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Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The direct effect of cortisol treatment on carp neutrophil viability was examined in vitro. Cortisol treatment caused an inhibition of neutrophil apoptosis. The effect was blocked by glucocorticoid receptor blocker RU486, showing that rescue from apoptosis was receptor mediated. Using binding studies with radioactive cortisol, a single class of glucocorticoid receptors was detected with high affinity (Kd = 2.6 nM) and low capacity (497 receptors/cell) for cortisol binding. Both in vitro and in vivo cortisol treatment did not affect neutrophil respiratory burst activity. These data indicate that cortisol can augment the supply of functional neutrophilic granulocytes in conditions of acute stress, which may be essential for survival, since phagocytes form the first line of defence against micro-organisms.
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PMID:Cortisol inhibits apoptosis in carp neutrophilic granulocytes. 987 37

The human response to surgical stress is characterized by massive release of neuroendocrine hormones, provoking catabolism, thermogenesis, and hyperglycemia. Considering the possible adverse outcomes of excessive stress hormones, understanding various components of the stress response may improve management of postoperative morbidity. Leptin, initially described as an adipocyte-derived signaling factor, may also play an important role in regulating the hypothalamo-pituitary-adrenocortical axis. In phase I, plasma leptin and cortisol were measured in women before, during, and after total abdominal hysterectomy. The anesthetic technique was strictly controlled, balanced anesthesia. In phase II, plasma leptin and cortisol levels were measured in cardiac surgery patients. These subjects were anesthetized with a high dose opioid technique that blunts the intraoperative surgical stress response. In phase I, mean leptin levels did not change over the week before surgery, had a maximal decrease to 49% of baseline 2 h after surgery, and increased to just above baseline 24 h postoperatively. Cortisol was 176% of the baseline just before surgery, peaked at 2 h after surgery (383%), and remained elevated 24 h (200%) and 48 h (165%) after surgery. During the first 2 h of surgery, the decrease in leptin parallels the increase in cortisol. In phase II, high dose fentanyl limited both the cortisol increase and the leptin decrease; thus, the ratio of cortisol increase to leptin decrease was similar for the cardiac patients and the hysterectomy patients. These data indicate that leptin has a role in the surgically induced acute stress response in humans. Early in surgery the decrease in leptin parallels the increase in cortisol. This suggests a possible relationship between the neurobiology of these two systems, which could have important implications for regulation of the neuroendocrine response to surgical stress.
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PMID:Leptin and the perioperative neuroendocrinological stress response. 1040 18

Prolonged stress is known to impair reproduction. It has been proposed that reproduction will also be impaired when a severe acute stress occurs during a period of elevated plasma concentrations of oestradiol, such as during the follicular phase of the oestrous cycle. In this experiment, we hypothesised that repeated acute and sustained elevation of cortisol would suppress the secretion of LH in ovariectomised pigs and that these effects would be enhanced in the presence of oestradiol negative feedback. Cortisol (or vehicle) was administered 12 hourly to ovariectomised pigs (n=6/treatment) for 8 days in the absence of oestradiol treatment and for a further 8 days during treatment with oestradiol. Vehicle was administered to 'control' pigs, 10 or 20 mg cortisol was administered i.v. to pigs to produce 'repeated acute' elevation of cortisol and 250 mg cortisol was administered i.m. to pigs to give a 'sustained' elevation of cortisol. Both before and during treatment with oestradiol, plasma concentrations of LH were monitored on the day before treatment, on the 4th and 8th days of treatment and following an i.v. injection of GnRH at the end of the 8th day of treatment. The repeated acute elevation of cortisol did not impair any parameters of LH secretion (i.e. mean plasma concentrations of LH, pulse amplitude or frequency, pre-LH pulse nadir or the LH response to GnRH) in the absence or in the presence of oestradiol. In contrast, when the elevation of cortisol was sustained, the mean plasma concentrations of LH and the pre-LH pulse nadir were significantly (P<0.05) lower on the 8th day of treatment than on the day before treatment and on the 4th day of treatment. Nevertheless, no other parameters of LH secretion were affected and these effects only occurred in the absence (not in the presence) of oestradiol. In conclusion, cortisol needed to be elevated for more than 4 days to impair the secretion of LH, and oestradiol did not enhance the impact of cortisol on LH secretion in ovariectomised pigs.
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PMID:Inhibition of the secretion of LH in ovariectomised pigs by sustained but not repeated acute elevation of cortisol in the absence but not the presence of oestradiol. 1058 21

Sympathetic activation leading to increased levels of blood catecholamines, and stimulation of the hypothalamic-pituitary inter-renal axis leading to increased cortisol, are difficult to avoid when handling animals. Yet, in research on effects of acute stress, elicitation of such responses must be minimized in the control groups. The work examines means to achieve a minimally disturbed state in rainbow trout (Oncorhynchus mykiss). Level of arousal was determined by adrenaline and cortisol concentrations in plasma, and by the spleen:somatic index. Fish were prepared for bleeding by rapid capture and concussion, by infusion of anesthetic into the undisturbed home tank, by confinement in black boxes, or by being fed alpha- and beta-receptor antagonists. Even when done quickly, netting and concussion yielded fish with ca. 200-pmol adrenaline/ml plasma. Cortisol was elevated (to > 10 ng/ml) within 30 s of stress initiation. Surreptitious infusion of anesthetic (2-phenoxyethanol, PE) into tanks yielded fish with lower adrenaline levels (means 19.34 and 19.58 pmols/ml in home tank and black boxes, respectively). Among fish given phentolamine and propranolol, spleen:somatic indices and plasma adrenaline were higher than in diet controls, whether undisturbed or stressed, indicative of successful receptor blockade. Since careful infusion of 2-PE yielded the lowest adrenaline levels, and requires no special apparatus, it is the method of choice for obtaining minimally stressed fish.
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PMID:Modulation of stress hormones in rainbow trout by means of anesthesia, sensory deprivation and receptor blockade. 1066 82

Although stress is linked to asthma exacerbation, underlying mechanisms are unclear. Given the shared relevance to stress and asthma, select neuroendocrine and immune responses to acute stressors and their impact on pulmonary function were examined, comparing responses between students with (n = 20) and without childhood asthma (n = 16). Students were challenged with speech and math tasks. Blood samples were collected five times: before tasks, immediately after first and second tasks, and 15 and 60 minutes posttasks. Pulmonary function was measured four times, excluding midtask point. Stress reactivity patterns did not differ between two groups. However, all measures showed significant changes across the challenge. Plasma epinephrine and norepinephrine rose during tasks and declined after tasks, p < .001. Cortisol mainly declined after tasks, p = .03. Leukocyte count increased during tasks with increased lymphocyte percentage that declined after tasks, while neutrophil percentage changed opposite to lymphocytes, p < .001 each. Changes in pulmonary function were significant, p < .05, but were not predicted by the magnitude of neuroendocrine and immune changes. Instead, neuroendocrine and immune levels explained 33%-51% of variance on concurrent pulmonary function. Findings indicate that acute stress induces significant neuroendocrine and immune changes that can affect pulmonary function. However, stress reactivity needs further investigation with larger samples and people with a more severe form of asthma.
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PMID:Neuroendocrine and leukocyte responses and pulmonary function to acute stressors. 1125 38

Siberian hamsters breed during the long days of spring and summer when environmental conditions (e.g., ambient temperatures, food availability) are favorable for reproduction. Environmental conditions may also influence the onset and severity of infection and disease, and photoperiodic alterations in immune function may comprise part of a repertoire of seasonal adaptations to help survive winter. In order to test the hypothesis that animals use day length to anticipate seasonal stressors and adjust immune function, we measured antigen-specific delayed-type-hypersensitivity (DTH) responses in the skin of male and female hamsters during long, "summer-like," or short, "winter-like" days, at baseline and following acute restraint stress. Sex steroid hormones were lower, and cortisol was higher, in males and females during short days. Baseline DTH was enhanced in short- compared to long-day males, and acute stress augmented this effect. In contrast, photoperiod alone did not influence the DTH response in females. As predicted, female hamsters exhibited significantly higher DTH responses than males during long days, but not during short days. However, this enhancement was observed in acutely stressed females only. Cortisol concentrations were significantly higher at baseline in females, and increased more in response to stress, compared to males in both photoperiods. These results suggest that photoperiod provides a useful cue by which stressors in the environment may be anticipated in order to adjust immune function. Furthermore, interactions among reproductive status and stress responses appear to mediate the expression of sex differences in immune responses in hamsters.
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PMID:Sex differences in photoperiodic and stress-induced enhancement of immune function in Siberian hamsters. 1458 38

This study tested the hypotheses that: (1) either acute stress induced by Burdizzo castration, or cortisol infusion would modulate plasma glucose, insulin and growth hormone (GH) concentrations; and (2) immune modulation induced by cortisol would be dependent on the pattern, intensity and duration of circulating cortisol concentrations. Fifty 9.2-month-old Holstein x Friesian bulls (232 +/- 2.0 kg) were blocked by weight and randomly assigned to one of five treatments (n = 10 per treatment): (1) sham handled control; (2) Burdizzo castration; (3) hydrocortisone infusion to mimic the castration-induced secretion pattern of cortisol; (4) hourly pulse infusion of hydrocortisone; and (5) sustained infusion of hydrocortisone for 8h. Blood samples were collected intensively on day 0, and weekly from days 1 to 35. Castration acutely increased plasma cortisol, GH and haptoglobin concentrations, suppressed lymphocyte in vitro interferon-gamma (IFN-gamma) production, but had no effect on plasma glucose and insulin concentrations. Cortisol infusion to simulate the castration-induced secretion pattern of cortisol, and pulse infusion of cortisol did not suppress the IFN-gamma production. A sustained infusion of cortisol resulted in the transient suppression of IFN-gamma production. Moreover, the sustained cortisol infusion resulted in increased plasma glucose, insulin and GH concentrations. The overall 14-day feed intakes and 35-day growth rates were not affected by treatments. In conclusion, cortisol infusion to induce immune suppression in vivo occurred only at pharmacological doses. Within physiological ranges, cortisol was not associated with the suppression of immune function, indicating that during castration cortisol per se is not responsible for the suppression of in vitro IFN-gamma production.
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PMID:Effect of cortisol infusion patterns and castration on metabolic and immunological indices of stress response in cattle. 1506 25

Psychologically stressful events have been reported to elevate nerve growth factor (NGF) serum concentrations. NGF and cortisol serum concentrations were measured in 20 healthy male volunteers before (3 p.m.) and after (5 p.m.) an academic oral presentation and on a control day. Cortisol showed a significant overall change (p=0.001), i.e. cortisol serum concentrations were increased on the lecture day at 3 p.m. (p=0.007; 155%) and at 5 p.m. (p=0.001; 175%) as compared with the control day. In contrast to cortisol no significant differences among the four serum NGF measurements was detected (Chi-quadrat 2.94, df=3, p=0.401), i.e. the NGF serum concentrations remained unchanged on the lecture day at 3 p.m. (p=0.279) and at 5 p.m. (p=0.627) as compared with the control day. We conclude that NGF serum levels do not change during acute stress, at least after this type of stressor.
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PMID:Measurement of nerve growth factor serum concentration in a psychologically stressful situation in men. 1520 31

The objective of this study was to evaluate fish response to acute stress induced by confinement after capture. Because of the previously reported presence of chemical compounds in the Tajo River basin where the study samplinig took place, an exposure biomarker to organic chemicals (retinol) was used. Cortisol and glucose were used as stress biomarkers. Plasma levels of cholesterol were used as lipidic metabolism indicators, and retinol level was used as a specific exposure biomarker. A reference site was established along 300 km of the Tajo River, and nine sampling sites were selected on the basis of whether various human activities and hydrographic characteristics were present. A total of 55 carp (Cyprinus carpio) and 52 barbel (Barbus bocagei) were examined. Cortisol and glucose levels were considered acceptable indicators of the response of the fish to induced stress. In the barbel, plasma retinol levels decreased at two of the sampling sites indicating possible exposure to organic compounds. The overall evaluation of these parameters enabled us to identify three sampling sites at which more studies should be carried out. The possible relationship between the health state of wild fish and the presence of organic compounds or sources of pollution was considered.
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PMID:A survey of potential stressor-induced physiological changes in carp (Cyprinus carpio) and barbel (Barbus bocagei) along the Tajo River. 1579 31

Stress increases plasma and brain concentrations of corticosteroids and neuroactive steroids. Cortisol is the most important stress hormone in the hypothalamic pituitary adrenocortical system. However, significant amounts of the mineralocorticoid deoxycorticosterone are also released during stress. Deoxycorticosterone undergoes biotransformation to allotetrahydrodeoxycorticosterone, a neuroactive steroid with anxiolytic and anticonvulsant properties. Our studies indicate that the anticonvulsant activity of deoxycorticosterone is mediated by its conversion to allotetrahydrodeoxycorticosterone, which is a potent positive allosteric modulator of GABA(A) receptors. Although the role of allotetrahydrodeoxycorticosterone within the brain is undefined, recent studies indicate that stress induces increases in allotetrahydrodeoxycorticosterone to levels that can activate GABA(A) receptors. These results might have significant implications for human stress-sensitive conditions such as epilepsy, panic disorder, post-traumatic stress disorder, and major depression. In epilepsy, a role for adrenal allotetrahydrodeoxycorticosterone in seizure susceptibility has been suggested. Recent preclinical studies indicate a role of neuroactive steroids in ethanol actions. Although these studies provide a better understanding of the role of allotetrahydrodeoxycorticosterone and related neuroactive steroids in acute stress, further studies are clearly warranted to ascertain the specific role of neuroactive steroids in the pathophysiology of chronic stress and related brain conditions.
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PMID:Physiological role of adrenal deoxycorticosterone-derived neuroactive steroids in stress-sensitive conditions. 1632 48


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