• Title/Summary/Keyword: spontaneously hypertensive rat

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THE EFFECT OF GINSENG ON BLOOD PRESSURE IN SPONTANEOUSLY HYPERTENSIVE RAT AND ESSENTIAL HYPERTENSION

  • Sohn E. Suk;Huh Bong Yul;Park Seong Chul;Park Chan Woong;Kim Hae Jung
    • Proceedings of the Ginseng society Conference
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    • 1980.09a
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    • pp.1-3
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    • 1980
  • To investigate the effect of ginseng on blood pressure (B.P.) in spontaneously hypertensive rat (SHR) and essential hypertension ginseng extract was given per se daily in 58 SHR and 35 essential hypertensive patients. SHR were divided into 5 groups according to the dosage of ginseng. In essential hypertension 1,000mg of ginseng extract was given. The B.P. in SHR was measured by tail cuff method. In essential hypertension side effect and changes in various laboratory examinations were evaluated. In SHR ginseng appeared to have hypertensive effect when it is given in small amount(10mg/kg). However, when it is given 60mg/kg/day or more difinite B.P. lowering effect was observed. The hypotensive effect was dosedependant and it lasted for 37days of observation. In essential hypertension in 12 $(80\%)$ among 15 patients hypotensive effect was seen with ginseng administration along and the effect lasted for 12 weeks. In the rest of hypertensive patients it is required addition of diuretics of other antihypertensive drugs to decrease B.P., no appreciable side effect was seen. In laboratory examinations no significant changes were seen except for serum cholesterol, ${\alpha}-and\;{\beta}-lipoprotein,$ and hematocrit. There was some evidence of relationship between plasma renin activity (PRA) and ginseng in hypotensive action.

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Effect of Gastrodiae Rhizoma Extract on Blood Pressure and Plasma Catecholamine Level in Unanaesthetized Spontaneously Hypertensive Rats (천마(天麻)엑기스가 Spontaneously Hypertensive Rat 에서 혈압(血壓) 및 혈장(血漿) Catecholamine 함량의 변화(變化)에 미치는 영향(影響))

  • Yang, Chae-Ha;Kwen, Yong-Zun;Kim, Mi-Ryeo
    • The Journal of Korean Medicine
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    • v.16 no.2 s.30
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    • pp.433-446
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    • 1995
  • The present study was carried out to investigate the effect of water extract and 70% ethanol extract from Gastrodiae Rhizoma on cardiovascular activities and plasma levels of catecholamines in unanaesthetized spontaneously hypertensive rats. The depressor response in SHR was observed during three to six hour period after an oral administration of water extract from Gastrodiae Rhizoma(GR). There was a statistically significant correlation between the magnitude of the depressor response induced by an oral administration of water extract from GR and the initial control blood pressure level. The increase in blood pressure induced by norepinephrine was less in Wistar rat treated with GR water extract than those without GR extract. No significant change in heart rate was observed in SHR receiving either water extract or ethanol extract from GR. Associated with the depressor response, there was a concomitant reduction in plasma levels of norepinephrine in SHR at 4 hour after an oral administration of water extract from GR. Plasma levels of norepinephrine and epinephrine were decreased slightly at 2 hour after an oral administration of ethanol extract from GR. These results suggest that the depressor effect of water extract from GR may be due, in part, to a decreased sympathoadrenal activity.

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Effect of gemigliptin on cardiac ischemia/reperfusion and spontaneous hypertensive rat models

  • Nam, Dae-Hwan;Park, Jinsook;Park, Sun-Hyun;Kim, Ki-Suk;Baek, Eun Bok
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.5
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    • pp.329-334
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    • 2019
  • Diabetes is associated with an increased risk of cardiovascular complications. Dipeptidyl peptidase-4 (DPP-IV) inhibitors are used clinically to reduce high blood glucose levels as an antidiabetic agent. However, the effect of the DPP-IV inhibitor gemigliptin on ischemia/reperfusion (I/R)-induced myocardial injury and hypertension is unknown. In this study, we assessed the effects and mechanisms of gemigliptin in rat models of myocardial I/R injury and spontaneous hypertension. Gemigliptin (20 and 100 mg/kg/d) or vehicle was administered intragastrically to Sprague-Dawley rats for 4 weeks before induction of I/R injury. Gemigliptin exerted a preventive effect on I/R injury by improving hemodynamic function and reducing infarct size compared to the vehicle control group. Moreover, administration of gemigliptin (0.03% and 0.15%) powder in food for 4 weeks reversed hypertrophy and improved diastolic function in spontaneously hypertensive rats. We report here a novel effect of the gemigliptin on I/R injury and hypertension.

Substrate-Perfusion Studies on Coronary Circulation and Myocardial Energy Metabolism in Spontaneously Hypertensive Rat Hearts (발현성 고혈압쥐의 관상순환 기능과 심장근의 에너지 대사에 관한 생체외 에너지원의 관류 연구)

  • 김은지
    • Journal of Nutrition and Health
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    • v.28 no.2
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    • pp.115-126
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    • 1995
  • The effects of energy-yielding substrates on coronary circulation, myocardial oxygen metabolism, and intramyocytic adenylates of perfused Wistar control rat(WC) and spontaneously hypertensive rat(SHR) hearts were examined under basal and $\beta$-adrenergic stimulation conditions. The perfusion medium (1.0mM Ca2+) contained 5mM glucose (+5U/l insulin) in combination with 5mM pyruvate, 5mM lacate, 5mM acetate, or 5mM octanoate as energy substrates. Hearts were perfused with each substrate buffer for 20min under basal conditions. Coronary functinal hyperemia was induced by infusing for 20min isoproterenol (ISO, 1uM), a $\beta$-receptor agonist. Cardiac adenylates, glycolytic intermediates, and coronary venous lactate were measured by using an enzymatic analysis technique. Under basal conditions, acetate and octanoate significantly increased coronary flow(CF) of WC in parallel with myocardial oxygen consumption. However, CF of SHR was partly attenuated by coronary vasoconstriction despite metabolic acidosis. In addition, pyruvate and lactate depressd ISO-induced coronary functional hyperemia in SHR. It should be noted that octanoate exhibited coronary dysfunction under ISO conditions. On the other hand, fat substrates depleted myocardial high energy phosphate pool and accumulated breakdown intermediates. In SHR with coronary vasoconstriction under basal conditions, and with depressed coronary functional hyperemia, high energy phosphates were greatly depleted. These results suggest that energy substrates in the myocardium and coronary smooth muscle alter remarkably coronary circulation, and that coronary circulatory function is associated with a reserve of high energy phosphates and a balance between breakdown and nono synthesis of energy phosphates. These findings could be explained by alterations in the cytosolic redox state manipulated by LDH and hence in the cytosolic phosphorylation potential, which might be involved in hypertension of SHR.

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Effects of Arginine Vasopressin on the Renal Function in Spontaneously Hypertensive Rats (Spontaneously Hypertensive Rat에서 Arginine Vasopressin의 신장효과)

  • Kim, Jong-Hun;Cho, Kyung-Woo;Yun, Young-Yi
    • The Korean Journal of Physiology
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    • v.21 no.2
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    • pp.291-296
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    • 1987
  • There have been reports on the aberration of the control mechanisms of the blood pressure, hormone secretion, and renal functions in spontaneously hypertensive rats (SHR). However, the contribution of the renin-angiotensin system in the maintenance of high blood pressure in SHR is still controversial. Recently, it has been reported that the negative feedback short loop control mechanism of the renin-angiotensin system may be changed in SHR. In the present experiment, it was attempted to explore the possible alterations in the effect of arginine vasopressin (AVP) on the renal function in SHR. Experiments have been done in anesthetized SHR as well as in normotensive Wistar and Sprague-Dawley rats as control groups. Pharmacologic doses of AVP (10-13 mU/rat/10 min) decreased urine volume, excreted amount of creatinine and para-amino-hippuric acid. No differences in these parameters was observed between normotensive and hypertensive rats. AVP increased sodium and potassium excretion, but the responses in SHR were suppressed as compared with normotensive rats. Intravenous infusion of AVP also increased blood pressure in normotensive and hypertensive rats and a vasopressor effect of AVP was attenuated in SHR. There was a positive correlation between the changes in blood pressure and excreted amount of sodium during AVP infusion. These data suggest that the attenuated natriuretic effect of intravenous infusion of AVP may be due to a difference in renal tubular responsiveness to AVP but not due to a difference in vasopressor responsiveness.

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Effects of Ginkgo biloba Leaf Extracts on the bevels of Neurotransmitters in the Spontaneously Hypertensive Rat Brain (은행잎 추출성분이 고혈압쥐의 뇌중 신경전달물질 함량에 미치는 영향)

  • 박혜영;주지연;김명희;신정희
    • Biomolecules & Therapeutics
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    • v.3 no.1
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    • pp.28-33
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    • 1995
  • Effects of Ginkgo biloba leaf extract (GBE) and its components kaempferol-coumaroyl glucosyl rhamnoside (Kc), quercetin-coumaroyl glucosyl rhamnoside (Qc), ginkolide (G) and bilobalide (B) on blood pressure and on the levels of neurotransmitters in the spontaneously hypertensive rat brain were examined. Blood pressure decreased about 10 mmHg after administration of GBE but without significance. The concentration of norepinephrine increased (3 times) and that of DOPAC was decreased (38%) after administration of Qc. And 3-MT concentration was increased (36%) by Kc administration in striatum. While Qc administration increased the concentration of Ach (260%) and Ch(29%) significantly, B administration increased Ch concentration in cerebral cortex.

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The Effect of Gamitongseong-san(GTS) on Spontaneously Hypertensive Rat(SHR) (가미통성산(加味通聖散)이 자발성 고혈압 흰쥐에 미치는 영향)

  • Choi, Eun-Hee;Lim, Dae-Woong;Jung, Tae-San;An, Ga-Yong;Chun, Hea-Sun;Jeon, Sang-Yun;Hong, Seok
    • The Journal of Internal Korean Medicine
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    • v.31 no.3
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    • pp.554-568
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    • 2010
  • Objective : This study was examined to investigate the effect of Gamitongseong-san(GTS) extract on spontaneous hypertension. Methods : After administering GTS extract to SHR for 4 weeks, we measured anti-oxygen effects, weight of body, heart and kidney, blood pressure, heart rate, aldosterone, catecholamine, electrolyte, uric acid, and BUN. Results : 1. GTS increased 2,2-diphenyl-1-picrylhydrazyl(DPPH) scavenging activity and superoxide dismutase(SOD) similar activity depending on the concentration. 2. GTS significantly decreased heart weight in spontaneously hypertensive rat. 3. GTS significantly decreased blood pressure and heart rate in SHR. 4. GTS significantly decreased aldosterone. 5. GTS significantly decreased norepinephrine and epinephrine. 6. GTS significantly decreased $K^+$. 7. GTS significantly decreased BUN. Conclusions : These results suggest that GTS may be usefully applied for the treatment of hypertension.

Myocardial Function and Metabolic Energetics in Low Flow Ischemia and with $\beta$-Adrenergic Stimulation in Spontaneously Hypertensive Rat Hearts

  • Kang, Young-Hee;Kang, Jung-Sook;Park, Han-Yoon
    • Preventive Nutrition and Food Science
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    • v.6 no.1
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    • pp.43-50
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    • 2001
  • The effects of cardiac ischemia-reperfusion and $\beta$-adrenergic stimulation on metabolic function and energetics were investigated in Lan gendorff-perfused spontaneously hypertensive rat (SHR) hearts. Sarcoplasmic reticulum {TEX}$Ca^{2+}${/TEX}-dependent ATPase and cardiac lactate dehydrogenase (LDH) are additionally studied. The perfusion medium (1.0 mM {TEX}$Ca^{2+}${/TEX}) contained 5 mM glucose(+5 U/L insulin) and 2 mM pyruvate as substrates. Global ischemia was induced by reducing perfusion pressure of 100 to 40 cm {TEX}$H_{2}${/TEX}O, followed by 20 min reperfusin. Isoproterenol (ISO, 1$\mu$M) was infused for 10 min. Coronary vascular resistance and myocardial oxygen consumption ({TEX}$MVO_{2}${/TEX}) of SHR were increased in parallel with enhanced venous lactate during ischemia and reperfusion compared to those of Sprague Dawley (SD) hearts. Although ischemia-induced increase in venous lactate and combined adenosine plus inosine was abolished, coronary vasodilation produced in SD during reperfusion. In SHR, depressed reactive hyperemia was associated with a fall in cardiac ATP and CrP/Pi ratio and a rise in intracellular lactate/Pyruvate ratio. On the other hand, ISO produced coronary functional hyperemia and an increase in {TEX}$MVO_{2}${/TEX}. However, these responses were less than those in SHR hearts. The ATPase activity of SHR was attenuated in free {TEX}$Ca^{2+}${/TEX} concentrations used under basal condition and with ISO compared to that of SD. Venous lactate output and cardiac LDH activity were augmented in SHR as influenced by ISO. These results demonstrate that coronary reactive and functional hyperemia was dpressed in SHR, which cold be explained by alterations in the cytosolic phosphorylation potential and the cytosolic redox state manipulated by LDH, and by abnormal free calcium handling.

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Electroacupuncture Delays Development of Hypertension through Increase of NO Level in Spontaneously Hypertensive Rats

  • Hwang, Hye-Suk;Kim, Yu-Sung;Lee, Ji-Eun;Han, Kyung-Ju;Choi, Sun-Mi;Koo, Sung-Tae
    • Korean Journal of Oriental Medicine
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    • v.13 no.2 s.20
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    • pp.149-155
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    • 2007
  • Objective : Using a spontaneously hypertensive rat (SHR) model of essential hypertension, this study investigated whether electroacupuncture (EA) could reduce early stage hypertension by examining whether EA increased nitric oxide (NO) levels in plasma, which compensates for elevated blood pressure (BP). Methods : EA was applied to the acupoint, Baekhoe (GV20), and to a non acupoint in the tail at 10 Hz and an intensity of 1 mA for 10 minutes on the first and fourth day of the week for three weeks under isoflurane anesthesia. In conscious SHR and normotensive Wistar Kyoto (WKY) rats, blood pressure was determined the day after EA treatment by the tail cuff method using an automatic BP monitoring system. We also measured NO concentration of blood serum in SHR and WKY. Results : Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were lower after 3 weeks of GV20 treatment than in non EA treated or non acupoint treated SHR rats. The NO level of plasma was significantly lower in hypertensive SHR than in normotensive WKY. EA prevented the augmentation of blood pressure, and also increased NO concentrations from $7.91{\pm}0.42$ ${\mu}M$ to $11.50{\pm}0.93$ ${\mu}M$ in SHR serum. Conclusions : We suggest that acupuncture may be an early intervention to delay the development of hypertension and enhance NO/NOS activity.

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Distributional Patterns of Phospholipase C Isozymes in Heart and Brain of Spontaneously Hypertensive and Normotensive Rats

  • Choi, Ji-Woong;Cho, Young-Jin;Cha, Seok-Ho;Lee, Kweon-Haeng;Lee, Sang-Bok
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.4
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    • pp.385-392
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    • 1997
  • The phospholipase C (PLC)-mediated intracellular signal transduction pathway is considered to be involved in the regulation of blood pressure. However, little information is available concerning the distributional and functional significance of PLC in the genetic hypertensive rats. As the first step of knowing the role of PLC on hypertension, we investigated the distribution of 6 PLC isozymes $(PLC-{\beta}1,\;-{\beta}3,\;-{\beta}4,\;-{\gamma}1,\;-{\gamma}2\;and\;-{\delta}1)$ in the heart and brain, which are concerned with hypertension, in the normotensive Wistar-Kyoto rat (WKY) and spontaneously hypertensive rat (SHR) using the western blotting and immunocytochemistry. The immunoreactivities of PLC isozymes in brain were detected, but there were no distributional and quantitative differences between the WKY and SHR. In the heart, but the immunoreactivities to $PLC-{\beta}1$ and $-{\gamma}2$ in the SHR were higher than those in WKY. In immunocytochemistry to confirm these western blotting data, $PLC-{\beta}1$ and $-{\gamma}2$ were localized in cardiac myocytes and the intensities of immunoreactivity in SHR were stronger than that in WKY. These results suggest that $PLC-{\beta}1$ and $-{\gamma}2$ would have possibility to concern with the establishment of spontaneous hypertension.

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