• Journal of radiological science and technology
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• v.21 no.1
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• pp.79-87
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• 1998

The total-bodies of 10 week-old Sprague-Dawley rats were irradiated with single doses 4.5 and 7.5 Gy, respectively. The effects on plasma and sciatic nerve platelet-derived growth factor(PDGF) concentrations and sciatic nerve PDGF ${\alpha}$ -and ${\beta}$ -receptors densities were examined up to 10 days post-treatment. There was no consistent significant variation in the plasma and sciatic nerve PDGF concentrations in time over the period of study between 4.5 and 7.5 Gy groups. Plasma PDGF concentrations were significantly reduced to 58% of control values between 5 and 10 days with 4.5 Gy and to 51% of control values as percentage of control values between 5 and 10 days with 7.5 Gy after irradiation, respectively(p<0.05). Sciatic nerve PDGF concentrations were increased to 118% of control values at 1 day with 4.5 Gy and to 130% of control values at 1 day with 7.5 Gy after irradiation, respectively(p>0.05). After irradiation, the levels of PDGF ${\alpha}$ -receptor protein density were reduced to 33% of control values at 2 days with 4.5 Gy and to 50% at 2 days with 7.5 Gy, while the levels of PDGF ${\beta}$-receptor protein density were reduced to maximally 26% of control values at 2 days with 4.5 Gy and to 27% at 2 days with 7.5 Gy, respectively, but both initial decreased levels of those were increased subsequently after 2 days following irradiation. These results suggest that the radiation-induced alteration of plasma and sciatic nerve PDGF concentrations, and sciatic nerve PDGF ${\alpha}$ -and ${\beta}$ -receptors densities may be involved in the pathogenesis of bone marrow stem cell and peripheral neuron damages.

• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.285-294
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• 2010

The purpose of this study was to evaluate the viability of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure by means of MTT assay, WST-1 assay. 12 teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both side of the first and second maxillary molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group 1 (Immediate extraction), group 2 (Slow freezing under pressure of 3 MPa), group 3 (Slow freezing under pressure of 2 MPa), group 4 (Slow freezing under no additional pressure), group 5 (Rapid freezing in liquid nitrogen under pressure of 2 MPa), group 6 (Rapid freezing in liquid nitrogen under no additional pressure), group 7 (low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa), group 8 (low-temperature preservation at $0^{\circ}C$ under no additional pressure), group 9 (low-temperature preservation at $-5^{\circ}C$ under pressure of 90 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$ water bath, then MTT assay, WST-1 assay were processed. One way ANOVA and Tukey HSD method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 7 ($0^{\circ}C$/2 MPa) showed higher viability of periodontal ligament cells than other group (2-6, 8) and this was statistically significant (p < 0.05), but showed lower viability than group 1, immediate extraction group (no statistical significance). By the results of this study, low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa suggest the possibility for long term preservation of teeth.

• Journal of Life Science
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• v.21 no.6
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• pp.829-837
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• 2011

The purpose of this study was to investigate the effects of ethanol extracts from red pepper seeds on cholesterol adsorption capacity and UDP-glucuronyl transferase activity. In vitro cholesterol adsorption capacity of 2%, 5% and 10% ethanol extracts from red pepper seed groups were significantly higher than that of the control group. Sprague-Dawley strain male rats weighing $100{\pm}10$ g were randomly assigned to one normal diet N group and experimental groups fed high fat and high cholesterol diet, which were divided into HF (0.0%), HEA (0.1%), HEB (0.2%), and HEC (0.5%) groups according to the amount of ethanol extracts from red pepper seeds added to their basal diet. The body weight gain in the HF group was higher than that in the N group, and those in the HEA, HEB and HEC groups were lower than that in the HF group However, there were no statistically significant differences among the all the groups. The hepatic triglyceride and total cholesterol contents in the N group was significantly lower than that in the HF group, and those in the HEA, HEB and HEC groups were lower than that in the HF group. The hepatic UDP-glucuronyl transferase activity in the N group was lower than that of the HF group and those in the HEA, HEB and HEC groups were lower than that of the HF group. The serum total cholesterol and triglyceride contents of the HF group were significantly higher than that of the N group, and those of the HEA, HEB and HEC groups were lower than that of the HF group. The serum HDL-cholesterol contents in all groups supplemented with the ethanol extracts from red pepper seeds were significantly higher than that of the HF group. The serum LDL-cholesterol contents of the HF group were significantly higher than that of the N group, and those of the HEA, HEB and HEC groups were lower than that of the HF group. The fecal total cholesterol contents were significantly higher in the HF group compared to the N group, and those of the HEB and HEC groups were lower than that of the HF group. The fecal triglyceride contents in the N group was higher than that of the HF group, and those of the HEA, HEB and HEC groups were lower than that of the HF group. This study suggested that the ethanol extracts from red pepper seeds have powerful health benefits by the UDP-glucuronyl transferase activity and lipid metabolism.

• Journal of Life Science
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• v.11 no.6
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• pp.582-594
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• 2001

This experiment was performed to investigate the effects of sulfur dioxide on the histological changes, properties of mucosubstances and glycoconjugates of the nasal respiratory mucosa in the rat. Sprague-Dawley male rats weighing about 200~250g were divided into a control group and SO$_2$ exposed groups. Again SO$_2$ exposed groups were divided into 10 ppm, 25 ppm, 50 ppm, 100 ppm, and 200 ppm subgroups, according to concentrations of SO$_2$ and each SO$_2$exposed groups were divided into 1, 3 and 6 hours groups. For the histological changes, hematoxylin-eosin(H-E) and periodic acid Schiff's(PAS) stainings were used, and for the properties of mucosubstances, PAS, alcian blue (AB) pH 2.5, pH 2.5-PAS, AB pH 1.0 and aldehyde fuchsin (AF) pH1.7-AB pH 2.5 were used. In all the SO$_2$ exposed groups, loss of cilia and detachment of epithelial cells, vacuolation of goblet cells were observed in the respiratory epithelium while epithelial squamous metaplasia and intraepthelial mucous cells were observed in the higher concentration of SO$_2$ and the degree of the loss cilia was higher according as concentration was higher and exposed time was longer. The intraepitheial mucous cells appeared most remarkable in the 50 ppm SO$_2$ exposed group. The numbers of goblet cells and acini of nasal septal gland were varied according to concentration of SO$_2$ and exposed time, but the numbers in the 25 ppm and 50 ppm, SO$_2$ exposed increased remarkably. However, the numbers in the 100 ppm and 200 ppm SO$_2$ exposed group had a tendency to decrease noticeably, or disappeared.

• Applied Microscopy
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• v.32 no.1
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• pp.67-80
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• 2002

This study was carried out to investigate the effects of deer antler extract on the regeneration of peripheral nerves. Sprague-Dawley male rats weighing about 300 gm were fed deer antler extract for 1, 2, and 3 weeks per oral (1.5 ml/100 gm B.W.), respectively, once a day and transected both sides of sciatic nerve of each leg. After keeping for 6 hours, sciatic nerves taken from proximal part of transected region were treated with conventional transmission electron microscopical method and then observed with electron microscope. The results obtained were summarized as follows; 1. Sciatic nerves of normal control group were not showing any sprouts and electron dense axolemmal projections were frequently observed. 2. Sciatic nerves of saline treated groups were showing axonal sprouts at the nodes of Ranvier. The length of them was usually short, and numerous vesicles, vacuoles and organelles including neurofilament were contained. The number of nodes of Ranvier containing sprouts from 100 longitudinal sectioned nerve fibers was 29 (29%) in 1 week treated group, 32 (32%) in 2 weeks treated group, and 30 (30%) in 3 weeks treated group, respectively. 3. Sciatic nerves of deer antler treated groups were showing axonal sprouts at the node of Ranvier as well. Although most of the sprouts were short, some sprouts of 2 weeks and 3 weeks treated groups were quite long. Sprouts usually contained numerous vesicles, vacuoles and cell organelles such as neurofilaments and mitochondria. The number of nodes of Ranvier containing sprouts from 100 longitudinal sectioned nerve fibers was 38 (38%) in 1 week treated group, 46 (46%) in 2 weeks treated group, and 48 (48%) in 3 weeks treated group respectively. The results described above explain pretreatment of deer antler extract improves the sprout formation of transected sciatic nerves, and then it suggests deer antler may be effective for the regeneration of peripheral nerves.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.155-161
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• 2001

This study was carried out to investigate cytotoxicity of paraquat or bentazone on NIH 3T3 fibroblasts, toxicity of paraquat or bentazone, and compensatory effects of 3-Methylcholanthrene(3-MC) on the rat liver. In order to MTT assay, the $5.0{\times}10^4$ cell/mL of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution of paraquat or bentazone(1, 25, 50, 100 ${\mu}M$ respectively). After the NIH 3T3 fibroblast of all groups were cultured in same condition for 48 hours. MTT assay were performed to evaluate the cytotoxicity of cell organelles. Paraquat or bentazone $MTT_{50}$ were 1668.97 ${\mu}M$ and 1506.97 ${\mu}M$, respectively. These $IC_{50}$ of paraquat or bentazone were decided low cytotoxicity by Borenfreund. In order to observe the toxicity and compensatory effects of paraquat or bentazone on the rat liver, Sprague-Dawley male rats were used as experimental animals and divided into paraquat or bentazone only treated group and simultaneous application group of paraquat or bentazone and 3-MC. At 30 min and 1, 3, 6, 12, 24, 48 and 96 hrs interval after each treatment, the animals were sacrificed by decapitation and liver were immediately removed, immersed in fixatives, and processed with routine method for light microscopic study. Paraffin sections were stained with H-E, PAM and Best Carmine. Under the light microscope, degenerative changes of hepatic lobules were frequently observed in portal area from 3 hrs after paraquat or bentazone treatment. All hepatic cells were induced degenerative change at 12 hrs and more severe degenerative change at 48 hrs after paraquat or bentazone treatment. Especially, hepatic cells of bentazone only treated group were distinctly showed pyknotic. Glycogen granules were increased in portal area at 3 hrs, all hepatic cells at 12 hrs and remarkably increased at 48 hrs after paraquat or bentazone treated group. But hepatic cells of bentazone only treated group were regeneration at 48 hrs from portal area and glycogen granules of hepatic cells of paraquat or bentazone and 3-MC combination treated group showed in central area only at 48 hrs. The results indicate that 3-MC may be decrease paraquat or bentazone cytotoxicity on the rat liver.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.555-563
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• 1995

This study was performed to investigate the effect of Aloe arborescens on the cadmium toxicity in rats. Thirty male Sprague-Dawley strains were divided into five groups consisting of a control group, a cadmium treatment group and 3 aloe(0.5%, 0.75%, 1%) treatment groups and observed for 9 weeks. The weight increment of the cadmium and 0.75% aloe group was higher than that of the cadmium treatment group(p<0.01). The food intake did not show the consistency rule among the experimental groups and the decrement tendency of food intake affected by cadmium feeding group. The decrement tendency of water intake affected by cadmium appeared to be suppressed by aloe treatment, especially cadmium and 0.75% aloe treatment group showed the remarkable increment of water intake. The diet efficiency of the control group was the highest among the experimental groups and that of cadmium and 0.75% aloe group was higher than other aloe treatment groups. The weight of each organ did not show consistency among the experimental groups but only the testicle of cadmium and 0.75% aloe treatment group was heavier than that of the control group. The cadmium accumulation was high in order of kidney>liver>spleen>heart>lung>testicle>brain. The cadmium content of the cadmium treatment group was more than that of cadmium and 0.5% aloe group, cadmium and 0.75% aloe group, cadmium and 1% aloe group. The cadmium content of cadmium and 0.75% aloe group was the lowest among other aloe treatment groups. Therefore, cadmium and 0.75% aloe is the most recommendable aloe treatment to eliminate the cadmium accumulated in organ.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.121-136
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• 2001

This study was performed to analyse the expression of VEGF and it's receptor(VEGFR) in the tension side of the periodontal ligament following orthodontic tooth movement. Upper first molars of Sprague-Dawley rats were moved medially using closed coil spring for 1, 2, 24 hours and 3, 7, 14 days. H&E staining, immunohistochemical staining and in situ hybridization methods were used to analyse the change of the expression of VEGF and VEGFR. The results from this study were as follows : 1. Following tensional force, periodontal ligament showed elongation of fibers, compression and congestion of vessels and regional hemorrhage. These tissue changes were recovered within 3 days of force application. New bone formation was seen after 3 days of force application and continued for the remaining experimental periods. 2. Following tensional force, VEGF and VEGF mRNA expression was increased in the periodontal ligament cells, osteoblasts and cementoblasts. This change was followed by increased vasculature in the periodontal ligament. 3. After 3 days of tensional force, VEGF and VEGF mRNA expression was confined mainly to the osteopaths and the periodontal ligament cells adjacent to the alveolar bone. After 2 weeks of force application, VEGF and VEGF mRNA expression was reduced to the level of control sample. 4. VEGFRs(Flt-1, Flk-1) showed similar expression pattern and it's expression was mainly seen in the endothelial cells and osteoblasts. Following tensional force VEGFR expression was increased in the endothelial cells and osteoblasts. In conclusion, in the tension side of the penodontal ligament, ligament cells, osteoblast and cementoblast showed increased expression of VEGF & VEGF mRNA. It preceded the increase of vasculature and new bone formation. The increased expression of VEGF mRNA in cementoblast may induce periodontal vessels, which distribute mainly the bone side half of periodontal ligament, grow in the direction of tensional force. Increased expression of VEGFR & VEGFR mRNA not only in endothelial cell but in osteoblast, osteocyte and periodontal cells showed VEGF acts not only in paracrine manner but in autocrine one.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.356-363
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• 2009

The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at $4^{\circ}C$for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group. By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.231-238
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• 1994

Backgroud: Since the demonstration of the fact that vascular relaxation by acetylcholine(Ach) results from the release of relaxing factor from the endothelium, the identity and physiology of this endothelium-derived relaxing factor(EDRF) has been the target for many researches. EDRF has been identified as nitric oxide(NO). With the recent evidences that EDRF is an important mediator of vascular tone, there have been increasing interests in defining the role of the EDRF as a potential mediator of hypoxic pulmonary vasoconstriction. But the role of EDRF in modulating the pulmonary circulation is not compeletely clarified. To investigate the endothelium-dependent pulmonary vasodilation and the role of EDRF during hypoxic pulmonary vasoconstriction, we studied the effects of $N^G$-monomethyl-L-arginine(L-NMMA) and L-arginine on the precontracted pulmonary arterial rings of the rat in normoxia and hypoxia. Mothods: The pulmonary arteries of male Sprague Dawley(300~350g) were dissected free of surrounding tissue, and cut into rings. Rings were mounted over fine rigid wires, in organ chambers filled with 20ml of Krebs solution bubbled with 95 percent oxygen and 5 percent carbon dioxide and maintained at $37^{\circ}C$. Changes in isometric tension were recorded with a force transducer(FT.03 Grass, Quincy, USA) Results: 1) Precontraction of rat pulmonry artery with intact endothelium by phenylephrine(PE, $10^{-6}M$) was relaxed completely by acetylcholine(Ach, $10^{-9}-10^{-5}M$) and sodium nitroprusside(SN, $10^{-9}-10^{-5}M$), but relaxing response by Ach in rat pulmonary artery with denuded endothelium was significantly decreased. 2) L-NMMA($10^{-4}M$) pretreatment inhibited Ach($10^{-9}-10^{-5}M$)-induced relaxation, but L-NMMA ($10^{-4}M$) had no effect on relaxation induced by SN($10^{-9}-10^{-5}M$). 3) Pretreatment of the L-arginine($10^{-4}M$) significantly reversed the inhibition of the Ach ($10^{-9}-10^{-5}M$)-induced relaxation caused by L-NMMA($10^{-4}M$) 4) Pulmonary arterial contraction by PE($10^{-6}M$) was stronger in hypoxia than normoxia but relaxing response by Ach($10^{-9}-10^{-5}M$) was decreased, 5) With pretreatment of L-arginine($10^{-4}M$), pulmonary arterial relaxation by Ach($10^{-9}-10^{-5}M$) in hypoxia was reversed to the level of relaxation in normoxia. Conclusion: It is concluded that rat pulmonary arterial relaxation by Ach is dependent on the intact endothelium and is largely mediated by NO. Acute hypoxic pulmonary vasoconstriction is related to the suppression on NO formation in the vascular endothelium.