• 대한수의학회지
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• 제37권1호
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• pp.167-176
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• 1997

The present investigation was focussed mainly on the development of the tumors and proliferating cells on the intestinal tracts of 1, 2-dimethyl-hydrazine(DMH)-treated young or adult rats. 26 rats(Wistar, 14 young rats weighting approximately 130~180gm and 12 adult rats weighting approximately 500~550gm) were given subcutaneously once weekly with 20mg of DMH/kg body weight(BW)/week for 8~22 weeks. Individual body weight were recorded weekly at the same day and time. The rats were killed at 8, 13, 15. 17, 19, 21 and 22 weeks. The intestinal tracts were opened longitudinally and carefully examined for tumors. The localization, number, and size of tumors were noted. Tumor-bearing areas were dissected out and fixed on neutral buffered 10% formalin and normal-looking mucosa from 8~22 weeks rats were also taken for fixation. Paraffin sections were stained by H-E for histopathological examination or with immunohistochemical stain for bromodeoxyuridine(Brdur) positive cells. 1. The growth proportion of body weight appeared to be decreased in the DMH-treated young rats than in control young rats and body weight of DMH-treated adult rats appeared to be 13.4% or less lower than weighted on 0 week. 2. Macroscopically, the developed tumors in the intestinal tracts were not observed as early as the 13 weeks after DMH treatment. The number of developed tumors per rat was found to be 14.3, 18.8, 22.3 in 15, 17 and 22 weeks. The numbers of tumors in intestinal regions per rat were 2.1, 4.3, 5.4, 2.5 in duodenum, jejunum, ilium and colon on 15 weeks, 2.3, 6.4, 7.8, 2.3, on 17 weeks, and 2.7, 9.3, 9.0, 1.3 on 22 weeks, respectively and the ileum and jejunum were higher in appearance rate of tumors and tumor types are dome shapes and diameter of largest tumor were 6.3mm. 3. Histopathologically, intestinal mucosa were thickened by the irregular distorted and distended crypts following hyperplasia. The tumors developed on the mucosa and submucosa and were recognized to be adenocarcinoma. 4. Immunohistochemically, the labeling index(LI) was calculated as the ratio of the number of Brdur-labeled cells to the total number of column cells of the crypts with longitudinal axis. LI of Brdur positive cells per crypt were 5.6%, 8.0% on small intestine of control and 22 week group, respectively and 3.7%, 12.7% on large intestine of control and 22 week group, respectively and were appeared to be increase in 22 week group than in control group and to be more number of proliferating cells in 22 week group than in control group. 5. LI of Brdur positive cells in 1, 2, 3, 4, 5 segments of crypt column were 11.7%, 10.7%, 3.8%, 0.6%, 0% in small intestine of control group and 23.5%, 11.8%, 2.3%, 2.4%, 0.8% in small intestine of 22 week group, and 5.4%, 7.4%, 3.8%, 1.0%, 0.4% in large intestine of control group and 29.5%, 20.3%, 5.9%, 6.3%, 1.3% in large intestine of 22 week group respectively. So results indicate that the number of proliferating cells by DMH treatment increase and were concentrated on the 1, 2 segments of crypt columns.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.234-238
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• 1996

The purpose of this study was to determine whether vitamin {TEX}$B_{6}${/TEX} deficiency and age affect the blood cho-lesterol profile in exercising rats. Fifty four rats were fed either a viramin {TEX}$B_{6}${/TEX} deficient dief(-{TEX}$B_{6}${/TEX}) of a control diet(+{TEX}$B_{6}${/TEX}) for 6 weeks, then subdivided into 3 groups:non-exercise group(NE), exercise and sacrifice group(ES), exercise and recuperation group(ER). ES group was exercised in treadmill({TEX}$10^{o}${/TEX}, 0.5~0.8km/h) for 2 hours and sacrifice. ER group was recuperated three days with respective diet after exercise. At week 3 and 6, and level of plasma total cholesterol(TC), high density lipoprotein cholesterol(HDL_C) and low density lipoprotein cholesterol(LDL_C) were compared. In NE group, there was no difference in the levels of TC, HDL_C and LDL_C between +{TEX}$B_{6}${/TEX} rats and -{TEX}$B_{6}${/TEX} rats. The plasma levels of TC and LDL_C of 6 weeks were higher than those of 3 weeks and on difference in HDL_V between 3 weeks rats and 6 weeks rats. In ES group, there was also no difference in the levels of TC, HDL_C and LDL_C between +{TEX}$B_{6}${/TEX} rats and -{TEX}$B_{6}${/TEX} rats and there was no difference in TC, LDL-cholesterol between 3 weeks rats and 6 weeks rats. The level of HDL_C pf 6 weeks was lower than that of 3 weeks rats. In ER group, there was no difference in the levels of TC and LDL_C not only between +{TEX}$B_{6}${/TEX} rats and-{TEX}$B_{6}${/TEX} rats but also between 3 weeks rats and 6 weeks rats. The level of HDL_C was lower in -{TEX}$B_{6}${/TEX} rats than in +{TEX}$B_{6}${/TEX} rats and higher in 6 weeks rats than in 3 weeks rats. These results suggest that vitamin {TEX}$B_{6}${/TEX} deficiency may affect the HDL_C during exercise and after recuperation. The desirable effect of exercise on plasma Cholesterol profile is strengthened in adult age than young age.

• Nutrition Research and Practice
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• 제11권1호
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• pp.25-32
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• 2017

BACKGROUND/OBJECTIVES: Stress-induced cognitive impairment is related to the suppression of hippocampal neurogenesis that results from an increase of oxidative stress. Therefore, the aim of this study was to investigate the effects of administration of a blueberry drink, having a high antioxidant power, on the cognitive performance of adult rats exposed to chronic mild stress. MATERIALS/METHODS: Twelve-week-old male Sprague-Dawley rats (n = 48) were randomly divided into four groups: control (CO), stress (ST), control + 5% blueberry drink (CO + B), and stress + 5% blueberry drink (ST + B). After eight weeks, the cognitive performance was assessed using a multiple T-maze water test. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and ascorbic acid were measured in the brain, and catecholamine concentrations were measured in plasma. RESULTS: The brain weights of the rats from the ST and ST + B groups were significantly lower than those of the rats from the CO and CO + B groups. The cognitive performance of the ST group was impaired when compared to that of the CO group. This impairment was significantly improved by the blueberry drink supplementation (P < 0.05). The brain SOD and CAT concentrations were not influenced by the stress or by the blueberry drink. However, the brain levels of GPx and ascorbic acid were significantly lower in the ST group than those in the CO group and were increased by the blueberry drink supplementation. The plasma catecholamine concentrations were affected by chronic mild stress and by the blueberry drink. The plasma norepinephrine and dopamine concentrations were decreased by the chronic stress and improved by the blueberry drink supplementation. The plasma epinephrine level was only influenced by the stress. CONCLUSION: These findings suggest that the blueberry drink may protect against the cognitive impairment induced by chronic mild stress.

• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.407-413
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• 2017

Vascular reactivity can be influenced by the vascular region, animal age, and pathologies present. Prostaglandins (produced by COX-1 and COX-2) play an important role in the contractile response to phenylephrine in the abdominal aorta of young rats. Although these COXs are found in many tissues, their distribution and role in vascular reactivity are not clear. At a vascular level, they take part in the homeostasis functions involved in many physiological and pathologic processes (e.g., arterial pressure and inflammatory processes). The aim of this study was to analyze changes in the contractile response to phenylephrine of thoracic/abdominal aorta and the coronary artery during aging in rats. Three groups of rats were formed and sacrificed at three distinct ages: prepubescent, young and old adult. The results suggest that there is a higher participation of prostanoids in the contractile effect of phenylephrine in pre-pubescent rats, and a lower participation of the same in old rats. Contrarily, there seems to be a higher participation of prostanoids in the contractile response of the coronary artery of older than pre-pubescent rats. Considering that the changes in the expression of COX-2 were similar for the three age groups and the two tissues tested, and that expression of COX-1 is apparently greater in older rats, COX-1 and COX-2 may lose functionality in relation to their corresponding receptors during aging in rats.

• Journal of Nutrition and Health
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• 제36권5호
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• pp.459-469
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• 2003

We examined the effects of calcium intake levels on mineral metabolism during pregnancy using calcium-deficient young adult rats. Five week-old female Sprague-Dawley rats were fed normal Ca (NCa, 0.5%) and low Ca (LCa, 0.15%) diets for five weeks (pre-pregnancy). The low Ca intake group was then divided into three groups and fed low Ca (0.15%), normal Ca (0.5%) and high Ca (1.5%) diets for 3 weeks (pregnancy). All of the rats were mated with normal male rats. The control group was fed a consistently normal Ca (0.5%) diet during pre-pregnancy and pregnancy. On the day after delivery, dams and their pups were sacrificed. We measured total protein, albumin, alkaline phosphatase and mineral content in serum and weight, length, breaking force, ash and mineral content in the femur and lumbar (L2-L4) of the dams. Whole body mineral content was measured in the pups. There was no difference in weight gain and food intake among the groups. Serum total protein and albumin were in the normal range but a little lower during pregnancy. High Ca supplementation decreased serum Mg and Fe during pregnancy. Weight, ash and Ca of the femur and lumbar significantly decreased in rats fed a chronically low Ca diet during pre-pregnancy and pregnancy. Calcium supplementation levels were above normal during pregnancy and increased the bone weight and breaking force of rats fed the low Ca diet during pre-pregnancy. However, Ca supplementation did not increase the ash and Ca contents in the bones. High Ca supplementation during pregnancy significantly decreased Mg in the bones and increased Ca and P in the kidneys. Ash content of pups from dams fed the chronically low Ca diet decreased but there was no difference in whole body Ca among the groups. Mg and Fe in the whole body decreased in pups from dams fed the high Ca diet. Pregnancy performance was reduced in dams fed the low Ca diet. These results suggest that above normal Ca supplementation levels during pregnancy restored maternal bone status to some extent in rats fed the chronically low Ca diet. The same could not be said for mineral content. Also, high Ca supplementation during pregnancy may deteriorate mineral composition in bones and other tissues. Therefore, more detailed research is needed to facilitate sound recommendations on appropriate calcium intake during pregnancy. (Korean J Nutrition 36(5): 459∼469, 2003)

• KSBB Journal
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• 제8권3호
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• pp.224-229
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• 1993

The feeding effects of Rosa rugosa roots powder extracted with two different extracting solvents on lipid metabolism in rats were evaluated. Rats were fed with purified diets containing methanol or 70% aqueous acetone extracts at a 1% level for 4 weeks. In addition, to examine the effects of age, rats with different ages (4weeks old vs. 3 months old) were fed with purified diets containing methanol extracts at a 1% level for 4weeks. Feeding of methanol extracts decreased the concentration of triacylglycerol in serum and liver, whereas the aqueous acetone extracts lowered the concentration of liver triacylglycerol with concomitant elevation of the concentration of serum triacylglycerol. The methanol extracts ameliorated the degree of increase in the serum triacylglycerol level in relation to age and decreased especially the concentration of free fatty acid in serum of adult rats. The results suggested possibility that the regulatory mechanism responsible for triacylglycerol-lowering effects of Rosa rugosa roots extracts in the liver could be modulated by differences in the components of extracts due to the variation in extracting solvents, and that the methanol extracts might be effective in lowering an age-dependent increase in the concentration of serum and liver triacylglycerol in rats.

• Toxicological Research
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• 제17권4호
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• pp.303-308
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• 2001

The potential for a given anticholinesterase pesticide to exhibit age-related toxicity is essential information for an accurate and proper risk assessment of that compound. This investigation was designed to study the age-related toxicity of active metabolites of four organophosphates using in vitro detoxification measurement. The blood samples were collected from 1 month and 18 months old rats. The $IC_{50}$ values of mouse brain recombinant AChE of chlorpyrifos-oxon, diazoxon, malaoxon and paraoxon were 10.35, 112.84, 151.28 and 18.43 nM, respectively. When the plasma of young rats, and $CaCI_2$were added, the $IC_{50}$ values of mouse brain recombinant AChE of chlorpyrfos-oxon, diazoxon, malaoxon and paraoxon were 31.89, 164.25, 139.94 and 16.36 nM, respectively. The $IC_{50}$ values of mouse brain recombinant AChE of chlorpyrifos-oxon, diazoxon, malaoxon and paraoxon were changed to 136.840, 1244.45, 654.54 and 52.66 nM by A-esterases In adult rats. These results suggest that four organophosphates have a potential toxicity to exhibit age-related sensitivity.

• Journal of Preventive Medicine and Public Health
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• 제43권2호
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• pp.131-137
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• 2010

Objectives: Bisphenol A diglycidyl ether (BADGE) is a liquid compound obtained by condensation of two molecules of epichlorohydrin with one molecule of bisphenol A. General and reproductive toxicity with BADGE has been reported higher than 1000 mg/kg/day. This study was performed to show the effects of acute exposure to BADGE below 1000 mg/kg/day on the testis in adult male rats. Methods: BADGE was administered by gastric lavage in a single dose of 500, 750, 1000, and 2000 mg/kg/day in 8-week old male SPF Sprague-Dawley rats. The right testis was processed for light microscopic analysis. The left testis was homogenized and spermatids were counted to determine the daily sperm production and daily abnormal sperm production. The sperm count, sperm motility, and incidence of abnormal sperm were estimated in the epididymis. In testicular sections, the seminiferous tubules were observed for qualitative changes. The progression of spermatogenesis was arbitrarily classified as full-matured, maturing, and immature. The specimen slide was observed at 3 points and 10 seminiferous tubules were evaluated at each point. Results: The male rats exposed to single oral dose of BADGE at 750, 1000, and 2000 mg/kg/day were significantly increased the number of immature and maturing sperm on the testis. There were no significant differences with respect to sperm head count, sperm motility, and sperm abnormality in the BADGE treatment groups. Conclusions: These results suggest that single oral exposure of BADGE 750 mg/kg/day can affect adult male testis development.

• Toxicological Research
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• 제8권2호
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• pp.265-272
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• 1992

Effects of repeated physical exercise on the carbon tetrachloride ($CCl_4$) hepatotoxicity were examined in adult female rats. Rats were introduced into a cylindrical rotating cage and forced to exercise for 1 hr each day, 6days/week, for 5 consecutive weeks at a speed starting from 10m/min, increased by 1m/min per day until the speed reached 27m/min. Significantly less body weight gain was observed in the exercise group suggesting that physical fitness had been induced in these animals. Eighteen hours following termination of the last exercise bout rats were treated with $CCl_4$(2 mmol/kg.ip). The $CCl_4$-induced heptotoxicity was significantly potentiated in the repeated exercise group compared to the resting sedentary animals as determined by changes in serum sorbitol dehydrogenase (SDH), glutamic oxaloacetic transaminase(GOT), glutamic pyruvic transaminase (GPT), and glucose-6-phosphatase(G-6-Pase) activities when measured 24hrs following the $CCl_4$ treatment. Hepatic drug metabolizing activity was determined in order to elucidate the underlying mechanism of potentiating action of the $CCl_4$ hepatotoxicity induced by repeated physical exercise. Repeated exercise increased the hepatic microsomal cytochrome P-450 contents and aminopyrine N-demethylase activity. The results suggest that the potentiation of $CCl_4$ hepatotoxicity by repeated exercise is associated with induction of the mixed function oxidase (MFO) enzyme system mediating the metabolism of $CCl_4$ to its active metabolite(s).

• Biomolecules & Therapeutics
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• 제7권4호
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• pp.322-328
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• 1999

In this study, it was tested whether the changes of catecholamines and its metabolites are related with the changes of blood pressure(BP) induced by different levels of lead exposure. Adult male SD rats were exposed to lead by giving drinking water containing 50(low doses), 200 and 1,000 ppm(high doses) of lead(as lead acetate) or sodium acetate(for control groups, supplying an identical amount of acetate) for 7 or 16 weeks. The systolic BP was measured in the unanesthetized state by the tail-cuff technique. Levels of catecholamines and its metabolites in urine were measured by HPLC-ECD. Rats receiving 200 and 1,000 ppm developed an elevation of systolic BP at 3 and 7 weeks compared with week 0, but blood pressure levels at 16 weeks returned to normal. For the 50 ppm lead treated group, systolic BP increased significantly at 7 weeks and 16 weeks. The concentrations of norepinephrine and VMA in the urine of lead exposed rats changed similarly to the changes of blood pressure, but blood viscosity levels in all lead treated rats increased continuously during all lead treatment periods. This result suggests that the changes of catecholamines and its metabolites in urine by lead intoxication may influence the changes of blood pressure.