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Plasma Cortisol Concentrations (plasma + cortisol_concentration)
Selected AbstractsResponses to handling and confinement stressors in juvenile great sturgeon Huso husoJOURNAL OF FISH BIOLOGY, Issue 4 2009B. Falahatkar The effects of acute stressors on physiological responses of juvenile great sturgeon or beluga Huso huso L. were investigated in two experiments. In the first experiment, fish were handled by placing them in containers at either low density (LD, one fish l,1) or high density (HD, four fish l,1) for 60 s. Concentrations of plasma cortisol, glucose and lactate were determined from blood collected at 0, 1, 3, 6 and 12 h after application of the stressor. Plasma cortisol concentrations increased after the disturbance in H. huso from both handling treatments, but changes were not significant. Plasma glucose rose significantly by 22·9 and 31·6% in LD and HD handling treatments, respectively, after 3 h. Significant increases in plasma lactate occurred within 1 h in both treatment groups, but that of the HD group was much higher. In the second experiment, fish were held at two different densities, LD (2 kg m,2 tank bottom surface area) and HD (7 kg m,2), for 8 weeks and then subjected to an aerial emersion handling stressor in a net for 60 s; blood samples were taken before handling (resting, 0 h) and at 1, 3, 6 and 9 h after handling. Plasma cortisol increased significantly in fish from the HD treatment from 8·8 ± 0·3 to 19·2 ± 2·4 ng ml,1 (mean ±s.e.) by 1 h after stress, but post-handling changes in the LD group were not significant. Significant increases in both plasma glucose and lactate were observed by 1 h in both treatment groups, with peak levels of plasma glucose evident at 3 h [69·4 ± 2·9 and 60·9 ± 1·7 mg dl,1 (mean ±s.e.) in LD and HD groups, respectively]. Plasma glucose levels were significantly higher in the LD group than in the HD group at 3 and 6 h. Post-handling haemoglobin content increased by 1 h and white blood cell numbers were reduced by 3 and 6 h in the HD treatment group compared with resting values, but changes in these blood features in the LD group were not significant. Acute handling did not affect haematocrit in either treatment. The results suggest that H. huso is relatively resistant to handling and confinement, and could tolerate normal hatchery practices associated with aquaculture. Because changes in cortisol concentrations were relatively low compared with those in most teleosts, glucose and lactate concentrations may be more useful as stress indicators in juvenile H. huso. This study also demonstrated that prior exposure to a chronic stressor, specifically high stocking density, could alter the physiological response to subsequent acute handling in H. huso. [source] Increased Cortisol Response to Surgery in Patients With Alcohol Problems Who Developed Postoperative ConfusionALCOHOLISM, Issue 8 2004Akira Kudoh Background: Patients with alcohol problems often develop postoperative confusion and have impaired cortisol, ACTH, and norepinephrine. However, the relationship between neuroendocrine responses to surgical stress and postoperative confusion remains unclear in patients with alcohol problems. Methods: Plasma cortisol, ACTH, and norepinephrine concentrations during and after surgery in 30 patients with alcohol problems and 30 control patients who underwent lower abdominal surgery were measured before the induction of anesthesia, 15 and 60 min after skin incision, 60 min after the end of surgery, the next day, and the second day after the operation. Results: Plasma cortisol concentrations (21.2 ± 4.7 ,g·dl,1) of patients with alcohol problems before anesthesia were significantly higher than 15.6 ± 4.8 ,g·dl,1 of control patients. Plasma cortisol and ACTH responses to surgery in patients with alcohol problems were not significantly increased compared with preoperative values. The incidence of postoperative confusion was significantly higher in patients with alcohol problems than that of control patients (33% vs. 3%). Plasma cortisol concentrations (29.7 ± 7.0, 31.2 ± 6.6, 30.3 ± 8.0, and 28.4 ± 6.2 ,g·dl,1) 15 and 60 min after the skin incision, 60 min after the end of surgery, and the next day after operation in postoperatively confused patients with alcohol problems were significantly higher than those of nonconfused patients with alcohol problems (23.0 ± 5.8, 22.7 ± 4.1, 22.4 ± 7.2, and 21.9 ± 5.5 ,g·dl,1). Conclusion: The cortisol response to surgical stress increases in patients with alcohol problems who develop postoperative confusion, although cortisol response to surgical stress decreases in patients with alcohol problems without postoperative confusion. [source] Changes in skin colour and cortisol response of Australian snapper Pagrus auratus (Bloch & Schneider, 1801) to different background coloursAQUACULTURE RESEARCH, Issue 5 2009Ben J Doolan Abstract A two-factor experiment was carried out to investigate the change in skin colour and plasma cortisol response of cultured Australian snapper Pagrus auratus to a change in background colour. Snapper (mean weight=437 g) were held in black or white tanks and fed diets containing 39 mg unesterified astaxanthin kg,1 for 49 days before being transferred from white tanks to black cages (WB) or black tanks to white cages (BW). Skin colour values [L* (lightness), a* (redness) and b* (yellowness)] of all snapper were measured at stocking (t=0 days) and from cages of fish randomly assigned to each sampling time at 0.25, 0.5, 1, 2, 3, 5 and 7 days. Plasma cortisol was measured in anaesthetized snapper following colour measurements at 0, 1 and 7 days. Fish from additional black-to-black (BB) and white-to-white (WW) control treatments were also sampled for colour and cortisol at those times. Rapid changes occurred in skin lightness (L* values) after altering background colour with maximum change in L* values for BW and WB treatments occurring within 1 day. Skin redness (a*) of BW snapper continued to steadily decrease over the 7 days (a*=7.93 × e,0.051 × time). Plasma cortisol concentrations were highest at stocking when fish were held at greater densities and were not affected by cage colour. The results of this study suggest that transferring dark coloured snapper to white cages for 1 day is sufficient to affect the greatest benefit in terms of producing light coloured fish while minimizing the reduction in favourable red skin colouration. [source] Postoperative elevated cortisol excretion is not associated with suppression of 6-sulfatoxymelatonin excretionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2005J. Derenzo This study tests the hypothesis that elevated postoperative excretion of cortisol is associated with suppression of the nocturnal excretion of 6-sulfatoxymelatonin, the chief metabolite of the circadian hormone, melatonin. Postoperative patients demonstrate circadian rhythm disturbances and suppression of nocturnal melatonin plasma concentration. Since the nocturnal surge in melatonin concentration in normal volunteers is time-locked to the circadian nadir of cortisol concentration, perhaps the attenuation of the nocturnal melatonin surge in postoperative patients results from prolonged elevation in the plasma cortisol concentration. In this observational study performed in 21 patients having unilateral hip or knee arthroplasty, urine was collected every 4 h for the first 48 h after surgery for measurement of urinary 6-sulfatoxymelatonin (EIA) and free cortisol (RIA) excretion. The total (P < 0.05) and peak (P < 0.02) nocturnal 6-sulfatoxymelatonin excretions were lower on the first than the second postoperative night. The nocturnal cortisol nadir preceded the 6-sulfatoxymelatonin surge in 20% of the subjects on night 1 and in 75% of the subjects on night 2. The lack of a consistent relationship between the magnitude or timing of cortisol excretion and 6-sulfatoxymelatonin excretion suggests that cortisol does not mediate postoperative 6-sulfatoxymelatonin suppression. [source] Development of cardiovascular function in the horse fetusTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005Dino A. Giussani In mammals, the mechanisms regulating an increase in fetal arterial blood pressure with advancing gestational age remain unidentified. In all species studied to date, the prepartum increase in fetal plasma cortisol has an important role in the maturation of physiological systems essential for neonatal survival. In the horse, the prepartum elevation in fetal cortisol and arterial blood pressure are delayed relative to other species. Hence, the mechanisms governing the ontogenic increase in arterial blood pressure in the horse fetus may mature much closer to term than in other fetal animals. In the chronically instrumented pony mare and fetus, this study investigated how changes in fetal peripheral vascular resistance, in plasma concentrations of noradrenaline, adrenaline and vasopressin, and in the maternal-to-fetal plasma concentration gradient of oxygen and glucose relate to the ontogenic changes in fetal arterial blood pressure and fetal plasma cortisol concentration as term approaches. The data show that, towards term in the horse fetus, the increase in arterial blood pressure occurs together with reductions in metatarsal vascular resistance, elevations in plasma concentrations of cortisol, vasopressin, adrenaline and noradrenaline, and falls in the fetal : maternal ratio of blood P and glucose concentration. Correlation analysis revealed that arterial blood pressure was positively related with plasma concentrations of vasopressin and noradrenaline, but not adrenaline in the fetus, and inversely related to the fetal : maternal ratio of blood P, but not glucose, concentration. This suggests that increasing vasopressinergic and noradrenergic influences as well as changes in oxygen availability to the fetus and uteroplacental tissues may contribute to the ontogenic increase in fetal arterial blood pressure towards term in the horse. [source] Adrenocorticotropic hormone-induced secretion of cortisol in goats is inhibited by androgenANIMAL SCIENCE JOURNAL, Issue 1 2006Yuko MAEJIMA ABSTRACT In a previous study, it was found that there are sex differences in goats with respect to the levels of cortisol secretion induced by transportation stress. We also found that treatment of castrated male goats with dihydrotestosterone (DHT) suppressed the increase in plasma cortisol concentration following transportation, but did not suppress the secretion of adrenocorticotropic hormone (ACTH). This suggests that androgen might block ACTH - induced cortisol secretion. In order to examine this hypothesis, the effects of androgen on ACTH-induced cortisol secretion in goats were investigated. First, castrated male goats were treated with testosterone (T), DHT or cholesterol (cho) for 21,25 days. Cho was used as a control for T and DHT treatment. Then, plasma cortisol concentrations were compared among the hormonal treatments after ACTH injection. Subsequently, the distribution of androgen receptors in the caprine adrenal gland was investigated. There were no differences in the basal cortisol concentrations among the hormonal treatments. However, plasma cortisol concentrations after ACTH injection were significantly lower in T - and DHT - treated goats than in cho - treated goats. Androgen receptors were present in 60% of the cells in the zonae fasciculata and reticularis of the adrenal cortex, the regions that secrete glucocorticoids. These results suggest that androgen may act directly on the adrenal cortex to suppress cortisol secretion induced by ACTH. [source] Rearing environment and hypothalamic-pituitary-adrenal regulation in young rhesus monkeys (Macaca mulatta)DEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2005John P. Capitanio Abstract A mammal's early social environment has important regulatory effects on its behavior and physiology, and this is especially true for regulation of the hypothalamic-pituitary-adrenal (HPA) system. The present study was designed to test hypotheses that various aspects of the social environment are important influences on HPA regulation. Seven hundred seventy eight, 3- to 4-month-old rhesus monkeys were studied as part of a standardized, 24-hr biobehavioral assessment program, which included blood sampling to determine plasma cortisol concentrations. Results indicate that nursery-rearing results in a reduced cortisol set-point for the HPA system, and, for nursery-reared (NR) animals, more peer exposure during infancy is associated with a higher set-point. Age and sex differences during this period were evident but small in magnitude. These data demonstrate the important regulatory role of the social environment on nonhuman primate physiology and suggest caution in assuming that differences between individuals' cortisol levels reflect only differences in perceptions of the "stressfulness" of events. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46:318,330, 2005. [source] Effect of Maternal Nutrient Restriction in Early Gestation on Responses of the Hypothalamic-Pituitary-Adrenal Axis to Acute Isocapnic Hypoxaemia in Late Gestation Fetal SheepEXPERIMENTAL PHYSIOLOGY, Issue 1 2000Paul Hawkins Epidemiological and experimental evidence suggests that maternal undernutrition during pregnancy may alter development of fetal organ systems. We have demonstrated previously that fetal hypothalamic-pituitary-adrenal (HPA) axis responses to exogenous corticotropin-releasing hormone (CRH) + arginine vasopressin (AVP), or adrenocorticotrophin hormone (ACTH), are reduced in fetuses of mildly undernourished ewes. To examine these effects further we tested HPA axis responses to acute isocapnic hypoxaemia in fetal sheep at 114-129 days gestation (dGA), following 15% reduction in maternal nutritional intake between 0 and 70 dGA. Fetuses from control (C) and nutrient-restricted (R) ewes were chronically catheterised and plasma ACTH and cortisol responses were determined at 114-115, 120-123 and 126-129 dGA during hypoxaemia (1 h) induced by lowering the maternal inspired O2 fraction (FI,O2). Basal plasma cortisol concentrations and HPA axis responses at 114-115 and 120-123 dGA did not differ between C and R fetuses. At 126-129 dGA, both plasma ACTH (P < 0.01) and cortisol (P < 0.05) responses were smaller in R fetuses compared to C fetuses. Fetal blood gas status, fetal body weight, body proportions and organ weights did not differ between the groups. We conclude that mild maternal undernutrition alters development of the fetal HPA axis producing a reduction in pituitary and adrenal responsiveness to endogenous stimuli. [source] Stress Hormone Dysregulation at Rest and After Serotonergic Stimulation Among Alcohol-Dependent Men With Extended Abstinence and ControlsALCOHOLISM, Issue 5 2001Robert M. Anthenelli Background: Alcohol dependence has been associated with long-lasting alterations in limbic-hypothalamic-pituitary-adrenal (LHPA) axis and serotonin (5-hydroxytryptamine [5-HT]) function. Other conditions that are associated with alcoholism (cigarette smoking and antisocial personality disorder [ASPD]) have been linked with disturbances in these interrelated systems. We evaluated the stress hormone response to 5-HTergic stimulation in alcohol-dependent men with extended abstinence (average abstinence duration, 4.3 months) and controls to determine the relative contributions of alcoholism, cigarette smoking, and ASPD on baseline and provoked plasma cortisol and adrenocorticotropin hormone (ACTH) concentrations. Methods: One hundred nine alcohol-abstinent men with alcohol dependence (62%), habitual smoking (70%), and ASPD (43%) received d,l-fenfluramine (100 mg po) in a randomized, double-blind, placebo-controlled, crossover trial. The group of recovering alcohol-dependent individuals included abstinent primary alcohol-dependent men and alcohol-dependent men with ASPD, whereas the group of non-alcohol-dependent men comprised healthy controls and non-alcohol-dependent men with ASPD. Plasma cortisol and ACTH levels were obtained at AM baseline and at half-hour intervals after drug administration. Subjective ratings of drug response and physiological measures were also obtained at baseline and every 30 min. Results: Abstinent alcohol-dependent men had significantly lower (approximately 20%) AM baseline plasma cortisol concentrations than non-alcohol-dependent men on both challenge days; however, no differences between the groups were observed with regard to resting AM plasma ACTH levels. After adjusting for these baseline differences, recovering alcohol-dependent men (area under curve = 35.6 ± 37.4 [,g/dl] × min) had a twofold greater cortisol response to fenfluramine than non-alcohol-dependent men (area under curve = 17.5 ± 32.5 [,g/dl] × min) (F= 5.1;df= 1,105;p < 0.03). The elevated cortisol response, which occurred primarily along the descending limb of the response curve, was paralleled by a nonsignificant statistical trend for alcohol-dependent men to also exhibit a greater ACTH response to fenfluramine at the 210-min (p < 0.07) and 240-min (p < 0.09) time points as compared with non-alcohol-dependent men. Cigarette smoking and ASPD did not affect hormonal responses, nor could the groups' subjective ratings and physiological measures be distinguished. Conclusions: Alcohol-dependent men with extended abstinence differed from age- and race-matched non-alcohol-dependent men in resting AM and fenfluramine-induced plasma cortisol levels. This dysfunction in glucocorticoid homeostatic mechanisms was associated with alcoholism and not with smoking or ASPD. We also observed a nonsignificant statistical trend for plasma ACTH levels to be elevated among alcohol-dependent men along the descending limb of the response curve. Alcohol-dependent men seemed to have inherited or acquired damage to 5-HT-regulated LHPA axis function, the precise mechanisms and sites of which remain to be determined. [source] Adrenocorticotropic hormone-induced secretion of cortisol in goats is inhibited by androgenANIMAL SCIENCE JOURNAL, Issue 1 2006Yuko MAEJIMA ABSTRACT In a previous study, it was found that there are sex differences in goats with respect to the levels of cortisol secretion induced by transportation stress. We also found that treatment of castrated male goats with dihydrotestosterone (DHT) suppressed the increase in plasma cortisol concentration following transportation, but did not suppress the secretion of adrenocorticotropic hormone (ACTH). This suggests that androgen might block ACTH - induced cortisol secretion. In order to examine this hypothesis, the effects of androgen on ACTH-induced cortisol secretion in goats were investigated. First, castrated male goats were treated with testosterone (T), DHT or cholesterol (cho) for 21,25 days. Cho was used as a control for T and DHT treatment. Then, plasma cortisol concentrations were compared among the hormonal treatments after ACTH injection. Subsequently, the distribution of androgen receptors in the caprine adrenal gland was investigated. There were no differences in the basal cortisol concentrations among the hormonal treatments. However, plasma cortisol concentrations after ACTH injection were significantly lower in T - and DHT - treated goats than in cho - treated goats. Androgen receptors were present in 60% of the cells in the zonae fasciculata and reticularis of the adrenal cortex, the regions that secrete glucocorticoids. These results suggest that androgen may act directly on the adrenal cortex to suppress cortisol secretion induced by ACTH. [source] Whole-body corticosteroid and plasma cortisol concentrations in larval and juvenile Atlantic cod Gadus morhua L. following acute stressAQUACULTURE RESEARCH, Issue 13 2006William King V Abstract Methods were developed to assess whole-body immunoreactive corticosteroid concentrations (IRC) and plasma levels of cortisol in Atlantic cod subjected to several common, acute stressors. A measurable corticosteroid stress response was observed at the first sampling in whole bodies of 8-day post-hatch (dph) larvae. Two groups of juveniles (,5 and 30 g) were subjected to a 30 s net stressor and whole-body IRC and plasma cortisol levels were determined. Post-stressor IRC in smaller fish rose approximately 14-fold, peaked at 1 h, were sustained for 3,6 h and returned to pre-stressor levels within 24 h. Post-stressor plasma cortisol levels in larger fish rose approximately 18-fold, peaked at 0.5,1 h, were sustained for 1,3 h and then returned to near pre-stressor levels after 24 h. Immunoreactive corticosteroid concentrations appeared to remain elevated longer than plasma cortisol levels suggesting that steroids other than cortisol were contributing to total immunoreactivity in homogenates. Juveniles exposed to either a grading procedure or high density transport had maximal IRC and plasma cortisol levels within 90 min which returned to pre-stressor levels within 24,72 h. A reduction in water salinity (20 g L,1) did not moderate the corticosteroid response in juveniles. The results show that Atlantic cod respond to common, acute stressors in a manner similar to other teleosts. Whole-body homogenates can be used to identify changes in IRC in response to acute stress in cod with the caveat that recovery IRC may differ from plasma cortisol concentrations. [source] ORIGINAL ARTICLE: Characteristics of plasma NOx levels in severe sepsis: high interindividual variability and correlation with illness severity, but lack of correlation with cortisol levelsCLINICAL ENDOCRINOLOGY, Issue 3 2010J. T. Ho Summary Objectives, Nitric oxide (NO) concentrations are elevated in sepsis and their vasodilatory action may contribute to the development of hyperdynamic circulatory failure. Hydrocortisone infusion has been reported to reduce nitric oxide metabolite (NOx) concentrations and facilitate vasopressor withdrawal in septic shock. Our aim was to determine whether NOx concentrations relate to (i) protocol-driven vasopressor initiation and withdrawal and (ii) plasma cortisol concentrations, from endogenous and exogenous sources. Demonstration of a relation between NOx, cortisol and vasopressor requirement may provide an impetus towards the study of hydrocortisone-mediated NOx suppression as a tool in sepsis management. Design, A prospective study of 62 patients with severe sepsis admitted to the intensive care unit. Measurements, Plasma NOx, total and free cortisol, and corticosteroid-binding globulin (CBG) concentrations were measured and related to protocol-driven vasopressor use for 7 days following admission. Results, Patients who developed septic shock (n = 35) had higher plasma NOx, total and free cortisol, and lower CBG concentrations than the nonseptic shock group (n = 27). Cortisol, CBG and NOx concentrations correlated with illness severity. Free cortisol, and to a lesser extent total cortisol, but not NOx concentrations, predicted septic shock. NOx concentrations were higher in nonsurvivors, and the concentrations were characteristically stable within individuals but marked interindividual differences were only partly accounted for by illness severity or renal dysfunction. NOx concentrations did not correlate with cortisol, did not relate to vasopressor requirement and did not fall after standard dose hydrocortisone, given for clinical indications. Conclusions, Nitric oxide production increased with sepsis severity but did not correlate with plasma cortisol or vasopressor requirement. NOx levels were not suppressed reproducibly by hydrocortisone. High interindividual variability of NOx levels suggests that absolute NOx levels may not be a suitable target for individualized hydrocortisone therapy. [source] | ||||||||||||||||