Differences In Hormonal Responses Research Articles

Species differences in hormonally mediated gene expression underlie the evolutionary loss of sexually dimorphic coloration in Sceloporus lizards.

Phenotypic sexual dimorphism often involves the hormonal regulation of sex-biased expression for underlying genes. However, it is generally unknown whether the evolution of hormonally mediated sexual dimorphism occurs through upstream changes in tissue sensitivity to hormone signals, downstream changes in responsiveness of target genes, or both. Here, we use comparative transcriptomics to explore these possibilities in 2 species of Sceloporus lizards exhibiting different patterns of sexual dichromatism. Sexually dimorphic S. undulatus develops blue and black ventral coloration in response to testosterone, while sexually monomorphic S. virgatus does not, despite exhibiting similar sex differences in circulating testosterone levels. We administered testosterone implants to juveniles of each species and used RNAseq to quantify gene expression in ventral skin. Transcriptome-wide responses to testosterone were stronger in S. undulatus than in S. virgatus, suggesting species differences in tissue sensitivity to this hormone signal. Species differences in the expression of genes for androgen metabolism and sex hormone-binding globulin were consistent with this idea, but expression of the androgen receptor gene was higher in S. virgatus, complicating this interpretation. Downstream of androgen signaling, we found clear species differences in hormonal responsiveness of genes related to melanin synthesis, which were upregulated by testosterone in S. undulatus, but not in S. virgatus. Collectively, our results indicate that hormonal regulation of melanin synthesis pathways contributes to the development of sexual dimorphism in S. undulatus, and that changes in the hormonal responsiveness of these genes in S. virgatus contribute to the evolutionary loss of ventral coloration.

Polymorphisms in hormonal-related genes might be associated with variations in permanent tooth crown size.

The variability in tooth crown size (TCS) is influenced by genetic factors and might be regulated by the difference in hormonal response. This study aimed to evaluate the association between variations in TCS of permanent teeth with associated factors and genetic polymorphisms in hormonal-related genes (ESR1, ESR2 and PTH). This cross-sectional study involved dental casts from 86 individuals of both sexes. Dental casts were used to determine the maximum TCS of all fully erupted permanent teeth (except third molars) in the mesiodistal (MD) and buccolingual (BL) dimensions. Data such as sex, ethnicity, dental group (incisor, canine, premolar and molar), dental arch (upper and lower) and genetic polymorphisms of hormonal-related genes were used. The DNA from each patient was collected to evaluate the genetic polymorphisms in ESR1 (rs2234693 and rs9340799), ESR2 (rs1256049 and rs4986938) and PTH (rs694, rs6256 and rs307247) through real-time PCR. The data were submitted to statistical analysis with a significance level of 0.05. In the MD dimension, the sex, dental group and dental arch were associated with variation in TCS (P < .05). In the BL dimension, the sex, dental group, dental arch and polymorphism in rs694 and rs307247 were associated with variation in TCS. In short, this study suggests that genetic polymorphisms of PTH are associated with variations in the BL TCS of permanent human teeth.

Leptin And Prolactin Responses During And After Exercise At Constant Or Alternating Intensity

Differential hormonal responses have been reported during exercise and recovery depending on the intensity and/or duration of exercise. PURPOSE: The aim of the present study was to examine leptin and prolactin responses during and after exercise protocols of the same mean intensity and duration but performed at constant (CON) or alternating (ALT) intensity in healthy participants. METHODS: Ten healthy males (age: 24.7 ± 4.7 yrs, body mass: 78.5 ± 8.9 kg, height: 180.8 ± 6 cm, body fat: 9.1 ± 3.1%, VO2max: 47.9 ± 6.5 ml/kg/min, lactate threshold (LT): 67.4 ± 3.6% of VO2max, hear rate (HR)max: 188 ± 12 b/min) underwent in a random order two cycling exercise protocols, each lasting 1 hour. On one occasion, exercise intensity was alternated between 47% of VO2max for 40 seconds and 120% of VO2max for 20 seconds, so as the mean intensity was the same, i.e., at 105% of LT. On the other occasion, exercise was constant at 105% of LT. Two-way ANOVA with repeated measures was used for statistics and data are presented as mean ± SD. RESULTS: No significant differences were observed in leptin and prolactin concentrations between the two protocols at any time point measured (p = 0.77 and p = 0.80, respectively). However, in CON leptin decreased (p < 0.05) between Rest and 30 min and 60 min Exercise, as well as 60 min Post Exercise, in contrast with ALT, where leptin values did not significantly alter over time (Rest: 1.70 ± 1.22 ng/ml vs 1.36 ± 1.14 ng/ml, 30 min Exercise: 0.84 ± 0.51 ng/ml vs 1.38 ± 1.10, 60 min Exercise: 0.70 ± 0.47 ng/ml vs 0.86 ± 0.50 ng/ml, 60 min Post Exercise: 1.03 ± 0.71 vs 1.21 ± 1.01 ng/ml in CON and ALT, respectively). In ALT, prolactin levels decreased (p = 0.01) at 60 min Exercise (1.30 ± 0.64 ng/ml), compared to Rest (2.20 ± 0.88 ng/ml), while in CON there were not significantly changes over time (Rest:1.94 ± 0.95 ng/ml, 30 min Exercise: 1.57 ± 0.51 ng/ml, 60 min Exercise: 1.52 ± 0.73 ng/ml, 60 min Post Exercise: 1.61 ± 0.74 ng/ml). CONCLUSIONS: CON and ALT exercise performed at mean intensity of 70% of VO2max appeared to induce similar leptin and prolactin responses during and 1 hour after the end of exercise. These findings suggest that specific hormonal responses to cycling exercise protocols of the same mean intensity and duration are not affected by the form (constant or alternating intensity) of exercise.

Genotypic-specific hormonal reprogramming and crosstalk are crucial for root growth and salt tolerance in bermudagrass (Cynodon dactylon).

Salt stress is one of the major abiotic factors limiting the productivity of bermudagrass (Cynodon dactylon). However, the role of hormonal reprogramming and crosstalk in regulating root growth and salt tolerance in bermudagrass was not reported. Here, we examined the physiological and hormonal responses of two contrasting bermudagrass genotypes; ‘C43,’ salt-tolerant ‘C198’ salt-sensitive. Under salt stress, ‘C43’ had better membrane stability and higher photosynthetic activity than the ‘C198.’ Salt stress promoted root growth and improved root/shoot ratio and root activity in ‘C43,’ but the root growth of ‘C198’ was inhibited by salt stress, leading to diminished root activity. The two bermudagrass genotypes also showed critical differences in hormonal responses, especially in the roots. The root contents of indole-3-acetic acid (IAA), cytokinin derivatives, such as trans-zeatin riboside (tZR) and dihydrozeatin riboside (DHZR) were increased in ‘C43,’ but decreased in ‘C198’ when exposed to salt stress. The root growth rate was positively correlated with the root IAA, tZR and DHZR, indicating their crucial role in root growth under salt stress. The expressions of TAA/YUCCA and CYP735A involved in IAA and tZR biosynthesis were induced by salt stress in ‘C43,’ but inhibited in ‘C198,’ leading to reduced hormone accumulations. Salt stress decreased the iP, tZ, and DHZ content in the roots of both genotypes, and no significant difference was observed between the two genotypes. Salt stress reduced the content of GA3 in both genotypes by inhibiting GA20ox and GA2ox genes, which could be attributed to the reduced shoot growth in both genotypes. The increased ABA level by salt stress was significantly higher in ‘C198’ than ‘C43.’ Furthermore, there were positive and negative correlations between different hormones and root growth, suggesting that root growth could be regulated by complex hormonal reprogramming and crosstalk. This study provides a foundation for understanding the underlying mechanisms of hormonal-mediated root growth and salt tolerance in bermudagrass.

Structural and Biophysical Mechanisms Driving Differential Hormone Response in Steroid Receptors

Steroid receptors (SRs) belong to the superfamily of ligand‐activated transcription factors that regulate a myriad of biological processes upon binding of cholesterol‐derived hormones. A poorly understood aspect of this transcriptional regulation is how diverse steroid hormones modulate the ligand binding domain (LBD) of steroid receptors to achieve selective transcriptional outcomes. Here we investigate hormone specificity in the ancestral steroid receptor 2 (ancSR2) which is transcriptionally activated by 3‐ketosteroid hormones and unresponsive to 3‐hydroxylated, A‐ring aromatized steroids (i.e., estrogens). Previous work uncovered evolutionarily conserved ligand sensing‐residues in the binding pocket of LBD which also enables hormone discrimination. Specifically, the L42 (Helix3)‐M75 (Helix5) interaction was predicted to enable discrimination between 3‐ketosteroids and estrogens. To further probe the role of these ligand sensors in mediating differential hormone responses, we mutated M75 to modulate the Helix3‐Helix5 interaction and determined how transcriptional function, protein structure and dynamics are impacted. Specifically, we have combined site‐directed mutagenesis with biophysical experiments, cell‐based assays, and molecular dynamics (MD) simulations. While our secondary structure measurements reveal minor impacts on structure, MD simulations reveal that M75 mutations modulate the status of the H3‐H5 interaction, subsequently affecting ancSR2 conformations in a hormone‐dependent manner. Additionally, hydrogen deuterium exchange‐mass spectrometry (HDX‐MS) measurements reveal conformational effects at regions distant from the mutation site that may modulate ancSR2 inter‐residue interaction networks for differential hormone response. The differential hormone response is supported in luciferase reporter assays as well as ligand binding assays. These studies will provide biophysical and structural insight into how steroid receptors achieve hormone‐specific transcriptional responses.

Single-nucleotide polymorphisms in genes related to oxidative stress and ion channels in chickens are associated with semen quality and hormonal responses to thermal stress

Heat stress causes economic loss of livestock industry in tropical areas. Exploring genetic markers for selection of thermotolerance will benefit chicken production. Oxidative stress and fluid–salt balance are tightly associated with thermotolerance and productivity in domestic animals. The study aimed to identify single-nucleotide polymorphisms (SNPs) in genes related to oxidative stress and ion-channel regulation and their associations with semen quality and hormonal responses. In total, 28 SNPs within 11 candidate genes were identified to associate with hormonal changes and semen quality in both broiler- and layer-type Taiwan country chickens (TCCs) after exposure to acute heat stress at 38 °C for 4 h. Acute heat stress significantly affected plasma levels of triiodothyronine and corticosterone and reduced sperm motility, viability, and concentrations in both strains at Day 1 after exposure. In the B-strain TCCs, five SNPs within NDUFA8 and DAB2IP had significant effects on plasma adrenaline and corticosterone levels, and six SNPs within TRPC1, SLC9A9, and TRPC7 markedly affected plasma corticosterone and triiodothyronine levels. In the L2 strain, 15 SNPs within PSMA2, TPK1, MTF1, and CUL1 exerted effects on plasma corticosterone and triiodothyronine levels. Five SNPs within CUL3, TRPC1, and SLC9A9 in the B strain and two SNPs within MTF1 in the L2 strain were associated with sperm concentrations at Day 1 after exposure to heat stress. In conclusion, acute heat stress impaired semen quality and altered plasma corticosterone and triiodothyronine levels in TCCs. Some SNPs involved in oxidative stress and ion-channel regulation were identified to associate with the hormonal and semen alterations. These SNPs in conjunction with differential hormonal responses and semen quality serve as genetic markers for thermotolerance selection in sire lines of chickens.

Hunger and Satiety Peptides: Is There a Pattern to Classify Patients with Prader-Willi Syndrome?

Hyperphagia is one of the main problems of patients with Prader-Willi syndrome (PWS) to cope with everyday life. The underlying mechanisms are not yet well understood. Gut-brain hormones are an interrelated network that may be at least partially involved. We aimed to study the hormonal profile of PWS patients in comparison with obese and healthy controls. Thirty adult PWS patients (15 men; age 27.5 ± 8.02 years; BMI 32.4 ± 8.14 kg/m2), 30 obese and 30 healthy controls were studied before and after eating a hypercaloric liquid diet. Plasma brain-derived neurotrophic factor (BDNF), leptin, total and active ghrelin, peptide YY (PYY), pancreatic polypeptide (PP), Glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and amylin were determined at times 0′, 30′, 60′ and 120′. Cluster analysis was used. When considering all peptides together, two clusters were established according to fasting hormonal standardized concentrations. Cluster 1 encompassed most of obese (25/30) and healthy controls (28/30). By contrast, the majority of patients with PWS were located in Cluster 2 (23/27) and presented a similar fasting profile with hyperghrelinemia, high levels of leptin, PYY, GIP and GLP-1, compared to Cluster 1; that may reflect a dysfunction of these hunger/satiety hormones. When peptide behavior over the time was considered, PP concentrations were not sustained postprandially from 60 min onwards in Cluster 2. BDNF and amylin did not help to differentiate the two clusters. Thus, cluster analysis could be a good tool to distinguish and characterize the differences in hormone responses between PWS and obese or healthy controls.

Hormonal Differences in Intimate Partner Violence Perpetrators When They Cope with Acute Stress: A Pilot Study.

Background: Only a few studies have paid attention to the ability of perpetrators of intimate partner violence (IPVAW) against women to cope with acute stress, including hormonal parameters. In fact, previous studies assessed how salivary testosterone (Tsal) and cortisol (Csal) changed after coping with an acute emotional stressor (directly related to IPVAW), and they concluded that an imbalance between the two hormones might be characteristic of these men. Nevertheless, they neglected to examine the role of other hormones, such as salivary oxytocin (OXsal), which also seemed to play an important role in behavioral regulation, and whether this response could be generalized to other types of stress not directly related to IPVAW. Methods: This study aims to assess whether IPVAW perpetrators (n = 19) present differential hormonal (Tsal, Csal, OXsal and their ratios) and psychological state (anxiety, anger, and general affect) responses when coping with an acute cognitive laboratory stressor (a set of neuropsychological tests performed in front of an expert committee) in comparison with non-violent men (n = 16). This quasi-experimental study also assessed whether the psychological state variables drive this different hormonal response. Results: Our results revealed that IPVAW perpetrators had lower Csal and higher Tsal/Csal ratio levels during the post-task period, as well as higher total levels (average) of OXsal than controls. We also found that, only in IPVAW perpetrators, high levels of baseline anxiety and negative affect were related to high rises in Csal during the stress task. Conclusions: These data present a background showing that IPVAW perpetrators and non-violent men cope differently with stress. These findings might help to identify idiosyncratic profiles of IPVAW perpetrators that can then be employed to establish their therapeutic needs. Moreover, we reinforced the importance of combining biological markers with self-reports, thus increasing the reliability of these forensic assessments.

RBM20-Mediated Pre-mRNA Splicing Has Muscle-Specificity and Differential Hormonal Responses between Muscles and in Muscle Cell Cultures

Pre-mRNA splicing plays an important role in muscle function and diseases. The RNA binding motif 20 (RBM20) is a splicing factor that is predominantly expressed in muscle tissues and primarily regulates pre-mRNA splicing of Ttn, encoding a giant muscle protein titin that is responsible for muscle function and diseases. RBM20-mediated Ttn splicing has been mostly studied in heart muscle, but not in skeletal muscle. In this study, we investigated splicing specificity in different muscle types in Rbm20 knockout rats and hormonal effects on RBM20-mediated splicing both in cellulo and in vivo studies. The results revealed that RBM20 is differentially expressed across muscles and RBM20-mediated splicing is muscle-type specific. In the presence of RBM20, Ttn splicing responds to hormones in a muscle-type dependent manner, while in the absence of RBM20, Ttn splicing is not affected by hormones. In differentiated and undifferentiated C2C12 cells, RBM20-mediated splicing in response to hormonal effects is mainly through genomic signaling pathway. The knowledge gained from this study may help further understand muscle-specific gene splicing in response to hormone stimuli in different muscle types.

Individual differences in hormonal responsiveness to social encounters: Commentary on Félix et al., 2020 and review of pertinent issues

The results of a recent study, Félix et al., 2020, give new information about the behavioral and endocrine correlates of individual differences in the potential for androgen response in male cichlid fish. We think the study raises issues that are pertinent to the study of hormones and competition in other species, particularly humans. Focusing mostly on androgen reactivity to social challenge, we emphasize the importance of inter-individual variability in physiology, personality, and motivation in studies of hormone responses to social encounters. Additionally, we give special attention to matters of “repeatability” and the timing of hormone sampling. We conclude with an appreciation of the value of comparative analysis in behavioral endocrinology.

Appetite-Regulating Hormones Are Reduced After Oral Sucrose vs Glucose: Influence of Obesity, Insulin Resistance, and Sex.

Fructose compared to glucose has adverse effects on metabolic function, but endocrine responses to oral sucrose vs glucose is not well understood. We investigated how oral sucrose vs glucose affected appetite-regulating hormones, and how biological factors (body mass index [BMI], insulin sensitivity, sex) influence endocrine responses to these 2 types of sugar. Sixty-nine adults (29 men; 23.22 ± 3.74 years; BMI 27.03 ± 4.96 kg/m2) completed the study. On 2 occasions, participants consumed 300-mL drinks containing 75 g of glucose or sucrose. Blood was sampled at baseline, 10, 35, and 120 minutes post drink for plasma glucose, insulin, glucagon-like peptide (GLP-1)(7-36), peptide YY (PYY)total, and acyl-ghrelin measures. Hormone levels were compared between conditions using a linear mixed model. Interaction models were performed, and results were stratified to assess how biological factors influence endocrine responses. Sucrose vs glucose ingestion provoked a less robust rise in glucose (P < .001), insulin (P < .001), GLP-1 (P < .001), and PYY (P = .02), whereas acyl-ghrelin suppression was similar between the sugars. We found BMI status by sugar interactions for glucose (P = .01) and PYY (P = .03); obese individuals had smaller increases in glucose and PYY levels after consuming sucrose vs glucose. There were interactions between insulin sensitivity and sugar for glucose (P = .003) and insulin (P = .04), and a sex by sugar interaction for GLP-1 (P = .01); men demonstrated smaller increases in GLP-1 in response to oral sucrose vs glucose. Sucrose is less efficient at signaling postprandial satiation than glucose, and biological factors influence differential hormone responses to sucrose vs glucose consumption.

Phytophthora nicotianae Infection of Citrus Leaves and Host Defense Activation Compared to Root Infection.

Currently, little is known about the host pathogen interaction between Phytophthora spp. and citrus roots versus leaves. Therefore, we compared the molecular events occurring in citrus roots and leaves after zoospore inoculation with Phytophthora nicotianae. We analyzed the physical characteristics and genetic responses to P. nicotianae infection of leaves and roots for susceptible and tolerant citrus rootstocks to examine the potential for leaves to model root responses to P. nicotianae infection. Leaves responded faster and stronger to P. nicotianae infection than roots, and leaves showed greater differential response than roots. In addition to differences in hormonal responses, sugar, phospholipase D (PLD), and phospholipase A (PLA) involvement in the interaction between citrus and P. nicotianae was identified. This work, for the first time, creates a solid P. nicotianae zoospore infection protocol, reports P. nicotianae infection on citrus leaves through stomata, and provides evidence that different host organs respond to the pathogen differentially in timing and magnitude. This work identifies the hormones, sugars, pathogenesis-related genes, PLDs, and PLAs that are involved in the molecular events occurring in citrus under infection of P. nicotianae zoospore, and advances our understanding of the mechanisms underlying the interaction.

Principles and approaches in Hans Eysenck's personality theory: Their renaissance and development in current neurochemical research on individual differences

The paper tried to demonstrate by selected experiments, how principles and approaches applied by H.J. Eysenck's exploration of individual differences are represented in current neurochemical personality research (NCPR) The principle of dimensionality, extrapolating behaviour from psychopathology to the range of healthy persons could be shown to be also valid for differences in hormone responses to serotonergic, dopaminergic and noradrenergic drug stimulation. Eysenck's approach to use drugs as research tools is verified by neurotransmitter challenge tests suitable to manifest the neurochemical basis of behaviour, e.g. the role of dopamine and noradrenaline for different aspects of arousal; and by inducing personality related behaviour, e.g. aggression, by manipulating serotonin supply. Constant refinement of theory emphasized by Eysenck is represented in NCRP by analysing constellations of responses to different drugs within and between different transmitter systems and by combinations of response parameters resulting in discrimination of neurochemically defined subtypes or clusters of personality dimensions. Finally the inverted U-shape function demonstrated in Eysenck's drug postulate could be further developed and explained by underlying neurochemical mechanisms. NCRP can thus help to understand the relationship between personality and psychiatric disorders, to disclose transmitter related clustering and discrimination of personality dimensions and to detect new neurochemical mechanisms.

Abstract P2-06-01: Intrinsic transcriptomic differences of luminal progenitors and mature luminal cells of the normal breast

Abstract Epithelial cells in the normal breast are organized hierarchically into stem, luminal progenitor (LP) and mature luminal cells (LC) with distinct gene expression patterns. However, whether these gene expression differences are cell-intrinsic, driven through LP-LC cell interactions or due to stromal-luminal cell interactions in the breasts of healthy women is incompletely understood. Furthermore, prior studies on these cell populations did not take genetic ancestry into consideration despite widely reported genetic ancestry-dependent differences in the normal breast biology and breast cancer susceptibility/outcome. We isolated LP and LC breast epithelial cells from core breast biopsies of healthy women representing European, African American and Latino ancestry (five each). After a brief propagation (five passages) under epithelial reprogramming assay conditions, transcriptomes and DNA methylomes were examined using RNA- and Methylcapture-sequencing. Differences in gene expression (FDR&amp;lt;0.05, fold change &amp;gt;2) in LC cells compared to LP cells were observed, with 1581 and 609 genes up- and down-regulated, respectively. These data were enriched for signaling networks associated with cell cycle control of chromosomal replication, mitotic roles of polo-like kinase (down-regulated genes), granulocyte adhesion and diapedesis and LXR/RXR signaling (up-regulated genes). Despite marked gene expression differences between LC and LP cells, only 14 upregulated genes and four down-regulated genes showed DNA hypo- and hyper-methylation, respectively, in LC cells compared to LP cells, suggesting a minimal role for DNA methylation in differential gene expression between the two cell types. Furthermore, of the 2190 differentially expressed genes, 7% (158 genes) were regulated by estrogen, suggesting that differences in hormone responsiveness contribute to differential gene expression in LP and LC cells. To determine relationships between genes differentially methylated and expressed in LC and LP cells and breast cancer, we used publicly available databases, including TCGA. Interestingly, all genes hypermethylated and expressed at lower levels in LC cells were similarly hypermethylated and expressed at lower levels in breast cancers compared to normal breast, suggesting that these genes are minimally altered in breast cancer. Furthermore, in LC compared to LP cells, of thegenes hypomethylated and expressed at higher levels, only four genes (AIM1L, PRSS27, PTK6 and UNC13D) showed a similar pattern in breast tumors compared to normal breast. Of these, PTK6 is significantly overexpressed in luminal and HER2+ breast cancers compared to basal-like breast cancers, suggesting that PTK6+ cells are the preferred cell-of origin of luminal breast cancers. Taken together, this is the first study to demonstrate that transcriptomic data of normal breast cells from healthy women can be used to further define cell-of-origin of tumors and identify cancer-specific gene expression changes in breast cancer. Citation Format: Fang Fang, Poornima Bhat-Nakshatri, Manjushree Anjanappa, Dough Rusch, Aaron Buechlein, Dave Miller, Kenneth P Nephew, Harikrishna Nakshatri. Intrinsic transcriptomic differences of luminal progenitors and mature luminal cells of the normal breast [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-06-01.

Applying different emotion regulation strategies while providing negative feedback: Introduction of a new laboratory protocol

One aim of creating a new laboratory protocol was to investigate stress responses while being confronted with a work-related task, that is, having to provide negative feedback. It was central to the development of the scenario to make potential testosterone and cortisol responses measurable. The first part of the protocol comprises the introduction to the cover story, that is, being a member of the assessors’ team as part of a larger assessment center program aiming to estimate the proficiency of students prior to their entry into professional life. Watching a video of one of the assessment center's candidates and having to assess his performance in a self-presentation task was introduced to personally involve participants in the feedback conversation they had to conduct with the same candidate later on.A second aim was to introduce an experimental manipulation in the form of instructions and brief tutorials regarding different emotion regulation strategies to apply. Participants were randomly assigned to one out of four conditions: expressive suppression (keeping a neutral expression); cognitive reappraisal (staying task-oriented and emotionally distanced); affect utilization (moving towards and using emotions); or control condition. Distinguishing these ways to regulate one's emotions enabled us to reveal differential hormonal stress responses: Applying either cognitive reappraisal or affect utilization strategies alleviated temporary testosterone declines compared with the other two conditions.This method article contains details regarding the procedure as well as the following documents in their original wording:• Introduction to the cover story (being a member of the assessors’ team, observation of the attendant’s self-presentation, assessment dimensions)• Slides and audio instructions regarding experimental conditions (how to regulate emotions)• Documents handed out to assist participants in conducting the feedback conversation

Could Age, Sex and Physical Fitness Affect Blood Glucose Responses to Exercise in Type 1 Diabetes?

Closed-loop systems for patients with type 1 diabetes are progressing rapidly. Despite these advances, current systems may struggle in dealing with the acute stress of exercise. Algorithms to predict exercise-induced blood glucose changes in current systems are mostly derived from data involving relatively young, fit males. Little is known about the magnitude of confounding variables such as sex, age, and fitness level—underlying, uncontrollable factors that might influence blood glucose control during exercise. Sex-related differences in hormonal responses to physical exercise exist in studies involving individuals without diabetes, and result in altered fuel metabolism during exercise. Increasing age is associated with attenuated catecholamine responses and lower carbohydrate oxidation during activity. Furthermore, higher fitness levels can alter hormonal and fuel selection responses to exercise. Compounding the limited research on these factors in the metabolic response to exercise in type 1 diabetes is a limited understanding of how these variables affect blood glucose levels during different types, timing and intensities of activity in individuals with type 1 diabetes (T1D). Thus, there is currently insufficient information to model a closed-loop system that can predict them accurately and consistently prevent hypoglycemia. Further, studies involving both sexes, along with a range of ages and fitness levels, are needed to create a closed-loop system that will be more precise in regulating blood glucose during exercise in a wide variety of individuals with T1D.

Exacting Responses: Lack of Endocrine Cephalic Phase Responses Upon Oro-Sensory Exposure.

Oro-sensory exposure (OSE) to food plays an important role in the regulation of food intake. One proposed underlying mechanism is the occurrence of cephalic phase responses (CPRs). CPRs include the pre-digestive endocrine responses induced by food-related sensory input. Yet, whether OSE duration or sweetness intensity affects CPRs is unknown. The objective of this study was to determine the independent and interactive effects of oro-sensory duration (chewing) and stimulation intensity (sweetness) on endocrine CPRs and satiation. Eighteen males (22 ± 2 years, BMI 22 ± 2 kg/m2) participated in a 2 × 2 randomized study with a control condition. Each session participants performed modified sham feeding (MSF) with one of the four gel-based model foods. During the control session no MSF was performed. Model foods differed in chewing duration (hard or soft texture) and sweetness (low or high intensity). During each session, eight blood samples were collected up till 25 min after MSF onset. Subsequently, food intake from an ad libitum lunch was measured. No typical CPR was found for insulin, pancreatic polypeptide (PP), and ghrelin. However, the overall PP response was 1.1 times greater for the hard sweet MSF condition compared to control (p = 0.02). Overall ghrelin responses were 1.1 times greater for the hard model food compared to the soft model food conditions (p = 0.003). These differences in endocrine response were not associated with differences in food intake at the subsequent meal. Exploratory sub-analysis of the responsive insulin curves showed that after 2.5 min of MSF the hard texture model foods insulin concentrations were 1.2 greater compared to the soft texture. These findings indicate that texture hardness and sweetness increase the overall PP response and that MSF on hard texture increases the overall ghrelin response compared to soft texture model foods. However, MSF on model foods does not lead to a typical CPR. This study, among others, shows that there are major dissimilarities in the endocrine responses to food stimulation between individuals. This emphasizes the importance of considering cephalic responders and non-responders. More research is needed to understand CPRs in relation to food texture and taste properties.

Adrenal Stress and Physical Performance During Military Survival Training.

The purpose of this research was to evaluate neuroendocrine and physical performance responses in sailors and Marines undergoing U.S. Navy Survival, Evasion, Resistance, and Escape (SERE) training. Participants were 20 men (Age: 25.3 ± 3.6 yr; Height: 178.1 ± 6.1 cm; Weight: 83.7 ± 12.6 kg). Men were further split into high fit (N = 10) and low fit (N = 10) subgroups based on physical fitness test scores. Blood samples were obtained at baseline (T1), stress (T2), and recovery (T3) timepoints, and were analyzed for plasma epinephrine, plasma norepinephrine, plasma dopamine, serum cortisol, serum testosterone, and plasma neuropeptide Y. Vertical jump and handgrip tests were performed at T1 and T2. Stress hormone concentrations were significantly elevated at T2, with a concomitant reduction in testosterone concentrations. NPY concentrations did not increase at T2, but decreased significantly at T3. Subjects maintained performance on vertical jump and handgrip tests from T1 to T2. Significant between group differences were observed in norepinephrine (high fit: 3530.64 ± 2146.54 pmol · L-1, low fit: 4907.16 ± 3020.85 pmol · L-1) and NPY (high fit: 169.30 ± 85.89 pg · ml-1, low fit: 123.02 ± 88.86 pg · ml-1) concentrations at T3. This study revealed that despite significant increases in stress hormone concentrations in all subjects during SERE, fitter subjects exhibited differential hormonal responses during recovery, with quicker return of norepinephrine and NPY to baseline concentrations. This suggests physical fitness level may have a protective effect in recovery from periods of high stress military training.Szivak TK, Lee EC, Saenz C, Flanagan SD, Focht BC, Volek JS, Maresh CM, Kraemer WJ. Adrenal stress and physical performance during military survival training. Aerosp Med Hum Perform. 2018; 89(2):99-107.

Behavioural and Hormonal Stress Responses to Social Separation in Ravens, Corvus corax.

Social life is profitable, but it facilitates conflicts over resources and creates interdependence between individuals. Separating highly social animals triggers intense reactions aimed at re‐establishing lost connections. Less is known, however, about behavioural and physiological responses to separation in socially facultative species, where individuals temporarily form groups and may subsequently leave them. Non‐breeding common ravens (Corvus corax) gather in large numbers at feeding and roosting sites, but otherwise spend time seemingly solitary or in small subgroups. We here studied how ravens cope with being socially isolated, and investigated the life characteristics that might explain potential individual differences. For this, we individually separated captive subadult ravens (n = 25) and housed them in physical and visual isolation from their group members across 4 d. During the separation period, we collected behavioural data and measured the amount of immunoreactive corticosterone metabolites from bird droppings to assess the ravens’ physiological stress response. We found behavioural indicators of stress at the start of the separation, when ravens showed higher levels of tension than of comfort – a pattern that reversed at the end of the separation. Furthermore, we found that the upbringing of ravens affected their behaviour during separation. Hand‐raised birds produced more vocalisations in the beginning of the separation, and were less active at the end, while the reverse pattern occurred with parent‐raised ravens. Contrary to our predictions, we did not find differences in hormonal responses between the beginning and end of the separation period or any link between hormonal responses and behaviours. Ravens’ behavioural responses to social separation stress seem to be dependent on their arousal states, although possible links with hormonal reactions remain unclear. Our results show that behavioural reactions are not always linked with hormonal responses to stress, and further emphasise the importance of investigating effects of early‐life experiences.

Sex differences in hormonal responses to stress and smoking relapse: a prospective examination.

Dysregulation in the hypothalamic-pituitary-adrenal axis has been shown to be associated with smoking relapse. No study has directly examined the role of sex differences in this relationship. Nicotine dependent men (n = 52) and women (n = 46) interested in cessation completed 2 laboratory stress sessions during ad libitum smoking and after 48 hr of abstinence. The laboratory session included baseline, stress, and recovery periods. Blood and saliva samples were collected at the end of each period for the measurement of cortisol and adrenocorticotropic hormone. Self-report measures of craving and withdrawal symptoms were also collected. Participants attended 4 weekly follow-up sessions for counseling where they provided biological samples and self-report measures including smoking status. Relapse was defined by smoking cigarettes for 7 consecutive days post-cessation. Results showed that 60 participants relapsed during the 4-week period. Cox regression models from the abstinence session showed that cortisol levels regardless of source were predictive of relapse but the direction of prediction was sex dependent (Sex × Hormone, all ps < .05). Follow-up analyses further revealed that lower cortisol levels predicted relapse in men whereas greater cortisol levels predicted relapse in women (ps < .05). Enhanced craving predicted early smoking relapse in men but not in women (ps < .05). Data from the ad libitum session showed no differences in predicting relapse. These findings highlight that sex differences in the hormonal response to stress and subjective craving during nicotine withdrawal are critical predictors of risk for understanding early relapse.