• The Korean Journal of Physiology and Pharmacology
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• v.3 no.5
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• pp.471-479
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• 1999

The Kv channel activity in vascular smooth muscle cell plays an important role in the regulation of membrane potential and blood vessel tone. It was postulated that increased blood vessel tone in hypertension was associated with alteration of Kv channel and membrane potential. Therefore, using whole cell mode of patch-clamp technique, the membrane potential and the 4-AP-sensitive Kv current in cerebral arterial smooth muscle cells were compared between normotensive rat and one-kidney, one-clip Goldblatt hypertensive rat (lK,lC-GBH rat). Cell capacitance of hypertensive rat was similar to that of normotensive rat. Cell capacitance of normotensive rat and 1K,lC-GBH rat were $20.8{\pm}2.3$ and $19.5{\pm}1.4$ pF, respectively. The resting membrane potentials measured in current clamp mode from normotensive rat and 1K,lC-GBH rat were $-45.9{\pm}1.7$ and $-38.5{\pm}1.6$ mV, respectively. 4-AP (5 mM) caused the resting membrane potential hypopolarize but charybdotoxin $(0.1\;{\mu}M)$ did not cause any change of membrane potential. Component of 4-AP-sensitive Kv current was smaller in 1K,lC-GBH rat than in normotensive rat. The voltage dependence of steady-state activation and inactivation of Kv channel determined by using double-pulse protocol showed no significant difference. These results suggest that 4-AP-sensitive Kv channels playa major role in the regulation of membrane potential in cerebral arterial smooth muscle cells and alterations of 4-AP-sensitive Kv channels would contribute to hypopolarization of membrane potential in 1K,lC-GBH rat.

• Korean Journal of Acupuncture
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• v.24 no.3
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• pp.165-177
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• 2007

Objectives : The purpose of this study was to examine effects of acupuncture by needle manipulation at $LR1{\cdot}Kl1$ on the blood pressure, plasma levels of ANP(atrial natriuretic peptide), renin and cardiomegalic index in hypertensive rat Induced by two kidney one clip(2K1C). Material and methods : The groups divided into 7 groups; Control, no treatment. Acu-1,acupuncture at $LR1{\cdot}Kl1$ bilaterally and the needle was twirled and rotated forward with the thumb of the right hand 6 times. Acu-2, acupuncture at $LR1{\cdot}Kl1$ bilaterally and the needle was twirled and rotated forward with the forefinger of the right hand 6 times. Acu-3, acupuncture at $LR1{\cdot}Kl1$ bilaterally and the needle was inserted in the opposite direction(body direction) as the channel runs, Acu-4, acupuncture at $LR1{\cdot}Kl1$ bilaterally, the needle was inserted in the opposite direction(body direction) as the channel runs and the needle was twirled and rotated forward with the forefinger of the right hand 6 times. The acupuncture executed 5times for 2 weeks. Results : Systolic blood pressure was decreased significantly in Acu-2, Acu-3 and Acu-4. Plasma renin was decreased significantly in Acu-2 and Acu-4. Plasma ANP was increased significantly in Acu-2, however was decreased significantly in Acu-4. Cardiac hypertrophy index was decreased significantly in Acu-1, Acu-2, Acu-3 and Acu-4. Conclusions : These results suggest that acupuncture by needle manipulation at $LR1{\cdot}Kl1$ is effective in hypertension by renal blood problem.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.2
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• pp.95-100
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• 2016

The aim of the present study is to investigate the hypotensive effect of Mantidis ootheca (WMO), Rosa laevigata (WIC), and Imperata cylindrica (WRL) in renovascular hypertension rats. Experimental hypertension model is 2-kidney and 1-clip (2K1C) induced rats. 2K1C rats were treated with WMO, WIC, and WRL at dose of 100 mg/kg/day orally for 3 weeks, respectively. Treatment groups with WMO, WIC, and WRL significantly lowered blood pressure. Interestingly, WMO, WIC, and WRL ameliorated endothelium-dependent and independent vascular relaxation in the phenylephrine-precontracted thoracic aorta in hypertension models. In addition, 2K1C-induced hypertension model increased plasma renin activity, however, WMO, WIC, and WRL attenuated those activities. These results suggest that WMO, WIC, and WRL ameliorates vascular dysfunction in 2K1C-induced hypertension models via the regulation of nitric oxide and renin-angiotensin-aldosterone system.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.138-143
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• 1999

Background: The endothelium-dependent vasorelaxation has been largely accounted for by the release of nitric oxide (NO). Three distinct isoforms of NO synthases (NOS) have been characterized, i.e., brain(bNOS), inducible (iNOS), and endothelial constitutive (ecNOS). Although hypertension hasbeen associated with a vascular endothelial dysfunction, changes in the vascular expression of NOS isoforms have not been established. The present study was aimed at exploring the vascular expression of NOS isozymes in hypertension. Material and Method: Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were induced in rats. The expression of different NOS isozymes in the thoracic aorta was determined by Western blot analysis. The vascular tissue contents of nitrites were measured by colorimetric assay. Result: Arterial blood pressure was significantly higher in experimental groups of 2K1C and DOCA-salt rats compared with their corresponding control rats. The vascular expression of bNOS as well as that of ecNOS was decreased in both models of hypertension. iNOS was not changed in DOCA-salt hypertension, but was also decreased in 2K1C hypertension. The vascular contents of nitrites were significantly decreased in DOCA-salt as well as in 2K1C hypertension. Conclusion: These results suggest that 2K1C and DOCA-salt hypertension are associated with decreases in the vascular expression of NOS isozymes and nitrite contents.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.191-196
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• 1994

Captopril, an inhibitor of angiotensin converting enzyme, is also known to inhibit the degradation of bradykinin. We examined the effects of intracerebroventricular (ICV) captopril on the central pressor response to bradykinin in normotensive, 2-kidney, 1 clip Goldblatt (GHR) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Captopril (1 mg) and bradykinin (5 nmol) were administered into the right lateral cerebral ventricle, and blood pressure and heart rate were continuously monitored throughout the experiment. ICV captopril alone did not affect the blood pressure within 10 minutes but it significantly augmented the central pressor response to bradykinin in GHR. On the contrary, captopril was without effect on the pressor response to bradykinin in normotensive and DOCA-salt rats. These findings indicate that endogenous kinins are not critical in regulating arterial pressure in normotensive and DOCA hypertensive rats. However, in GHR, an enhanced activity of the brain kallikrein-kinin system in maintaining the high blood pressure is suggested.

• Journal of Ginseng Research
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• v.23 no.2 s.54
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• pp.81-87
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• 1999

The effect of saponin and non-saponin of Panax Red Ginseng on the blood pressure and nitric oxide production were investigated in the conscious free moving one-kidney, one-clip Goldbaltt hypertensive (lK, 1C-GBH) rats. Mean blood pressure in the control and lK, 1C-GBH rats was decreased by the administration of ginseng saponin (100 mg/kg, i.v.). The hypotensive effect induced by ginseng saponin was reached maximum at 2-4 minutes and was slowly recovered to the initial level of blood pressure. Also ginseng saponin induced reflex tachycardia in the conscious both rats. Contrast to the response induced by ginseng saponin, hypotensive effect induced by non-saponin of panax ginseng is minimal. Plasma nitric oxide concentration was increased by the treatment of ginseng saponin (100 mg/kg, i.p for 5 days) in both rats. It has been shown by western blotting that the expression level of the protein for endothelial nitric oxide synthase (eNOS) in the aorta of rats was not increased by the treatment of ginseng saponin (100 mg/kg, i.p). However, eNOS activity in aortic homogenates of both rats were increased by the treatment of ginseng saponins. From the above results, the hypotensive effect of saponin was greater than that of non-saponin of Panax Red Ginseng. The lowering effect of blood pressure by ginseng saponin may be due to the increase of plasma nitric oxide concentration via the increase of endothelial nitric oxide synthase activity in the renovascular hypertensive and control rats.

• Journal of Acupuncture Research
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• v.20 no.6
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• pp.1-12
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• 2003

Objective : The aim of this experiments was to investigate the effects of Kyongo Puryu(originated from ${\ll}$Classic on Difficulty${\gg}$), Kyongo Um-gok(originated from ${\ll}$Ling Shu${\gg}$) acupuncture on the Blood Pressure, Cardiomegalic index, and plasma levels of atrial natriuretic peptide in Hypertensive RAT induced by 2K1C. Methods : The effects of Kyongo(L8) Puryu(K7), Kyongo(L8) Um-gok(K10) acupuncture on Blood Pressure in Hypertensive RAT induced by Two Kidney One Clip(2K1C). Results : I. Blood Pressure was decreased significantly after acupuncture of L8 K7. II. Cardiomegalic index decreased significantly after acupuncture of L8 Puryu, L8 K10. IlI. Plasma levels of atrial natriuretic peptide was increased significantly after acupuncture of L8 K7.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.65-70
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• 2001

The present study was aimed to explore pathophysiological implications of nitric oxide in the development of left and right ventricular hypertrophy. To induce selective left and right ventricular hypertrophy, rats were made two-kidney, one clip (2K1C) hypertensive and treated with monocrotaline (MCT), respectively. Six weeks later, the hearts were taken and their ventricular tissue mRNA and protein expression of endothelial constitutive isoform of nitric oxide synthase (NOS) were determined by reverse transcription-polymerase chain reaction and Western blot analysis, respectively. In 2K1C hypertensive rats, the expression of NOS mRNA was increased in parallel with its proteins in the left ventricle, but not in the right ventricle. In MCT-treated rats, the expression of NOS mRNA and proteins were proportionally increased in the right ventricle, but not in the left ventricle. These results suggest that the expression of NOS is specifically increased in association with the ventricular hypertrophy, which may be a mechanism counteracting the hypertrophy.

• Journal of Acupuncture Research
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• v.20 no.1
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• pp.1-12
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• 2003

Objectives : The purpose of this study is to compare Xingjian(LR2) Shaofu(HT8) with Dadun(LR1) Shaofu(HT8) on Blood Pressure in Hypertensive RAT induced by Two Kidney One Clip(2KIC). Methods : This experiments was to investigate the effects of LR2 HT8(originated from ${\ll}$Classic on Difficulty${\gg}$ Shi Ze Xie Qi Zi), LR1 HT8(originated from ${\ll}$Ling Shu${\gg}$ Sheng Ze Xie Zhi) acupuncture on the blood pressure, cardiomegalic index, and plasma levels of atrial natriuretic peptide in hypertensive rat induced by 2K1C. Results: 1. Blood pressure was decreased significantly after third acupuncture of LR2 HT8. 2. Blood pressure was decreased significantly after acupuncture of LR2 HT8, but was increased after LR2 HT8. 3. Cardiomegalic index was not changed after acupuncture of LR2-HT8 and LR1-HT8 4. Plasma levels of atrial natriuretic peptide was increased significantly after acupuncture of LR2 HT8 but LR1 HT8 was not changed.

• The Korean Journal of Pharmacology
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• v.23 no.2
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• pp.123-131
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• 1987

The possible inolvement of central opiate system in the control of cardiovascular function and in the antihypertensive action of clonidine has been examined in unanesthetized rats with shamoperated or 2-kidney, 1-clip (2K1C) renal hypertension. In both groups of rats, intraventricular clonidine $(3-30\;{\mu}g/kg)$ produced hypotension and bradycardia. Hypotensive action of clonidine was more potent in the hypertensive rats than in the normotensive sham-operated rats. Yohimbine $(30\;{\mu}g/kg,\;i.v.t.)$ inhibited the hypotension and bradycardia produced by clonidine. Naloxone ($50\;{\mu}g/kg$, i.v.t.) inhibited the action of clonidine in 2K1C hypertensive rats but not influenced in the sham-operated rats. Intraventricular morphine $(10-100\;{\mu}g/kg)$ also reduced rats. Intraventricular morphine $(10-100\;{\mu}g/kg)$ also reduced blood pressure and heart rate in both groups of rats. But these effects were not affected by yohimbine, but antagonized by naloxone ($50\;{\mu}g/kg$, i.v.t.). Chronic treatment of 2K1C rats with clonidine ($3{\times}20\;{\mu}g/kg$, p.o.,) for 14 days from 1 day after 2K1C operation) suppressed the development of hypertension and maintained the blood pressure in normal level and this errect of clonidine was abolished by naloxone (2 mg/kg, i. p.). In the 2K1C hypertensive rats, immunoreactive ${\beta}-endorphin$ content was significantly decreased, but maximum binding (Bmax) of $(^3H)-naloxone$ was significantly increased in brain of 2K1C hypertensive rats. However, Kd value was not changed. These results suggest that the opioidergic component might be involved in the antihypertensive action of clonidine only in hypertensive and that central opiate system might play important roles in pathophysiology of development and maintenance of hypertension.