Effects of restraint stress on iron, zinc, calcium, and magnesium whole blood levels in mice

Early life stress and iron metabolism in developmental psychoneuroimmunology

An estimated 250 million children face adverse health outcomes from early life exposure to severe or chronic social, economic, and nutritional adversity, highlighting/emphasizing the pressing concern about the link between ELS and long-term implications on mental and physical health. There is significant overlap between populations experiencing high levels of chronic stress and those experiencing iron deficiency, spotlighting the potential role of iron as a key mediator in this association. Iron, an essential micronutrient for brain development and immune function, is often depleted in stress conditions. Iron deficiency among the most common nutrient deficiencies in the world. Fetal and infant iron status may thus serve as a crucial intermediary between early chronic psychological stress and subsequent immune system changes to impact neurodevelopment. The review presents a hypothesized pathway between early life stress (ELS), iron deficiency, and neurodevelopment through the hypothalamic-pituitary-adrenocortical (HPA) axis and the IL-6-hepcidin axis. This hypothesis is derived from (1) evidence that stress impacts iron status (2) long-term neurodevelopmental outcomes that are shared by ELS and iron deficiency exposure, and (3) possible mechanisms for how iron may mediate the relation between ELS and iron deficiency through alterations in the developing immune system. The article concludes by proposing future research directions, emphasizing the need for rigorous studies to elucidate how stress and iron metabolism interact to modify the developing immune system. Understanding these mechanisms could open new avenues for improving human health and neurodevelopment for women and children globally, making it a timely and vital area of study in psychoneuroimmunology research.

Early-life adversity is associated with poor iron status in infancy

Exposure to early-life adversity (ELA) and iron deficiency early in life are known risk factors for suboptimal brain and socioemotional development. Iron deficiency may arise from and co-occur with ELA, which could negatively affect development. In the present study, we investigated whether ELA is associated with iron deficiency in infants receiving no iron supplementation. This study is a secondary analysis of extant data collected in the 1990s; participants were healthy infants from working-class communities in Santiago, Chile (N = 534, 45.5% female). We measured stressful life events, maternal depression, and low home support for child development during infancy and assessed iron status when the infant was 12 months old. Slightly more than half of the infants were iron-deficient (51%), and 25.8% were iron-deficient anemic at 12 months. Results indicated that ELA was associated with lower iron levels and iron deficiency at 12 months. The findings are consistent with animal and human prenatal models of stress and iron status and provide evidence of the association between postnatal ELA and iron status in humans. The findings also highlight a nutritional pathway by which ELA may impact development and present a nutritionally-focused avenue for future research on ELA and psychopathology.

The Interaction between Psychological Stress and Iron Status on Early-Life Neurodevelopmental Outcomes

This review presents evidence from animal and human studies demonstrating the possible connection and significant impact of poor iron status and psychological distress on neurocognitive development during pregnancy and the neonatal period, with implications for long-term cognition. Stress and iron deficiency are independently prevalent and thus are frequently comorbid. While iron deficiency and early-life stress independently contribute to long-term neurodevelopmental alterations, their combined effects remain underexplored. Psychological stress responses may engage similar pathways as infectious stress, which alters fundamental iron metabolism processes and cause functional tissue-level iron deficiency. Psychological stress, analogous to but to a lesser degree than infectious stress, activates the hypothalamic-pituitary-adrenocortical (HPA) axis and increases proinflammatory cytokines. Chronic or severe stress is associated with dysregulated HPA axis functioning and a proinflammatory state. This dysregulation may disrupt iron absorption and utilization, likely mediated by the IL-6 activation of hepcidin, a molecule that impedes iron absorption and redistributes total body iron. This narrative review highlights suggestive studies investigating the relationship between psychological stress and iron status and outlines hypothesized mechanistic pathways connecting psychological stress exposure and iron metabolism. We examine findings regarding the overlapping impacts of early stress exposure to iron deficiency and children's neurocognitive development. We propose that studying the influence of psychological stress on iron metabolism is crucial for comprehending neurocognitive development in children exposed to prenatal and early postnatal stressors and for children at risk of early iron insufficiency. We recommend future directions for dual-exposure studies exploring iron as a potential mediating pathway between early stress and offspring neurodevelopment, offering opportunities for targeted interventions.

Blood chemistry and biliverdin differ according to reproduction and tourism in a free-living lizard

Changes in the physiological health of species are an essential indicator of changing conditions and environmental challenges. Reponses to environmental challenges can often induce stress, influence physiology, and change metabolism in organisms. Here we tested blood chemistry parameters indicative of stress and metabolic activity using an i-STAT point-of-care blood analyzer in seven populations of free-ranging rock iguanas exposed to varying levels of tourism and supplemental feeding. We found significant differences in blood chemistry (glucose, oxygen, carbon dioxide, hematocrit, hemoglobin, calcium, potassium, and biliverdin levels) among populations exposed to varying levels of tourism, and some variation between sexes and reproductive states. However, different variables are not directly related to one another, suggesting that the causal physiological pathways driving tourism-induced differences are influenced by mechanisms that are not detected by common analyses of blood chemistry. Future work should investigate upstream regulators of these factors affected by tourism. Regardless, these blood metrics are known to be both stress sensitive and related to metabolic activity, suggesting that exposure to tourism and associated supplemental feeding by tourists are generally driven by stress-related changes in blood chemistry, biliverdin, and metabolism.

Pharmaco-Toxicological Effects of Atypical Synthetic Cathinone Mephtetramine (MTTA) in Mice: Possible Reasons for Its Brief Appearance over NPSs Scene

Over the last year, NPSs have been steadily on the rise in the illicit drug market. Among these, synthetic cathinones seem to become increasingly popular among young adults, mainly because of their ability to replicate the effects of traditional psychostimulant drugs, such as cocaine, MDMA and amphetamines. However, scarce data are available about the in vivo pharmaco-toxicology of these new substances. To this end, this study focused on evaluation of effects induced by repeated administration of mephtetramine (MTTA 0.1-30 mg/kg i.p.) in mice. This atypical cathinone highlighted a sensorial (inhibition of visual and acoustic reflexes) and transient physiological parameter (decrease in breath rate and temperature) change in mice. Regarding motor activity, both a dose-dependent increase (accelerod test) and biphasic effect (drag and mobility time test) have been shown. In addition, blood and urine samples have been analysed to enrich the experimental featuring of the present study with reference to evaluation of potential toxicity related to consumption of MTTA. The latter analysis has particularly revealed important changes in blood cells count and blood and urine physicochemical profile after repeated treatment with this atypical cathinone. Moreover, MTTA induced histological changes in heart, kidney and liver samples, emphasizing its potential toxicity.

Evaluation of the hematological and clinical biochemical markers of stress in broiler chickens

Background and Aim:

Stress significantly affects health and productivity of animals. There is need for affordable and easy-to-assay markers of physiological stress in broilers. This study evaluated hematological and serum biochemical markers of physiologic stress in broiler chickens.

Materials and Methods:

Thirty day-old broiler chickens were assigned to three groups of ten broilers each during the 56-day study. Group 1 broilers served as the control and were not exposed to any stressors; Group 2 broilers were stocked at the stress density of 50 kg BW m^–2 from day 49 to 56 while Group 3 broilers had their feed withdrawn 36 h before blood collection on day 56. Blood samples were collected on day 49 (pre-stress sample) and day 56 (post-stress sample) from all the birds and subjected to hematological and serum biochemical analysis.

Results:

The parameters did not vary significantly (p>0.05) pre-stress. Post-stress, there were significant variations in the heterophil, lymphocyte, and eosinophil counts and in the heterophil to lymphocyte ratio across the three groups. The concentrations of the plasma fibrinogen and serum albumins, sodium, and sodium to potassium ratio of the broilers varied significantly across the groups.

Conclusion:

Heterophil, eosinophil, and lymphocyte counts, the heterophil to lymphocyte ratio, plasma fibrinogen, serum albumin, sodium, and sodium to potassium ratio are significant markers of physiological stress in broilers.

Repeated Restraint Stress Enhances Hepatic TFR2 Expression and Induces Hepatic Iron Accumulation in Rats

Abnormal hepatic iron metabolism is detrimental to health. The objective of this study was to detect repeated restraint stress on liver iron metabolism in rats. Twenty-four male rats aged 7 weeks were randomly divided into 2 groups: control group (Con) and repeated restraint stress group (RS). Rats were subjected to 6 h of daily restraint stress for 14 consecutive days in the repeated restraint stress group. The results showed that repeated restraint stress exposure decreased growth performance including impaired final weight (P = 0.07), reducing average daily gain (P = 0.01), and average daily feed intake (P = 0.00) during the 14-day experimental period. Repeated restraint stress exposure did not affect hemoglobin content and plasma iron parameters except downregulated unsaturated iron-binding capacity (P = 0.04). Repeated restraint stress exposure inhibited liver development (P = 0.03) and induced liver iron accumulation (P = 0.05). In addition, repeated restraint stress downregulated the expression of transferrin (TF) and transferrin receptor 2 (TFR2) at the mRNA level (P < 0.01), but upregulated at the protein level (P = 0.03 for TF; P = 0.00 for TFR2). These results indicated that repeated restraint stress induces hepatic iron accumulation, which is closely related to higher expression of hepatic TFR2 protein in rats.

The Effects of Psychological and Environmental Stress on Micronutrient Concentrations in the Body: A Review of the Evidence

Stress is the nonspecific response of the body to any demand for change. Excess or chronic psychological or environmental stress is associated with an increased risk of mental and physical diseases, with several mechanisms theorized to be associated with its detrimental effects. One underappreciated potential mechanism relates to the effects of psychological and environmental stress on micronutrient concentrations. Micronutrients (vitamins and minerals) are essential for optimal physical and mental function, with deficiencies associated with an array of diseases. In this article, animal and human studies investigating the effects of various psychological and environmental stressors on micronutrient concentrations are reviewed. In particular, the effects of psychological stress, sleep deprivation, and physical exercise on micronutrient concentrations and micronutrient excretion are summarized. Micronutrients identified in this review include magnesium, zinc, calcium, iron, and niacin. Overall, the bulk of evidence suggests stress can affect micronutrient concentrations, often leading to micronutrient depletion. However, before definitive conclusions about the effects of stress can be made, the impact of different stressors, stress severity, and acute versus chronic stress on micronutrient concentrations requires investigation. Moreover, the impact of stress on micronutrients in different populations varying in age, gender, and premorbid health status and the durability of changes after a stressor is resolved require examination. The medical, physical, and psychological implications of nutrient changes caused by a stressor also remain to be determined.

Long-Term Dexamethasone Exposure Down-Regulates Hepatic TFR1 and Reduces Liver Iron Concentration in Rats

Exposure to stress is known to cause hepatic iron dysregulation, but the relationship between prolonged stress and liver iron metabolism is not yet fully understood. Thirty 13-week-old female Sprague-Dawley rats were randomly divided into two groups, as follows: the control group (saline-injection) and the dexamethasone group (Dexamethasone (Dex)-injection 0.1 mg/kg/day). After the 21-day stress trial, the results showed that chronic Dex administration not only impaired serum corticosterone (p = 0.00) and interleukin-6 (IL-6) (p = 0.01) levels, but also decreased white blood cell counts (p = 0.00), and reduced blood lymphocyte counts (p = 0.00). The daily Dex-injection also significantly reduced body weight (p < 0.01) by inhibiting food intake. Consecutive Dex administration resulted in decreased iron intake (p = 0.00), enhanced serum iron levels (p = 0.01), and increased the serum souble transferrin receptor (sTfR) content (p = 0.00) in rats. Meanwhile, long-term Dex exposure down-regulated duodenal cytochrome b (DCYTB) (p = 0.00) and the divalent metal transporter 1 (DMT1) (p = 0.04) protein expression, but up-regulated ferroportin (FPN) protein expression (p = 0.04). Chronic Dex administration reduced liver iron concentration (p = 0.02) in rats. Hepatic transferrin receptor 1 (TFR1) expression was lowered at the protein level (p = 0.03), yet with uncoupled mRNA abundance in Dex-treated rats. Enhanced iron-regulatory protein (IRP)/iron-responsive element (IRE) binding activity was observed, but did not line up with lowered hepatic TFR1 protein expression. This study indicates that long-term Dex exposure reduces liver iron content, which is closely associated with down-regulated hepatic TFR1 protein expression.

Objective assessment of health or pre-chronic disease state based on a health test index derived from routinely measured clinical laboratory parameters

OBJECTIVE

To develop a quantitative system to enable the objective assessment of health or pre-chronic disease state.

METHODS

On the basis of measured values and reference ranges, we obtained the organ function index (mean of the cut-off ratios of albumin and creatinine), blood lipid index (mean of the cut-off ratios of triglycerides, cholesterol, high-density lipoproteins and low-density lipoproteins), stress index (mean of the cut-off ratios of neutrophils and glucose), and the health test index (mean of the above three indexes, HTI). Elderly populations, individuals with nonalcoholic fatty liver disease and administrators were included in the groups of observed subjects to verify the organ function index, blood lipid index and stress index.

RESULTS

The scores of the three indexes were all statistically higher in the observed group than in the control group (p < 0.05). The mean HTI score was 0.7 ± 0.07 and was normally distributed in the control population. The rates of hypertension, obesity, fatty liver disease and health (undetectable organic diseases) increased with increasing HTI scores in a random population.

CONCLUSIONS

The HTI is easily derived from routinely measured clinical laboratory parameters. It can reflect the health status of an individual and may be a useful tool for the quantitative differentiation of health status.

Methodology using a portable X-ray fluorescence device for on-site and rapid evaluation of heavy-atom contamination in wounds: a model study for application to plutonium contamination

Workers decommissioning the Fukushima-Daiichi nuclear power plant damaged from the Great East Japan Earthquake and resulting tsunami are at risk of injury with possible contamination from radioactive heavy atoms including actinides, such as plutonium. We propose a new methodology for on-site and rapid evaluation of heavy-atom contamination in wounds using a portable X-ray fluorescence (XRF) device. In the present study, stable lead was used as the model contaminant substitute for radioactive heavy atoms. First, the wound model was developed by placing a liquid blood phantom on an epoxy resin wound phantom contaminated with lead. Next, the correlation between the concentration of contaminant and the XRF peak intensity was formulated considering the thickness of blood exiting the wound. Methods to determine the minimum detection limit (MDL) of contaminants at any maximal equivalent dose to the wound by XRF measurement were also established. For example, in this system, at a maximal equivalent dose of 16.5 mSv to the wound and blood thickness of 0.5 mm, the MDL value for lead was 1.2 ppm (3.1 nmol). The radioactivity of 239Pu corresponding to 3.1 nmol is 1.7 kBq, which is lower than the radioactivity of 239Pu contaminating puncture wounds in previous severe accidents. In conclusion, the established methodology could be beneficial for future development of a method to evaluate plutonium contamination in wounds. Highlights: Methodology for evaluation of heavy-atom contamination in a wound was established. A portable X-ray fluorescence device enables on-site, rapid and direct evaluation. This method is expected to be used for evaluation of plutonium contamination in wounds.

Impact of long term Fe³⁺ toxicity on expression of glutathione system in rat liver

The free radicals within the body, produced by metabolic activities or derived from environmental sources are relatively related to hepatoxicity. Since heavy metals including iron have the ability to produce free radicals, the liver glutathione system neutralizes them to protect cells against any damage. The objective of this study is to indicate the toxic effects of iron on the glutathione system at the enzymatic and molecular level. Thus, any possible correlation between enzymatic and molecular levels can be determined. According to our results, while mRNA expression of glutathione reductase (Gsr) and glutathione S-transferases (Gsta5) genes were not affected by long-term exposure to various concentrations of iron (Fe(3+)), transcription level of glutathione peroxidase (Gpx2) was influenced in the presence of toxic iron. Whereas the enzyme activites of GSR (GR), GPX and GST were significantly affected in rat liver.

Quantitatively plotting the human face for multivariate data visualisation illustrated by health assessments using laboratory parameters

Objective. The purpose of this study was to describe a new data visualisation system by plotting the human face to observe the comprehensive effects of multivariate data. Methods. The Graphics Device Interface (GDI+) in the Visual Studio.NET development platform was used to write a program that enables facial image parameters to be recorded, such as cropping and rotation, and can generate a new facial image according to Z values from sets of normal data (Z > 3 was still counted as 3). The measured clinical laboratory parameters related to health status were obtained from senile people, glaucoma patients, and fatty liver patients to illustrate the facial data visualisation system. Results. When the eyes, nose, and mouth were rotated around their own axes at the same angle, the deformation effects were similar. The deformation effects for any abnormality of the eyes, nose, or mouth should be slightly higher than those for simultaneous abnormalities. The facial changes in the populations with different health statuses were significant compared with a control population. Conclusions. The comprehensive effects of multivariate may not equal the sum of each variable. The 3Z facial data visualisation system can effectively distinguish people with poor health status from healthy people.

Chronic psychological stress activates BMP4-dependent extramedullary erythropoiesis

Psychological stress affects different physiological processes including haematopoiesis. However, erythropoietic effects of chronic psychological stress remain largely unknown. The adult spleen contains a distinct microenvironment favourable for rapid expansion of erythroid progenitors in response to stressful stimuli, and emerging evidence suggests that inappropriate activation of stress erythropoiesis may predispose to leukaemic transformation. We used a mouse model to study the influence of chronic psychological stress on erythropoiesis in the spleen and to investigate potential mediators of observed effects. Adult mice were subjected to 2 hrs daily restraint stress for 7 or 14 consecutive days. Our results showed that chronic exposure to restraint stress decreased the concentration of haemoglobin in the blood, elevated circulating levels of erythropoietin and corticosterone, and resulted in markedly increased number of erythroid progenitors and precursors in the spleen. Western blot analysis revealed significantly decreased expression of both erythropoietin receptor and glucocorticoid receptor in the spleen of restrained mice. Furthermore, chronic stress enhanced the expression of stem cell factor receptor in the red pulp. Moreover, chronically stressed animals exhibited significantly increased expression of bone morphogenetic protein 4 (BMP4) in the red pulp as well as substantially enhanced mRNA expression levels of its receptors in the spleen. These findings demonstrate for the first time that chronic psychological stress activates BMP4-dependent extramedullary erythropoiesis and leads to the prolonged activation of stress erythropoiesis pathways. Prolonged activation of these pathways along with an excessive production of immature erythroid cells may predispose chronically stressed subjects to a higher risk of leukaemic transformation.

The relationship between Type D personality, affective symptoms and hemoglobin levels in chronic heart failure

BACKGROUND

Anemia is associated with poor prognosis in heart failure (HF) patients. Contributors to the risk of anemia in HF include hemodilution, renal dysfunction and inflammation. Hemoglobin levels may also be negatively affected by alterations in stress regulatory systems. Therefore, psychological distress characterized by such alterations may adversely affect hemoglobin in HF. The association between hemoglobin and Type D personality and affective symptomatology in the context of HF is poorly understood.

AIM

To examine the relationship between Type D personality and affective symptomatology with hemoglobin levels at inclusion and 12-month follow-up, controlling for relevant clinical factors.

METHODS

Plasma levels of hemoglobin and creatinine were assessed in 264 HF patients at inclusion and at 12-month follow-up. Type D personality and affective symptomatology were assessed at inclusion.

RESULTS

At inclusion, hemoglobin levels were similar for Type D and non-Type D HF patients (p = .23), and were moderately associated with affective symptomatology (r = -.14, p = .02). Multivariable regression showed that Type D personality (β = -.15; p = .02), was independently associated with future hemoglobin levels, while controlling for renal dysfunction, gender, NYHA class, time since diagnosis, BMI, the use of angiotensin-related medication, and levels of affective symptomatology. Change in renal function was associated with Type D personality (β = .20) and hemoglobin at 12 months (β = -.25). Sobel mediation analysis showed significant partial mediation of the Type D - hemoglobin association by renal function deterioration (p = .01). Anemia prevalence increased over time, especially in Type D patients. Female gender, poorer baseline renal function, deterioration of renal function and a longer HF history predicted the observed increase in anemia prevalence over time, while higher baseline hemoglobin was protective.

CONCLUSION

Type D personality, but not affective symptomatology, was associated with reduced future hemoglobin levels, independent of clinical factors. The relation between Type D personality and future hemoglobin levels was mediated by renal function deterioration.

Role of zinc in the development and treatment of mood disorders

PURPOSE OF REVIEW

The present review is a critical examination of the most recent published work on the role of zinc in the development and treatment of mood disorders.

RECENT FINDINGS

Clinical studies and experimental work using animal models have both revealed a link between zinc status and neuropsychological disorders such as depression and anxiety. Not only has zinc deficiency been shown to induce depression-like and anxiety-like behaviors, supplementation has been used as a treatment for major depression. Zinc administration improves the efficacy of antidepressant drugs in depressed patients and may have a particular role to play in treatment-resistant patients. Recent investigations into the molecular mechanisms responsible for these observations suggest a role for zinc in the regulation of neurotransmitter systems, antioxidant mechanisms, neurotrophic factors, and neuronal precursor cells.

SUMMARY

The data reviewed here not only indicate a role for zinc deficiency in the development of mood disorders, but also show that zinc may also be important in their treatment. Given the prevalence of zinc deficiency in human populations, this work has the potential to influence strategies to prevent and treat these disorders.

Chronic psychological stress alters body weight and blood chemistry in European starlings (Sturnus vulgaris)

One hallmark of chronic stress is a decrease in body weight that rebounds once chronic stress is alleviated. We applied chronic psychological stress by exposing European starlings (Sturnus vulgaris) to a previously validated chronic stress protocol (CSP) consisting of 4 different randomly applied stressors per day. Experimental design consisted of a 21 day CSP (CSP1), a 60day recovery (R1), a second 14 day CSP (CSP2), and a second 30 day recovery (R2). Body weight decreased by approximately 5% during CSP1, but overshot to 5-10% above initial body weight during R1. To investigate underlying mechanisms, we periodically measured 12 biochemical analytes, including aspartate aminotransferase (AST), creatine kinase (CK), bile acids, total protein, albumin, globulin, glucose, uric acid, calcium (Ca(++)), phosphorus (PHOS), potassium (K(+)), and sodium (Na(+)). AST and CK increased at the beginning of CSP1, suggesting muscle breakdown. Additionally, decreases in albumin and total protein paired with stable uric acid, but no associated change in glucose, suggested protein breakdown as a secondary energy source. Changes in blood parameters that occurred during CSP1 did not reverse during R1. During CSP2 and R2, weight loss and gain occurred in different proportions. CSP2 produced an approximate 15% decrease in body weight, but R2 resulted in only re-gaining 5% of this weight, although this was equivalent to the pre-CSP1 weight. In summary, protein metabolism appeared to mediate weight loss during chronic stress, but over-gaining weight was not a good indicator of recovery.

Role of zinc in maternal and child mental health

Mental health problems in women, children, and adolescents are a significant public health issue. Given current barriers to the effective treatment of these problems, researchers are looking to the field of nutrition for potential alternatives to better understand and address mental health issues. The purpose of this article was to review current evidence on the relation between zinc and mental health disorders with a focus on 2 mental health problems that commonly affect women and children: depression and attention-deficit hyperactivity disorder (ADHD). A literature search of the databases Medline and PsychInfo was conducted with the use of key terms. The review included articles from 1975 to May 2008, but focused on articles published in recent years. Relations between zinc concentrations and behavior in animals; the relation between zinc deficiency, depression, and ADHD in patient and community samples; and the potential biological mechanisms for these relations were explored. The data support a relation between low concentrations of zinc and mental health problems, especially in at-risk populations. Evidence for the potential use of zinc in treating mental health problems comes mainly from patient populations and is strongest when zinc is given in combination with pharmacologic treatment. Less conclusive evidence exists for the effectiveness of zinc alone or in general community samples. Recommendations for further research in this area are provided.