• The Korean Journal of Physiology and Pharmacology
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• 제11권4호
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• pp.155-161
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• 2007

In order to characterize the role of sympathetic activity in obesity, we repeatedly assessed sympathetic activity via power spectral analyses of heart rate variability in the same subjects at 7, 11, 25, and 60 weeks, using monosodium glutamate (MSG)-induced obese and control rats. The effects of lower sympathetic activity on obesity were also evaluated. Fat mass in MSG rats was already higher at 7 weeks, but the sympathetic activity did not differ between 7 and 25 weeks. Between 25 and 60 weeks, the increase in fat mass, food efficiency, and body weight gain was higher in MSG rats. The increase in sympathetic activity between 25 and 60 weeks and sympathetic activity at 60 weeks were lower in MSG rats. Fat mass at 60 weeks was inversely correlated with changes in sympathetic activity between 25 and 60 weeks. Reduced plasma epinephrine levels by bilateral adrenal demedullation induced increase of fat mass. In, an attenuated increase of sympathetic activity with age may partly be responsible for aggravated obesity in MSG rats. Additionally, reduced sympathetic activity per se induced obesity in rats. These results suggest that lower sympathetic activity contributes to obesity in rats.

• 약학회지
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• 제35권5호
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• pp.384-388
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• 1991

To explore the effect of monosodium-L-glutamate(MSG) on CCI$_{4}$-damaged liver in Wister male rat, 5% MSG solution as drink water were administered after S.C. injection of 0.1 mg/kg CC1$_{4}$ twice a week for 4 weeks. After last administration of MSG, heptic glutathione(GSH) dependent system was assayed. It showed that MSG increased significanly hepatic glutathione(GSH) and glutathione peroxidase(GSH$_{px}$), but decreased glutathione-S-transferase(GST) acivity in normal rats. MSG increased significantly the GSH$_{px}$ and GST activities in rats with CCI$_{4}$-induced liver damage. These results indicate that decrease of GSH dependent systems in CC1$_{4}$ liver injury might be partially elevated by coadministration of MSG.

• 한국임상수의학회지
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• 제16권2호
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• pp.265-271
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• 1999

These experiments were performed to investigate the effect of saline, monosodium L-glutamate(MSG), MSG-phenylalanine, and/or phenylalanine on TH-immunoreactivity in arcuate nucleus of hypothalamus and hind limb area of cerebral cortex in rats using the immunohistochemical methods. The result were as follows: 1. TH-immunoreactive neurons in hind limb area of cerebral cortex and arcuate nucleus of hypothalamus were decreased in MSG treated group compared to the saline treated group and also lesions in arcuate nucleus and median eminence of hypothalamus were increased with MSG treatment 2. TH-immunoreactive neurons in median eminence and arcuate nucleus were increased in phenylalanine treated group compared to the saline treated group and also neurons were more increased in lamina V of hind limb area of cerebral cortex with phenylalanine treatment. 3. TH-immunoreactive neurons in median eminence and arcuate nucleus were decreased in MSG-phenylalanine treated group compared to the phenylalanine treated group and increased compared to the MSG treated group. In lamina V of hind limb area of cerebral cortex, TH-immunoreactive neurons were more decreased in MSG-phenylalanine treated group than that of the phenylalanine treated group, and more increased than that of MSG treated group. These experiments indicated that TH-immunoreactive neurons in hypothalamus and cerebral cortex were increased due to the activation of phenylalanine and decreased by suppressing activation of phenylalanine through MSG treatment.

• 한국식품위생안전성학회지
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• 제30권1호
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• pp.120-125
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• 2015

본 연구는 Sprague-Dawley 계통의 4주령 랫드에서 MSG의 반복경구투여 독성평가와 행동실험을 통해 어린랫드의 인지능력과 불안감에 미치는 영향을 평가하기 위해서 시행하였다. 시험군은 MSG 대신 distilled water를 투여한 대조군(Control, n = 4), MSG를 3 g/kg을 투여한 군(Low, n = 4), MSG를 5 g/kg을 투여한 군(High, n = 4)으로 나누어 4주 동안 주5회 경구투여를 하였다. MSG의 안정성을 확인하기 위해 다음과 같은 관찰 및 검사를 하였다. 검사항목으로는 체중의 변화, 임상증상, 행동실험인 T-maze, Elevated-plus-maze와 혈액학적 검사, 혈청생화학적 검사, 병리조직학적 검사를 관찰한 결과 모든 투여군 및 대조군에서 특이할 만한 임상증상과 체중변화는 관찰되지 않았으며, 폐사 및 빈사 동물은 시험 전 기간을 통하여 발견되지 않았다. 행동실험인 T-maze 결과 MSG 고용량 투여군에서 움직이는 횟수가 감소하다 증가하는 양상을 보였고, Elevated-plus-maze 실험에서는 MSG 고용량 투여군의 Open arm의 출입빈도가 증가하는 등 유의적인 변화가 나타났다. 혈액학적 검사 및 혈청생화학적 검사에서는 대조군과 비교 시 유의적인 변화가 관찰되었지만 그 수치가 정상범위 안에 포함되기 때문에 이상을 나타내지 않았다. 병리조직검사 또한 약간의 염증발생 소견이 나왔지만 정상범위 안에 포함되기 때문에 이상을 나타내지 않았다고 판단했다. 따라서, 어린랫드를 이용한 MSG의 반복투여 독성시험 결과 특이할만한 신체적인 변화는 나타나지 않았으나 고용량의 MSG 투여는 어린랫드에서 인지능력의 저하 및 행동의 불안을 유발할 가능성이 있다고 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권4호
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• pp.213-221
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• 2010

The hypothalamic-pituitary-adrenal (HPA) axis is the primary endocrine system to respond to stress. The HPA axis may be affected by increased level of corticotrophin-releasing factors under chronic stress and by chronic administration of monosodium glutamate (MSG). The purpose of this study was to investigate whether chronic MSG administration aggravates chronic variable stress (CVS)-induced behavioral and hormonal changes. Twenty-four adult male Sprague-Dawley rats, weighing 200~220 g, were divided into 4 groups as follows: water administration (CON), MSG (3 g/kg) administration (MSG), CVS, and CVS with MSG (3 g/kg) administration (CVS＋MSG). In addition, for the purpose of comparing the effect on plasma corticosterone levels between chronic stress and daily care or acute stress, 2 groups were added at the end of the experiment; the 2 new groups were as follows: naive mice (n=7) and mice exposed to restraint stress for 2 h just before decapitation (A-Str, n=7). In an open field test performed after the experiment, the CVS＋MSG group significant decrease in activity. The increase in relative adrenal weights in the CVS and CVS＋MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS＋MSG group as compared to all other groups, except the naive group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

• 한방재활의학과학회지
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• 제18권1호
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• pp.33-46
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• 2008

Objectives : Obesity is a metabolic disease resulted from various causes including nutritional disproportion, hormonal imbalance, and hypothalamic nuclei disorder. Samhwang-tang(Sanhuang-tang, SHT) is composed of 5 herbs (Ephedrae Herba, Scutellariae Radix, Typhae pollen, Acori Rhizoma and Ansu Semen) and is frequently used for obese patients. This study investigated anti-obesity effects of SHT on the rats. Methods : Obesity was induced by high fat diet (HFD), monosodium L-glutamate injection (MSG) and ovariectomy (OVX) in the Sprague-Dawley rats. Water extract of SHT was treated for 2 weeks, then changes of body weight gain and epididymal fat cell size were measured. In OVX animals, c-Fos and neuropeptide Y (NPY) expressions in hypothalamic nuclei were observed with immunohistochemistry. Results : SHT treatment demonstrated significant decrease of body weight gain in obesity induced by HFD and OVX, but not in obesity induced by MSG. SHT treatment demonstrated significant decrease of fat cell size in obesity induced by HFD, but not in obesity induced by MSG. On c-Fos and NPY expressions in hypothalamic nuclei, SHT treatment resulted significant decrease of immuno-reactivity of c-Fos and NPY in obesity induced by OVX. Conclusions : These results suggest that SHT has a weight loss effect against obesity induced by nutritional disproportion of diet intake and hormonal imbalance, especially without central nervous system disorder.

• 약학회지
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• 제36권1호
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• pp.73-79
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• 1992

To achieve better understanding of the effects of monosodium-L-glutamate(MSG) against $CCl_4$ fatty liver in Wister male rats, 5% MSG solution was given as drinking water and $CCl_4$ 0.1 ml/kg was injected subcutaneously twice a week for four weeks. It was showed that increased hepatic phospholipid and hepatic triacylglycerol levels by $CCl_4$ challenge were significantly decreased by additionnal MSG, respectively. However, MSG had no apparent effect on the elevated hepatic cholesterol level in the presence of $CCl_4$. Histologically, additional MSG markedly inhibited fatty degeneration, spotty necrosis, inflammation and periportal vascular proliferation manifested by $CCl_4$. respectively. These results indicated that effects of MSG against $CCl_4$ induced-fatty liver appeared to be involved with partial restoration of altered hepatic lipid composition.

• Parasites, Hosts and Diseases
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• 제36권2호
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• pp.127-132
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• 1998

폐포자충증에 대한 이종항혈청의 예방 및 치료효과를 검증하고자 이 연구를 수행하였다. 횐쥐 (위스타)를 15마리씩 나누어 9개 실험군을 설정하고, 스테로이드 주사로 면역억제시켜 폐포자충의 감염을 유발하였다. 흰쥐 유래의 폐포자충 조항원을 토끼에 투여하여 얻은 면역혈청 중에서 IgG 항체만을 분리하여 실험에 사용하였다. 각 실헙군에 따라 면역억제 시작 2주전부터 억제 후 6주후 사이에 면역항체 주입을 시작하였고, 주 2회씩 7곤주 동안 주입하였다 대부분의 실험군에서는 면역항체를 일회에 0.4 ml (단백질량 0.976 mg)씩 주입하였고, 용량에 따른 예방 및 치료효과를 비교하기 위하여 0.2 ml (단백질량 0.488 mg)와 0.6 ml (단백질량 1.464 mg) 주입 실험군을 설정하였다. 그 결과 실험군별로 실험기간인 7틱주간 살아남고 폐에 세균감염이 없는 흰쥐 2-12마리에서 결과를 얻었다. 폐도말검사 결과 모든 개체에서 폐포자충이 확인되었고, 실험군에 따라 포낭형 수의 평균이 최저 13.5 (3군)에서 최고 52.5 (1군) 사이에 있었다. 통계학적인 검증 결과 기준이 되는 1군에 비하여 유의한 병원체의 감소가 확인된 실험군은 0.4 nU의 항체를 주 2회씩 7주간 주입한 3군, 5주간 주입한 4군, 3주간 주입한 5군과, 0.2 U를 7주간 주입한 8군이었다. 면역항체를 0.4 ml씩 9주간 주입한 2군과 항체를 0.6 ml씩 7주간 주입한 9군은 차이가 유의하지 않았다. 이 항체는 폐포자충의 표면에 있는 주항원 당단백질인 MSG (m3iorsurfaceycoprotein) 중에서 40-55, 92, 116, 200 kDa 분획과 주로 반응하였다. 이들 항원 분획이 숙주의 방어기전과 관련된 항체를 유발하는 항훤이며, 이 항원자극에 의하여 형성된 이종항체가 흰쥐의 폐포자충 감 염초기에 수동면역의 효과가 있어 예방이나 치료에 활용될 수도 있음을 확인하였다.

• Parasites, Hosts and Diseases
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• 제38권3호
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• pp.151-158
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• 2000

Pneumocystis carinii is a major opportunistic pathogen which has been found in the lungs of a wide variety of mammalian host species, and the fact suggests the possibility of intraspecific variation. Until now, P. carinii from different mammalian species are differentiated as subspecies, and the rats are known to be infected by two subspecies. The present study investigated genetic heterogeneity of P. carinii isolates from two strains of rats in Korea and China by molecular karyotyping, RFLP and sequencing analysis. Karyotypes of P. carinii were grouped into three, two from two strains of rats In Korea and one from rats in China. However RFLP of PCR product of ribosomal and MSG gene of the P. carinii isolates showed same pattern. The sequence homology rates of ${\alpha}-tubulin$ DNA of the P. carinii isolates were 96% in Seoul Wistar rats, 93% in Seoul Sprague-Dawley rats, and 85% in Chinese Sprague-Dawley rats. The present finding confirmed that P. carinii from rats in Korea are grouped into two karyotype strains which are different from that of P. carinii from rats in China. The Chinese isolate shows a little different sequences of ${\alpha}-tubulin$ DNA.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.246-246
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• 1996

The glucuronide conjugates of morphine have been claimed to exert significant neuropharmacological effects. Morphine-6-glucuronide (M6G) may be a potent opioid agonist in vivo, and morphine-3-glucuronide (M3G) may act as a weak opioid antagonist. The present study addressed the permeability of the blood-brain barrier (BBB) for these metabolites compared to morphine. Tracers were prepared by enzymatic glucuronidation of U-methyl-$^3$H]-morphine. Brain uptake in rats was measured by the internal carotid artery perfusion technique and after i.v. bolus injections. In the perfusion experiments morphine showed a permeability-surface area product (PS) of 3.52${\pm}$0.61 ${\mu}$L min$\^$-1/ g$\^$-1/ Uptake seems to be mediated by passive diffusion and was not saturable by 100 ${\mu}$M morphine in the perfusate. The BBB permeability of [$^3$H]-M3G and [$^3$H]-M6G was too low to be quantified after 5 min of perfusion. Brain uptake of [$^3$H]-M3G and [$^3$H]-M6G 60 min after i.v. bolus injection reached 0.0060${\pm}$0.0003 and 0.0030${\pm}$0.0005% injected dose per g, respectively. From these brain concentrations and from the corresponding plasma concentration - time curves, BBB PS values of 0.14${\pm}$ 0.02 ${\mu}$L min$\^$-1/g$\^$-1/ and 0.11 ${\pm}$ 0.01 ${\mu}$L min$\^$-1/g$\^$-1/, respectively, were calculated. The ratio of BBB PS values is complementary to the analgesic potencies of morphine and M6G after different routes of administration. The low PS of MSG explains, why it is approximate]y equipotent to morphine after systemic injection, although it is about 2 orders of magnitude more potent than morphine after administration directly into the central nervous system.