• Development and Reproduction
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• v.13 no.3
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• pp.183-190
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• 2009

In mammals, puberty is a dynamic transition process from infertile immature state to fertile adult state. The neuroendocrine aspect of puberty is started with functional activation of hypothalamus-pituitary-gonadal hormone axis. The timing of puberty can be altered by many factors including hormones and/or hormone-like materials, social cues and metabolic signals. For a long time, attainment of a particular body weight or percentage of body fat has been thought as crucial determinant of puberty onset. However, the precise effect of high-fat (HF) diet on the regulation of hypothalamic GnRH neuron during prepubertal period has not been fully elucidated yet. The present study was undertaken to test the effect of a HF diet on the puberty onset and hypothalamic gene expressions in immature female rats. The HF diet (45% energy from fat, HF group) was applied to female rats from weaning to around puberty onset (postnatal days, PND 22-40). Body weight and vaginal opening (VO) were checked daily during the entire feeding period. In the second experiment, all animals were sacrificed on PND 36 to measure the weights of reproductive tissues. Histological studies were performed to assess the effect of HF diet feeding on the structural alterations in the reproductive tissues. To determine the transcriptional changes of reproductive hormone-related genes in hypothalamus, total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Body weights of HF group animals tend to be higher than those of control animals between PND 22 and PND 31, and significant differences were observed PND 32, PND 34, PND 35 and PND 36 (p<0.05). Advanced VO was shown in the HF group (PND $32.8{\pm}0.37$ p<0.001) compared to the control (PND $38.25{\pm}0.25$). The weight of ovaries (p<0.01) and uteri (p<0.05) from HF group animals significantly increased when compared to those from control animals. Corpora lutea were observed in the ovaries from the HF group animals but not in control ovaries. Similarly, hypertrophy of luminal and glandular uterine epithelia was found only in the HF group animals. In the semi-quantitative RT-PCR studies, the transcriptional activities of KiSS-1 in HF group animals were significantly higher than those from the control animals (p<0.001). Likewise, the mRNA levels of GnRH (p<0.05) were significantly elevated in HF group animals. The present study indicated that the feeding HF diet during the post-weaning period activates the upstream modulators of gonadotropin such as GnRH and KiSS-1 in hypothalamus, resulting early onset of puberty in immature female rats.

• The Journal of Internal Korean Medicine
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• v.35 no.3
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• pp.223-243
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• 2014

Objectives: To provide information on the safety of GST (GamiSasangja-tang; CnidiiFructus, Sophora Root, Angelica Gigas Root, Clematidis Radix, Stemonae Radix, Spirodelae Herba), we carried out a 13-week repeated oral dose toxicity and a 4-week recovery test of GST in Sprague-Dawley rats. Methods: Female and male rats were treated with GST at oral doses of 1,250, 2,500, and 5000 mg/kg. The GST was administered for 13 weeks. Mortality, clinical signs, body weight changes, food consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights and histological markers were monitored during the study period. The rats were then monitored for 4 extra weeks to determine recovery time after the study period. Results: We found no mortality or abnormalities among clinical signs, body weight, food consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights or histological markers in any of the rats tested. Conclusions: The no-observed adverse effects level (NOAEL) is considered as over 5000 mg/kg for male and female rats.

• Journal of Oriental Neuropsychiatry
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• v.23 no.3
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• pp.143-160
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• 2012

Objectives : To provide information on the safety of ACM, we carried out a 13-week repeated oral dose toxicity and a 4-week recovery test of ACM in Sprague-Dawley rats. Methods : Female and male rats were treated with ACM with oral doses of 800, 2000, and 5000 mg/kg. The ACM was administered for 13 weeks. Mortality, clinical signs, body weight changes, food consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights and histological markers were monitored during the study period. Moreover, the rats were monitored for 4 extra weeks to determine recovery time after the study period. Results : We found no mortality and no abnormalities in clinical signs, body weight, food consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights and histological markers in any of the rats tested. Conclusions : The no-observed adverse effects level (NOAEL) was considered as over 5000 mg/kg for male and female rats.

• Safety and Health at Work
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• v.3 no.3
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• pp.224-234
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• 2012

Objectives: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. Methods: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. Results: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. Conclusion: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).

• Natural Product Sciences
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• v.22 no.3
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• pp.180-186
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• 2016

This research is to estimate the toxicity of Atractylodis Rhizoma Alba (ARA) in F344 rats and to find a dose level for the 13 weeks toxicity study. A hot water extract of ARA (ARWE) was administered orally to F344 rats at dose levels of 0 (vehicle control), 500, 1000, 2000, 3500, and 5000 mg/kg/day for 2 weeks. Each group was composed to five male and five female F344 rats. According to the result, there were no ARWE-related adverse changes in mortality, body weights, food consumption, urinalysis, hematology, clinical chemistry, gross finding at necropsy, and organ weight examination. Salivation was observed in 3500 and 5000 mg/kg/day in male and female rats but it could not have found any relationship with ARWE administration. Based on our findings, ARWE may not cause toxicity in rats under the experimental conditions. Therefore, dose level of 5000 mg/kg/day as a highest treatment group in 13-week exposure study is recommended for further toxicity assessment.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.367-373
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• 2004

The prevalence of type-2 diabetes increases remarkably in post-menopausal women, possibly because insulin secretion fails to compensate for the insulin resistance induced in various tissues by estrogen insufficiency. However, this has not been fully defined. Therefore, the present study investigated whether an ovariectomy (OVX) would increase insulin resistance and decrease the $\beta$-cell function and mass in female rats with and without a $90\%$ pancreatectomy (Px). Female rats aged 15 weeks were divided into four groups: 1) OVX + Px, 2) SOVX (sham operation of OVX) + Px, 3) OVX + SPx (sham operation of Px), and 4) SOVX + SPx, and given a $30\%$ fat diet for 8 weeks. At the end of the experimental period, the islet function and insulin resistance were determined using a hyperglycemic clamp and a euglycemic hyperinsulinemic clamp, respectively. The OVX only increased the body weight in the SPx rats, which was partially related to the food intake. Yet, the OVX did increase the peripheral insulin resistance, while the Px increased this resistance further. The OVX and Px both exacerbated the islet function, as measured by the insulin secretion pattern, while delaying and decreasing the first-phase insulin secretion. The OVX only decreased the proliferation of $\beta$-cells in the Px rats, while increasing apoptosis in both the Px and SPx rats. As a result, the OVX decreased the $\beta$-cell mass in the Px rats, but increased the mass in the SPx rats. In conclusion, an OVX was found to accelerate the development and progression of diabetes by increasing the insulin resistance and decreasing the $\beta$-cell mass. Therefore, menopause can be a risk factor for type-2 diabetes, mainly due to a deceased proliferation of $\beta$-cells.

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1096-1104
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• 1996

This study was performed to evaluate the effect of sodium cholride supplementation on bone metabolism in female rats consuming a low calcium diet. Twenty five female rats were divided into three dietary groups (control Na : 0.1038%, 1% Na : 1.036%, 2% Na : 2.072%). All experimental diets contained 0.27% Ca and were fed to rats with deionized water for 7 weeks. Bone mineral density(BMD) and bone mineral content(BMC) of total body, spine and femur were measured using energy x-ray absorptiometry(DEXA) by small animal software. Then Ca efficiency was calculated from BMD and BMC. Serum Ca, P, Na and urine Ca, P, Na were determined. Urinary pyridinoline, serum ALP were measured to monitor bone resorption. Following 7 weeks, sodium cholride supplemented groups had higher urinary Ca excreteion, urinary pyridinoline, crosslinks value and serum ALP. There was no significant difference in case of serum Ca among all groups. Sodium chloride supplemnted groups had lower Ca effciency of total, spine and femur BMD and BMC than that of control group. In conclusion high salt intake not only increases urinary Ca excretion as urinary Na excretion does but also increase bone resorption and decrease Ca efficiency of each bone. It is been suggested that high salt intake may be harmful for bone maintenance. Therfore, the decrease of salt intake to the level of recommendation would be desirable.

• The Journal of Korean Medicine
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• v.30 no.3
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• pp.79-85
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• 2009

Aim : To evaluate the pharmaceutical safety of the herbal formula Myelophil, composed of Astragali Radix and Salviae Radix, via systemic subacute toxicological study using SD rats. Methods : Forty male and 40 female SD rats were fed with Myelophil (5000, 2500 or 1250 mg/10 mL/kg) or distilled water for four weeks. Adverse effects were examined intensively by comparing the differences between normal and drug-administered groups using clinical signs, necropsies, histopathologic findings, hematology, urinalysis, and blood biochemical analysis. Results : No altered clinical symptoms including body weight, diarrhea, anorexia, death, and abnormal necropsy of major organs were observed in male or female rats. No drug-induced abnormalities in histopathological finding, hematological values, urinalysis, and blood biochemical values were found at any doses of Myelophil. Conclusion : Myelophil should be very safe when used in a clinical application with a wide therapeutic index.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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• pp.143-151
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• 1996

This study was performed to investigate the effect of dietary dried anchovy and non-fat dried milk on serum and femur Ten months old female rats were divieded into 6 groups(ST, A-middle, A-high, M-middle, M-high, A+M), and fed the diet containing different level of food calcium for 8 weeks. The results obtained were summerized as follow: 1. The rats' weight gain were not significantly different from the fed groups, but food intake were significantly higher or lower level in the group of A-high than the other groups. 2. Serum calcium concentration was significantly increased in the A-middle group, the M-high group were significantly decreased. Serum phosphorous contents of M-high group were increased significantly higher than ST group. The serum magnesium contents were increased significantly higher than in the A-middle group. Serum iron contents of other experimental groups were significantly higher than ST group. All experimental groups were significantly lower copper contents in serum than ST group. 3. The more rats took dried anchovy and non-fat dried milk, the longer the length of femur. But this trend is not statistically difference. In the breaking force of left femur, most of all experimental group were stronger than ST group. 4. The calcium, phosphorous contents of ash, dry, wet weight of right femur in A+M group were higher than any other groups.

• Journal of Nutrition and Health
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• v.29 no.2
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• pp.166-176
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• 1996

Effect of fish oil feeding was investigated on morphological changes of thoracic aora in female rats after bilateral oophorectomy(OVX). Fifty four healthy female rats of Spraque-Dawley strain, were divided into sham group, OVX group and , OVX and fish oil feeding, group. Experimental animals were sacrificed at the end first, eighth week and sixteenth week after operation, thoracic aorta blood sample were collected. The results obtained were as follows ; 1) Total cholesterol and LDL-cholesterol contents in serum were significantly higher in the sham and OVX groups than fish oil feeding group. Serum HDL-cholesterol levels among three exjperimentnal group were lowest in the OVX group. 2) In the sham operation group, as experimental period prologed the endothelial cells were distorted round shape and enlarged, and the subendothelial layer was widened in tunical intima. The elastic lamina were disrupted in tunica group. In the fish oil feeding group, the endothelial cells and subendothelial layer in tunica intima, and the elastic lamina in tunica media were intance. From the present results, it was suggested that fish oil feeding may prevent the atherosclerotic changes in thoracic aorta and serum cholesterol induced by oophhorectomy in the rats.