• Biomedical Science Letters
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• v.8 no.2
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• pp.83-88
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• 2002

To investigate the skin toxicity of xylene, xylene (25 mg/$\textrm{cm}^2$) has been sequentially applied to the rat skin for four days. On the light microscopic examination, epithelium was left out with infiltration of inflammatory cells in border with dermis, and formation of new epithelial layer was shown under the inflammatory zone. Application of xylene to the rat skin showed the marked rise of cutaneous xanthine oxidase activity whereas, He activities of oxygen free radical scavenging enzymes, superoxide dismutase and glutathione S-transferase, were significantly declined. Furthermore, the content of cutaneous glutathione was more and less decreased in rat skin applied with xylene. In conclusion, these results suggest that a part of oxygen free radical may be responsible for morphological changes in skin by applying xylene to the rat skin.

• The Korean Journal of Zoology
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• v.36 no.2
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• pp.193-199
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• 1993

The protein po;vmorphisms and allele frequencies of wild house rat (Rattus norvegicus) population in Korea were studied. The studied proteins and enzymes were transferrin (Tf), albumin (Alb), fumarate hvdratase (FH), phospho!loucomutase (PGM), lactate dehvdrogenase A (LDHA) and lactate dehvdrogenase B (LDHB). There were two transferrin alleles, TP and Tf in Korean wild house rat popu1ation. The Tf2 allele was found for the first time by a starch gel, and confirmed by a polvacrvlamide gel isoelectric focusing and immunoblotting. The allele frequencies of TP and TF were 0.985 and 0.015, respectively. Two common alleles fumarate hydratase, FHa and FHb were found, and frequencies of FHa and FPP were calculated to be 0.714 and 0.286, respectively. The kequenw of FH in Korean wild house rat was higher than that of Finnish and Czechoslovakian population. Alb, PGM, LDHA and LDHB are only one phenotype each and all. Therefore, these proteins seem to be monomorphic in Korean wild house rat population.

• Natural Product Sciences
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• v.15 no.3
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• pp.125-129
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• 2009

Neurodegenerative diseases such as Alzheimer's disease, stroke, and Parkinson's disease, are caused by neuronal cell death. Apoptosis, oxidative stress, inflammation, excitotoxicity or ischemia are discussed to play a role of neuronal cell death. In order to find the candidate of neuroprotective agent, neuroprotective activity of some medicinal plants was investigated with in vitro assay system using glutamate-induced neurotoxicity in primary cultures of rat cortical cells. The aqueous methanolic extracts of twenty-seven medicinal plants were evaluated the protective effects against glutamate-injured excitotoxicity in rat cortical cells at the concentration of 50 $\mu$g/ml and 100 $\mu$g/ml, respectively. Among them, extracts of Lonicera japonica, Taraxacum platycarpum, Polygonum aviculare, Gardenia jasminoides, Forsythia viridissima, Lygodium japonicum, Panax notoginseng, Akebia quinata, Anemarrhena asphodeloides and Phellodendron amurense showed significantly neuroprotective activities against glutamate-induced neurotoxicity in primary rat cortical cells.

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.189-200
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• 1996

The purpose of this study was to find the effect of honey on the sugar metabolism In Sprague-Dawley rats. All experimental rats were fed ad libitum, for seven weeks, 68% saccharide diet anti 10% or 20% honey from acacia, sumac and miscellaneous flower honey, respectively, and sucrose. The amount of glucose in whole blood was increased in all groups fed with honey except the group fed with 10% sumac honey solution. The amount of fructosamine in serum of rat taken diet with honey solution was increased in comparison with normal group, control group, sucrose group. The amount of fructosamine in serum of rat taken diet with honey solution was high in order of sumac honey > miscellaneous flower honey > acacia honey. The amount of lactate and pyruvate in whole blood of rat taken diet with sucrose group or honey group were decreased in comparison with the normal group and control group. The amount of $\beta$-hydroxybutyrate in serum of rat taken diet with sucrose or honey was increased in comparison with the normal group, control group.

• Progress in Superconductivity
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• v.12 no.2
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• pp.124-128
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• 2011

We have developed a high-$T_C$ SQUID magnetometer system to measure magnetocardiograms of laboratory rats. White noise of the measurement system was about 50 fT/$Hz^{1/2}$ when measured in a magnetically shielded box. We optimized the measurement position to obtain clear MCG wave from rat's small heart by using grid measurements. With the optimization, the MCG signal was successfully detected with the peak amplitude of about 50 pT. We could observe well defined P-, QRS-, and T-wave from the rat MCG. The results suggest that the developed system has a strong potential to monitor the progress of heart disease model using laboratory rat.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.703-708
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• 2003

This study was carried out to compare the efficacy of carboxymethyl chitosan fabric (CMCF) with that of the combination of low molecular weight heparin (LMWH) and CMCF for the prevention of postoperative adhesions in the rat. Adhesions were induced by suturing both the ileal serosa and peritoneum scraped until petechial bleeding occurred. CMCF were sutured between two surfaces, and LMWH were instilled intraperitoneally immediately before closure of the peritoneomuscular layer. The adhesions were blindly assessed 2 weeks later by using a tensiometer. The mean tensile strength(Newton) of formed adhesions was $2.59{\pm}0.85$ in control group, $2.10{\pm}0.75$ in the CMCF group and $1.53{\pm}0.44$ in the CMCF+LMWH group. The most favorable prevention against adhesion was achieved in the CMCF+LMWH group. Therefore, we could conclude that CMCF+LMWH were effective in prevention against postoperative adhesion in the rat.

• The Journal of the Korean dental association
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• v.10 no.1
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• pp.15-21
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• 1972

In the periodic amputated rat incisor pulp, the distribution of five isoenzymes of lactic acid dehydrogenase was evaluated and the total LDH activity was assayed. This study hs established the followings; 1) It demonstrates the existence of five distinct isoenzymes of LDH, with LDH-1 and LDH-2 predominating, in the rat incisor pulp. 2) The total LDH activity in periodically amputated rat incisor pulp is markedly increased as compared to the normal rat incisor pulp. 3) It is possible that the periodic amputation of tooth effects the pattern of LDH isoenzymes in the pulp, especially LDH-1 and LDH-2 region.

• Biomedical Science Letters
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• v.12 no.4
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• pp.427-433
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• 2006

We investigated the effect of propolis on the activity of antioxidant enzymes in rat liver exposed by X-ray irradiation. The dosage of propolis showed the effect of lowering the concentration of superoxide anion in irradiated rat liver, suggesting that propolis has a significant role to remove superoxide anion as an antioxidant and/or by activating the antioxidant enzyme. The activities of superoxide dismutase (SOD) and glutathione reductase (GR), disturbed by X-ray irradiation, were restored in 30 days to normal status in the group which dosed propolis before X-ray irradiation. Interestingly, catalase (CAT) and glutathione peroxidase (GPOX) activities were highly increased with feeding propolis to rat compared to untreated group, whereas glutathione s-transferase (GST) activity was little affected. Taken together, it suggests that the propolis has a protective role in the rat liver cells against X-ray irradiation by increasing and recovering the activities of antioxidant enzymes.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.720-726
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• 1996

The neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells could be attenuated by diterpene constituents of Ginkgo biloba leaves, ginkgolides A, B and C. At the concentration of 100 nM, ginkgolides up-regulated the activity of glutathione reductase in primary cultures of rat cortical cells exposed to 100 ${\mu}$M glutamate. Furthermore, ginkgolides increased the content of reduced glutathione in glutamate-treated cortical cells. However, ginkgolides showed little effect in reducing superoxide dismutase activity. Ginkgolides did, however, markedly block the production of malondialdehyde, a byproduct of lipid peroxidation in glutamate-treated rat cortical cells.

• Korean Journal of Pharmacognosy
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• v.26 no.1
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• pp.51-56
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• 1995

To devise an in vitro screening method for antihepatotoxic activity, $CCl_4-induced$ cytotoxicities in primary cultures rat hepatocytes were examined. When rat hepatocytes were intoxicated with 0.5, 1.0 or 1.5 mM $CCl_4$ for 1.5, 3 or 19hr, in order of LDH>GOT>GPT release form hepatocytes was increased in a dose-dependent manner. Treatment with 1.5 mM $CCl_4$ for 1.5 hr showed maximum increase in activity of LDH, GOT or GPT released in the medium compared with the control. At this experimental condition, well known antihepatotoxic substances, glycyrrhizin and silybin markedly inhibited $CCl_4-induced$ cytotoxicities. These results demonstrated that the screening method using $CCl_4-induced$ injury in primary cultured rat hepatocytes might be suitable in vitro assay for antihepatotoxic activity.