Differences In Adaptive Responses Research Articles

Cellular and serotonergic correlates of habituated neuroendocrine responses in male and female rats.

Male and females appear equally capable of showing habituated hypothalamic-pituitary-adrenal (HPA) axis output responses to repeated exposures of the same challenge. Whether this reflects, within males and females, common mechanisms of decreased neuronal activity within stress responding, afferents to the paraventricular hypothalamic nucleus (PVH), the final common pathway to the HPA axis, has not been examined. Here we compared in adult male and female rats the extent to which declines in HPA axis responses to repeated restraint are met by habituated cellular (Fos) responses, in addition to changes in serotonin (5-hydroxytryptamine; 5-HT) expression and signaling, which normally stimulates the HPA axis. Thus, alterations in this component of HPA axis drive could provide an underlying basis for sex differences in adaptive responses. Males and females showed reliable declines in ACTH and corticosterone responses after 10 daily episodes of repeated restraint, recapitulated, in largest part, by similar regional patterns of Fos habituation, including within the PVH, several stress sensitive cell groups of the limbic forebrain, as well as within the raphe nucleus. Serotonin staining in the dorsal raphe and terminal profiles in the forebrain continued to reflect a higher pre-synaptic capacity for the 5-HT system in females. The sexual dimorphism encountered within the lateral septum and medial preoptic area of control animals was less distinguished in the repeat condition, however, whereas 5-HT varicosities in the PVH increased after repeated restraint only in females. Relative to their singly restrained counterparts, males displayed an increase in 5-HT 1 A receptor expression in the raphe nucleus after repeated restraint, whereas females showed a decrease in 5-HT 1 A mRNA levels in the hippocampus and in the zona incerta, representing the most proximal of cell groups expressing the 5-HT 1 A receptor in the vicinity of the PVH. In conclusion, similar regional profiles of cellular habituation in males and females suggest common CNS substrates of neuroendocrine adaptation. However, this process may be met by underlying sex differences in serotonergic control, given the respective roles for pre- and postsynaptic 5-HT 1 A receptors in mediating serotonin availability and signal transfer.

Sexual differences in root growth and antioxidant characteristics in Salix viminalis exposed to cadmium stress

Salix viminalis is a typical dioecious shrub willow, which has been widely used in the heavy metal polluted soil phytoremediation due to its fast growth rate, deep root system, and metal-resistance trait. It has been reported that dioecious plants present sex-specific characteristics when exposed to biotic and abiotic stress. However, different responses to heavy metal cadmium stress between male and female plants of S. viminalis have not been clarified. In this study, male and female S. viminalis clones were treated by 100 μM cadmium stress for a period of 21 days, and the root morphology, hydrogen peroxide content, malondialdehyde, and free proline content, antioxidant enzyme activities, and glutathione content were investigated after every 7-day interval. The results showed that female plants of S. viminalis developed thicker root diameter and volume and also accumulated more hydrogen peroxide than males at the first 7-day interval. Furthermore, sexual dichotomous indexes showed the most significant on the second 7-day interval. These findings suggest that male plants of S. viminalis have stronger cadmium tolerance than female plants and sexual differences in adaptive responses to cadmium are duration dependent, which adds to present evidence of sex-related responses to environmental stress in dioecious plants. Novelty statement Salix viminalis, a dioecious shrub willow, has been widely used in phytoremediation, yet sexually differences in tolerance to cadmium of which remained unclear. This study focused on different responses to cadmium stress between roots of male and female S. viminalis. Results show that male plants of S. viminalis have stronger cadmium tolerance than female plants, which indicates male S. viminalis should be more considered to be applied for phytoremediation and ecological restoration of cadmium-accumulated soil considering cadmium tolerance characteristics. The findings can provide valuable evidence and insights for researches focused on phytoremediation with dioecious woody plants and sexual dimorphism under abiotic stress.

Effects of High Altitude on Sleep and Respiratory System

The purpose of this review is to discuss the pathogenesis, clinical manifestations, and diagnosis treatment of sleep apnea at high altitude as well and acute altitude illnesses. Differences in adaptive responses of different native highlander populations are leading to interesting new insights into high-altitude physiology. Periodic breathing at altitude is a physiologic response to hypobaric oxygen and patients with obstructive sleep apnea have transition of respiratory events from obstructive to central at altitude. Acetazolamide is first-line therapy for periodic breathing at altitude. Other acute altitude illnesses are best treated with descent to a lower altitude.

Gender differences in adaptive reactions of students in the development of educational innovations as a factor of sustainable development

The sustainability of the development of society depends and is secure by the safety of health of human capital. The article presents the results of a study of gender differences in adaptive reactions of students in the development of educational innovations using the non-invasive method of heart rate variability. Comparative analysis of heart rate measurements among the surveyed students showed that both boys and girls had tachycardia during the lessons. In boys, an increase in the stress index revealed that was reliably associated with the tension of the parasympathetic system, and in girls - the sympathetic system of autonomic regulation of heart rhythm control. A wide individual range of adaptive reactions of the cardiovascular system of young men and women to the impact of ICT revealed. The data obtained more indicative of biological (sex) differences in adaptive responses in the implementation of information technology in education. Our research has shown gender differences in adaptive responses. We observed a significant correlation between stress and the reaction of the autonomic nervous system. It is necessary to prevent the disturbance of the adaptive of the body. Therefore, we must create a safe environment for the health of students. It is desirable to reduce the time spent in the information space (up to 80 minutes, followed by a break). Since the research conducted on a small sample and one educational institution, it is necessary to research this issue on a larger representative sample.

Sexual dimorphism in oxidant-induced adaptive homeostasis in multiple wild-type D. melanogaster strains

Sexual dimorphism includes the physical and reproductive differences between the sexes, including differences that are conserved across species, ranging from the common fruit fly, Drosophila melanogaster, to humans. Sex-dependent variations in adaptive homeostasis, and adaptive stress responses may offer insight into the underlying mechanisms for male and female survival differences and into differences in chronic disease incidence and severity in humans. Earlier work showed sex-specific differences in adaptive responses to oxidative stressors in hybrid laboratory strains of D. melanogaster. The present study explored whether this phenomenon is also observed in wild-type D. melanogaster strains Oregon-R (Or-R) and Canton-S (Ca-S), as well as the common mutant reference strain w[1118], in order to better understand whether such findings are descriptive of D. melanogaster in general. Flies of each strain were pretreated with non-damaging, adaptive concentrations of hydrogen peroxide (H2O2) or of different redox cycling agents (paraquat, DMNQ, or menadione). Adaptive homeostasis, and changes in the expression of the Proteasome and overall cellular proteasomal proteolytic capacity were assessed. Redox cycling agents exhibited a male-specific adaptive response, whereas H2O2 exposure provoked female-specific adaptation. These findings demonstrate that different oxidants can elicit sexually dimorphic adaptive homeostatic responses in multiple fly strains. These results (and those contained in a parallel study [1]) highlight the need to address sex as a biological variable in fundamental science, clinical research, and toxicology.

Diminished Resistance to Hyperoxia in Brains of Reproductively Senescent Female CBA/H Mice.

BackgroundWe have explored sex differences in ability to maintain redox balance during acute oxidative stress in brains of mice. We aimed to determine if there were differences in oxidative/antioxidative status upon hyperoxia in brains of reproductively senescent CBA/H mice in order to elucidate some of the possible mechanisms of lifespan regulation.Material/MethodsThe brains of 12-month-old male and female CBA/H mice (n=9 per sex and treatment) subjected to 18-h hyperoxia were evaluated for lipid peroxidation (LPO), antioxidative enzyme expression and activity - superoxide dismutase 1 and 2 (Sod-1, Sod-2), catalase (Cat), glutathione peroxidase 1 (Gpx-1), heme-oxygenase 1 (Ho-1), nad NF-E2-related factor 2 (Nrf2), and for 2-deoxy-2-[18F] fluoro-D-glucose (18FDG) uptake.ResultsNo increase in LPO was observed after hyperoxia, regardless of sex. Expression of Nrf-2 showed significant downregulation in hyperoxia-treated males (p=0.001), and upregulation in hyperoxia-treated females (p=0.023). Also, in females hyperoxia upregulated Sod-1 (p=0.046), and Ho-1 (p=0.014) genes. SOD1 protein was upregulated in both sexes after hyperoxia (p=0.009 for males and p=0.011 for females). SOD2 protein was upregulated only in females (p=0.008) while CAT (p=0.026) and HO-1 (p=0.042) proteins were increased after hyperoxia only in males. Uptake of 18FDG was decreased after hyperoxia in the back brain of females.ConclusionsWe found that females at their reproductive senescence are more susceptible to hyperoxia, compared to males. We propose this model of hyperoxia as a useful tool to assess sex differences in adaptive response to acute stress conditions, which may be partially responsible for observed sex differences in longevity of CBA/H mice.

Elucidation of miRNAs-Mediated Responses to Low Nitrogen Stress by Deep Sequencing of Two Soybean Genotypes

Nitrogen (N) is a major limiting factor in crop production, and plant adaptive responses to low N are involved in many post-transcriptional regulation. Recent studies indicate that miRNAs play important roles in adaptive responses. However, miRNAs in soybean adaptive responses to N limitation have been not reported. We constructed sixteen libraries to identify low N-responsive miRNAs on a genome-wide scale using samples from 2 different genotypes (low N sensitive and low N tolerant) subjected to various periods of low nitrogen stress. Using high-throughput sequencing technology (Illumina-Solexa), we identified 362 known miRNAs variants belonging to 158 families and 90 new miRNAs belonging to 55 families. Among these known miRNAs variants, almost 50% were not different from annotated miRNAs in miRBase. Analyses of their expression patterns showed 150 known miRNAs variants as well as 2 novel miRNAs with differential expressions. These differentially expressed miRNAs between the two soybean genotypes were compared and classified into three groups based on their expression patterns. Predicted targets of these miRNAs were involved in various metabolic and regulatory pathways such as protein degradation, carbohydrate metabolism, hormone signaling pathway, and cellular transport. These findings suggest that miRNAs play important roles in soybean response to low N and contribute to the understanding of the genetic basis of differences in adaptive responses to N limitation between the two soybean genotypes. Our study provides basis for expounding the complex gene regulatory network of these miRNAs.

Differences in adaptive response to heat stress comparing heat‐tolerant and heat‐sensitive cattle over 24‐hour periods

Little is known about the heat adaptive ability of bovine raised in different thermal environments. Heat-sensitive Angus steers (ANG) from Missouri (MO;n=5) and Oklahoma (OK;n=5) were tested with the heat-tolerant Romosinuano breed (RO;n=5) from Florida in environmental chambers at the University of Missouri. Steers were maintained at thermoneutrality (TN; 19–22°C) through Day 8, followed by 2 weeks of cycling heat stress (HS; 26–36 and 30–40 °C for ANG and RO, respectively). RO were kept at a higher ambient temperature (Ta) to incur a similar level of HS as ANG. Respiration rate (RR), and both rectal (Tre) and skin temperatures, were measured every hour for 24 hours at TN, Early Heat (EH), and Late Heat (LH). All animals increased (p<0.05) RR and Tre from TN to HS. MO decreased (p<0.05) Tre and RR from EH to LH by 0.18°C and 9.5 bpm, while OK exhibited no differences (p>0.05). RO had similarities with OK by showing no difference in Tre (p>0.05) from EH to LH. However, RO decreased RR (p<0.05) from EH (102.2 bpm) to LH (84.3 bpm) similar to MO. Likewise, there were temporal skin temperature differences during HS for ANG but not for RO. Results suggest that there are regional differences in bovine response to heat stress that are related to their climatically diverse environments. It is possible to identify phenotypic markers that characterize adaptation levels to heat stress across breeds. USDA Agreement No. 58-6227-3-016

Allometric and biochemical responses of grapevines subjected to drought and enhanced ultraviolet-B radiation

Background and Aims: The aim of this study was to evaluate differences in adaptive responses in grapevines (Vitis vinifera L. cv Soultanina) exposed to either drought, enhanced ultraviolet-B (UV-B) radiation or the combination of the two environmental stresses. Methods and Results: Results indicated pronounced effects on allometric parameters in plants exposed to the enhanced UV-B radiation. The combined application of drought and enhanced UV-B radiation considerably affected shoot growth rate and leaf dry weight. Guaiacol peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), superoxide dismutase (SOD, 1.15.1.1) and catalase (CAT, 1.11.1.6) activities increased significantly in the enhanced UV-B radiation treatment. Drought resulted in a significant increase in proline concentration, while the exposure of plants to enhanced UV-B radiation resulted in the production of UV-B absorbing compounds (UVabs). Conclusions: Under drought conditions proline accumulation seemed to be the main mechanism of adaptation contributing to plant's antioxidant defence. On the other hand, under enhanced UV-B radiation, the accumulation of the UV-B absorbing compounds and the increase in antioxidant enzymes activities constitute the main mechanisms of grapevine adaptation. Significance of the Study: The data obtained indicate the occurrence of two different mechanisms of adaptation in response to the stressor applied. Furthermore, the patterns of proline and UVabs concentration changes under stress conditions suggest that the biosynthesis of these two compounds might follow competing metabolic pathways.

Sex‐related adaptive responses to interaction of drought and salinity in Populus yunnanensis

We used Populus yunnanensis Dode., a native dioecious species in southwestern China, as a model species to study morphological, physiological, biochemical and ultrastructural responses to drought, salinity and their combination. Females exhibited more growth inhibition, gas exchange rate depression and reactive oxygen species (ROS) accumulation; higher lipid peroxide levels, lower osmotic adjustment capacity and ascorbate-glutathione cycle enzyme activities; and more damage to cell organelles than did males under drought, salinity and especially under their combination. In addition, we found sex-specific responses in total chlorophyll content (TC), carotenoid concentration and carbon isotope composition under different osmotic stresses. Our results indicated that: (1) females are more sensitive and suffer from greater negative effects than do males under drought, salinity and especially under their combination; (2) sexual differences in adaptive responses to drought, salinity and their combination are context dependent; and (3) sex-specific reactions under a combination of stresses are distinct from single-stress responses. Thus, these results provide evidence for adaptive differentiation between sexes in responses to osmotic stresses and in the sensitivity to environmental change.

The phagocyte NADPH oxidase (NOX2) regulates adaptive immune response at the level of both T cells and APCs (138.7)

Abstract Absence of phagocyte NADPH oxidase (NOX2) activity causes chronic granulomatous disease (CGD), a primary immunodeficiency characterized by recurrent bacterial infections. In addition to this innate immune dysfunction, CGD patients or animal models display an altered, perhaps augmented, adaptive immune response. It has been previously shown that T cells express the phagocyte oxidase and also been proposed that NOX2 expression alters APC function. The goal of this study was to determine if the differences in adaptive responses are inherent to T cells, or if other cells create an environment that promotes T helper polarization. Anti-CD3 activation of purified naive T cells from NOX2-deficient mice led to augmented IFNγ and IL-17 secretion. NOX2-deficient antigen presenting cells (APC) showed selective increases in GM-CSF, IL-6, TNF and MCP-1 induced by LPS challenge in vitro. APC function was measured using OVA-specific OT-II T cells, and oxidase deficient APC induced more IFNγ and IL-17 upon antigen stimulation. Adoptive transfer of OT-II T cells into wild type or NOX2(-/-) hosts followed by immunization with OVA in the presence of either CFA or Alum revealed altered cytokine profiles of T cells after restimulation in vitro. These results suggest roles for the phagocyte NADPH oxidase in shaping the adaptive and innate immune responses in both a T cell and APC dependent fashion.

Different adaptive responses of leaf physiological and biochemical aspects to drought in two contrasting populations of seabuckthorn

Two contrasting populations of seabuckthorn ( Hippophae rhamnoides L.) from western China were employed to study their differences in adaptive responses to drought. The Daofu population was from a wetter upland climate region, whereas the Dingxi populations was from a drier lowland climate region. A completely randomized design with two factors, two populations and two watering regimes (100% and 25% of the soil water holding capacity), was used. In both populations, drought significantly decreased growth and the net photosynthesis rate (A), and significantly increased the root/shoot ratio (RS), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX) activities, and abscisic acid (ABA) and proline contents. Compared with the Daofu population, drought induced a greater RS value, higher CAT, GPX, and APX activities, and a higher ABA content in the Dingxi population, whereas the gas exchange traits, for example, the stomatal limitation value (LS) and intercellular CO2 concentration (Ci), were less responsive to drought in the Dingxi population. The two populations may have developed different strategies to tolerate drought, such as different pathways to dissipate excess absorbed light energy, to resist oxidative stress, and to keep water status. Such factors enable the Dingxi population to tolerate drought better than the Daofu population.

A histomorphometric study of adaptive responses of cancellous bone in different regions in the sheep mandibular condyle following experimental forward mandibular displacement

Forward mandibular displacement in animal models is associated with faster and/or redirected condylar growth. Here the effect of forward displacement induced with an intraoral appliance on modelling/remodelling of the mandibular condyle was investigated in eight, 4-month-old, castrated male Merino sheep, randomly allocated to experimental and control groups ( n=4 in each group). The study period was 15 weeks, during that time, (1) calcein, (2) tetracycline, and (3) alizarin red S fluorochromes were given to all animals from day 1. Midsagittal sections of the temporomandibular joints were selected for analysis. Dynamic variables of bone formation, static indices of bone-forming and -resorbing activity, and structural indices of trabecular bone were estimated histomorphometrically. The sampling site was divided into two regions for analysis: (a) a ‘subchondral region’ (2 and 3 labels only), believed to be the bone newly formed during the experimental period; (b) a ‘central region’ (labelled by all three fluorochromes), believed to be the bone that existed before the experiment. Regional differences in adaptive response were found. In the experimental group, the bone-volume fraction (BV/TV) of the subchondral regions had decreased, although the specific bone-surface and bone-formation rates had increased. This low BV/TV was associated with decreased trabecular thickness and increased trabecular separation. In the central condylar region of the experimental group, BV/TV was unchanged, but an increased osteoid surface was apparent when the eroded surface was taken into consideration. These adaptive condylar responses to forward mandibular displacement appeared to be the result of increased osteoblastic activity. Further studies are recommended to examine why the subchondral and central regions responded differently.

Differences in the time course of haloperidol-induced up-regulation of rat striatal and mesolimbic dopamine receptors

Regional differences in the onset and persistence of increased dopamine D2 receptor density in rat brain were studied following daily injections of haloperidol for 3, 7, 14, or 28 days. Striatal [ 3H] - spiroperidol Bmax values were significantly increased following 3 – 28 days of haloperidol treatment, as compared to saline controls. Olfactory tubercle Bmax values were significantly increased only after 14 or 28 days of haloperidol treatment. Nucleus accumbens Bmax values were significantly increased only in the 14-day drug treatment group, suggesting that dopamine D2 receptor up-regulation in nucleus accumbens may reverse during ongoing neuroleptic treatment. These findings suggest that important differences in adaptive responses to chronic dopamine blockade may exist between dopaminergic synapses located in various rat brain regions.

Alterations in metabolite levels in carbohydrate and energy metabolism of rat in hemorrhagic shock and sepsis

For comparison of the extent of metabolite content alteration caused by etiologically different types of shock, septic peritonitis and hemorrhagic shock (mean arterial blood pressure at 40 mm Hg for 1 h or 2 h) were produced in rats. Contents of metabolites were determined in the liver and the muscle. Characteristic differences were found in the alteration modes of hepatic lactate level, muscle adenine nucleotide concentrations, and muscle protein content between these shock models. Rapid and significant alterations were observed in the levels of adenine nucleotides, glucose-6-phosphate and lactate in the liver in both types of shock. Hepatic energy charge and contents of glycogen and protein also significantly decreased. On the other hand, noticeable changes in the muscles were elevation of lactate level and the decrease of phosphocreatine and protein concentrations. Another distinct chnge was the decrease of total adenine nucleotide content in the muscle of septic rats, whereas it remained unchanged in the muscle of hemorrhagic shock rats. Thus, the changes of metabolite levels did not occur simultaneously in different tissues, and their rate and magnitude varied between different types of shock. The difference in adaptive response of metabolism may result in pathophysiologic diversity in shock.

Nutritional stress and growth: sex difference in adaptive response.

AbstractMost of the residents of Heliconia, Colombia, live in a continual state of malnutrition characterized by a lack of protein and an excess of carbohydrate in the diet. Kwashiorkor and Marasmus are frequently observed when such dietary imbalances occur. These conditions are seen in Heliconia, but even when the recognized symptoms of clinical malnutrition are absent, there are long‐term morphological changes associated with protein deficiency.In the present study, interest is centered on the relative effects of protein deficiency on the skeletal maturation of apparently healthy boys and girls. Incidental comparisons of clinically‐diagnosed Kwashiorkor and Marasmus patients with each other and with non‐affected controls are also made. It is seen that skeletal maturation in early life is delayed in almost all Heliconia children when compared to U.S. standards. Female controls appear to experience a form of catch‐up growth beginning in the preadolescent period, while male controls appear more severely retarded throughout adolescence. The result is a reduction in stature most pronounced in boys and a concomitant reduction in sexual dimorphism for overall body size. The Kwashiorkor‐ and Marasmus‐affected children show a more severe retardation of skeletal growth with no significant sex difference in their response.