• The Korean Journal of Physiology and Pharmacology
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• 제28권6호
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• pp.515-526
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• 2024

We investigated whether endurance exercise training (EXT) ameliorates circadian rhythm (CR)-induced risk factors by improving skeletal muscle (SKM) mitochondrial biogenesis, reducing oxidative stress, and modulating apoptotic protein expression. We distinguished between regular and shift workers using the National Health and Nutrition Examination Survey (NHANES) and investigated the health problems caused by shift work (CR disturbance) and the potential therapeutic effects of exercise. In our animal study, 36 rats underwent 12 weeks of CR disturbance, divided into regular and irregular CR groups. These groups were further split into EXT (n = 12) and sedentary (n = 12) for an additional 8 weeks. We analyzed SKM tissue to understand the molecular changes induced by CR and EXT. NHANES data were analyzed using SAS 9.4 and Prism 8 software, while experimental animal data were analyzed using Prism 8 software. The statistical procedures used in each experiment are indicated in the figure legends. Our studies showed that CR disturbance increases dyslipidemia, alters circadian clock proteins (BMAL1, PER2), raises apoptotic protein levels, and reduces mitochondrial biogenesis in SKM. EXT improved LDL-C and HDL-C levels without affecting muscle BMAL1 expression. It also enhanced mitochondrial biogenesis (AMPK, PGC-1α, Tfam, NADH-UO, COX-I), antioxidant levels (Catalase, SOD1, SOD2), and apoptotic protein (p53, Bax/Bcl2) expression or activity in SKM. We demonstrated that shift work-induced CR disturbance leads to dyslipidemia, diminished mitochondrial biogenesis, and reduced antioxidant capacity in SKM. However, EXT can counteract dyslipidemia under CR disturbance, potentially lowering the risk of cardiovascular disorders.

• Sleep Medicine and Psychophysiology
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• 제9권1호
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• pp.9-13
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• 2002

Alzheimer's disease (AD) is one of the most common and devastating dementing disorders of old age. Most AD patients showed significant alternation of sleep structure as well as cognitive deficit. Typical findings of sleep architecture in AD patients include lower sleep efficiency, higher stage 1 percentage, and greater frequency of arousals. The slowing of EEG activity is also noted. Abnormalities in REM sleep are of particular interest in AD because the cholinergic system is related to both REM sleep and AD. Several parameters representing REM sleep structure such as REM latency, the amount of REM sleep, and REM density are change in patients with AD. Especially, measurements of EEG slowing during tonic REM sleep can be used as an EEG marker for early detection of possible AD. In addition, a structural defect in the suprachiasmatic nucleus is suggested to cause various chronobiological alternations in AD. Most of alternations related to sleep make sleep disturbances common and disruptive symptoms of AD. In this article, the author reviewed the alternation of sleep structure and circadian rhythm in AD patients.

• The Korean Journal of Zoology
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• 제35권4호
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• pp.509-517
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• 1992

LiCl (0.047 M)은 Goldhamster의 활동주기 (T)를 평균 1.6시간 연장시키고, 동물 중 20%엑서 단축되는 것으로도 관찰되었다. 1시간 통안의 빛자극(75 Lux)에 의해 주기현상 시점 변화가 나타나는 데 LICI에 의해서 0.3 h 더욱 delav되었고 advance 현상은 1.5 h 감소되었으며 delay엔h advance 전환시기는 1시간 늦게 나타났다. 반면에 7 Lux의 빛 자극에서는 delay가 2.4시간으로 더 증가되었으며 advance 현상은 2.6시간으로 저하되었고, 30분 늦게 delay에서 advance로 전환되었다. subjective day 동안에는 빛자극에 의한 LiCl 효과가 전혀 보이지 않았다. Phase-Response-Curve(PRC)는 Circadian Time에서 delay-advance로 전환되는 mid-subjective night에 점진적으로 변화되는 weak phase curve로 형성되었다. 이 PRC에서 Li이 빛에 대한 민감성을 둔화시키는 효과를 볼 수 있다.

• Journal of Korean Neurosurgical Society
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• 제62권5호
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• pp.519-525
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• 2019

Objective : The circadian pattern of the onset time of aneurysmal subarachnoid hemorrhage (aSAH) has been reported by various authors. However, the effect of the degree of physical exertion on the circadian pattern has not been studied in detail. Therefore, we conducted this study to investigate the effect of physical exertion on the circadian pattern of aSAH. Methods : Of the 335 patients presenting with aSAH from January 2012 to December 2017, 234 patients with identifiable onset time and metabolic equivalent (MET) values were enrolled. The onset time of aSAH was divided into 4-hour intervals. The patient's physical exertion was then assessed on a scale between 1 and 8 METs using generally accepted MET values, and categorized into two groups-light exertion (1 to 4 METs) and moderate to heavy exertion (5 to 8 METs)-to determine the effect of the degree of physical exertion on the onset time distribution of aSAH. Multivariate analysis was used to calculate the odds ratio (OR) between the two groups to determine the effect of the degree of physical exertion on each set of time periods. Results : There was a definite bimodal onset pattern that peaked at 08:00-12:00 hours followed by 16:00-20:00 hours (p<0.001). MET values at all time intervals were found to be significantly higher than the night time (00:00-04:00 hours) values (p<0.031). The MET value distribution showed a unimodal pattern that slightly differed from the bimodal distribution of the onset time of aSAH. There were no significant differences in the ORs of each time interval according to the degree of the MET value. Conclusion : This study reaffirmed that aSAH occurs in a bimodal pattern, especially showing the highest prevalence in the morning. Although aSAH could be related to daily activity, there were no significant changes in diurnal variations affected by the degree of physical exertion.

• Journal of Plant Biology
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• 제25권1호
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• pp.21-36
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• 1982

The activity of photosystem II in isolated chloroplast form the leaves of Sedum sarmentosum was measured. The photoreduction rate of DCPIP by photosystem II showed the circadian rhythm with a peak at near midday sample for a continuing fine day and at near afternoon between nidday and sunset sample for a continuing cloudy day in summer. The optimum light intensity of photoreduction by photosystem II in the chloroplast preparation was about 5~9$\times$$10^4$ lux. The saturated light intensity was over 9$\times$$10^1$lux. Photosystem II activity was inhibited by even the lowest concentration of lead. When Pi and ATP of the same concentration as Pb were added to the reaction mixture containing Tris buffer lacking of Pi prior to Pb incubation, photosystem II activity was protected from Pb-inhibiting effect by the pretreament of Pi and ATP. It was assumed that Pb inhibiiton was probably due to one, P-depriving by the precipitates of $Pb_3$ $($Pb_4$)_2$ in the reaction mixture and the other, partially Pb-combing with Pi groups of the active site of photosystem II.

• Journal of Physiology & Pathology in Korean Medicine
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• 제38권5호
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• pp.173-178
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• 2024

The liver is a major organ in human metabolism and is responsible for systemic circulation and metabolism. The traditional concepts of wind related to the nervous and motor system have limitations in explaining the role of the liver in human metabolism. To overcome these limitations, it is necessary to focus on the physiological activity and pivotal role of bioactive gases in the metabolism of gas flow. Additionally, the action of bioactive gases occurs in the presence of chromoprotein, such as heme protein, which acts as a photoreceptor between the eyes and the liver, ultimately involved in the circadian cycle and metabolism. This series of processes demonstrates that the unique theories of Korean medicine-where the liver governs the wind and the eyes-are accurately aligned from a metabolic perspective, suggesting that Korean medicine physiology can be integrated and appreciated from a modern medical standpoint.

• Journal of Korean Academy of Nursing
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• 제39권3호
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• pp.422-432
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• 2009

Purpose: In this study rest-activity rhythm, sleep pattern and quality of life of patients with restless legs syndrome were compared with those of a normal group. Methods: The participants in this study were 36 patients with restless legs syndrome diagnosed by a neurologist and 36 participants in the normal group. An actigraph, sleep diary, Pittsburgh Sleep Quality Index and Insomnia Severity Index scale were used as measurement tools for the study. Chi-square test, Lamda test, t-test and Kendall's correlation with SPSS 12.0 program were used to analyze the data. Results: Patients with restless legs syndrome had a higher rest-activity rhythm curve of Least 5 hr's activity(L5) and Most 10 hr's activity(M10) than those of normal group and sleep problems included decreased sleep efficiency and increased sleep latency, wake time and number of awakenings. The scores for the subscales of quality of life in patients with restless legs syndrome were lower than the normal group for general health, physical functioning, role limitations due to emotional problems, role limitation due to physical problems, social functioning, bodily pain, vitality and mental health. Conclusion: The results suggest that further studies are needed to identify rest-activity rhythm according to symptom severity and to develop nursing interventions which consider rest-activity rhythm.

• Journal of East-West Nursing Research
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• 제25권1호
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• pp.17-25
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• 2019

Purpose: This study investigated the factors influencing sleep quality in adults according to age groups. The escriptive study was conducted in metropolitan areas of South Korea to control for possible sleep differences between adults living in rural areas and those living in cities. Participants were 450 adults between 19 and 65 years old. Methods: Self-administered questionnaires consisting of including the Korean Modified Sleep Leeds Evaluation Questionnaire, the International Physical Activity Questionnaire and the Perceived Stress Scale were used to assess the quality of adults' sleep. Results: Sleep quality was poor across the all age groups Stress and subjective health status were influencing factors of sleep quality among participants in their 20s; subjective health status and circadian rhythm (evening-type) were influencing factors of those in their 30s; subjective health status, alcohol consumption, and work days of less than 8 hours were influencing factors among participants in their 40s; and stress, circadian rhythm (evening-type), subjective health status, work days of over 11 hours, past smoking habit, and light physical activity were influencing factors of those aged 50 years and over. Conclusion: The quality of sleep was low across the all adult age groups in South Korea. Although the factors influencing quality of sleep differed by age groups, they in general indicate the need to focus on maintaining and controlling health status in sleep interventions.

• The Korean Journal of Physiology
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• 제1권1호
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• pp.43-49
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• 1967

Nine male rats in which 90% or more of the hippocampal tissue was removed through a small hole made in the neocortex at the boundary between the parietal and the occipital lobes (hippocampal group), 3 male rats with similar neocortical damage alone (operated control group), and 9 normal control male rats (normal control group) were prepared. Their general activity was measured for 48 hours in an activity cage by recording the number of beams they interrupted. The amount of food and water intake was also checked simultaneously. Results obtained were as follows: 1. The general activity of the hippocampal group was 2 to 3 times as great as that of the operated control or the normal control group. 2. All of the 3 groups demonstrated clear-cut circadian variation of activity, the diurnal and the nocturnal activity being in the ratio 22 : 78. 3. The amount of food and water consumed by the hippocampal group did not differ significantly from that by the opperated control or the normal control group. In the course of the experiment which continued for 3 months the hippocampal group gained weight least among the 3 groups.

• Animal cells and systems
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• 제6권4호
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• pp.293-299
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• 2002

We investigated seasonal variation of diurnal activity patterns in Jeiu ponies (Equus caballus). The data were collected from a semi-natural herd during daylight hours from March to September 1998. Over all months the mean proportion of time spent grazing was 83.7% ( $\pm$29.7 S.D.): that resting was 15.7$\pm$17%, grooming 0.7$\pm$1.2%, and moving 0.56$\pm$5.4%, Activity patterns varied with the seasons. The mean proportion of grazing mares peaked during late winter and early spring (March), when there was not enough food, and declined during other seasons (between May and September), when food was abundant. The mean proportion of mares that were resting and mutual grooming peaked in spring (April and May), at which time the weather was warm and food became abundant. During other seasons when grasses started to grow and the weather was mildly cool, these activities were less common. The mean proportion of mares that were moving peaked in June, although it was a small proportion of the total activity. For those mares without foals, resting periods were longer in older mares than in younger mares, but for the mares with foals this pattern was not evident. From these data, we hypothesize that the dominance hierarchy of the mares effects the diurnal activity pattern.