• Korean Journal of Psychosomatic Medicine
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• v.3 no.2
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• pp.159-165
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• 1995

The primary aim of this study is to find out the relationship of examination stress with serum cortisol and prolatin levels. 20 male medical students participated in this study. Global assessment of recent stress (GARS) scale and SCL-90R were used to measure stress perception and psychopathology. Radioimmunoassay was used to assess serum cortisol and prolactin. Serum cortisol level was significantly higher during exam period than during nonexam period. However, there was no significant difference in serum prolactin level between the two periods. In psychopathology, only interpersonal sensitivity had a significantly negative correlation with serum cortisol level during exam period. On the other hand, stress perception had no significant correlation with serum cortisol and prolactin levels during each of exam and non-exam period. The results suggest that cortisol is more likely to be associated with psychological stress such as examination than prolactin, and that specific psychopathology such as interpersonal sensitivity is more likely to be associated with lower serum cortisol level.

• Journal of Nutrition and Health
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• v.23 no.4
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• pp.229-236
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• 1990

We made S.D male rats eat 3.6% tryptophan(trp) or tyrosine(thr)-enriched diet for 4 days and measured the trp or tyr use in serum of stressed rats as well as cortisol, glucose and free fatty acid(ffa) changes in serum. When control group had received stress treatment, their tyr level has dropped significantly but no changes in trp level and their cortisol, glucose, ffa levels in serum were increased significantly all together. Trp-enrichment alone can't change serum cortisol and ffa levels but trp pools in serum and brain enlarged by dietary enrichment. Trp-enriched group's serum glucose concentration was significantly lower than control-dieted group. When trp-enriched group received stress treatment, their responses to stress were different from control-dieted group. Serum trp concentration of trp-enriched-with-stress group has dropped significantly and cortisol level was increased significantly but not as much as control-dieted-with-stress group. Glucose and ffa levels of trp-enriched-with-stress group did not increase at all. Tyr-enriched group has also larger serum pool of tyr and lowest basal cortisol level in all three diet group. tyr-enriched group's and ffa levels were in normal range and those responses to stress were same pattern with control diet group. Most importantly in tyr-enriched-with-stress group, only slight but not significant increase of cortisol level was shown.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.35-41
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• 2010

Among the dogs boarding at an animal hospital, 10 dogs each were selected as a free boarding group and a kennel boarding group. Each group was further divided into 5 puppies and 5 mature dogs to examine the changes in their serum cortisol concentrations during boarding (5 days). We collected blood at day 8 and then analyzed the blood corpuscles, ran a biochemical serum test, and an additional urine test before boarding to check their health status. After collecting the dog's blood at 9:00 am, 3:00 pm, and 9:00 pm, we analyzed the cortisol concentration by the radioimmunoassay (RIA) method. The daily serum cortisol concentration at 9:00 am, 3:00 pm, and 9:00 pm, had a circadian rhythm during both the free and kennel boarding periods in both puppies and adults. Furthermore, the average daily serum cortisol concentration was significantly increased during the 1st, 2nd, and 3rd day after free boarding in the puppy group (P < 0.01). In adults from the free boarding group, the serum cortisol concentration dramatically increased on the 1st day (P < 0.01), as well as on the 2nd and 3rd day (P < 0.05). Interestingly, the average daily serum cortisol concentration was significantly increased on the 1st day after kennel boarding as well as during the entire period of kennel boarding in the puppy group (P < 0.05). In the adult kennel boarding group, serum cortisol concentration was significantly increased during the whole kennel boarding period (P < 0.01). An interesting result was that circadian rhythmicity in the sum of the daily serum cortisol concentrations was present in the free boarding group, but not in the kennel boarding group in both puppies and adults. In summary, cortisol was released depending on the degree of stress in free and kennel boarded dogs. Taken together, these results suggest that cortisol, a stress hormone, should be maintained at physiological concentrations in a circadian rhythm when the animals are hospitalized.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.711-717
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• 1993

This study was performed to examine the charges of serum cortisol concentrations on the normal conditions in Korean native goats by enzyme-linked immunosorbent assay(ELISA). The Korean native goats were 4 to 30 months old and weighted 6.0 to 28kg. The goats were allowed ad libitum access to water and food. To minimize the stress with handing and blood sampling, animals were adapted for 2 weeks before the experiment. After adaptation, intravenouse catheter was inserted left intact a jugular vein of 6 goats and blood samples were done 2~3 days later. Experimental animals were divided into 2 groups which was non-catheterized and catheterized group in order to examine the effect for changes of serum concentration and circadian rhythm of cortisol. The results were obtained as follows ; The sensitivity of serum cortisol concentration was $20pg/m{\ell}$. The intra-assay and inter-assay coefficient of variation were below 2.5% and 5%, respectively. Serum concentration of cortisol was more higher in noo-catheterized group$(32.84{\pm}16.78ng/m{\ell})$ than catheterized group$(23.20{\pm}10.29ng/m{\ell})$. The difference according to months old in serum concentration of cortisol was the more higber on 4~6 than 7~12 and lowest over 12 months old. A circadian rhythm in the serum concentration of cortisol in Korean native goats was not found significantly with 2 hours sampling intervals.

• Safety and Health at Work
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• v.10 no.1
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• pp.109-113
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• 2019

Background: In both developed and developing countries, noise is regarded as the most common occupational hazard in various industries. The present study aimed to examine the effect of sound pressure level (SPL) on serum cortisol concentration in three different times during the night shift. Methods: This case-control study was conducted among 75 workers of an industrial and mining firm in 2017. The participants were assigned to one of the three groups (one control and two case groups), with an equal number of workers (25 participants) in each group. Following the ISO 9612 standard, dosimetry was adopted to evaluate equivalent SPL using a TES-1345 dosimeter. The influence of SPL on serum cortisol concentration was measured during the night shift. The serum cortisol concentration was measured using a radioimmunoassay (RIA) test in the laboratory. Repeated measure analysis of variance and linear mixed models were used with ${\alpha}=0.05$. Results: The results indicated a downward trend in the serum cortisol concentration of the three groups during the night shift. Both SPL and exposure time significantly affected cortisol concentration (p < 0.0001, p < 0.0001). Conversely, age and body mass index had no significant influence on cortisol concentration (p = 0.360, p = 0.62). Conclusion: Based on the obtained results, increasing SPL will lead to enhancement of serum cortisol concentration. Given that cortisol concentration varies while workers are exposed to different SPLs, this hormone can be used as a biomarker to study the effect of noise-induced stress.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.1-7
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• 1998

The present study was performed to evaluate circadian rhythm of blood nortisol concentration and change of blood cortisol concentration by various stress type in domestic cats. The ELISA kit for cortisol measurement was evaluated on the effective assay range, day to day variation, within-run variation and accuracy. The results were 1-1,000 ng/ ml, 0.7-5.9%, 0.9-4.5% and 98%, respectively. The circadian rhythm of serum cortisol concentration is presented in cats. Change of serum cortisol concentration was also examined with several stressors, stimulation with hamster as a prey, beep electronic sounds, vehicle transportation and unfamiliar environment. Unfamiliar environment showed most remarkable change in serum cortisol level.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.450-455
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• 2010

Background: High cortisol levels are frequently observed in patients with severe infections are of prognostic value in sepsis. The aim of this study was to evaluate the clinical usefulness of serum cortisol in assessment for the severity of community-acquired pneumonia (CAP). Methods: This study analyzed the results of 52 CAP subjects admitted in Changwon Fatima Hospital between July 2008 to May 2010. Total serum cortisol, infection markers such as C-reactive protein (CRP), procalcitonin (PCT) and CURB (Confusion, Uremia, Respiratory rate, Blood pressure)-65 were examined retrospectively. Results: In clinically unstable subjects on admission day 4, baseline serum cortisol, CURB-65, and CRP were elevated significantly compared to those of stable subjects. Area under curve (AUC) of cortisol, CRP, and CURB-65 from ROC curves were 0.847, 0.783, and 0.724 respectively. In the subjects with serum cortisol ${\geq}22.82{\mu}g/dL$, CRP, PCT, CURB-65 score, and mortality were significantly elevated. Conclusion: These findings suggest that measurement of serum cortisol in early stage may provide helpful information in the assessment of CAP severity.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1662-1668
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• 2015

We investigated differences between effects of natural- and bucket-suckling methods on basal serum oxytocin (OT) and cortisol concentrations, and the effect of OT concentration on affiliative and investigative behavior of calves to a novel object. Ten Japanese Black calves, balanced with birth order, were allocated evenly to natural-suckling (NS) and bucket suckling (BS) groups. Blood samples were collected at the ages of 1 and 2 months (1 week after weaning) calves, and serum OT and cortisol concentrations were measured using enzyme-linked immunosorbent assay and enzymeimmunoassay tests, respectively. Each calf at the age of 2 months (2 weeks after weaning) was released into an open-field with a calf decoy, and its investigative and affiliative behaviors were recorded for 20 minutes. In 1-month-old calves, the basal serum OT concentration ($25.5{\pm}4.9$ [mean${\pm}$standard deviation, pg/mL]) of NS was significantly higher than that of BS ($16.9{\pm}6.7$) (p<0.05), whereas the basal cortisol concentration ($5.8{\pm}2.5$ [mean${\pm}$standard deviation, ng/mL]) of NS was significantly lower than that in BS ($10.0{\pm}2.8$) (p<0.05). Additionally, a negative correlation was noted between serum OT and cortisol concentrations in 1-month-old calves (p = 0.06). Further, the higher serum OT concentration the calves had at 1 month old, the more investigative the calves were at 2 months old but not affiliative in the open-field with a calf decoy. Thus, we concluded that the natural suckling method from a dam elevates the basal serum OT concentration in calves, and high serum OT concentrations induce investigative behavior and attenuate cortisol concentrations.

• Journal of Korean Biological Nursing Science
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• v.24 no.4
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• pp.235-242
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• 2022

Purpose: To investigate associations of perceived stress level, serum cortisol level, and telomere length of community-dwelling adults in Korea. Methods: Data of a total of 135 community-dwelling adults aged over 40 years living in D metropolitan city from December 2020 to March 2021 were collected. Perceived stress level over the past month were measured using the Perceived Stress Score. Serum cortisol level was analyzed using a chemiluminescent microparticle immunoassay. Telomere length was determined using quantitative real-time polymerase chain reaction. The statistical package SPSS 23.0 was used to perform Chi-square test, independent t-test, and Pearson's correlation coefficient analysis. Results: There was no association between perceived stress and serum cortisol level (r = .07, p= .402). Serum cortisol level was not significantly associated with telomere length either (r = -.15, p= .081). However, the higher the perceived stress level, the shorter the telomere length (r= -.29, p= .001). Conclusion: These results suggest that perceived stress might induce physiological stress, which might partially affect gene biology. Further longitudinal research is needed to investigate the effect of perceived stress on telomere length. Intervention for relieving stress should be included in stabilizing the genetic environment of adults.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.115-120
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• 2000

We have investigated the effect of short-term immobilization stress on the serum concentrations of cortisol and DHEAS in BALB/c male mice. Serum cortisol and DHEAS concentrations were measured by radioimmunoassay(RIA). We found there were significantly increased in the cortisol levels in 30 min-stressed group(Ⅰ-30N) compared with control(C) group (p＜0.01), and also increased with significance in 120 min-stressed group(I-120N) compared with C group(p＜0.01). Cortisol concentrations were significantly increased in both 30 min-stressed group(Ⅰ-30T), and 120 min-stressed group(Ⅰ-120T) compared with C group(p＜0.01). The sustained increase of cortisol levels were observed in both SG treated and SG non-treated group. Serum cortisol levels were lower in SG treated group than SG non-treated group with significance(p＜0.01). By contrast, DHEAS levels were slightly decreased without significance in Ⅰ-30N, but significantly decreased in Ⅰ-120N compared with C group(p＜0.01). There were slightly decreased in the DHEAS levels in Ⅰ-30T, but significantly decreased in Ⅰ-120T compared with C group(p＜0.01). However, SG treatment did not induce any significant changes of DHEAS levels in both 30 min and 120 min-stressed group. Though short-term immobilization stress, the continuous decline of DHEAS levels were observed. Therefore, these results show that short-term immobilization stress affects the serum concentrations of cortisol and DHEAS in mice.