Hypothalamic-pituitary-adrenal System Research Articles

Comparing the pharmacological effects of the prepared folium of Epimedium brevicornu Maxim. and Epimedium sagittatum Maxim. on kidney-Yang deficiency syndrome and liver injury complications

Yinyanghuo, a famous herb, includes the folium of Epimedium brevicornu Maxim. and Epimedium sagittatum Maxim. It is believed that their processed products, the prepared slices of the folium of Epimedium brevicornu Maxim. (PFEB) and Epimedium sagittatum Maxim. (PFES) have greater efficacy in tonifying kidney Yang to treat kidney-Yang deficiency syndrome (KDS). However, there are few studies comparing the pharmacological effects of PFEB and PFES, and the underlying mechanisms. This study compared their effects on improving hypothalamic-pituitary-adrenal (HPA) axis, immune system and sexual characteristic, as well as repairing liver injury complications in the KDS model mice. Additionally, the mechanisms of the effects relevance to their main components were explored. It was found that PFEB was more effective than PFES in increasing cAMP/cGMP ratio, SOD activity, CRH and ACTH levels, eNOS and testosterone levels, splenic lymphocytes proliferation, while in decreasing MDA content, atrophy of spleen and thymus, splenic lymphocytes apoptosis, and PDE5 level. PFES showed stronger protection than PFEB in decreasing triglyceride and hepatic lipid. The contents of baohuoside I and epimedin A, B were much higher in PFEB, while Epimedin C, Icariin, 2-O″-rhamnosylicaridide II were higher in PFES. Consequently, PFEB exhibits superior efficacy over PFES in tonifying the kidney-Yang by improving the neuroendocrine-immune network, including HPA axis, immune systems, and corpus cavernosum. However, PFES has better recovery effect on mild hepatic lipid caused by KDS. The efficacy difference between PFEB and PFES in kidney-Yang and liver may be attributed to the content variations of baohuoside I.

ВЛИЯНИЕ ЭКСПЕРИМЕНТАЛЬНОЙ ДЕПРЕССИИ НА ФУНКЦИОНАЛЬНОЕ СОСТОЯНИЕ ГИПОТАЛАМО-ГИПОФИЗАРНО-НАДПОЧЕЧНИКОВОЙ СИСТЕМЫ

Objective: To study the effect of modelled depression not associated with stress on the hypothalamic-pituitary-adrenal system (HPAS) in mice. Methods: The experiment was conducted on the twenty-four C57BL/6 mice weighing 20-25 g, divided into two groups: an experimental one, involving animals with reserpine-induced depression, and a control one, the animals of which were administered normal saline instead of reserpine solution. At the end of the experiment, behavioral tests were performed (open field, sucrose preference, forced swimming), and the corticosterone concentration in blood was measured using ELISA. Image analysis of histological changes in the adrenal gland and thymus was performed. All results were statistically processed using SPSS 27.0.1 software, with p<0.05 indicating the significance of differences. Results: Animals of the experimental group showed a significantly higher level of corticosterone in the blood (p<0.01), significant changes in behavior in the open field test (distance traveled, rearing, frequency of urination and defecation, p<0.01), reduced sucrose preference (p<0.01) and shortened duration of the active phase in the forced swimming test (p<0.01) than the animals of the control group. Besides, in the mice of the experimental group, a significant increase in the volume density of the zona fasciculata of the adrenal cortex was found (p<0.05), as well as the area of its spongiocytes and their nuclei (p<0.05). In the thymus of the experimental animals, a significant decrease in the cortex-medulla ratio was noted (p<0.05); and an increase in the volume density of tingible body macrophages (p<0.05) compared to the control group of mice. Conclusion: Modelled depression, not associated with stress, the depth of which was assessed by behavioral tests, caused activation of the HPAS, manifested by increased corticosterone levels, hyperplasia of the zona fasciculata of the adrenal cortex, hypertrophy of its spongiocytes and their nuclei, as well as changes in the thymus, indicating associated immunosuppression. Thus, the study showed that, along with the well-known phenomenon of the development of depression against the background of chronic stress-associated activation of HPAS, there is an inverse mechanism leading to activation of the HPAS during the development of depression not associated with stress, which must be taken into account when developing the new strategies of treating depression. Keywords: Depression, hypothalamic-pituitary-adrenal system, corticosterone, immune system, mice.

Pathogenesis of the crosstalk between reproductive function and stress in animals - part 2: Prolactin, thyroid, inflammation and oxidative stress.

Stress has a significant impact on reproductive health and fertility in both humans as well as various animal species. In particular, chronic stress can disrupt the delicate balance of the hormonal system that regulates reproductive function, leading to a variety of reproductive disorders and fertility issues. Beside the action of the hypothalamic-pituitary-adrenal (HPA) system and the sympatho-adrenomedullary system (SAM), other subsequent mechanisms have been incriminated. Thus, stress has also been associated with increased prolactin level, resulting in an inhibition of the hypothalamo-pituitary-gonadal (HPG) system leading to several reproductive disorders. Thyroid function is inhibited during chronic stress, and therefore considered an important regulator of reproductive function. Thus, and in particular by interfering with the HPA system, stress-induced immune dysregulation can have adverse effects on reproduction. In addition, oxidative stress and inflammation have been proposed as potential mechanisms by which chronic stress affects reproductive function. This is caused by an increase in reactive oxygen species (ROS) production that has a harmful effect on cells. Furthermore, inflammation can lead to tissue damage and scarring, which can affect fertility. The present review completes the complex mechanism linking stress and reproduction through the current knowledge in various animal species in a comparative point of view.

Biological stress responses to multitasking and work interruptions: A randomized controlled trial

In the course of digitalization, new stressors are emerging. In modern working and living environments, two ubiquitous, technology-mediated stressors are multitasking demands and work interruptions. However, biological stress response patterns to multitasking and work interruptions have been sparsely investigated so far. We thus aimed to comprehensively assess biological stress response patterns to both stressors and, additionally, test whether responses differ between digital and partially non-digital settings. A controlled experimental set-up was established and humans’ biological markers of the Sympathetic Nervous System (SNS), the hypothalamic-pituitary adrenal (HPA) axis, and the immune system were assessed. N = 186 healthy participants (mean age: 23.2 ± 4.3 years, 74.7% female, body mass-index: 22.3 ± 3.1 kg/m2) took part in this pre-registered study. Each participant was randomly assigned to one of 6 experimental conditions (1 digital single-task, 3 dual-tasks [2 parallel tasks and 1 interruption], 1 multitasking, and 1 passive, control condition). Each one of the dual-tasking as well as the multitasking conditions included a non-digital sub-task, i.e., performing a task in presence of an examiner. All other conditions involved digital tasks only. Salivary alpha-amylase (sAA) levels as a marker for SNS reactivity significantly changed in work interruptions, parallel dual-tasking, and multitasking conditions. No changes were found for control conditions. Furthermore, no significant changes over time and no differences between the conditions were identified for three biological markers: cortisol as marker for HPA axis activity as well as for two immune system markers (secretory Immunoglobulin-A, C-reactive protein). A time course similar to sAA was found for perceived stress: with increases during task execution and decreases afterwards in multitasking and parallel dual-tasking. Yet, it did not change for the work interruption, passive control, and single-tasking condition. Overall, our findings show that dual- and multitasking are perceived as stressful and are associated with an activation of the SNS, but not with responses of HPA axis or immune system. This was consistent for digital as well as partially digital task demands. Our findings will also inform future research into the differential stress effects of digital and non-digital tasks to advance our understanding of biological stress response-patterns to multitasking and work interruptions. Therefore, our findings are highly relevant for understanding the long-term biological health effects of stress in modern (digitalized) environments.

The pharmacological effects and safety of the raw and prepared folium of Epimedium brevicornu Maxim. on improving kidney-yang deficiency syndrome and sexual dysfunction.

Background: Kidney-Yang deficiency syndrome (KDS) is a group of diseases related to hypothalamic-pituitary-adrenal (HPA) axis and sexual dysfunction. The folium of Epimedium brevicornu Maxim. (FEB) includes raw and prepared slices, named RFEB and PFEB, respectively. PFEB is traditionally believed to be good for tonifying kidney-Yang and improving sexual dysfunction. However, there are few studies comparing the pharmacological effects of RFEB and PFEB, and their underlying mechanisms. In this study, we aimed to compare the effects and safety of RFEB and PFEB on the HPA axis and sexual function. Additionally, the mechanisms of their roles in relation to the neuroendocrine-immune (NEI) network in the KDS model mice were explored. Methods: Male adult C57BL/6 mice were treated with corticosterone to establish a KDS mouse model, and RFEB and PFEB were administered intragastrically. Corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH), cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), testosterone levels and oxidative damage indexes were measured. The mRNA and protein levels of CRH and ACTH in hypothalamus and pituitary, endothelial nitric oxide synthase (eNOS) and phosphodiesterase 5 (PDE5) in corpus cavernosum were examined. TNFα, IL-6, NF-κB, eNOS and PDE5 were investigated in mouse corpus cavernosum. Results: Our results showed that PFEB was more effective than RFEB in increasing corticosterone-suppressed ACTH levels, enhancing CRH levels and cAMP/cGMP ratio, and reducing oxidative damage. In vivo, PFEB significantly increased eNOS and inhibited PDE5 expression in corpus cavernosum. PFEB showed stronger protective effect on normal spleen lymphocytes from apoptosis both in vitro and in vivo. Additionally, it noticeably inhibited the levels of inflammatory cytokines in corpus cavernosum. Both RFEB and PFEB were safe and did not cause any clinical signs of toxicity in mice at the dosage of 20 times dosages of that in the Chinese Pharmacopeia. Conclusion: We demonstrated that PFEB was better than RFEB at tonifying the kidney-Yang by comparing their effects on improving the NEI network, which includes the HPA axis, immune system and corpus cavernosum. This study revealed that PFEB could significantly improve the sexual function of KDS mice by regulating the HPA axis and activating the immune system through the NEI network.

Pregnancy-specific anxiety and gestational length: The mediating role of diurnal cortisol indices

BackgroundPreterm birth or shorter gestation is a common adverse pregnancy outcome. Pregnancy-specific anxiety is robustly associated with risk for shorter gestation. Hypothalamic-pituitary-adrenal (HPA) dysregulation, indicated by diurnal cortisol index variability [slope, area-under-the-curve (AUC) or cortisol awakening response (CAR)], could mediate associations between pregnancy-specific anxiety and shorter gestation. The purpose of this study was to explore whether diurnal cortisol index variability mediates associations between pregnancy-specific anxiety and gestational length. MethodsA sample of 149 women from the Healthy Babies Before Birth study reported pregnancy-specific anxiety in early pregnancy. Saliva samples were taken at three times during pregnancy, for two days each, at wake, 30 min post wake, noon, and evening. Diurnal cortisol indices were calculated using standard approaches. Pregnancy cortisol index variability was calculated across pregnancy timepoints. Gestational length was derived from medical charts. Covariates were sociodemographics, parity and obstetric risk. Mediation models were tested using SPSS PROCESS. ResultsThere was a significant indirect effect of pregnancy-specific anxiety on gestational length via CAR variability, b(SE)= −0.102(0.057), .95CI [− 0.227,− 0.008]. Higher pregnancy-specific anxiety was associated with lower CAR variability, b(SE)= −0.019(0.008), p = .022, and lower CAR variability was associated with shorter gestation, b(SE)= 5.29(2.64), p = .047. Neither AUC or slope variability mediated associations between pregnancy-specific anxiety and gestational length. ConclusionLower CAR variability during pregnancy mediated the association between higher pregnancy-specific anxiety and shorter gestational length. Pregnancy-specific anxiety could dysregulate HPA axis activity, as indicated by lower CAR variability, demonstrating the importance of the HPA axis system in regulating pregnancy outcomes.

Do categorically distinct stressors alter the attention to visual food cues?

Stressor exposure affects food intake as well as the preference for high or low palatability foods, but little is known about how stressor types impact the visual attention to food images. We used eye tracking methodology in humans to determine if activation of the hypothalamus–pituitary-adrenal (HPA) axis and sympathetic nervous system is associated with changes in attention to food images as determined by measuring changes in oculomotor activity. Specifically, we tested two questions: 1) Do categorically distinct stressors alter aspects of visual attention to food images as determined by oculomotor activity (i.e., saccade latency, gaze duration, and saccade bouts)? 2) Do categorically distinct stressors differentially affect visual attention to food images of high or low palatability? A total of sixty participants were randomly divided into one of three test groups: controls, an anticipatory stressor group, or a reactive stressor group. We measured salivary cortisol and salivary alpha-amylase (sAA) before and after stressor exposure to confirm activation of the HPA axis and sympathetic nervous system, respectively. Following stressor exposure participants performed an eye-tracking test using a standardized food picture database (Food-pics). We analyzed saccade latency, gaze duration, and saccade bouts in balanced pairs of food and non-food images. Salivary cortisol was elevated by both stressors, although the elevation in salivary cortisol to the reactive stressor was driven by women only. sAA was elevated only by the anticipatory stressor. There were main effects of image type for all three eye-tracking variables, with initial saccades of shorter latency to food images and longer gaze duration and more saccade bouts with food images. Participants exposed to the reactive stressor reduced gaze duration on food images relative to controls, and this affect was not linked to palatability or salivary cortisol levels. We conclude that the reactive stressor decreased time spent looking at food, but not non-food, images. These data are partly consistent with the idea that reactive stressors reduce attention to non-critical visual signals.

Development of Post-Stroke Cognitive and Depressive Disturbances: Associations with Neurohumoral Indices.

Neuropsychiatric complications, in particular cognitive and depressive disorders, are common consequences of ischemic stroke (IS) and complicate the rehabilitation, quality of life, and social adaptation of patients. The hypothalamic-pituitary-adrenal (HPA) system, sympathoadrenal medullary system (SAMS), and inflammatory processes are believed to be involved in the pathogenesis of these disorders. This study aimed to explore these systems in IS patients, including those with post-stroke cognitive and depressive disorders, within a year after IS. Indices of the HPA axis, inflammatory system, and SAMS were measured in blood serum (cortisol, interleukin-6 (IL-6)), plasma (adrenocorticotropic hormone), and saliva (cortisol, α-amylase). During one year after mild/moderate IS (NIHSS score 5.9 ± 4.3), serum cortisol and salivary α-amylase levels remained elevated in the total cohort. In the group with further cognitive decline, serum and salivary cortisol levels were elevated during the acute period of IS. In the group with poststroke depressive disorder, salivary α-amylase was constantly elevated, while serum IL-6 was minimal during the acute period. The results suggest prolonged hyperactivation of the HPA axis and SAMS after IS. Specifically, post-stroke cognitive impairment was associated with hyperactivation of the HPA axis during the acute IS period, while post-stroke depressive disorder was associated with the chronic inflammatory process and hyperactivation of SAMS during the follow-up period.

Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis.

Numerous studies on humans and animals have indicated that the corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) stimulate both individually and synergistically secretion of adrenocorticotropic hormone (ACTH) by corticotropic cells in anterior pituitary. With aim to characterize and better comprehend the mechanisms underlying the effects of AVP on Hypothalamic-Pituitary-Adrenal (HPA) axis ultradian dynamics, AVP is here incorporated into our previously proposed stoichiometric model of HPA axis in humans. This extended nonlinear network reaction model took into account AVP by: reaction steps associated with two separate inflows of AVP into pituitary portal system, that is synthesized and released from hypothalamic parvocellular and magnocellular neuronal populations, as well as summarized reaction steps related to its individual and synergistic action with CRH on corticotropic cells. To explore the properties of extended model and its capacity to emulate the effects of AVP, nonlinear dynamical systems theory and bifurcation analyses based on numerical simulations were utilized to determine the dependence of ultradian oscillations on rate constants of the inflows of CRH and AVP from parvocellular neuronal populations, the conditions under which dynamical transitions occur due to their synergistic action and, moreover, the types of these transitions. The results show that under certain conditions, HPA system could enter into oscillatory dynamic states from stable steady state and vice versa under the influence of synergy reaction rate constant. Transitions between these dynamical states were always through supercritical Andronov-Hopf bifurcation point. Also, results revealed the conditions under which amplitudes of ultradian oscillations could increase several-fold due to CRH and AVP synergistic stimulation of ACTH secretion in accordance with results reported in the literature. Moreover, results showed experimentally observed superiority of CRH as a stimulator of ACTH secretion compared to AVP in humans. The proposed model can be very useful in studies related to the role of AVP and its synergistic action with CRH in life-threatening circumstances such as acute homeostasis dynamic crisis, autoimmune inflammations or severe hypovolemia requiring instant or several-days sustained corticosteroid excess levels. Moreover, the model can be helpful for investigations of indirect AVP-induced HPA activity by exogenously administered AVP used in therapeutic treatment.

Real-time racial discrimination, affective states, salivary cortisol and alpha-amylase in Black adults.

Perceived racial discrimination has been associated with the autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis activities-two major stress response systems. To date, most studies have used cross-sectional data that captured retrospective measures of the racial discrimination associated with current physiological stress responses. The purpose of this study was to examine the relationship between racial discrimination measured in real-time and physiological stress responses. Twelve healthy Black adults completed baseline surveys and self-collected saliva samples 4x/day for 4 days to measure cortisol and alpha amylase (AA) as a proxy of HPA and ANS systems, respectively. Real-time racial discrimination was measured using ecological momentary assessments (EMA) sent to participants 5x/day for 7 days. Multilevel models were conducted to examine the relationship between racial discrimination and stress responses. In multilevel models, the previous day's racial discrimination was significantly associated with the next day's cortisol level at wakening (β = 0.81, partial r = 0.74, p<0.01) and diurnal slope (β = -0.85, partial r = -0.73, p<0.01). Also, microaggressions were significantly associated with the diurnal cortisol slope in the same day, indicating that on the day when people reported more microaggressions than usual, a flatter diurnal slope of cortisol was observed (β = -0.50, partial r = -0.64, p<0.01). The concurrent use of salivary biomarkers and EMA was feasible methods to examine the temporal relationship between racial discrimination and physiological stress responses. The within-person approach may help us understand the concurrent or lagged effects of racial discrimination on the stress responses. Further studies are needed to confirm the observed findings with a large sample size and to improve stress related health outcomes in racial/ethnic minorities.

History of adrenal discovery

The names of the majority neurotransmitters are little known to the average citizen. But the mention of adrenaline immediately generates a storm of associations. Someone's head will have a profile of Jason Statham from film of the same name. The purpose of the article. The adrenaline rushed a symbol of something risky and attractive in its own way, but what is adrenaline from the point of view of a neurophysiologist - the goal proposed article. A number of studies have shown that y athletes during training and competitive loads increases the activity of sympatho-adrenal and hypothalamic pituitary-adrenal systems. In this case there is an activation of physical activity mechanisms of general adaptation, which leads to changes in hormonal spectrum, which provides mobilization as energy and plastic reserves of the body, as well as its restoration. One of the groups of stress hormones produced by the cerebral layer of the adrenal glands and called catecholamines. This group includes hormones adrenaline and norepinephrine. Both hormones are synthesized fromamino acids of tyrosine under the influence of nerve impulses. The main hormone of this group is adrenaline. We set for the aim is to study the historical stages that preceded the discovery adrenal hormones, using comparative and historical methods. Relevance of research. In 1894 George Oliver and Edward Schaefer demonstrated vasoconstrictor (vasoconstrictor) and pressor effect of extraction from the adrenal glands. An important role in study of the properties of adrenaline played a role Leipzig surgeon Heinrich Brown, about the possibility use of adrenaline under local anesthesia. So adrenaline, widely used in anesthesiology, which remains relevant to this day. Conclusions. Study of historical information about the discovery hormones form a holistic view and expand knowledge in the field physiology and pathophysiology of the endocrine system.

Maternal deprivation effect on morphine-induced CPP is related to changes in opioid receptors in selected rat brain regions (hippocampus, prefrontal cortex, and nucleus accumbens)

Early-life environmental conditions affect offspring's development. Maternal deprivation (MD) can induce persistent changes that give rise to neuropsychiatric diseases including substance abuse disorders. However, long-lasting mechanisms that determine vulnerability to drug addiction remain unknown. We hypothesized that MD could induce changes in Opioid system, HPA (hypothalamic-pituitary-adrenal) axis, and BDNF (brain-derived neurotrophic factor), so may be involved in the drug abuse in later life. Male offspring of Wistar rats (n = 8 per group) were subjected to 3 h of daily MD during postnatal days 1–14. In adulthood, morphine-induced CPP (conditioned place preference) was investigated using two doses of morphine (3 and 5 mg/kg). Serum corticosterone level was measured by ELISA method. The expression level of genes in selected brain regions (hippocampus, prefrontal cortex, and nucleus accumbens) was determined by qPCR (quantitative PCR). A greater morphine-induced CPP was observed in MD rats with 3 and 5 mg/kg morphine compared to controls. MD group had a higher corticosterone level. A significant decrease was observed in the expression of BDNF gene (in all of the selected brain regions) and GR (glucocorticoid receptor) gene (in the hippocampus and nucleus accumbens) in MD rats. Also, a significant increase in the expression of μ Opioid receptor (in all of the selected brain regions) and κ Opioid receptor (in the prefrontal cortex and nucleus accumbens) was observed in MD rats. Our results suggest that MD induces alterations in the HPA axis function, BDNF level, and Opioid receptors system that enhance vulnerability to morphine at adulthood.

Calibration and recalibration of stress response systems across development: Implications for mental and physical health.

Decades of human and animal research demonstrates that stress responsive neuroendocrine systems calibrate to the harshness of environmental conditions during fetal and early postnatal life. Emerging evidence indicates that if conditions change markedly over childhood, the hypothalamic pituitary adrenal (HPA) axis may recalibrate during puberty, another period that involves heightened neural plasticity and rapid maturation of neurobehavioral systems. These recent findings have prompted increased interest in the potential for stress system calibration/recalibration over development. To direct research in this area, this chapter integrates and discusses theoretical perspectives and empirical evidence pertaining to calibration and recalibration of the stress response. We describe how these concepts relate to other constructs, including sensitive periods, plasticity, and programming. We then consider four potential periods of calibration/recalibration: fetal, infancy, puberty, and pregnancy/lactation. In each section, we discuss evidence that the HPA and/or sympathetic medullary adrenal (SAM) system undergoes developmental change, rendering it more plastic and amenable to shift its activity in response to environmental conditions. We also review findings that the impacts of environmental harshness on stress responding persist beyond these periods. We then articulate that marked change in the quality of the environment (from harsh to benign or vice versa) is required in order for recalibration to occur, and that recalibration would result in shifts in stress responding to more closely align with the profiles of individuals who have experienced these conditions throughout life. Finally, we reflect on whether recalibration of the HPA and SAM system may extend to the other stress-responsive neurobehavioral systems.

Climatic stress in pregnant sows: adaptive responses and effects on productivity

The article presents data from the scientific literaturedescribing the influence of microclimate parameters on thebody of sows and their offspring. The key factors of thenormal course of physiological processes in the body of sowsand piglets are the optimal temperature, light, air velocity andhumidity. Sensitivity of sows to climatic factors increasessignificantly during pregnancy and lactation. At elevatedoutdoor temperatures, heat stress develops, which negativelyaffects well-being and productivity of sows and significantlyharms the offspring due to intrauterine temperature load. Itis established that there are differences in genetic tolerance to high temperature between different breeds of sows.Changes in physiological and behavioral parameters can beobserved at different stages of the reproductive cycle of sows.Pregnant sows respond to heat stress by increasing rectal andskin temperature, respiration rate and reducing their overallactivity. Elevated ambient temperature during late pregnancyincreases the catabolism of lipids and proteins in the bodyof sows, the concentration of adrenocorticotropic hormone,cortisol in the blood increases. Heat-exposed sows also havea shorter gestation period and a lower nest weight of pigletsat birth. During lactation, there are changes in general andfeed behavior, reduced feed intake and as a result, the processof milk production is disrupted. In particular, it was foundthat with increasing temperature from 20.0 to 29.0 °C milkproduction in sows decreases from 10.43 to 7.35 kg/day(p &lt;0.05). The content of immunoglobulins, vitamins andmicroelements in milk decreases. This leads to a violation ofimportant physiological functions of the body of piglets andhas a negative impact on their growth and development. Themost critical periods for sows are the end of summer and thebeginning of autumn, when anestrus is observed, the rates offertilization, farrowing, fertility and weight gain of piglets arereduced. This is due to an imbalance in the hypothalamicpituitary-adrenal system and high levels of melatonin in theblood. The use of physiological and behavioral indicatorsis necessary to prevent climatic stress and increase animalproductivity. Key words: physiology, pigs, stress factors, thermoregulation, behavior, reproductive system, pregnancy, lactation.

Abstract 11105: Real Time Racial Microaggression and Physiological Stress Responses Among Young and Middle Aged Black Adults

Introduction: Perceived racial discrimination has been associated with dysregulation of sympathetic-adrenal-medullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axis, two major physiological stress response systems linked to cardiovascular disease outcomes. Most studies, to date, used cross-sectional data that captured retrospective measures of lifetime racial discrimination associated with current physiological stress responses. Relative to overt racial discrimination, a subtle form of racial discrimination, known as microaggression is more prevalent, yet most commonly measured retrospectively, and understudied. The purpose of this pilot study was to examine the relationship between microaggression measured in real-time and physiological stress responses. Methods: Twelve healthy Black adults (mean age=43.4 years) completed baseline surveys, and self-collected saliva 4x a day for 4 days to measure cortisol and alpha amylase (AA) as a proxy of HPA and SAM systems, respectively. Real-time microaggression was measured using ecological momentary assessments (EMA) sent to participants 5x a day for 7 days. Multilevel models were conducted to examine the relationship between microaggressions and the SAM and HPA axis activities. Results: In the bivariate analyses, the area under the curve with respect to ground (AUCg: total cortisol output throughout the day) was significantly associated with the same day microaggression (r=.40, p=.02). Microaggression was associated with cortisol awakening response (CAR) on the same day (r=.34, p=.04). In multilevel models, microaggression was associated with wake-up cortisol level on the same day (β=.22, p=.05). Microaggression was also associated with wake-up AA levels both the same day (β=.58, p&lt;.01) and the next day (β=.40, p=.05). Conclusions: Microaggression was associated with same day and next day physiological stress responses. We determined that concurrent use of salivary biomarkers and EMA was feasible methods to examine the temporal relationship between microaggression and physiological stress responses. Future work will include the development of an intervention that buffers the physiologic stress response related to microaggression to improve cardiovascular health.

Alterations of Stress-Related Glucocorticoids and Endocannabinoids in Hair of Chronic Cocaine Users.

BackgroundPrevious research in animals and humans has demonstrated a potential role of stress regulatory systems, such as the hypothalamic-pituitary-adrenal (HPA) axis and the endocannabinoid (eCB) system, in the development of substance use disorders. We thus investigated alterations of HPA and eCB markers in individuals with chronic cocaine use disorder by using an advanced hair analysis technique.MethodsWe compared hair concentrations of glucocorticoids (cortisone, cortisol) and the eCBs 2-arachidonylglycerol, anandamide (AEA), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA) between 48 recreational cocaine users (RCU), 25 dependent cocaine users (DCU), and 67 stimulant-naïve controls. Self-reported substance use and hair concentrations of substances were also assessed.ResultsSignificantly higher concentrations of hair cortisone were found in RCU and DCU compared with controls. Hair concentrations of OEA and PEA were significantly lower in DCU compared with RCU and controls. Additionally, within cocaine users, elevated cocaine hair concentration was a significant predictor for increased glucocorticoid and decreased OEA hair levels. Moreover, higher 3,4-methyl​enedioxymethamphetamine hair concentration was correlated with elevated cortisone and AEA, OEA, and PEA levels in hair within cocaine users, whereas more self-reported cannabis use was associated with lower eCBs levels in hair across the total sample.ConclusionOur findings support the hypothesis that the HPA axis and eCB system might be important regulators for substance use disorders. The mechanistic understanding of changes in glucocorticoid and eCB levels in future research might be a promising pharmacological target to reduce stress-induced craving and relapse specifically in cocaine use disorder.

Oxidative stress in the skin: Impact and related protection.

Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness and wrinkles. Besides these, skin microbiota are also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.

Mental fatigue accompanied with whole body cold exposure before exercise impairs endurance exercise performance

Purpose Endurance exercise performance is impaired by cold exposure before exercise via an enhanced sympathetic activation. Mental fatigue induced by psychological task before exercise deteriorates endurance exercise performance, but the impact of a simultaneous load of mental fatigue and cold exposure on endurance exercise performance is remained unknown. The purpose of this study is to test the hypothesis that mental fatigue during cold exposure before exercise further impairs endurance exercise performance. Methods Nine male young subjects performed the Stroop color word test (500 stimuli/set×2, 55 min in total) as mental stress (MS) trial, while watched a documentary DVD as control (CON) trial during whole body cold exposure using a water-perfused suit (10˚C for 10 min then 15˚C for 50 min). After that participants performed a cycling test at 80% VO2max to the exhaustion after warm-up for 4 min. Subjective fatigue index (SFI) were measured before and immediately after mental stress and exercise. Plasma adrenaline ([Ad]p), noradrenaline ([Norad]p), and cortisol ([Corti]p) concentrations were measured before and immediately after mental load and exercise. Time to exhaustion (TE) was evaluated as endurance cycling performance. This study received an ethics approval from our institution. Results Percent changes from baseline of SFI were higher in the MS trial than in the CON trial at post Intervention and post exercise (p < 0.001). Significant effects of interaction (time × trial) were found on [Ad]p (p = 0.026), while not on [Norad]p nor on [Corti]p. TE was shortened but not significantly for the MS trial (767 ± 63 s) compared with the CON trial (813 ± 51 s), and an effect size of the difference was d = 0.271. The difference (Δ) between the trials (MS - CON) of TE was negatively correlated with Δ[Ad]p (r = - 0.605, p = 0.085) or Δ[Norad]p (r = - 0.661, p = 0.074), but not with Δ[Corti]p (r=0.251, p=0.514) determined immediately after exercise. Conclusions These findings support our hypothesis, thus mental fatigue accompanied with whole body cold exposure before exercise would further impair endurance exercise performance compared with cold exposure alone via the enhanced sympathoadrenal medullary system rather than hypothalamic pituitary adrenal system.

Correlation Differences between Sex and Stress Hormones in Men And Women

The excessive aggression is an actual problem of modern society but the mechanisms of aggressiveness development have not been sufficiently investigated. Women aggression is considered to differ from men one and results obtained on males cannot be extrapolated on females. Sex hormones have a crucial role in the generation of sexually dimorphic aggression circuits during development and their maintenance during adulthood. Hypothalamic pituitary adrenal axis and sympathoadrenal system are major neuroendocrine systems that respond to stress. Stress hormones are involved into behavioral reactions of organism. Gonadal, hypothalamic pituitary adrenal axes, and sympathoadrenal system are tightly interrelated and every of them can influence another one. The purpose of the study was to estimate correlation differences between sex and stress hormones in men and women. Material and methods. Forty healthy young people aged 18 to 22 years with a body mass index of 19-24 (21 women and 19 men) were enrolled in the study. Hormone levels in blood serum were determined by Testosterone, Estradiol, Cortisol ELISA kits (Italy), Epinephrine/Norepinephrine (EPI) ELISA kit (China). Results and discussion. In all phases of the menstrual cycle, the level of cortisol in women was lower than in men, but in the luteal phase these differences were not statistically significant. In all phases of the menstrual cycle, the blood serum norepinephrine content in women was lower than in men, but in the follicular phase these differences were not statistically significant. The level of epinephrine in women during ovulation and luteal phase did not differ from the level of epinephrine in men, but in follicular phase it was significantly lower. Calculations of correlations between individual hormones revealed a significant difference between them in men and women. Positive correlations between testosterone and estradiol and between cortisol and epinephrine; a strong negative correlation between epinephrine and testosterone/norepinephrine ratio were found in men. Positive correlation between testosterone and cortisol and negative correlation between estradiol and cortisol/testosterone ratio were revealed in women. Conclusion. In women, strong correlations were found between cortisol and sex hormones; in men, strong interrelationship was revealed between cortisol and epinephrine. Both in men and in women (in all phases of the menstrual cycle), high positive correlations between testosterone/norepinephrine and cortisol/norepinephrine ratios were observed

Secretagogin Mediates the Regulatory Effect of Electroacupuncture on Hypothalamic-Pituitary-Adrenal Axis Dysfunction in Surgical Trauma.

Electroacupuncture (EA) improves hypothalamic-pituitary-adrenal (HPA) axis disorder by reducing corticotropin-releasing hormone (CRH) synthesis and release in the paraventricular nucleus (PVN). However, the potential mechanism underlying CRH regulation remains unclear. Secretagogin (SCGN) is closely related to stress and is involved in regulating the release of CRH. We hypothesized that SCGN in the PVN might trigger the HPA system and be involved in EA-mediated modulation of HPA dysfunction caused by surgical trauma. Serum CRH and adrenocorticotropic hormone (ACTH) and plasma corticosterone (CORT) levels at 6 h and 24 h after hepatectomy were determined by radioimmunoassay. CRH and SCGN protein levels in the PVN were detected by western blot and immunofluorescence, and CRH and SCGN mRNA levels in the PVN were determined by means of real-time polymerase chain reaction (RT-PCR) and in situ hybridization (ISH). Our studies showed that serum CRH, ACTH, and CORT levels and PVN CRH expression were significantly increased at 6 h and 24 h after hepatectomy in the hepatectomy group compared with the control group, and those in the EA+hepatectomy group were decreased compared with those in the hepatectomy group. The protein and mRNA levels of SCGN in the PVN were also increased after hepatectomy, and their expression in the EA+hepatectomy group was decreased compared with that in the hepatectomy group. When SCGN expression in the PVN was functionally knocked down by a constructed CsCI virus, we found that SCGN knockdown decreased the serum CRH, ACTH, and CORT levels in the SCGN shRNA+hepatectomy group compared with the hepatectomy group, and it also attenuated CRH expression in the PVN. In summary, our findings illustrated that EA normalized HPA axis dysfunction after surgical trauma by decreasing the transcription and synthesis of SCGN.