• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.23-23
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• 2003

It has been suggested that the impairment of smooth muscle cell (SMC) function by alterations in the $Ca^{2+}$-activated $K^{+}$ ( $K_{Ca}$ ) channels accounts for the reduction in coronary reserve during left ventricular hypertrophy (LVH). However, this hypothesis has not been fully investigated. The main goal of this study was to assess whether the properties of $K_{Ca}$ channels in coronary SMCs were altered during LVH. New Zealand white rabbits (0.8-1.0 kg) and Sprague-Dawley rats (300-400 g) were randomly selected to receive either an injection of isoproterenol (300 $\mu\textrm{g}$/kg body weight) or an equal volume of 0.9％ saline (1 mL/kg body weight). The animals developed LVH 10 days after injection. In patch-clamp experiments, the unitary current amplitude and open probability for the $K_{Ca}$ channels were significantly reduced in LVH patches compared with control patches. The concentration-response curve of the $K_{Ca}$ channel to [C $a^{2+}$]$_{i}$ was shifted to the right. Inhibition of the $K_{Ca}$ channels with TEA was more pronounced in LVH cells than in the control cells. The whole-cell currents of $K_{Ca}$ channels were reduced during LVH. Western blot analysis indicated no differences in $K_{Ca}$ channel expression between the control and LVH coronary SM membranes. In contraction experiments, the effect of a high $K^{+}$concentration on the resting tension of the LVH coronary artery was greater than on that of the control. The effect of TEA on the resting tension of the LVH coronary artery was reduced as compared with the effect on the control. Our findings imply a novel mechanism for reduced coronary reserve during LVH.ing LVH.

• Korean Journal of Animal Reproduction
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• v.15 no.1
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• pp.15-22
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• 1991

To determine the preventive effects of selenium and/or vitamin E on placenta retention in Holstein dairy cows. The cows were divided six groups ; control, Se, vit.E 1x, vit.E 3x, Se + vit./E 1x and Se + vit.E 3x in Cooong Nam province. 50mg of Se as sodium selenite and 700 IU of vit. E as dl-${\alpha}$ tocopherol acetate were injected 21 day perior to expected calving date, and 700 IU vit.E was injected 3 times at 21, 14 and 7 days perior to expected calving date in vit.E 3x groups. The cows which did not expelled their placenta until 12 hours post-parturient were termed as cow of placenta retention. The i.m. injection of a single dose of selenium and vit.E has significantly(P<0.05) affected the incidence of retained placenta by 7.0% versus 25.6% of controls, but a single injection of selenium or vit.E and a combination of selenium 1x and vit.E 3x has not significantly affected. But they affected neiher subsequent reproductive performances nor milk yields.

• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.17-22
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• 2009

The effect of Bu-Zhong-Yi-Qi-Tang (BZYQT) on the changes of ultraviolet (UV) light B radiation-induced apoptotic sunburn cell (SBC) and epidermal ATPase-positive dendritic cell (DC) in SKH1- hr or ICR mouse were investigated. The mice were treated with UVB (200 mJ/$cm^2$) and were sacrificed 24 h later. BZYQT (50 mg/kg of body weight) or vehicle (saline) was given i.p. at 36 and 12 h before irradiation, and 30 min after irradiation or BZYQT cream (0.2%) or cream base (vehicle) was topically treated at 24 h and 15 min before irradiation, and immediately after irradiation. The skin of SKH1-hr mouse prepared from the back of untreated mice exhibited about 0.3 SBC/cm length of epidermis, and 24 h after UV irradiation, the applied areas show an increased number of SBCs. But the frequency of UVB-induced SBC formation was reduced by intraperitoneal injection of BZYQT extract (p < 0.01). The numbers of DC in normal ICR mouse were 628.00 ${\pm}$ 51.56 or 663.20 ${\pm}$ 62.58 per $mm^2$ of ear epidermis. By 1 day after UVB treatment, the number of ATPase-positive cells/$mm^2$ were decreased by 39.0% or 27.1% in i.p. or topical application group with vehicle. Treatment of BZYQT was associated with increase of 33.9% in i.p. group (p < 0.05) or 2.7% in topical application group in the number of ATPase positive cells compared with the irradiation control group. The results presented herein that BZYQT administration could reduce the extent of skin damages produced by UVB.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.1-14
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• 2006

The purpose of the present study was to evaluate the histologic results of bone cavities that were surgically created in the calvaria of rabbit and filled with $HA/{\beta}-TCP$ composite powders, which had been developed in Korea (Dentium, Korea). Ten young adult rabbits were used. Four defects were surgically produced in calvaria of each rabbit. Each rabbit was anesthetized with Ketamine-HCI (5 mg/kg, Yuhan Cor. Korea) and Xylazine-HCI (1.5 ml/kg, Yuhan Cor. Korea)). An incision was made to the bony cranium and the periosteum was reflected. Using a trephine bur (external diameter: 8 mm, 3i, USA), 4 'through-and-through' bone defects were created with copious irrigation, and classified into 4 groups: control group: no graft materials, experimental group I: normal saline + graft materials: experimental group II: venous blood + graft materials: experimental group III: graft materials only. The defects were randomly filled with graft materials. The defects were closed with resorbable suture material. At the end of the surgical procedure, all animals received a single intramuscular injection of antibiotics Gentamicin (0.1 mg/kg, Dae Sung Microb. Korea). Rabbits were sacrificed with phentobarbital (100 mg/kg) intravenously at 1-, 2-, 4-, 6- and 8-week after. Specimens were treated with hydrochloric acid decalcifying solution (Fisher Scientific, Tustin, CA) and sectioned by bisecting the 8 mm diameter defects. The histologic specimens were prepared in the general method with H & E staining at 6 ${\mu}m$ in thickness. The results were as follows; 1. New bone formation showed from after 2-week of surgery in defect area. As time lapsed, lots of new bone formation and mature bones showed. 2. Histologically, degree of new bone formation could not be discerned among the experimental groups. But, for experimental group II, lots of cells gathered around graft materials after 1-week of surgery, new bone formed slightly faster and than the others at 1-week after. For experimental group I, a few inflammatory finding showed around graft material at after 1-week and after 2-week of surgery. 3. No bone formation did show for control group. Based on histologic results, the new $HA/{\beta}-TCP$ composite powders appeared to act as a scaffolding material for regeneration of osseous defects.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.468-477
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• 2009

Purpose: Hydrodynamic-based procedure is a simple and effective gene delivery method to lead a high gene expression in liver tissue. Non-invasive imaging reporter gene system has been used widely with herpes simplex virus type 1 thymidine kinase (HSV1-tk) and its various substrates. In the present study, we investigated to image the expression of HSV1-tk gene with 5-(2-iodovinyD-2'-deoxyuridine (IVDU) in mouse liver by the hydrodynamicbased procedure. Materials and Methods: HSV1-tk or enhanced green fluorescence protein (EGFP) encoded plasmid DNA was transferred into the mouse liver by hydrodynaminc injection. At 24 h post-injection, RT-PCR, biodistribution, fluorescence imaging, nuclear imaging and digital wholebody autoradiography (DWBA) were performed to confirm transferred gene expression. Results: In RT-PCR assay using mRNA from the mouse liver, specific bands of HSV1-tk and EGFP gene were observed in HSV1-tk and EGFP expressing plasmid injected mouse, respectively. Higher uptake of radiolabeled IVDU was exhibited in liver of HSV1-tk gene transferred mouse by biodistribution study. In fluorescence imaging, the liver showed specific fluorescence signal in EGFP gene transferred mouse. Gamma-camera image and DWBA results showed that radiolabeled IVDU was accumulated in the liver of HSV1-tk gene transferred mouse. Conclusion: In this study, hydrodynamic-based procedure was effective in liver-specific gene delivery and it could be quantified with molecular imaging methods. Therefore, co-expression of HSV1-tk reporter gene and target gene by hydrodynamic-based procedure is expected to be a useful method for the evaluation of the target gene expression level with radiolabeled IVDU.

• Journal of the Korean Society of Food Culture
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• v.18 no.3
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• pp.202-210
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• 2003

The purpose of this study was to investigate the effects of dietary purple sweet potato(Ipomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C), induced hepatotoxicity rats fed control diet(EC), normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachlolide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(AST/GOT) of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G6Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.6
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• pp.435-440
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• 2010

Valproic acid (VPA) is a well-known anti-epileptic and mood stabilizing drug. A growing number of reports demonstrate that VPA is neuroprotective against various insults. Despite intensive efforts to develop new therapeutics for stroke over the past two decades, all treatments have thus far failed to show clinical effect because of treatment-limiting side effects of the drugs. Therefore, a safety-validated drug like VPA would be an attractive candidate if it has neuroprotective effects against ischemic insults. The present study was undertaken to examine whether pre- and post-insult treatments with VPA protect against brain infarct and neurological deficits in mouse transient (tMCAO) and permanent middle cerebral artery occlusion (pMCAO) models. In the tMCAO (2 hr MCAO and 22 hr reperfusion) model, intraperitoneal injection of VPA (300 mg/kg, Lp.) 30 min prior to MCAO significantly reduced the infarct size and the neurological deficit. VPA treatment immediately after reperfusion significantly reduced the infarct size. The administration of VPA at 4 hr after reperfusion failed to reduce the infarct size and the neurological deficit. In the pM CAO model, treatment with VPA (300 mg/kg, i.p.) 30 min prior to MCAO significantly attenuated the infarct size, but did not affect the neurological deficit. Western blot analysis of acetylated H3 and H4 protein levels in extracts from the ischemic cortical area showed that treatment with VPA increased the expression of acetylated H3 and H4 at 2 hrs after MCAO. These results demonstrated that treatment with VPA prior to ischemia attenuated ischemic brain damage in both mice tMCAO and pMCAO models and treatment with VPA immediately after reperfusion reduced the infarct area in the tMCAO model. VPA could therefore be evaluated for clinical use in stroke patients.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.191-200
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• 2014

We investigated the anxiolytic-like activity of ${\alpha}$-asarone (AAS) from Acorus gramineus in an experimental rat model of anxiety induced by repeated administration of the exogenous stress hormone corticosterone (CORT). The putative anxiolytic effect of AAS was studied in behavioral tests of anxiety, such as the elevated plus maze (EPM) test and the hole-board test (HBT) in rats. For 21 consecutive days, male rats received 50, 100, or 200 mg/kg AAS (i.p.) 30 min prior to a daily injection of CORT. Dysregulation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Daily AAS (200 mg/kg) administration increased open-arm exploration significantly in the EPM test, and it increased the duration of head dipping activity in the HBT. It also blocked the increase in tyrosine hydroxylase (TH) expression in the locus coeruleus (LC) and decreased mRNA expression of brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, in the hippocampus. These results indicated that the administration of AAS prior to high-dose exogenous CORT significantly improved anxiety-like behaviors, which are associated with modification of the central noradrenergic system and with BDNF function in rats. The current finding may improve understanding of the neurobiological mechanisms responsible for changes in emotions induced by repeated administration of high doses of CORT or by elevated levels of hormones associated with chronic stress. Thus, AAS did exhibit an anxiolytic-like effects in animal models of anxiety.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.263-270
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• 2000

To evaluate the involvement of nitric oxide production on the endothelium-dependent relaxation in diabetes, we have measured vascular and endothelial function and nitric oxide concentration, and the expression level of endothelial nitric oxide synthase in the streptozotocin-induced diabetic rats. Diabetic rats were induced by the injection of streptozotocin (50 mg/kg i.v.) in the Sprague-Dawley rats. Vasoconstrictor responses to norepinephrine (NE) showed that maximal contraction to norepinephrine $(10^{-5}\;M)$ was significantly enhanced in the aorta of diabetic rats. Endothelium-dependent relaxation induced by acetylcholine was markedly impaired in the aorta of diabetic rats, these responses were little improved by the pretreatment with indomethacin. However, endothelium-independent relaxation induced by nitroprusside was not altered in the diabetic rats. Plasma nitrite and nitrate $(NO_2/_3)$ levels in diabetic rats were significantly lower than in non-diabetic rats. Western blot analysis using a monoclonal antibody against endothelial cell nitric oxide synthase (eNOS) revealed that the protein level was lower in the aorta of diabetic rats than in non-diabetic rats. These data indicate that nitric oxide formation and eNOS expression is reduced in diabetes, and this would, in part, account for the impaired endothelium-dependent relaxation in the aorta of streptozotocin-induced diabetic rats.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3907-3912
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• 2015

Purpose: To investigate the antitumor activity and mechanism of chloroquine (CQ) in combination with cisplatin (DDP) in nude mice xenografted with gastric cancer SGC7901 cells. Materials and Methods: 35 cases of gastric cancer patients with malignant ascites were enrolled and intraperitoneal cisplatin injection was performed. Ascites were collected before and 5 days after perfusion for assessment of autophagy levels in cancer cells. In addition, 24 tumor-bearing mice were randomly divided into control, DDP, CQ and CQ + DDP groups. Results: In 54.3% (19/35) of patients the treatment was therapeutically effective (OR), 5 days after peritoneal chemotherapy, 13 patients had the decreased ascites Beclin-1 mRNA levels. In 16 patients who had NR, only 2 cases had decreased Beclin-1 (P=0.001). Compared with the control group, the xenograft growth in nude mice in the DDP group was low, and the inhibition rate was 47.6%. In combination with chloroquine, the inhibition rate increased to 84.7% (P<0.01). The LC3-II/I ratio, and Beclin1 and MDR1/P-gp expression were decreased, while caspase 3 protein levels increased (P<0.05). Conclusions: Antitumor ability of cisplatin was associated with autophagy activity and chloroquine can enhance chemosensitivity to cisplatin in gastric cancer xenografts nude mice.