• Journal of Community Nutrition
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• v.8 no.4
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• pp.207-213
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• 2006

The present study was conducted to investigate the effect of oolong tea extract on blood glucose level and antioxidant system in diabetic rats. The Sprague-Dawley rats were fed on AIN-76 based experimental diets containing 1 % oolong tea extract for 6 weeks. They were induced to be diabetic by receiving streptozotocin (45mg/kg BW) intramuscularly. Blood glucose, blood and hepatic concentration of vitamins A and E, and antioxidant enzyme activities were measured. Oolong tea extract feeding decreased the plasma glucose in diabetic rats. Dietary supplementation of oolong tea extract did not affect antioxidative enzyme activities such as superoxide dismutase, glutathione peroxidase and catalase in diabetic rats. The plasma level of retinol was increased in diabetic rats by feeding oolong tea extract. Plasma and hepatic levels of ${\alpha}$-tocopherol were higher in diabetic rats fed oolong tea extract. In conclusion, these results suggest that oolong tea extract consumption might reduce the plasma glucose in diabetic rats and protect the oxidative damage from diabetic stress to some extent.

• The Korean Journal of Physiology
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• v.30 no.2
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• pp.269-278
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• 1996

The mechanism of impaired endothelium-dependent relaxation in the aorta of one-kidney, one clip Goldblatt hypertensive (1K,1C-GBH) rats was investigated. 8 week-old Wistar-Kyoto (WKY) rats were made hypertensive by left renal artery stenosis with contralateral nephrectomy. Endothelium-dependent relaxation was significantly reduced in 1K,1C-GBH rats as compared with WKY rats. However, the relaxation by sodium nitroprusside in 1K,1C-GBH rats was not reduced as compared with WKY rats. The impairment of endothelium-dependent relaxation in 1K,1C-GBH rats was partially restored by the pretreatment of indomethacin or SQ29548. When the nitric oxide production was inhibited by L-nitroarginine methyl ester, acetylcholine (ACh) induced a endothelium-dependent contraction that was greater in 1K,1C-GBH rats than in WKY rats. Endothelium-dependent contraction by ACh was completely abolished by indomethacin or SQ29548. However, imidazole, tranylcypromine and superoxide dismutase did not affect the endothelium-dependent contraction in 1K,1C-GBH rats. These results suggest that impaired endothelium-dependent relaxation in the 1K,1C-GBH rats might be due to the simultaneous release of EDCF, and that prostaglandin B2 may be involved as a mediator of endothelium-dependent contraction.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.850-857
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• 2001

The study was designed to observe whether the conjugated linoleic acid supplemented to diet could reduce plasma levels of glucose and lipids which were increased in 27-weeks old Otsuka Long Evans Tokushima Fatty(OLETF) rats. Twenty male OLETF rats of 7 weeks old were fed an experimental diet containing 4.5%(w/w) total fat including 1% CLA and six of twenty rats were sacrified at 6 weeks feeding. The rest of OLETF rats was divided into 2 groups, one group was continuously fed for 14 weeks more the same experimental diet containing 1% CLA and the other group was fed control diet which eliminated CLA. CLA did not significantly reduce food intake and body weight gain in OLETF obese rats. Plasma triglyceride and total cholesterol level were significantly increased at older age of OLETF obese rats, but CLA could significantly reduce plasma cholesterol and triglyceride increased in obese rats. However, CLA was not strong enough to reduce the increased plasma glucose level and hepatic lipogenic enzyme acitivies. CLA was mostly deposited in epididymal fat pad and could be incorporated into hepatic microsomal membrane and did interfere the conversion of C18 : 0 into C18 : 1 in liver. In conclusion, CLA could have anti-atherogenic effect by reducing plasma cholesterol and triglyceride which was increased in genetically obese rats, but CLA(1%) was not good source of dietary fatty acid to reduce body fatness and plasma glucose which was increased by obese gene in older rats.

• Journal of Nutrition and Health
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• v.27 no.9
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• pp.949-956
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• 1994

The effect of zinc deficiency on certain immunological parameters was investigated using intragastric tube feeding to obviate decreased food intake and altered eating pattern. Male, Fischer 344 rats were bilaterally adrenalectomized(ADX) or sham operated(SHAM). ADX rats received 0.9% NaCl in their drinking water and corticosterone injections at the dose of 1mg/kg of body weight three times per day. After recovery, one half of ADX and SHAM animals were tube-fed a purified, liquid diet containing either two ppm of zinc(zinc-deficient, force-fed ; ZDF) or 50ppm(zinc-replete, force-fed ; ZRF) for 19 days. They received identical amounts of diet based on the intake of ad libitum-fed, zinc-replete rats. Although they received identical amounts of food, ZDF rats grew at a slower rate compared to ZRF rats in both SHAM and ADX rats. Regardless of surgery, force-feeding rats the zinc-deficient diet resulted in a substantial decrease in serum zinc levels. The weights of the thymus, lymph node, and spleen were lower in SHAM-ZRF rats compared to SHAM-ARF rats. Marginal zinc deficiency caused lymphopenia in SHAM animals. However, these differences in lymphoid tissues and cells between SHAM-ZDF and SHAM-ZRF rats disappeared in ADX rats. These results indicate that the impaired growth of lymphoid tissues observed in zinc-deficient, sham-operated animals can be attributed to elevated serum corticosterone levels under the conditions of our experiments.

• Korean Journal of Rural Living Science
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• v.5 no.2
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• pp.125-134
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• 1994

This study was performed to observe the effects of dietary fat levels and sources on lipids contents and cellularities of liver, brain, and adipose tissue of early weaned rats. Male Sprague-Dawley rats were prematurely weaned from postnatal 17th day with the experimental diets differ in fat levels : low(5%), medium(10%), high(20%) and fat sources : butter, soybean oil, butter＋ soybean oil. On the postnatal 29th day, contents of total lipid, triglyceride, cholesterol and phospholipid of serum, liver, brain and adipose tissue were determined, and DNA was determined to assess the cell growth. Rats early weaned fed high fat diet showed lower total lipid and triglyceride levels in serum and liver than those fed medium or low fat diet Rats early weaned fed high fat diet had adipocytes of fewer number, but larger size than those of rats fed low or medium fat diets. Rats early weaned fed soybean oil diet had more adipocytes thu those fed butter diet. Rats normally weaned to commercial chow diet showed lower total lipid, triglyceride, and cholesterol levels in serum and liver, had fewer adipocytes than all early weaned rats except for rats fed high fat-butter diet. These results suggest that high fat-butter diet is ideal weaning diet at early weaning.

• Journal of Food Hygiene and Safety
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• v.9 no.2
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• pp.57-66
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• 1994

The benefits of milk on the rats supplemented with cholesterol and vitamin D2 in diet was investigated. A total of 150 male rats of Sprague-Dawley strain, 5 weeks of age, were divided into 6 groups with the diet. Cholesterol control group was fed the diet containing 1.0% choleterol and 50,000 IU/100 g of vitamin D2 for 24 months, and M0.5, M1, M2 and M5 of milk groups were fed the diet containing cholesterol, vitamin D2 and 0.5, 1, 2 and 5 of reference daily intakes of whole milk, respectively. No remarkable differences of growth, diet intake, and food effciency ratio among groups were observed though rats in cholesterol control group showed abrupt decrease of diet intake and body weight showed slightly higher relative organ weights than did the rats in control group. The rats in cholesterol control group showed the highest serum total cholesterol level. The rats in milk groups showed lower total cholesterol level and higher high density lipoprotein (HDL)-cholesterol fraction than did the rats in cholesterol control group though no tendency was observed among milk groups. In milk groups, aorta, heart, kidney and liver of rats showed milder calcification and necrosis or fat degeneration compared with those in cholesterol control group. The above results suggest that whole milk could have beneficial effect on the cholesterol-and -vitamin D2-induced atherosclerosis in rats.

• Journal of Nutrition and Health
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• v.27 no.3
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• pp.228-235
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• 1994

The purpose of this study was to investigate the effect of vitamin B6 deficiency on the concentration of energy metabolite in streptozotocin-induced diabetic rats. Thirty rats were fed a vitamin B6 deficient diet(-B6) or a control diet(+B6) for 5 weeks and then subdivided into 3 groups respectively ; base group, one day diabetic group and three day diabetic group. Diabetes of rats were induced by streptozotocin injection into the tail vein. Glucose, glycogen, protein, alanine, triglyceride and free fatty acids were compared in plasma, liver skeletal muscle of rats. Also, the total urinary nitrogen and glucose excretion were compared. Compared with +B6 rats, the increase of plasma glucose in -B6 rats due to the diabetes was smaller. After diabetes was induced, the level of plasma alamine was not changed in -B6 rats while increased significantly(p<0.05) in +B6 rats. The increase of urinary nitrogen excretion was smaller and the increase of muscle protein was larger in -B6 rats at the first day diabetes was induced. The levels of plasma free fatty acid and liver triglyceride were significantly (p<0.05) higher in -B6 rats after diabetes was induced. These results suggest that vitamin B6 deficiency may impair the adaptation of animals to the energy metabolism related due to a decrease of the body protein catabolism of fatty acid oxidation in diabetes and aggravate fatty liver which is one of the chronic complications of diabetes.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.492-497
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• 1997

A difference in ethanol metabolism between premature and young adult rats was examined. Female SD rats, either 4wk or 12wk old, were injected with a single dose of ethanol (1.5g /kg) through jugular vein and the blood ethanol level was monitored for 300 min using a gas chromatographic method. Reduction of blood ethanol level per unit of time was less and the area under the blood concentration-time curve (AUC) was significantly greater in young adults compared to premature rats. Activity of hepatic alcohol dehydrogenase was not influenced by the age increase. Total cytochrome P-450, cytochrome $b_5$. or aminopyrine N-demethylation was not different between premature rats and young adult rats. However, p-nitrophenol hydroxylation and p-nitroanisole O-demethylation activities were significantly higher in premature rats. The relative liver weight was 45% greater in premature rats leading to an overall increase in ethanol metabolizing activity in these animals. The results indicate that the reduction in ethanol elimination in young adult rats appears to be mostly associated with the decrease in relative liver weight as the age of animals increases.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1120-1126
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• 2007

An iron-fortified whey protein concentrate (Fe-WPC) was prepared by addition of ferric chloride to concentrated whey. A large part of the iron in the Fe-WPC existed as complexes with proteins such as ${\beta}$-lactoglobulin. The bioavailability of iron from Fe-WPC was evaluated using iron-deficient rats, in comparison with heme iron. Rats were separated into a control group and an iron-deficiency group. Rats in the control group were given the standard diet containing ferrous sulfate as the source of iron throughout the experimental feeding period. Rats in the iron-deficiency group were made anemic by feeding on an Fe-deficient diet without any added iron for 3 wk. After the iron-deficiency period, the iron-deficiency group was separated into an Fe-WPC group and a heme iron group fed Fe-WPC and hemin as the sole source of iron, respectively. The hemoglobin content, iron content in liver, hemoglobin regeneration efficiency (HRE) and apparent iron absorption rate were examined when iron-deficient rats were fed either Fe-WPC or hemin as the sole source of iron for 20 d. Hemoglobin content was significantly higher in the rats fed the Fe-WPC diet than in rats fed the hemin diet. HRE in rats fed the Fe-WPC diet was significantly higher than in rats fed the hemin diet. The apparent iron absorption rate in rats fed the Fe-WPC diet tended to be higher than in rats fed the hemin diet (p = 0.054). The solubility of iron in the small intestine of rats at 2.5 h after ingestion of the Fe-WPC diet was approximately twice that of rats fed the hemin diet. These results indicated that the iron bioavailability of Fe-WPC was higher than that of hemin, which seemed due, in part, to the different iron solubility in the intestine.

• Journal of Pharmacopuncture
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• v.18 no.4
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• pp.12-19
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• 2015

Objectives: This study was done out to evaluate the effects of Sida rhombifolia methanol extract (SRM) on diabetes in moderately diabetic (MD) and severely diabetic (SD) Sprague-Dawley rats. Methods: SRM was prepared by soaking the powdered plant material in 70% methanol and rota evaporating the methanol from the extract. Effective hypoglycemic doses were established by performing oral glucose tolerance tests (OGTTs) in normal rats. Hourly effects of SRM on glucose were observed in the MD and the SD rats. Rats were grouped, five rats to a group, into normal control 1 (NC1), MD control 1 (MDC1), MD experimental 1 (MDE1), SD control 1 (SDC1), and SD experimental 1 (SDE1) groups. All rats in the control groups were administered 1 mL of distilled water (DW). The rats in the MDE1 and the SDE1 groups were administered SRM orally at 200 and 300 mg/kg body weight (BW), respectively, dissolved in 1 mL of DW. Blood was collected initially and at intervals of 1 hour for 6 hours to measure blood glucose. A similar experimental design was followed for the 30-day long-term trial. Finally, rats were sacrificed, and blood was collected to measure blood glucose, lipid profiles, thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH). Results: OGTTs indicated that two doses (200 and 300 mg/kg BW) were effective hypoglycemic doses in normal rats. Both doses reduced glucose levels after 1 hour in the MDE1 and the SDE1 groups. A long-term trial of SRM in the MD group showed a reduced glucose level, a normal lipid profile, and normal GSH and TBARS levels. In SD rats, SRM had no statistically significant effects on these parameters. Normal weight was achieved in the MD rats, but the SD rats showed reduced BW. Conclusion: The study demonstrates that SRM has potential to alleviate the conditions of moderate diabetic, but not severe diabetes.