 0.86) and tonic immobility (P = 0.37)) were unaffected by F. Overall, minimal effects of F were seen on pullet and hen behavior and stress.

Investigating the effect of parental pre-gestational stress on ethological parameters in male rat offspring

Investigating the effect of parental pre-gestational stress on ethological parameters in male rat offspring

Performance, slaughter traits and serum corticosterone levels in COBB500 broiler chickens fed lycopene-supplemented diets during heat period

Poultry farmers in the tropics suffer great losses in broiler production especially during the post brooding phase as a result of heat stress occasioned by high ambient temperature. This study therefore, investigated the ameliorative effects of synthetic lycopene dietary supplement on growth performance, slaughter traits and serum corticosterone (CORT) levels of COBB500 broiler chickens reared during heat period. A total of 120 birds were selected at 4th week of rearing and allotted into a control group (C) and three experimental groups designated as T1, T2 and T3. Each group had 3 replicates. The four groups were fed the same starter diet for 4 weeks and then differently on finisher diet supplemented with lycopene at 0mg/kg feed (control), 5mg/kg (T1), 10mg/kg (T2), and 15mg/kg (T3) for 3 weeks. Data obtained were analyzed for statistical differences using ANOVA. The results showed that lycopene supplementation increased feed intake significantly (p&lt;0.05) in the birds under groups T1 and T3. Final body weights and weight gain were statistically similar across the groups but numerically improved in the lycopene-supplemented broilers. While the thigh muscle weight increased significantly (p&lt;0.05) across the groups with increasing supplementation, feed conversion ratio (FCR) decreased optimally (2.03) at 15mg/kg supplementation level leading to improved general performance. The supplement also decreased serum CORT concentration significantly (p&lt;0.05) at 5mg/kg level. Therefore, lycopene can be supplemented in diets at 5mg/kg feed as an anti-stress and performance enhancer in COBB500 broiler chickens reared under hot climate.

CRF binding protein activity in the hypothalamic paraventricular nucleus is essential for stress adaptations and normal maternal behaviour in lactating rats

To ensure the unrestricted expression of maternal behaviour peripartum, activity of the corticotropin-releasing factor (CRF) system needs to be minimised. CRF binding protein (CRF-BP) might be crucial for this adaptation, as its primary function is to sequester freely available CRF and urocortin1, thereby dampening CRF receptor (CRF-R) signalling. So far, the role of CRF-BP in the maternal brain has barely been studied, and a potential role in curtailing activation of the stress axis is unknown.We studied gene expression for CRF-BP and both CRF-R within the paraventricular nucleus (PVN) of the hypothalamus. In lactating rats, Crh-bp expression in the parvocellular PVN was significantly higher and Crh-r1 expression in the PVN significantly lower compared to virgin rats. Acute CRF-BP inhibition in the PVN with infusion of CRF(6–33) increased basal plasma corticosterone concentrations under unstressed conditions in dams. Furthermore, while acute intra-PVN infusion of CRF increased corticosterone secretion in virgin rats, it was ineffective in vehicle (VEH)-pre-treated lactating rats, probably due to a buffering effect of CRF-BP. Indeed, pre-treatment with CRF(6–33) reinstated a corticosterone response to CRF in lactating rats, highlighting the critical role of CRF-BP in maintaining attenuated stress reactivity in lactation. To our knowledge, this is the first study linking hypothalamic CRF-BP activity to hypothalamic-pituitary-adrenal axis regulation in lactation. In terms of behaviour, acute CRF-BP inhibition in the PVN under non-stress conditions reduced blanket nursing 60 min and licking/grooming 90 min after infusion compared to VEH-treated rats, while increasing maternal aggression towards an intruder. Lastly, chronic intra-PVN inhibition of CRF-BP strongly reduced maternal aggression, with modest effects on maternal motivation and care.Taken together, intact activity of the CRF-BP in the PVN during the postpartum period is essential for the dampened responsiveness of the stress axis, as well as for the full expression of appropriate maternal behaviour.

Circadian Corticosterone Profile in Laying Hens (Gallus gallus domesticus).

Measurement of blood corticosterone concentrations has been established as an indicator for assessment of acute distress. Therefore, knowledge on physiological fluctuations is required, but previous studies allow little conclusion on daily fluctuations in domestic chickens (Gallus gallus domesticus). To verify the presence of a circadian corticosterone rhythm in socialized chickens, blood samples were taken at four-hour intervals from 12 laying hens kept in groups of four over three days, each. Prior to experiments, hens were adapted to repeated handling for stress reduction. Corticosterone concentration was determined using radioimmunoassay. Blood sampling time and duration were recorded, and audio and video recordings were analyzed to assess the impact of behavior on corticosterone concentrations. Despite individual fluctuations, most hens showed a circadian course with two peaks per day. Statistics revealed a significant peak during the day (between 12:00 p.m. and 04:00 p.m.) and a tendency for a second peak at night (12:00 a.m.). The daily corticosterone peak was not explained by daytime social stress and needs to be seen as an endophenotype. The role of nightly corticosterone production has to be investigated in further studies. There might be a relation between corticosterone and reproduction since the only hen not showing peaks was not laying eggs.

Efficacy of Saccharomyces cerevisiae Fermentation Product and Probiotic Supplementation on Growth Performance, Gut Microflora and Immunity of Broiler Chickens.

Concern for global health security and the environment due to the emergence of antibiotic-resistant bacteria and antibiotic residues in meat and other livestock products has led many countries to restrict the use of antibiotics in animal feed. This experiment was performed to assess the impact of dietary supplementation of a probiotic (Bacillus subtilis) and a postbiotic (Saccharomyces cerevisiae fermentation product) on growth performance, carcass traits, blood haemato-biochemical profile, gut microflora, gut morphology, and immune response in broilers as an alternative to antimicrobials in poultry production system to minimize the effect on global health security. A total of 324 one-day-old Ven Cobb 400 broiler chicks were randomly divided into three dietary groups, each containing 12 replicated pens, and each replicate contained nine chickens. The dietary groups consisted of (1) a basal diet without any growth promoters (T1), (2) the basal diet augmented with Bacillus subtilis at 200 g/MT feed (T2), and (3) the basal diet supplemented with Saccharomyces cerevisiae fermentation product at 1.25 kg/MT feed (T3). To calculate body weight gain, all birds and residual feed were weighed on a replicated basis on days 0, 7, 14, 21, 28, 35, and 42; mortality was recorded daily. At the end of the trial (42 d), two chickens from each replicate were slaughtered for carcass traits, gut microflora, and morphology measurements. Blood samples were collected for the haemato-biochemical profile on 35 d and antibody titer on 28 d and 35 d. Feeding with SCFP (T3 group) significantly improved average daily feed intake (ADFI) and average daily gain (ADG) of chickens compared to the T1 (control) and T2 (probiotic) groups from 1 to 14 days of age. Feed conversion ratio (FCR) was significantly improved in SCFP-fed birds (T3) relative to the control (T1) over the entire experimental period. Carcass traits and blood haemato-biochemical parameters remained unaffected by any diets. However, cholesterol levels and concentrations of corticosterone were significantly lower in T3 compared to T2 and T1 groups. Total E. coli, Enterohaemorrhagic E. coli, ESBL-producing Enterobacteriaceae, and Salmonella counts were significantly lower in T2 and T3 groups compared to T1 group and Salmonella counts were lower in T3 when compared to T2. However, there was no significant difference in Lactobacillus count among treatment groups. A significant increase in villi height and villi-height-to-crypt-depth ratio (VH: CD) was observed in both T3 and T2 groups. On day 28, the T3 and T2 groups exhibited a significant increase in antibody titers against Newcastle disease virus and infectious bursal disease virus. It can be concluded that Saccharomyces cerevisiae fermentation product and Bacillus subtilis probiotic could be viable alternatives to antimicrobials in poultry production considering beneficial impacts in broilers fed an antibiotic-free diet.

Impact of chronic psychological stress on platelet membrane fatty acid composition in a rat model of type 1 diabetes Mellitus

BackgroundChronic stress and diabetes mellitus are highly associated with oxidative stress and inflammation, resulting in cell membrane disruption and platelet activity. This study aims to evaluate the impact of chronic psychological stress on the composition of the platelet phospholipid membrane and platelet activation in type 1 diabetes mellitus (T1DM).MethodsWe enrolled 35 mature healthy female Wistar rats and randomly divided them into 4 groups, namely the control group (n = 9), stress group (n = 10), T1DM group (n = 8), and T1DM + Stress group (n = 8). The Wistar rats were treated in different experimental conditions for 28 days while being provided free access to feed and water. The concentration of corticosterone in blood serum and hair samples was measured using a competitive enzyme-linked immunosorbent assay. Gas chromatography-mass spectrometry was conducted to identify the methyl esters of fatty acids (FAs) in the platelet phospholipid membrane. A quantitative determination of 11-dehydro-thromboxane B2 in the blood serum was also performed using a competitive enzyme-linked immunosorbent assay.ResultsAfter 28 days, the concentration of corticosterone in blood serum (ng/mL) was observed to be higher in the stress group as compared to the T1DM and T1DM + Stress groups (P = 0.031 and P = 0.008, respectively). The percentage of C 16:0 FA in the platelet membrane was greater in the T1DM + Stress group, but its levels of C 20:1 omega (ω) 9 FA, including C 18:3ω3 FA, C 20:5ω3 FA, and the total sum of ω3 FAs, were lower as compared to the control group (P = 0.016; P = 0.016; P = 0.031; P = 0.016, P = 0.031). The concentration of 11-dehydro-thromboxane B2 in blood serum (pg/mL) was observed to be higher in the stress group than in rats with T1DM (P = 0.063).ConclusionChronic psychological stress is related to higher levels of corticosterone, saturated FAs acids in the platelet membrane, and greater platelet activation. This study proves how a low percentage of unsaturated fatty acids in the DM and stress groups indicates the disturbing impact of the oxidative/inflammatory environment to lipid metabolism and neuroendocrine response.