• Title/Summary/Keyword: wistar rat

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The Effect of Eicosanoid Analogues on the Change to Blood Pressure in Rat (Eicosanoid 유도체가 흰쥐 혈압 변화에 미치는 영향)

  • 윤재순;윤연숙;신정희;최현진;최진아
    • Biomolecules & Therapeutics
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    • v.3 no.2
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    • pp.104-110
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    • 1995
  • Arachidonic acid (AA, C20 : 4, $\omega$-6) and eicosapentanoic acid (EPA,C20 : 5, $\omega$-3), which are polyunsaturated fatty acids forming eicosanoids, were tested for their effects on blood pressure in Wistar rats and SHR. AA is the most important precursor for the biosynthesis of eicosanoids which include the prostaglandins, prostacyclin (PGI$_2$), thromboxane $A_2$ (TXA$_2$) and the leukotriens. TXA$_2$is a potent vasoconstrictor and a powerful inducer of platelet aggregation causing myocardial infarction and hypertention. In contrast, PGI$_2$ induces vasodilation and inhibits platelet aggregation. In this study, AA markedly increased blood pressure, but its effect was antagonized by both EPA, a structural analog of AA, and dazmegrel, a TX synthetase inhibitor. Also, AA enhanced the antihypertensive effects of hydralazine and captopril, and EPA reduced TXA$_2$ production. These results indicate that the hypotensive effects of EPA might be closely related to the decrease in TXA$_2$ biosynthesis due to competitive inhibition by structural similarity of the EPA to the AA, the precursor of TXA$_2$.

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Embryo and Fetal Developmental Toxicity Study on Gamma-Irradiated Korean Ginseng in Rats (방사선 조사 인삼이 랫드의 기형유발에 미치는 영향에 관한 연구)

  • 박귀례;신재호;김판기;이유미;장성재
    • Toxicological Research
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    • v.17 no.1
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    • pp.27-32
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    • 2001
  • Korean ginseng products have been fumigated with ethylene oxide (EO) for sterilization and prolongation of storage periods. However, there had been controversies indicating that consumption of EO treated foods might cause harmful effects in human. In Korea, the use EO gas for food treatment was banned in 1991. Since then, irradiation technique has been developed as an alternative. This study was carried out to evaluate the safety of irradiated ginseng on embryo and fetal developmental toxicity effects in rats. Either EO gas fumigated or $\gamma$-irradiated ginseng was administered to pregnant Wistar rats by oral gavage from gestational day 7 to 17. The amount of irradiation used in this study was 5, 10 and 30 kGy, respectively. There were no treatment related changes of dams in deaths, clinical signs, food consumption and body/organ weight. No treatment related changes in implantation ratio, litter size, sex ratio and body/organ weight of fetuses were observed. Also, no F1fetuses with external, visceral, head and skeletal mal-formation were observed. The results of this study showed that $\gamma$-irradiated ginseng, up to 30 kGy, has no adverse effects on fetal development of rats.

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Evaluation of Peri- and Postnatal Toxicity of Gamma-Irradiated Korean Ginseng in Rats (방사선 조사 인삼이 랫드의 태자와 신생자의 발달 및 모체기능에 미치는 영향에 관한 연구)

  • 박귀례;한순영;김판기;신재호;장성재
    • Toxicological Research
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    • v.17 no.1
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    • pp.17-25
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    • 2001
  • Korean ginseng products have been fumigated with ethylene oxide (EO) for sterilization and prolongation of storage periods. However, there had been controversies indicating that consumption of EO treated foods might cause harmful effects in human. In Korea, the use EO gas for sterilization of food was banned in 1991. Since then, irradiation technique has been developed as an alternative. This study was carried out to evaluate the safety of irradiated ginseng on peri- and postnatal developmental toxicity in rats. Either EO gas fumigated or gamma-irradiated ginseng was administered to pregnant Wistar rats by oral gavage from gestational day 16 to postnatal day 21. The amount of irradiation used in this study was 5, 10 and 30 kGy, respectively. There were no treatment related changes of dams in deaths, clinical signs, and parturition. No treatment related changes in food consumption, body/organ weight and lactation of dams were observed. Also, no F1 fetuses in external abnormality, physical development, reflex/sensory junctions and behavioral development were found. The results of this study showed that gamma-irradiated ginseng, up to 30 kGy, has no adverse effects on the peri- and postnatal development of rats.

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Involvement of calcineurin and PKB/Akt in development of hereditary hypertension (유전적 고혈압 발병에 대한 Calcineurin 및 PKB/Akt의 연관성)

  • Hong, Yonggeun;Cho, Jae-hyun;Kim, Joo-heon
    • Korean Journal of Veterinary Research
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    • v.44 no.1
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    • pp.7-13
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    • 2004
  • Severe hypertension (>180 mmHg) develops in spontaneously hypertensive rats (SHR) after 12 wk-old; however, it is not clear whether what kinds of molecular mechanism leads to altered cardiac performance following developmental stages in SHR. Also, although the effect of calcineurin (Cn) to promote cardiomyocyte hypertrophy in vivo and in vitro is established, its overall necessity as a hypertrophic mediator is currently an area of ongoing debate. Thus, we have examined i) body weight and blood pressure, ii) differences of expression and distribution of signaling molecules such as Cn, protein kinase B/Akt (PKB/Akt), and extracellular signal-regulated kinase (ERK) between SHR and their age-matched control Wistar-Kyoto (WKY) rats following developmental stages. In 16 wk-old SHR compared with WKY, 2-dimentional echocardiography showed cardiac enlargement and hypertrophy of left ventricle, significantly. Taken together, we suggest that Cn is associated with hereditary cardiac hypertrophy, the process being related to the molecular signaling mechanisms involving PKB/Akt and ERK.

The Effects of Dietary Magnesium on Systolic Blood Pressure and Electrolyte Distribution in Normotensive and Spontaneously Hypertensive Rat (정상 혈압쥐와 본태성 고혈압쥐에 있어 식이상의 마그네슘 섭취가 수축기 혈압과 전해질 배분에 미치는 영향)

  • 배현수
    • Journal of Nutrition and Health
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    • v.22 no.2
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    • pp.91-101
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    • 1989
  • This study was performed to investigate the effects of different dietary magnesium levels on systolic blood pressure and mineral distribution in normotensive and spontaneously hypertensive rats. In experiment 1, Normotensive rats(NTR ; Sprague Dawley, Female) were given diets containing regular magnesium (0.05% Mg ; rMg), marginal magnesium (0.01% Mg ; mMg) or marginal magnesium with stress(0.01% Mg + stress ; mMg + Str). In experiment 2, spontaneously hypertensive rats (SHR ; Kyoto Wistar, Femal) were fed diets containing regular magnesium(0.05% Mg ; rMg) and high magnesium (0.2% Mg ; hMG). The following were found ; 1) NTR treated with marginal magnesium with stress showed significant increase in systolic blood pressure (SBP). Marginal magnesium diet without stress resulted in nonsignificant increase in SBP. Significant in crease of blood pressure showed in NTR treated with marginal magnesium and stress was associated with decreased magnesium and increased calcium content in femur, reticulocyte and plasma. 2) In experiment 2, magnesium supplementation to SHR showed significant attenuation of their systolic blood pressure with increasing age. The attenuation of SBP showed in SHR was associated with increased magnesium, lowered calcium content in cardiac muscle and reticulocyte and decreased plasma sodium and aldosterone level.

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Nitric Oxide Synthase Expressions in ADR-induced Cardiomyopathy in Rats

  • Liu, Baogang;Li, Hongli;Qu, Hongyan;Sun, Baogui
    • BMB Reports
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    • v.39 no.6
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    • pp.759-765
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    • 2006
  • In this study, we investigate Nitric oxide synthase (NOS) expressions in adriamycin (ADR)-induced cadiomyopathy in rats. Sixty male Wistar rats were randomly divided into two main groups: control and ADR groups. Myocardial histopathological observation was performed; Expressions of 3 isoforms of NOS genes were examined by RT-PCR analysis; Expressions of 3 isoforms of NOS protein was assessed by Western blot analysis. Myocardium exhibited intensive morphological changes after 8 weeks of ADR treatment. The expression levels of inducible NOS (iNOS) gene and protein were significantly increased in ADR-treated rats after 8 weeks of treatment and then slightly increased at weeks 9 and 10. No significantly difference of neuronal NOS (nNOS) or endothelial NOS (eNOS) gene and protein were observed in the myocardium obtained from the control rats and ADR-injected rats at any time point. iNOS gene expression is selectively induced by ADR in heart. The upregulation of iNOS gene and protein may be somehow correlated with morphological changes seen in heart of rat treated with ADR.

Expression of caveolin-3 as positive intracellular signaling regulator on the development of hypertrophy in cardiac tissues

  • Kim, Joo-Heon;Han, Jin;Kim, Yong-Kwon;Yang, Young-Ae;Hong, Yonggeun
    • Korean Journal of Veterinary Research
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    • v.45 no.4
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    • pp.537-544
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    • 2005
  • We have examined distribution and expression of caveolin-3 (cav-3), one of three caveolin isoforms from 16-wks-old spontaneously hypertensive rats (SHR) compared with age-matched control wistar-kyoto (WKY) rats. The expression of cav-3 was increased, whereas expression of PKB/Akt and calcineurin (Cn) was not changed in cardiac tissues of SHR compared to WKY rats. Interestingly, expression of cav-3, PKB/Akt and Cn were decreased in plasma membrane fraction in SHR compared to WKY rats. In H9c2 cardiomyoblast cells treated with phenylephrine ($50{\mu}M$, 48hr) or isoproterenol ($10{\mu}M$, 48hr), the expression of cav-3 was markedly enhanced compared to nontreated cells. Upon immunofluorescence analysis, cav-3 was localized in plasma membrane of control H9c2 cells. However phenylephrine or isoproterenol treatment caused translocation of cav-3 to perinuclear region. These results suggest that cav-3 plays as positive regulators in the development of hypertrophy in cardiac tissues of SHR rats.

Effect of Flunarizine on Experimental Ischemia and Hypoxia in Rats and Mice (실험적(實驗的) 뇌허혈(腦虛血) 및 저산소증(低酸素症)에 대한 Flunarizine의 약효(藥效) -뇌장해에 대한 Flunarizine 효능-)

  • Kim, Eun-Mi;Kim, Young-Jin;Shin, Jeoung-Hee;Yun, Jae-Soon
    • YAKHAK HOEJI
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    • v.32 no.5
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    • pp.343-350
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    • 1988
  • Recent hypothesis suggested that intracellular accumulation of calcium is a common denominator of ischemic celullar damage. Flunarizine, a calcium entry blocker, posses vasodilating properties in cerebral vascular beds and clinically used in circulatory disorders. The present study was designed to evaluate the effect of flunarizine on ischemic and hypoxic brain damage. An ischemic model was made by bilateral carotid artery ligation (BCAL) in Wistar strain rat. Hypoxic model was made by intravenous injection(i.v.) of KCN to rats and mice. In mice, flunarizine not only reduced the mortality of KCN, but also delayed the onset time of convulsion. The contents of ATP, creatine phosphate and glucose, cerebral energy metabolite, decreased 30 minutes after BCAL and KCN i, v, while that of lactate increased. But these variations were suppressed by flunarizine. Furthermore, increase in the dosage of flunarizne generally promoted the recovery of cerebral energy metabolites in hypoxic animals. The results suggest that flunarizine had a protective effect against ischemic and hypoxic brain damage due to its ameliorating action on the cerebral energy metabolism.

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Effect of DHEA administration during dexamethasone treatment on mass of hindlimb muscles of rat (Dexamethasone 치료기간 중의 DHEA 투여가 쥐의 뒷다리근 질량에 미치는 영향)

  • Choe, Myoung-Ae;Shin, Gi-Soo;Lee, Eun-Ju;An, Gyeong-Ju
    • Journal of Korean Biological Nursing Science
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    • v.3 no.1
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    • pp.63-74
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    • 2001
  • The purpose of this study was to determine the effect of DHEA with dexamethasone on body weight and wet weight and relative weight of atrophied hindlimb muscles induced by dexamethasone treatment. $200{\sim}225g$ Wistar rats were divided into control(C), dexamethasone(D), dexamethasone and DHEA(DDH) groups. Dexamethasone was injected daily at a dose of 5mg/kg. DHEA was administered daily at a dose of 5mg/kg by oral ingestion during 7days. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. Body weight and muscle weight of plantaris and gastrocnemius of dexamethasone group decreased significantly compared with that of control group. Muscle weight of plantaris of DDH group increased significantly compared with dexamethasone group. Body weight of DDH group decreased significantly compared to control group, but relative weight of plantaris and gastrocnemius of DDH group increased significantly compared to control group. Based on these results, it can be suggested that DHEA administration during dexamethasone treatment can be suggested that DHEA administration during dexamethasone treatment can increase weight of atrophied plantaris muscle induced by dexamethasone treatment.

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Effects of Atrial Natriuretic Peptide on Renal and Endocrine Functions in Spontaneously Hypertensive Rats (Spontaneously Hypertensive Rat에 있어서 Atrial Natriuretic Peptide의 신장기능과 몇가지 호르몬 분비에 미치는 영향)

  • Kim, San-Ho;Kim, Suhn-Hee;Seul, Kyung-Hwan;Cho, Kyung-Woo
    • The Korean Journal of Physiology
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    • v.22 no.1
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    • pp.41-53
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    • 1988
  • The present study was undertaken to clarify the involvement of atrial natriuretic peptide in the development of hypertension in spontaneously hypertensive rats. Plasma concentration of immunoreactive atrial natriuretic peptide was higher in spontaneously hypertensive rats than in normotensive Sprague-Dawley and Wistar rats. Plasma renin concentration was lower in SHR than in normotensive rats, as observed in earlier experiments. Hydration-induced increase in urine flow and urinary excretions of sodium and potassium were smaller in SHR than in normotensive control rats. Intraarterial infusion of atrial natriuretic peptide resulted in increases in urine flow, urinary excretions of sodium and potassium in both hypertensive and normotensive rats. Renal response to atrial natriuretic peptide was markedly suppressed in SHR. Plasma renin and aldosterone concentration were suppressed by atrial natriuretic peptide in both SHR and normotensive rats. The responses were not significantly different in both groups. These results suggest that the renal responsiveness to atrial natriuretic peptide may be suppressed in SHR by some mechanisms still remaining obscure.

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