• YAKHAK HOEJI
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• v.33 no.5
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• pp.300-307
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• 1989

Expression of transferrin gene in various organs of rat was studied using rat transferrin cDNA. The hybridization method of $[^{35}S]-labeled$ transferrin cDNA with transferrin mRNA in cytoplasmic preparations was used to measure the level of transferrin mRNA. The rat from 15-day old fetus to 21-day old postnatal were employed as an animal model. In the liver, the level of transferrin mRNA increased with increasing age. However, the level of transferrin mRNA in brain was significantly lower than that in liver and the level did not increase with age.

• Neonatal Medicine
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• v.17 no.1
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• pp.44-52
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• 2010

Purpose : The aim of this study was to develop a model for necrotizing enterocolitis (NEC) in the neonatal rat using endotoxin and hypoxia, a plausible insult in a neonatal intensive care and to investigate the role of apoptosis as the underlying mechanism. Methods : Newborn rats were given oral endotoxin and intermittent 8% hypoxia$\pm$caspase inhibitor. The intestinal histology was evaluated using hematoxylin-eosin staining. Apoptosis was analyzed with TUNEL staining and by measuring the caspase 3 activity in the intestinal lysates. IEC-6 cells were assessed for apoptosis and the expression of Bax, Bcl-2, Fas and FasL was measured after treatment with endotoxin and hypoxia. Results : Oral endotoxin (5 mg/kg) and exposure to 8% hypoxia of 60-min duration twice induced human NEC-like lesions in the rat intestine. Intestinal tissue revealed increased apoptosis and caspase-3 activity. After caspase inhibitor treatment, the grades of both apoptosis and NEC were significantly reduced. IEC-6 cells exhibited increased apoptosis and caspase 3 activity after endotoxin and hypoxia treatment and significantly increased Bax/Bcl- 2 ratio compared to control cells. Conclusion : This neonatal rat model of NEC which was induced by oral endotoxin and intermittent hypoxia showed increased apoptosis of intestinal epithelial cells that was mediated by caspase 3 activation. Our model has a advantage in the study of NEC because the use of much more clinically plausible insults may provide a suitable model for the investigation of its pathophysiology and therapeutic trials.

• Korean Journal of Acupuncture
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• v.22 no.1
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• pp.7-21
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• 2005

Objectives : In the present study, the effect of electroacupuncture (EA) applied to SI6 and won-rak point on the ankle sprain model was examined. A common source of persistent pain in humans is the lateral ankle sprain. Methods : To model this condition, the rat's right ankle was bent repeatedly, overextending lateral ligaments, for 4 min under enflurane anesthesia. The rat subsequently showed swelling of the ankle and a reduced stepping force of the affected limb for the next several days. The reduced stepping force of the limb was presumably due to a painful ankle. EA was applied to the several acupuncture point on the contralateral forelimb for 30 min under gaseous anesthesia. After the termination of EA, behavioral tests measuring stepping force and Paw volume were Periodically conducted during the next 4 h and 18 h respectively. Results : EA applied to $SI_6$ with won-rak point produced more powerful improvement of stepping force of the sprained foot than to $SI_6$ alone lasting for at least 4 h. However, neigher $KI_4$ point nor $BL_{64}$ point produced any significant increase of weight bearing force. The improvement of stepping pressure was interpreted as an analgesic effect. The analgesic effect was specific to the acupuncture point since the analgesic effort on the ankle sprain pain model could not be mimicked by EA applied to $KI_4$ or $BL_{64}$. In addition, EA applied to $SI_6$ with won-rak combination point showed inhibitory effect on the paw edema induced by ankle sprain. Also, COX-2 protein expression increased by ankle sprain were suppressed by the EA stimulation. Conclusion : These data suggest that EA with won-rak combination point produces a more potent analgesic effect on the ankle sprain pain model in the rat and that EA with won-rak combination point induced anti-inflammatory effect through the suppression of COX-2 protein expression.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.277-285
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• 1993

To investigate the effects of dietary calcium levels on the Ca metabolism in a rat model of ovariectomized osteoporosis, two studies were conducted. In Expt. I, five week-old femalc rats ovariectomized and fed a low Ca diet(0.06% Ca) for four weeks were compared with rats fed a normal (0.53% Ca) or low Ca diet under the sham-operated condition. Ovariectomized rats showed a significant increase in body weight and food intake. In rats fed the low Ca diet, a remarkable decrease was shown regardless of ovariectomy in serum Ca concentration, breaking force of bones, Ca and phopsphrus contents of bones, and apparent absorption and retention of Ca. Furthermore hte decrease of Ca contents of serum and bones in rats ovariectomized and fed the low Ca diet was similar to that in rats model of postmenopausal osteoporosis. In Expt. II, rats ovariectomized and fed on the low Ca diet for four weeks were divided into three groups, those given low Ca diet, normal Ca diet and high Ca diet(1.06%) respectively. The results indicated that supplementations of Ca at the intake level of 0.53% and 1.06% for 4 weeks tend to improve the relative Ca deficiency shown in experimental rat model of ovariectomized osteoporosis.

• YAKHAK HOEJI
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• v.41 no.2
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• pp.260-267
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• 1997

To establish prediabetes in vitro model concerning the etiology of IDDM(Insulin Dependent Diabetes Mellitus) in cellular level we have designed prediabetes in vitro models in pa ncreatic beta cells. HIT-T15, RINm5F and isolated rat islets were chosen as pancreatic beta cells, and streptozotocin (STZ) used as diabetogenic agent. Degree of beta cell destruction to establish prediabetic in vitro model was determined by cell proliferation and insulin release using thymidine uptake and radio immuno assay. When HIT-T15 and RINm5F cells were treated with STZ, the degree of cell deterioration was dependent upon the origin and passage number of beta cells, and in the case of isolated islets STZ showed the more sensitivity than above two beta cell lines. The concentration and exposure time of STZ treatment to establish prediabetes in vitro model in beta cell lines and isolated rat islets were 2 ~ 10mM, 30 min. and 1 ~ 5mM, 30 min., respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.1
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• pp.33-41
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• 2004

We developed a cardiac cell model to explain the phenomenon of mechano-electric feedback (MEF), based on the experimental data with rat atrial myocytes. It incorporated the activity of ion channels, pumps, exchangers, and changes of intracellular ion concentration. Changes in membrane excitability and $Ca^{2+}$ transients could then be calculated. In the model, the major ion channels responsible for the stretch-induced changes in electrical activity were the stretch-activated channels (SACs). The relationship between the extent of stretch and activation of SACs was formulated based on the experimental findings. Then, the effects of mechanical stretch on the electrical activity were reproduced. The shape of the action potential (AP) was significantly changed by stretch in the model simulation. The duration was decreased at initial fast phase of repolarization (AP duration at 20% repolarization level from 3.7 to 2.5 ms) and increased at late slow phase of repolarization (AP duration at 90% repolarization level from 62 to 178 ms). The resting potential was depolarized from -75 to -61 mV. This mathematical model of SACs may quantitatively predict changes in cardiomyocytes by mechanical stretch.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.100-107
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• 1999

Apoptosis is now widely recognized as a common form of cell death and represents mechanism of cell clearance in many physiological situations where deletion of cells is required. In vivo administration of bacterial lipopolysaccharide (LPS) to Balb/c mice induced DNA fragmentation in the thymus. DNA fragmentation in the thymus was roughly dependent on the dose of LPS injected and reached the peak 18 hours after injection. This apoptosis in the thymus might be mediated due to LPS stimulant. DEN (diethylnitrosamine) has been shown to cause liver cancer in experimental animals and humans. The hepatic tumorigenesis was induced by ad libitum feeding of DEN only. It was suggested that DEN induced hepatic tumorgenesis in rat is a good reproducible model for studying biochemical and pathophysiological changes associated with the development of hepatic tumorigenesis and apoptosis.

• Advances in Traditional Medicine
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• v.5 no.1
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• pp.37-42
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• 2005

The crude methanolic extract of the leaves of Amoora cucullata Roxb. was investigated for its possible anti-inflammatory activity using carrageenin induced rat paw edema model and cotton pellet implantation method in rat. The extract was also studied for its antinociceptive activity using acetic acid induced writhing model in mice. At the doses of 200 and 400 mg/kg body weight, the extract showed significant anti-inflammatory activity in both models. At the same doses, the extract also significantly reduced the number of acetic acid-induced abdominal constriction (writhing) in mice. The crude extract also showed significant diuretic activity in albino mice.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.2
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• pp.103-113
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• 2009

This study was performed to evaluate the effect of HCB on the bone mass and its related factors in estrogen-deficient animal model. The model rats of osteoporosis showed a significant decrease in bone density, bone ash density, calcium content of femur bone. At the 14th day after ovariectomy-surgery, rats were administered with HCB, extract of Houyttnia cordata, per orally, and continued for 10 weeks. And osteoporosis related parameters were determined to investigate the effect of HCB. Osteoporotic rats showed lower serum estrogen level, higher body weight than normal rats, and showed atrophy of uterine horns.

• Biomedical Science Letters
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• v.28 no.2
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• pp.137-144
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• 2022

Poria cocos is a natural substance known to have anticancer, antioxidant and anti-inflammatory effects. The aim of this study is to investigate the analgesic effects of Poria cocos extract (PCE). We evaluated the analgesic effects of PCE using adjuvant induced arthritis rat model. Male SD rats were administered intra-orally with PCE according to prescribed dosage, during 6 days. After 6 days later, serum TNF-α, IL-1β, and IL-6 levels were measured by ELISA. In our experiment, administration of PCE decreased TNF-α, IL-1β, IL-6 and PGE2 level in serum. Furthermore, it was confirmed that allodynia was relieved in evaluation of pain behavior. It was confirmed that administration of PCE reduces nociceptive pain by reducing nociceptive stimuli by acting as an anti-inflammatory drug.