• Bulletin of Food Technology
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• v.11 no.4
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• pp.61-69
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• 1998

간 독성 물질인 2-Nitropropane (2-NP)을 쥐의 복강내로 주사한 후에 조직에서의 지질산화(lipid peroxidation (LPO), malondialdehyde 와 4-hydroxyalkenal의 생산량)와 간 독성의 지표로서 혈청내의 soritol dehydrogenase(SDH) 활성을 측정하였다. 수많은 독성 물질에 대하여 방어효과를 보이는 멜라토닌(melatonin)을 2-NP 투여 30분전에 주사하여 2-NP에 대한 방어효과를 조사하였다. 2-NP 투여시에 LPO와 SDH 활성은 시간 (0, 4, 8, 24h) 및 2-NP의 농도 (0, 1, 2, 4mmol/kg)에 따라 증가하였고, 4mmol/kg의 2-NP을 투여한 24시간 후에는 간 (P<0.001), 폐 (P<0.05), 신장(P<0.001)에서 LPO가 유의적으로, 혈청에서의 SDH 활성은 470배 증가하였다. 멜라토닌을 농도에 따라 투여시(2.5, 5, 10 mg/kg) 간, 폐 신장에서 LPO가 간에 대하 발암성 물질인 2-NP가 지질산화도 유도 할 수 있으며, 약리적인 수준의 멜라토닌이 2-NP의 독성을 감소시킬 수 있음을 나타낸다.

• Development and Reproduction
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• v.5 no.1
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• pp.1-8
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• 2001

Golden hamsters show the reproductive activity that is determined by the photoperiod (length of light per day). Photoperiod is an environmental factor that is predictable through an entire year. The hamsters are sexually active in summer during which day length exceeds night time. The critical length is at least 12.5 hours of light in a day where reproductive function is maintained. The information of photoperiod is mediated by the pineal gland because removal of pineal gland blocks the influence of photoperiod on reproductive activity. The hamsters without pineal gland maintain sexual activity and promote it in a situation that suppresses gonadal activity. The pineal gland secretes melatonin that reflects the photoperiod. The appropriate administrations of melatonin into both pineal intact and pinealectomized hamsters lead to a gonadal reression. The results suggest that melatonin constitutes a part of control mechanism whereby environmental information is transduced to neuroendocrine signal respensible for the functional integrity of the reproductive system. Despite of the intense studies, the action site of melatonin is on the whole unknown. It is mainly due to the lack of acute efffct of melatonin on the secretion of reproductive hormones. However, sexually regressed animals display the low levelsof gonadotropins and the augmentation of the hypothalamic gonadotropin-releasing hormone (GnRH) content, implying that the antigonadotropic effects either by photoperiod and/or by the treatment of melatonin are mediated by the GnRH neuronal system. The action mechanism by which melatonin exerts its effect on GnRH neuron needs to be investigated. Recent cloning of melatonin receptor will contribute to examine various and putative potencies of melatonin via its anatomical identification and the action mechanism of melatonin on target tissues at the molecular level.

• Development and Reproduction
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• v.6 no.1
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• pp.45-54
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• 2002

Reproductive activity of golden hamsters(Mesocricetus auratus) is regulated by the photoperiod. They are sexually active in summer and inactive in winter. Melatonin, a pineal hormone, has been known to mediate sexual activities in seasonal breeding animals. Melatonin receptor was recently identified in several animal species including hmm. But little has been known about it in relation to the reproductive activities of golden hamsters. By using reverse transcription polymerase chain reaction(RT-PCR) methods, a portion of the melatonin receptor gene(309 nucleotides) was identified in golden hamsters. The nucleotide sequence of the melatonin receptor and the amino acid sequence deduced were compared to those reported in other animals. Melatonin receptors were obviously detected in hypothalamus, pituitary containing pars tuberalis, blood, and spleen. Although the testicular weights and the levels of reproductive hormones were dramatically affected by photoperiods, the expression of melatonin receptor was not markedly changed by them. These results suggest that the action of melatonin in regulating reproduction might be mainly due to the affinity of melatonin receptor rather than the density fi melatonin receptor.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.224-231
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• 2002

Photoperiod (length of light per day) is a major factor in regulating reproductive function in golden hamsters. The information of photoperiod is transmitted to the reproductive endocrine system by melatonin. Thus the effects of melatonin aye investigated in male golden hamsters exposed to photoperiods. Paired testicular weights were markedly reduced in the animals housed in short photoperiod $(SP,\le{12\;hours\;day^{-1})$ and injected with melatonin in the evening, but not in long photoperiod $(LP,\le{12.5}\;hours\;day^{-1})$ and injected with melatonin in the morning. The histological examination of regressed testes showed reduction of tubular lumen diameter including the numbers of cells and Leydig cell number. The mean values of both follicle stimulating hormone (FSH) and luteinizing hormone (LH) were also lowered in the sexually inactive animals than in the sexually active animals. Melatonin receptor was identified by reverse-transcription polymerase chain reaction (RT-PCR) and its expression was examined in various tissues to scrutinize the action site of melatonin. It turned out 309 nucleotides and was definitely expressed in hypothalamus and pituitary including spleen, retina, and epididymis. And gonadotropin releasing hormone (GnRH) gene, which is a key element in regulating reproduction, was identified by RT-PCR but the expression of GnRH was not modified by the treatment of melatonin. Taken together, photoperiod via melatonin indirectly affects reproductive endocrine system, possibly through the release of GnRH, not the synthesis of GnRH.

• Journal of Acupuncture Research
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• v.27 no.5
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• pp.105-115
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• 2010

목적 : 침은 다양한 질환의 치료에 보편적으로 쓰이고 있으며 고혈압, 당뇨, 정신질환 등을 포함한 스트레스성 질환에도 활용되고 있다. 결박 스트레스는 스트레스 호르몬(코르티코스테론, 멜라토닌)의 혈장 농도를 크게 증가시키는 간단하고 효과적인 스트레스 요인이다. 본 연구는 결박 스트레스를 시행한 백서의 스트레스 호르몬의 혈중 농도에 대한 전기침의 효과를 조사하였다. 방법 : 결박 그룹은 2시간의 결박 스트레스를 받았으며 결박 스트레스 및 고주파수 전침그룹과 결박 스트레스 및 저주파수 전침그룹은 결박 스트레스와 고주파수 전침, 또는 결박 스트레스와 저주파수 전침을 동시에 각각 시행하였다. 급성 스트레스 유발 시에는 결박 스트레스를 1차례, 만성 스트레스 유발 시에는 7차례 시행하였다. 전기침 자극에는 우측 족삼리($ST_{36}$)를 사용하였다. 결박 스트레스 및 전기침으로 유도된 코르티코스테론과 멜라토닌의 농도를 측정하기 위해서 결박 스트레스 및 전기침 자극이 시작된 30분, 60분, 90분, 120분 후에 백서를 단두하여 혈액 샘플을 채취하였다. 결과 : 급성 스트레스 유발 시에는 고주파수 전침그룹의 코르티코스테론 혈장 농도가 증가하였고 멜라토닌 농도의 시간적 패턴을 변화시켰으나 저주파수 전침그룹에서는 유의한 변화가 없었다. 만성 스트레스 유발 시에는 고주파수 전침그룹의 혈장 코르티코스테론과 멜라토닌 농도가 유의하게 감소되었으나 저주파수 전침그룹에서는 변화가 없었다. 결론 : 이러한 결과는 전침이 결박 스트레스로 유도된 스트레스 호르몬의 혈장 농도 및 시간적 분비패턴을 변화시키는 효과가 있으나 스트레스 호르몬 반응을 변화시키는 데 있어서 주파수에 따른 유의한 차이가 있다는 것을 의미한다.

• The Journal of Korean society of community based occupational therapy
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• v.7 no.1
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• pp.9-16
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• 2017

Objective : The study was to find out the effect of sleep disorder bt melatonin when we applied the evironmental change to rats wirh sleep disorder. Methods : We performed the study in lab which is located in Gyungbuk. We divided 26 rats into two groups. The experimental group had the environmental change for 3 days. The control group didn't have the change. We checked the level of melatonin of each group. Results : There was a significant difference of the level of melatonin in experimental group after applying the environmental change for 3 days (p=.000). The level of melatonin was increased a little for 3 each day in control group, but there was no significance(p=.212). There was a significant difference of the level of melatonin in both groups before and after applying the environmental change. However, the level of melatonin was increased significantly in experimental group, and the level was decreased significantly in control group. Conclusion : The patients with sleep disorder are increasing in modern society. We made a animal model with sleep disorder to find out the effect of the environmental change. We applied the environment like human's and could know the improvement effect of sleep disorder.

• Journal of Dairy Science and Biotechnology
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• v.34 no.1
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• pp.37-41
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• 2016

Melatonin is a hormone produced by the pineal gland in dark conditions. It plays a major role in the regulation of the sleep-wake cycle. Melatonin synthesis is known to be suppressed by environmental light. Cortisol is a steroid hormone that is a major indicator of physiological alterations due to stressful stimuli. It also displays a circadian rhythm, like melatonin. The highest levels are encountered during early morning and the lowest levels are observed at around midnight. In the present study, the effects of milking time on the melatonin and cortisol concentrations of raw milk and milk powder at the summer and winter solstices were examined. The melatonin concentration in milk increased significantly if cows were milked in the dark at night (p<0.05). The melatonin concentration in milk powder showed the same pattern with respect to the milking time (p<0.05). However, no significant difference in the cortisol concentration was observed between day- and night-time milk. Although the time of day did not affect the level of milk cortisol, seasonal factors affected the release of cortisol in milk (p<0.05). In conclusion, night-time milk is rich in endogenous melatonin. In this respect, it has potential applications for the development of melatonin rich-dairy products, which serve as natural sources of melatonin.

• The Journal of Korean society of community based occupational therapy
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• v.8 no.2
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• pp.29-37
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• 2018

Objective : Sleep disorder caused by stress or disease to elderly currently. We tried to make clear constant exercise according to exercise intensity would have effect on sleep disorder in elderly using EEG and melatonin. Methods : Thirty subjects were over 65 years old who lived a senior facility in some parts. They were able to communicate and understand the purpose of the study. They also expressed their intension to participate actively in experiment. They should have alert consciousness and orientation about time, place, and people. Sleep disorder was assessed via below 6 hr total sleep time and Pittsburge Sleep Quality Index, which was satisfied with both of criterion at the same time. Exercises composed of low intensity walking, moderate aerobic exercise, and high intensity resistance strength. We used QEEG 8-System (LAXTHA Inc. KOREA) to check wave type and Polysomnograpy (Compumedics, Australia) to test quality of sleep. and Histologic features were observed by TTC (triphenyltetrazolium chloride) staining and H & E (Hematoxylin & Eosin) staining. Results : There was a significant sleep index and change of melatonin after aerobic exercise. There was a significant SOL, S1, S2, and SWS in aerobic exercise, but there was a significant SWS in walking and resistance strength. There was a significant change of delta wave especially in frontal and temporal region between exercises. Conclusion : They had different effects according to type of exercise, when elderly who have chemical, behavioral change of circadian rhythms did exercise consistently. Aerobic exercise had more effect on sleep disorder than other exercise. Therefore, we may supply proper exercise to elderly and high quality of life.

• Journal of Veterinary Clinics
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• v.31 no.4
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• pp.313-315
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• 2014

A 13-month old, intact female, miniature Schnauzer dog was presented with history of dermatitis, pruritus and pain of ear pinnae with delayed puberty. The basal serum growth hormone level was 0.01 ng/ml, which was much lower than the reference range (1.80-2.00 ng/ml). On the xylazine stimulation test, the dog was no responsive to administration of xylazine. The dog was diagnosed as isolated type pituitary dwarfism. Treatment was aimed to improve alopecia with oral melatonin. After initiation of treatment, alopecia of the ear pinnae has been improved.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.323-328
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• 2006

An experiment was conducted to investigate the effects of dietary betaine on egg production, estradiol, progesterone, and melatonin secretion in laying hens. Seventy two ISA-Brown laying hens were placed into individual cage and fed four different levels of betaine (0, 300, 600, 1,200 ppm) in diets for four weeks. Basal diets were mainly mixed with corn-soybean and contained 2,800 kcal/kg ME and 16% CP. Dietary supplementation of betaine showed significantly higher (p<0.05) egg weight and daily eggmass than controls, but did not have consistent influence on the egg production. The serum estradiol was statistically different in betaine treatments compared to that of control (p<0.05). No significant changes in serum progesterone concentrations were observed by the addition of betaine in diets. Serum melatonin concentrations also increased with betaine supplementation in diets (p<0.05). The results of this study indicate that the dietary betaine may contribute to increase daily eggmass, serum estradiol and melatonin concentration in laying hens.