• Toxicological Research
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• v.16 no.3
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• pp.201-209
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• 2000

In association with the international validation program to establish a rodent uterotrophic assay, we conducted preliminary uterotrophic assay proposed by GECD using immature female rats. In the present study, oral and subcutaneous routes were chosen to compare the effects of estrogenic com-pounds in the two dosing regimens. The reference compound ethinyl estradiol (EE) and the antagonist ZM189154(ZM) were administered by gavage or subcutaneously (s.c.) to immature female SD rats from 20 to 22 days of age. For each study, sixty-six female rats were randomly assigned to eleven groups: Untreated control, EE 0,0.01, 0.03, 0.1, 0.3, 1.0,3.0 and 10.0 $\mu\textrm{g}$/kg, EE 3.0 $\mu\textrm{g}$/kg(gavage)/0.3 $\mu\textrm{g}$/kg(s.c) & ZM 0.1 mg/kg, and EE 3.0 $\mu\textrm{g}$/kg(gavage)/0.3 $\mu\textrm{g}$/kg (s.c) & ZM 1.0 mg/kg. There were no treatment-related changes in clinical signs, body weights, food consumption, and necropsy findings in any groups of two studies. The wet and blotted uterus weights increased dose-dependently. Histopathological examination revealed that diameter of uterine duct, height of uterine luminal epithelium. and height oj vaginal epithelium increased dose-dependently. The proliferating cell nuclear antigen (PCNA) immunoreactive cells were increased in number dose-dependently. The estrogenic effects observed in the present studies occurred at $\geq$ 0.3 $\mu\textrm{g}$/kg of oral dose and $\geq$ 0.1 $\mu\textrm{g}$/kg of s.c. dose. An antagonistic effect of ZM against EE was found in both uterus weight and histopathological parameters. From the results obtained, it can be concluded that dose-dependence of the uterotrophic assay using EE and ZM was well demonstrated by gavage and subcutaneous administration and that the estrogenic effects of EE by s.c. dose were higher than those by gavage administration. In addition, blotted uterus weight was more sensitive than wet uterus weight and vaginal epithelial height was found to be the most sensitive parameter among the parameters examined.

• Development and Reproduction
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• v.24 no.4
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• pp.263-275
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• 2020

The proper administration of melatonin has well been documented to induce testicular regression in seasonal breeding animals. The subcutaneous injections of melatonin in the afternoon, not in the morning, consistently occurred testicular involution in the male Syrian (golden) hamsters whose reproductive activity is regulated by the photoperiod. But the effects of daily melatonin via gavage have not been estimated. Golden hamsters housed in long photoperiod (LP) were divided into 5 groups: the control animals housed in LP or in short photoperiod (SP) and animals treated daily with low (15 ㎍), middle (150 ㎍), and high dosages (1,500 ㎍) of pure melatonin by using gavage in the evening for 8 weeks. As results, LP control animals had large testes and SP controls displayed small and entirely regressed testes. The animals treated with various dosages of melatonin showed collectively degenerating effects on the weights of testes, epididymides, and seminal vesicles in the middle and high dosage groups, with the individual differences as well. The high dosages induced testicular regression in more proportion than the middle dosages did. The low dosage had large testes like the LP control animals. The small and inactive testes shown in some animals of both middle and high groups presented the complete regression as those of the animals maintained in SP. These results strongly suggest that the administrations of melatonin lead to testicular involution in the male golden hamsters when it is administered through gavage.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.3
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• pp.318-327
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• 2015

Purpose: The purposes of this study were to compare confidence in practice of intermittent gavage tube feeding and participants' satisfaction by three types of feedback; professor verbal feedback, professor feedback with smartphone video, and peer feedback with smartphone video. In addition, frequently failed items in the intermittent gavage tube feeding procedure were analyzed. Methods: Data were collected from a convenience sample of 78 nursing college students in November 2014. Students were randomly assigned to the control group, experimental group I (smartphone video with professor feedback) or group II (smartphone video with peer feedback). Data were analyzed using descriptive statistics including chi-square test, ANOVA, and Scheffe test with SPSS 21.0. Results: Confidence in practice of intermittent gavage tube feeding and satisfaction with feedback were highest in experimental group I that had professor feedback with smartphone video. For the procedure, the most frequently failed item was giving an explanation to patients about the purpose and the procedure of tube feeding. Conclusion: The results indicate that professor verbal feedback with smartphone video is the most benefit to the nursing students in acquiring core nursing practice skills.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.660-669
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• 2023

BACKGROUND/OBJECTIVES: To investigate the effect and regulatory mechanism of resveratrol supplementation on the mitochondrial energy metabolism of rats with exercise-induced fatigue. MATERIALS/METHODS: Forty-eight Sprague-Dawley male rats were divided randomly into a blank control group (C), resveratrol group (R), exercise group (E), and exercise and resveratrol group (ER), with 12 rats in each group. Group ER and group E performed 6-wk swimming training with 5% wt-bearing, 60 min each time, 6 days a wk. Group ER was given resveratrol 50 mg/kg by gavage one hour after exercise; group R was only given resveratrol 50 mg/kg by gavage; group C and group E were fed normally. The same volume of solvent was given by gavage every day. RESULTS: Resveratrol supplementation could reduce the plasma blood urea nitrogen content, creatine kinase activity, and malondialdehyde content in the skeletal muscle, increase the total superoxide dismutase activity in the skeletal muscle, and improve the fatigue state. Resveratrol supplementation could improve the activities of Ca²⁺-Mg²⁺-ATPase, Na⁺-K⁺-ATPase, succinate dehydrogenase, and citrate synthase in the skeletal muscle. Furthermore, resveratrol supplementation could up-regulate the sirtuin 1 (SIRT1)-proliferator-activated receptor gamma coactivator-1α (PGC-1α)-nuclear respiratory factor 1 pathway. CONCLUSIONS: Resveratrol supplementation could promote mitochondrial biosynthesis via the SIRT1/PGC-1α pathway, increase the activity of the mitochondrial energy metabolism-related enzymes, improve the antioxidant capacity of the body, and promote recovery from exercise-induced fatigue.

• Toxicological Research
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• v.20 no.2
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• pp.143-151
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• 2004

This study was to investigate single and repeated-dose toxicities of CJ-11555, an anticirrhotic agent, in Sprague-Dawley (SO) rats. In single-dose oral toxicity study, the test article were administered once by gavage to males and females at dose levels of 0 and 2,000 mg/kg. No dead animals and abnormal necropsy findings were found in control and CJ-11555 treated group. Therefore, the approximate lethal dose of CJ-11555 was considered to be higher than 2,000 mg/kg in rats. In the 4-week repeated oral toxicity study, the test article was administered once daily by gavage to male and female rats at dose levels of 0, 10, 50 and 200 mg/kg/day for 4-weeks. In clinical signs, yellow-colored urine and yellow hair coat were observed in the 50 and 200 mg/kg male and female groups. In hematology, erythrocyte count and hemoglobin were significantly decreased in the 200mg/kg male and female groups. In serum biochemistry, total cholesterol was significantly increased and aspartate aminotransferase (AST) was significantly decreased in the 50 or 200 mg/kg male and female groups. In histopathological examinations, centrilobular hepatocellular hypertrophy in the liver, congestion and pigmentation in the spleen, hyaline droplets in the kidney were observed in the 50 and 200 mg/kg male and female groups. In toxicokinetic study, CJ-11555 was dose-dependent in systemic exposure and showed better absorption in female with minimum accumulation after multidosing. Based on these results, it was concluded that the 4-week repeated oral dose of CJ-11555 resulted in the suppression of AST activity and centrilobular hepatocellular hypertrophy in both sexes at a dose level of 50 or 200 mg/kg/day. The target organ was estimated to be liver, spleen and male's kidney. The no-observed-adverse-effect level (NOAEL) for CJ-11555 in rats following gavage for at least 4-week is 10 mg/kg/day.

• Toxicological Research
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• v.23 no.4
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• pp.405-413
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• 2007

This study was to investigate single and repeated-dose toxicities of Tensolin-$F^{(R)}$, an anti-wrinkle agent, in Sprague-Dawley (SD) rats or ICR mice. In single-dose oral toxicity study, the test materials were administered once by gavage to male and female SD rats at dose levels of 0 and 2,000 mg/kg. No dead animals and abnormal necropsy findings were found in control and Tensolin-$F^{(R)}$ treated group. Therefore, the approximate lethal dose of Tensolin-$F^{(R)}$ was considered to be higher than 2,000 mg/kg in rats. In the 4-week repeated oral toxicity study, the test material was administered once daily by gavage to male and female ICR mice at dose levels of 0, 25, 50 and 100 mg/kg/day for 4-weeks. In the results, no abnormality was observed in mortality, clinical findings, body weight changes, food and water consumptions, opthalmoscopic findings, necropsy findings, histopathological findings. In hematological analysis, there was a trend of increase in reticulocyte at male 25 mg/kg, although such changes were in normal ranges. On the other hand, there was a trend of decrease in hemoglobin at female 50, 100 mg/kg, such changes were in normal ranges. In addition, serum biochemical parameters including sodium, BUN and chloride increased at 25, 50 and 100 mg/kg. Relative organ weights of right testis, brain, lung and left epididymis were increased in 100 mg/kg groups of male rats in contrast to not change in female groups. However, these changes of relative organ weights, hematological and serum biochemical parameters were not accompanied with related signs such as histopathological changes or clinical findings. In conclusion, 4-week repeated oral dose of Tensolin-$F^{(R)}$ to ICR mice did not cause apparent toxicological change at the dose of 25, 50, 100 mg/kg body weight. Consequently the no-observed-adverse-effect level (NOAEL) for Tensolin-$F^{(R)}$ in ICR mice following gavage for at least 4-week is higher than 100 mg/kg/day.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.132-132
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• 2003

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.45-45
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• 2003

The present study was conducted to investigate the potential embryo-fetal toxicity of Artesunate, an antimalarial drug, in Sprague-Dawley rats. The test item was orally administered by gavage to pregnant rats (22 females per group) from days 6 through 15 of gestation at dose levels of 0, 2, 4 and 8 mg/kg/ day. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.202-202
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• 2002

DA-8159, a new pyrazolopyrimidinone derivative for erectile dysfunction, was administered by gavage at levels of 0, 17.5, 70, and 280 mg/mg to Sprague-Dawley male rats from 28 days before mating to the end of mating period, and to remales from 14 days before mating to day 6 of gestation.(omitted)

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.122-127
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• 2001

4-tert-octylphenol (OP) is a surfactant additive widely used in the manufacture of a variety of detergents and plastic products. Also, OP is known to have estrogenic activity by interacting with development and functions of endocrine system. This study was carried out to obtain toxicokinetic parameters of OP in male Sprague-Dawley rats. Male rats were administered OP, by either single oral (gavage) applications of 50, 100 or 200 mg/kg body weight. or a single intravenous injections of 1, 5 or 10 mg/kg body weight. Blood samples taken at several time intervals after administration were obtained from the femoral artery. Analysis of blood samples for OP was performed by gas chromatography mass spectrometry (GC/MS). The detection limit of OP was 1.9 ng/$m\ell$ at SIM (selected ion monitoring) mode of GC/MS. Calibration curve for analysis of the concentrations of OP in plasma was (OP/butylphenol peak area ratio) = 0.0294 $\times$ (plasma cone.) + 0.028 ($r^2$= 0.9991). The OP plasma concentration was 3921 ng/$m\ell$ immediately after single intravenous application, decreased rapidly within 45 min, and was detectable at low concentration up to 6 hr after application. When administered orally in rats (50, 100 and 200 mg/kg), OP was detected in the blood early after gavage administration, indicating the rapid initial uptake from gastrointestinal tract, with Tmax obtained from 0.67~0.83 hr. Using the AUC (area under the curve) of plasma concentration vs. time, low oral bioavailabilities of 1.2, 5.0 and 5.3% were calculated for the 50, 100 and 200 mg/kg groups, respectively.