Influencia de diferentes situaciones de estrés en la actividad enzimática muscular en bovino de lidia (bos taurus) / Influence of different stressful situations in the muscular enzymatic activity in bullfighting bulls (Bos taurus)

En este estudio se han utilizado 15 bóvidos de la raza de lidia (Bos taurus), divididos en tres grupos, con diferentes edades, características del transporte y condiciones de lidia (machos de 3-4 años lidiados en la plaza de tientas y en plaza portátil y animales de 4 años lidiados en plaza fija), para estudiar el posible efecto de diferentes situaciones de estrés y ejercicio en la liberación de diferentes enzimas musculares. Se tomaron muestras de sangre de todos los animales. En las analíticas sanguíneas se obtuvieron los valores de cortisol y de las enzimas CPK, LDH y AST. En relación con estas enzimas, hubo una mayor liberación de CPK y LDH en los novillos lidiados en plaza de toros portátil, aunque las diferencias no fueron estadísticamente significativas. El comportamiento de la enzima AST no fue el mismo que el de la CPK y la LDH, lo que indicaría según los datos obtenidos en este estudio, que esta enzima no sería un buen indicador del daño o fatiga muscular. Este mayor daño o fatiga muscular se detectó en los animales que se lidiaron en plazas de toros portátiles, sin descanso previo en los corrales. En estos mismos animales, hubo una correlación entre la liberación de cortisol y la de enzimas musculares(AU)

In order to check the possible effect of different stressful situations in the release of different muscular enzymes in fifteen fighting bulls (Bos taurus) divided in three groups according to age, transport characteristics and bullfighting conditions (young bulls fought in a trial bullring and in a portable bullring and bulls fought in a permanent bullring) were used in this study. Samples of blood were taken from all animals. Values of cortisol and CPK, LDH and AST enzymes were obtained from blood samples. A higher CPK and LDH release was detected in young bulls fought in a portable bullring, although statistical differences were not found. The behaviour of the enzyme AST was different from CPK and LDH enzymes, what would indicate, according with the data of the present study, that the values of AST would not be a good indicator of muscular damage or fatigue. This higher muscular damage or fatigue was detected in animals fought in a portable bullring which had not a rest period in pens before the bullfight. In these animals a correlation between the release of cortisol and muscular enzymes was detected(AU)

[Effect of mutation-induced excess brain concentration of intermediates of the kynurenine pathway of tryptophan metabolism on stress resistance and courtship behavior and communicative sound production in male Drosophila melanogaster].

The resistance of courtship behavior and communicative sound production to heat shock (37 degrees C, 30 min) was studied in wild-type Canton S (CS) male Drosophila melanogaster and males of two strains with defects in the kynurenine pathway of tryptophan metabolism (KPTM) caused by mutations cinnabar (block at the level of kynurenine-3-hydroxylase leading to accumulation of kynurenic acid, a neuroprotective metabolite, in the brain) and cardinal (block at the level of phenoxazinone synthetase causing accumulation of 3-hydroxykynurenine, an oxidative stress generator, in the brain). Males of each strain were divided into four groups. Males from control groups were not exposed to heat shock. The other groups were exposed to heat shock at the late embryonic/early larval (the first instar) developmental stage, when mushroom bodies are formed (HS1 groups); at the prepupal stage, when the brain central complex develops (HS2 groups); or at the imago stage 1 h before the experiment (HS groups). All males were tested at an age of five days. Virgin and fertilized five-day-old CS females served as courtship objects. The courtship behavior and singing of control CS and cinnabar males were similar. Control cardinal males also had high motivation, but their courtship efficiency was lower because of less precise movements (wing vibration was often not accompanied by sound production) and hyperexcitability. Exposure of first-instar larvae to heat shock had almost no effect on behavior or singing of adult males of any strain. In cardinal males exposed to heat shock at the prepupal stage or, especially, at the imago stage 1 h before the test (the HS2 and HS groups), courtship was strongly impaired, and various distortions appeared in their sound signals, which indicated disturbance of coordination between elements of the song center and their interaction with pacemakers. These effects were much milder or absent altogether in HS2 and HS wild-type males and, especially, cinnabar males. Thus, permanent excess of 3-hydroxykynurenine in the male brain dramatically decreased their stress resistance. In contrast, excess of kynurenic acid alleviated the consequences of stress.

Malocclusion induces chronic stress.

We examined the effect of occlusal disharmony in senescence-accelerated (SAMP8) mice on plasma corticosterone levels, spatial learning in the water maze, fos induction, hippocampal neuron number, expression of glucocorticoid receptors (GR) and glucocorticoid receptor messenger ribonucleic acid (GRmRNA) in hippocampus and inhibitor of glucocorticoid (metyrapone). Bite-raised aged mice had significantly greater plasma corticosterone levels than age-matched control mice as well as impaired spatial memory and decreased Fos induction and a number of neurons in hippocampus. GR and GRmRNA expressions were significantly decreased in aged bite-raised mice compared with age-matched control mice. Pretreatment with metyrapone inhibited not only the bite-raised induced increase in plasma corticosterone levels, but also the reduction in the number of hippocampal neurons and impaired spatial learning. These datas suggest that the bite-raised condition may enhance the aging process in hippocampus, thereby leading to impairment of spatial memory by stress.

[Dehydroepiandrosterone sulfate effect at the conversion of corticosterone to 11-dehydrocorticosterone in stress conditions: the scheme of regulation].

It had been shown that the reaction of conversion of corticosterone (CS) to 11-dehydrocorticosterone (11-DHCS) was increased in chronic intermissions, but not in sharp stress influences in male rats, especially under dehydroepiandrosterone sulfate (DHEAS) employment. The injection of naltrexone 20 min before DHEAS in dose 0.1 mg/kg which selectively blocked the mu-opiate receptors canceled this effect that indicated the participation of in-opiate receptors in such regulation. The DHEAS effect realized through the endogenous ACTH, and such was of the central nature. On the base of ourselves and the literature dates we intraduced the scheme of DHEAS- and mu-opiate-dependent regulation of CS/11-DHCS interchangings.

Human microRNAs regulate stress-induced immune responses mediated by the receptor NKG2D.

MICA and MICB are stress-induced ligands recognized by the activating receptor NKG2D. A microRNA encoded by human cytomegalovirus downregulates MICB expression by targeting a specific site in the MICB 3' untranslated region. As this site is conserved among different MICB alleles and a similar site exists in the MICA 3' untranslated region, we speculated that these sites are targeted by cellular microRNAs. Here we identified microRNAs that bound to these MICA and MICB 3' untranslated region sequences and obtained data suggesting that these microRNAs maintain expression of MICA and MICB protein under a certain threshold and facilitate acute upregulation of MICA and MICB during cellular stress. These microRNAs were overexpressed in various tumors and we demonstrate here that they aided tumor avoidance of immune recognition.

Vanadate inhibits endoplasmic reticulum stress responses.

The disruption of endoplasmic reticulum function leads to an accumulation of unfolded proteins, which results in endoplasmic reticulum stress. In the present study, we investigated the effect of vanadate on such stress. Endoplasmic reticulum stress increased glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP) expressions in glial cell cultures. We found that vanadate inhibited the endoplasmic reticulum stress-induced increase in GRP78 and CHOP expressions at both mRNA and protein levels. Thus, these results suggest that vanadate modulates endoplasmic reticulum stress responses and that novel vanadate-responsive protein(s) might be involved in these processes.

Effect of bacterial lipopolysaccharide on the reproductive axis of prepubertal and peripubertal female rats. Ontogenic changes in the immune-neuroendocrine interactions.

The immune, endocrine and nervous systems are closely interrelated, which allows the organism to respond to different types of stress such as infection. Chronic infectious and inflammatory conditions are often accompanied by an impaired reproductive function. Leptin, a hormone produced by adipose tissue, exerts a regulatory function on the reproductive axis. It has homology with other proinflammatory cytokines and could be modified by lipopolysaccharide (LPS). Therefore, these studies were designed to investigate the effect of LPS administration on the neuroendocrine mechanisms involved in the regulation of the reproductive axis during sexual maturation. Fifteen- and 30-day-old female rats were injected with a single dose of LPS 250 microg/kg (i.p.) and then nitric oxide synthase (NOS) activity, hypothalamic excitatory/inhibitory amino acids and Gn-RH content, serum LH and leptin concentration were studied. In 15-day-old female rats LPS treatment did not modify hypothalamic inducible (iNOS) and constitutive (cNOS) NOS activity, Gn-RH, glutamate (GLU) and GABA content. Also serum LH and leptin levels were not modified. In 30-day-old rats LPS increased iNOS and cNOS activity (p < 0.001) and hypothalamic Gn-RH content (p < 0.001). At this age hypothalamic GABA content was significantly decreased (p < 0.001) without changes in GLU content, and serum LH (p < 0.001) and leptin (p < 0.0001) decreased significantly. In summary, current studies have demonstrated that LPS administration to 15- and 30-day-old female rats results in a different response of the hypothalamus-pituitary-gonadal axis and of the adipose tissue, demonstrating an ontogenic response of the immune-neuroendocrine system to LPS administration.

Tetraploid citrus rootstocks are more tolerant to salt stress than diploid.

Citrus trees are subject to several abiotic constraints such as salinity. Providing new rootstocks more tolerant is thus a requirement. In this article, we investigated salt stress tolerance of three tetraploid rootstock genotypes when compared to their respective diploid rootstocks (Poncirus trifoliata, Carrizo citrange, Cleopatra mandarin). Plant growth, leaf fall and ion contents were investigated. At the end of the experiment, leaf fall was observed only for diploid Poncirus trifoliata plants as well as chlorosis symptoms for Poncirus trifoliata and Carrizo citrange diploid plants. The diploid Cleopatra mandarin plants growth rate was not affected by salt stress and has even been increased for tetraploid Cleopatra mandarin. Ion contents investigation has shown lower accumulations of chloride ions in leaves of the tetraploid plants when compared to diploid plants. Our results suggest that citrus tetraploid rootstocks are more tolerant to salt stress than their corresponding diploid.

A complex barcode underlies the heterogeneous response of p53 to stress.

The tumour suppressor p53 is activated following stress and initiates a heterogeneous response in a cell-, tissue- and stress-dependent manner. This heterogeneity is reflected in the different physiological outcomes that follow p53 activation. One mechanism that may contribute to this variability is the promoter selectivity of p53 target genes. p53 is at the hub of numerous signalling pathways that are triggered in response to particular stresses, all of which can leave their mark on p53 by way of post-translational modifications and interactions with cofactors. The precise combination of these marks, much like the bars in a barcode, dictates the behaviour of p53 in any given situation.

Bioluminescent response of individual dinoflagellate cells to hydrodynamic stress measured with millisecond resolution in a microfluidic device.

Dinoflagellate bioluminescence serves as a model system for examining mechanosensing by suspended motile unicellular organisms. The response latency, i.e. the delay time between the mechanical stimulus and luminescent response, provides information about the mechanotransduction and signaling process, and must be accurately known for dinoflagellate bioluminescence to be used as a flow visualization tool. This study used a novel microfluidic device to measure the response latency of a large number of individual dinoflagellates with a resolution of a few milliseconds. Suspended cells of several dinoflagellate species approximately 35 microm in diameter were directed through a 200 microm deep channel to a barrier with a 15 microm clearance impassable to the cells. Bioluminescence was stimulated when cells encountered the barrier and experienced an abrupt increase in hydrodynamic drag, and was imaged using high numerical aperture optics and a high-speed low-light video system. The average response latency for Lingulodinium polyedrum strain HJ was 15 ms (N>300 cells) at the three highest flow rates tested, with a minimum latency of 12 ms. Cells produced multiple flashes with an interval as short as 5 ms between individual flashes, suggesting that repeat stimulation involved a subset of the entire intracellular signaling pathway. The mean response latency for the dinoflagellates Pyrodinium bahamense, Alexandrium monilatum and older and newer isolates of L. polyedrum ranged from 15 to 22 ms, similar to the latencies previously determined for larger dinoflagellates with different morphologies, possibly reflecting optimization of dinoflagellate bioluminescence as a rapid anti-predation behavior.

Metabolic and molecular stress responses of sublittoral bearded horse mussel Modiolus barbatus to warming sea water: implications for vertical zonation.

The present study set out to investigate the thermal limits of the Mediterranean bivalve Modiolus barbatus, acclimated to various temperatures, and includes a comparison of laboratory determined limits with its temperature-dependent restriction to deeper water layers in its natural habitat. Thermal responses and limits were determined by integrating information from various levels of biological organization, including the expression of Hsp70 and Hsp90, the phosphorylation of stress-activated protein kinases, p38 mitogen-activated protein kinase (p38 MAPK) and cJun-N-terminal kinases (JNKs) as well as metabolic adjustments. The latter were assessed by examining temperature effects on the activity of the key glycolytic enzyme pyruvate kinase (PK). The expression of Hsp70 and Hsp90 was activated when mussels were acclimated to temperatures above 20 degrees C. Increased phosphorylation of p38 MAPK and JNKs at about the same temperatures indicate activation of MAPK signaling cascades and their potential involvement in the induction of Hsp genes. As indicated by the activity of PK, Modiolus barbatus maintains some aerobic capacity when acclimated to temperatures up to 24 degrees C, while further warming probably caused metabolic depression and a shift from aerobic to anaerobic metabolism. An increase in mortality occurred in parallel, during acclimation to temperatures above 24 degrees C. Our results indicate that both the biochemical stress indicators and metabolic status respond in parallel once hypoxemia becomes extreme. Comparison with our previous study of thermal limits and vertical distribution in M. galloprovincialis dwelling in shallow waters emphasizes the relevance of maintained aerobic scope over that of passive tolerance for permanent vertical zonation at higher temperatures in the field. These findings and conclusions are in line with the concept of oxygen and capacity limited thermal tolerance and the associated systemic to molecular hierarchy of thermal limitation.

The effects of examination stress on salivary cortisol, immunoglobulin A, and chromogranin A in nursing students.

This study aimed to assess the effects of examination stress on salivary cortisol, immunoglobulin A (IgA), and chromogranin A (CgA) in nursing students. Saliva samples were collected from 15 healthy females before and immediately after the one-hour examination, and two hours after the examination. Salivary cortisol, IgA, and CgA concentrations were determined by enzyme-linked immunosorbent assay. Both IgA and CgA concentrations statistically increased immediately after the examination (P < 0.05) and decreased two hours after the examination. No significant differences were observed between before and after the examination in the salivary cortisol concentration. These findings suggest that the acute stress due to the examination is associated with raised salivary IgA and CgA, but not cortisol.

[Influence of prenatal stress on free radical oxidation lipids, both proteins and activity of superoxiddismutase in neurones and glial cells of the rat brain cortex].

Processes of free radical oxidation of protein, lipids, and activity of superoxiddismutase in neurons and glial cells of the rat brain cortex in ontogenesis and after prenatal stress. Irrespective of age, the level of free radical oxidation of lipids and proteins in neurons is higher in comparison with the glia. The same was found in the study of superoxiddismutase activity. After prenatal stress, the level of free radical oxidation of lipids is reduced both in neurons, and in the glia. On the contrary, the contents of oxidation of proteins rises in neurons on the average fourfold. Activity of superoxiddismutase in animals who had suffered from prenatal stress is considerably reduced in neurons remaining unchanged in glial cells.

Decreased glucose tolerance but normal blood glucose levels in the field in the caviomorph rodent Ctenomys talarum: the role of stress and physical activity.

Hystricomorph rodents have a divergent insulin molecule with only 1-10% of the biological activity in comparison to other mammalian species. In this study, we used the subterranean rodent Ctenomys talarum as a model and performed blood glucose tolerance tests (GTTs) with trained and untrained individuals to evaluate blood glucose regulation and the possible role of physical activity as a compensatory mechanism. Additionally, we evaluated the variations in blood glucose during acute and chronic stress and gathered data in the field to evaluate natural-occurring variations in blood glucose levels. The GTTs showed that C. talarum have a diminished capacity of regulating blood glucose levels in comparison to other mammals and suggest that unexplored differences in the compensatory mechanisms, insulin structure and/or glucose transporters exist within species of hystricomorph rodents. However, blood glucose levels in the field stayed within the normal mammalian range. Physical activity did not prove to be a compensatory mechanism for blood glucose regulation. The individuals did not display important increases in blood glucose after acute stressors and managed to adequately regulate blood glucose during chronic stress. We suggest that the species may not face a selective pressure favoring a more tightly, mammalian like, capacity of regulating blood glucose levels.

Tunicamycin-induced ER stress upregulates the expression of mitochondrial HtrA2 and promotes apoptosis through the cytosolic release of HtrA2.

Recent studies provide some evidence that the HtrA2 protein is intimately associated with the pathogenesis of neurodegenerative disorders and that endoplasmic reticulum (ER) quality control and ER stress-associated cell death play critical roles in neuronal cell death. However, little is known about the intimate relationship between HtrA2 and ER stress-associated cellular responses. In the present study, we have demonstrated that the HtrA2 protein level was gradually and significantly increased by up to 10-fold in the mitochondria under tunicamycin (Tm)-induced ER stress, which eventually promoted cell death through the release of HtrA2 into the cytoplasm. Using an ecdysone-inducible mammalian expression system, we demonstrate that the extent of cell death in 293-HtrA2 cells was approximately 20 times higher under Tm-induced ER stress, indicating that the increase in the HtrA2 protein level in the mitochondria itself is necessary but not sufficient for the promotion of cell death. Taken together, these results suggest that HtrA2 may serve as a mediator of ER stress-induced apoptosis and ER-mitochondrial cross-talk in some cellular processes.

Tumor-microenvironment interactions: dangerous liaisons.

The interaction between microenvironmental components and tumor cells is bidirectional. Tumor cells and their products are capable of regulating and altering gene expression in nontumor cells residing in or infiltrating into the microenvironment and exert selective pressures on such cells, thereby shaping their phenotype. Conversely, microenvironmental components regulate gene expression in tumor cells thereby directing the tumor into one or several possible molecular evolution pathways, some of which may lead to metastasis. This review summarizes six instances in which the tumor liaises with different components of its microenvironment. These liaisons result, in most cases, in enhanced tumor progression. In these cases (responses of tumor and nontumor cells to microenvironmental stress, the interaction of the tumor with fibroblasts, endothelial cells and macrophages, the formation of the metastatic niche, and the interaction of the tumor with immunoglobulins) the tumor, directly or indirectly, alters the phenotype of its interaction partners thereby enlisting them to promote its progression. Does the tumor need all these pathways to form metastasis? Is there a hierarchy of interactions with respect to impact on tumor progression? These questions remain open. They may be answered by approaches employed in the analysis of hypercomplex systems.

The role of the glutamatergic system in posttraumatic stress disorder.

Antiglutamatergic agents, such as lamotrigine, have been used successfully for the treatment of posttraumatic stress disorder (PTSD). They could be potentially acting through the stabilization of the corticotropin-releasing factor (CRF) systems. Glutamate mediates CRF release in various brain regions involved in the pathophysiology of PTSD, antiglutamatergic agents could stabilize the CRF system and, thereby, improve the symptom complex of PTSD (reexperiencing, hyperarousal, and avoidance). The role of glutamate and CRF in PTSD and other anxiety disorders are still being elucidated. However, it is clear that the glutamatergic systems play a role in the pathophysiology of PTSD.

Differential transferrin expression in placentae from normal and abnormal pregnancies: a pilot study.

BACKGROUND: The placenta is an important site for iron metabolism in humans. It transfers iron from the mother to the fetus. One of the major iron transport proteins is transferrin, which is a blood plasma protein crucial for iron uptake. Its localization and expression may be one of the markers to distinguish placental dysfunction. METHODS: In the experimental study we used antibody preparation, mass spectrometric analysis, biochemical and immunocytochemical methods for characterization of transferrin expression on the human choriocarcinoma cell line JAR (JAR cells), placental lysates, and cryostat sections. Newly designed monoclonal antibody TRO-tf-01 to human transferrin was applied on human placentae from normal (n = 3) and abnormal (n = 9) pregnancies. RESULTS: Variations of transferrin expression were detected in villous syncytiotrophoblast, which is in direct contact with maternal blood. In placentae from normal pregnancies, the expression of transferrin in the syncytium was significantly lower (p < 0.001) when compared to placentae from abnormal ones (gestational diabetes, pregnancy induced hypertension, drug abuse). CONCLUSION: These observations suggest that in the case of abnormal pregnancies, the fetus may require higher levels of transferrin in order to prevent iron depletion due to the stress from the placental dysfunction.

Estrogen receptor-alpha and -beta regulate the human corticotropin-releasing hormone gene through similar pathways.

Corticotropin-releasing hormone (CRH) plays a central role in controlling stress response. In this study, we aimed to identify the regulatory effect of estrogen receptor (ER) on CRH and the underlying mechanism. We investigated the regulation of CRH mRNA in the BE(2)-C cell line, a human neuroblastoma cell line which express endogenous CRH. Quantitative reverse transcriptase-polymerase chain reactions showed that in the presence of estradiol overexpressing ER alpha or ER beta in BE(2)-C cells increased the transcription of CRH. Chromatin immunoprecipitation assays in this cell line also showed that both ER alpha and ER beta can be recruited to the CRH promoter with the treatment of estradiol. However, electrophoretic mobility shift assays did not show direct binding between estrogen receptors and two estrogen response elements (ERE) half sites in the CRH promoter. To clarify the regulatory mechanism, site-directed mutagenesis and reporter gene assay in the CHO cell line were used. When the ERE half sites and the cAMP regulatory element (CRE) in the CRH promoter were disrupted, ER-mediated up-regulation of CRH promoter activity reduced. Between the two ERE half sites studied, the -316 ERE half site contributed more to the constitutive CRH expression induced by ER. In summary, our results confirm the stimulation of ER alpha and ER beta on CRH expression and demonstrate the important roles of the ERE half sites and CRE for the action of ER alpha and ER beta.

Fatty acid analyses may provide insight into the progression of starvation among squamate reptiles.

Fasting-induced changes in fatty acid composition have been reported to occur within the body lipids of several types of animals; however, little is known about the changes in fatty acid profiles exhibited by reptiles subjected to prolonged fasting. This study characterizes the fatty acid profiles of six reptile species subjected to sublethal periods of fasting lasting 0, 56, 112, and 168 days. Analyses of fatty acid methyl esters (FAMEs) conducted on the total body lipids of rattlesnakes (Crotalus atrox), ratsnakes (Elaphe obsoleta), pythons (Python regius), boas (Boa constrictor), true vipers (Bitis gabonica), and monitor lizards (Varanus exanthematicus) revealed that all of the species exhibited similar characteristic changes in their fatty acid profiles during starvation stress. According to ANOVAs, the four most effective indicators of the onset of starvation were significant increases in the [1] fatty acid unsaturation index as well as ratios of [2] linoleic to palmitoleic acid, [3] oleic to palmitic, and [4] arachidonic to total fatty acid concentrations. The results of this study suggest that FAME analyses might be useful for identifying nutritional stress and/or starvation among squamate reptiles; however, forthcoming studies will be required to validate the generality of these responses. I also review the potential limitations of this approach, and suggest experiments that will be important for future applications of FAME analyses. Ultimately, it is hoped that FAME analyses can be used in conjunction with current practices as an additional tool to characterize the prevalence of starvation experienced by free-living reptiles.