• 제목/요약/키워드: AngiotensinII

검색결과 257건 처리시간 0.023초

Effects of Central GABA and Glutamate on Blood Pressure and Single Unit Spikes in the RVLM of Rats

  • Park, Jae-Sik;Lee, Zee-Ihn;Jang, Jae-Hee;Ahn, Dong-Kuk
    • The Korean Journal of Physiology and Pharmacology
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    • 제6권3호
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    • pp.149-154
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    • 2002
  • The blood pressure (BP) is regulated by the nervous system and humoral factors, such as renin- angiotensin system, vasopressin and others. In the present study, we examined the central effects of glutamate and GABA on the cardiovascular regulation by injection of these substances into the lateral ventricle and also investigated the relationship between these central effects and the action of angiotensin II (Ang). Male Sprague Dawley rats, $350{\sim}400$ g, were anesthetized with urethane and instrumented with an arterial catheter for direct measurement of BP and heart rate (HR), and an guide cannula in the lateral ventricle for drug injection. A glass microelectode was inserted into the rostral ventrolateral medulla (RVLM) for recording single unit spikes. Barosensitive neurons were identified by changes of single unit spikes in RVLM following intravenous injection of nitroprusside and phenylephrine. The effects of GABA and glutamate injected into the lateral ventricle were studied in single neuronal activity of the RVLM in addition to changes in BP and heart rate, and compared the results before and after treatment with intravenous losartan, nonpeptide Ang II-type 1 receptor antagonist (1 mg/100 g BW). Intracerebroventricular administration of GABA decreased systolic blood pressure (SBP) and HR, but increased the firing rates in the RVLM. However, intracerebroventricular glutamate injection produced effects opposite to GABA. After pretreatment of intravenous losartan, the central effects of GABA on BP and firing rate in the RVLM were significantly attenuated and that of glutamate showed a tendency of attenuation. These results suggested that central GABA and glutamate regulated BP and firing rates in RVLM were inversely related to BP change. The central effects of GABA or glutamate on the autonomic nervous function were modulated by humoral factor, Ang II, by maintaining BP.

Effect of Brain Angiotensin II Receptor Antagonists and Antisense Oligonucleotide on Drinking and Renal Renin in Rats

  • Cho, Hyeon-Kyeong;Yang, Eun-Kyoung;Han, Hee-Suk;Lee, Won-Jung;Phillips, M. Ian
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권2호
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    • pp.137-142
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    • 2000
  • The physiological roles of brain angiotensin II in mediating water deprivation-induced drinking and in regulating renal renin release were assessed in male Sprague-Dawley rats. Specific $AT_1$ receptor antagonists, losartan and SK 1080, and antisense oligonucleotide (AS-ODN) directed to $AT_1$ receptor mRNA were intracerebroventricularly (i.c.v.) administered in conscious unrestrained rats. When water was given 20 min after i.c.v. injection of $AT_1$ receptor antagonists in 48-h water-deprived rats, losartan and SK 1080 produced approximatly 20% and 50% decrease in 1-h water intake, respectively. In contrast, i.c.v. treatment of the AS-ODN to $AT_1$ receptor mRNA for 24-h did not alter 1-h water intake in 24-h water-deprived rats, but prevented the increase in overnight water intake after 24-h water-deprivation. Six-day i.c.v. treatment of AS-ODN did not alter either the basal plasma renin concentration or renal cortical levels of renin and renin mRNA. The present results suggest that endogenous brain Ang II plays an important role in thirst and water intake through $AT_1$ receptors, but further studies are required to elucidate its regulatory role in renal renin synthesis.

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Effect of Blood Pressure on Contractility of Vascular Smooth Muscle and Endothelium-Dependent Relaxation

  • Suh, Suk-Hyo;Park, Yee-Tae;Lee, Dong-Chul;Seo, Pil-Won;Kim, Ki-Whan
    • The Korean Journal of Physiology
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    • 제29권2호
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    • pp.279-289
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    • 1995
  • This study was designed 1) to develop a hypertensive animal model in which the blood pressures (BPs) of symmetric regions (right and left upper extremities) are significantly different and 2) to test the effect of BP per se on the contractility and endothelium-dependent relaxation of vascular smooth muscle. Rabbits were anesthetized with sodium pentobarbital and ventilated with room air via animal respirator. The transverse aorta was exposed through the left second intercostal space and the lumen of the aorta was narrowed partially by ligation using 3-0 silk and a probe at a point between the origins of the brachiocephalic trunk and the left subclavian artery. Four to eight weeks postoperatively, BPs were measured in the carotid artery as the high BP area (proximal to coactation site) and in the femoral artery as the low BP area (distal to coarctation site). In the animal model, pressure-overload hypertension was developed and the BP of the right subclavian artery was higher than that of the left subclavian artery. The concentrations of circulating epinephrine, norepinephrine, angiotensin I, and angiotensin II were measured. The right and left subclavian arteries and their branches were used for isometric tension recording in organ baths and their responsiveness to phenylephrine, serotonin, acetylcholine, and sodium nitroprusside were examined. The BPs of carotid and femoral artery in control animals were $116{\pm} 12/75{\pm}9\;mmHg (mean ${\pm}SEM$) and $130{\pm}16/68{\pm}9\;mmHg$ respectively, while those of carotid and femoral artery in the hypetensive animals were $172{\pm}6/111{\pm}10\;mmHg$ and 136{\pm} 4/100 {\pm}9\;mmHg$ respectively. There were no significant differences in the concentrations of circulating epinephrine, norepinephrine, angiotensin I, and angiotensin II between controls and the animal models. No significant differences were found in the vascular sensitivities to phenylephrine and serotonin between the high pressure-exposed vessels and the low pressure-exposed vessels. However, the endothelium-dependent relaxation to acetylcholine and nitroprusside-induced relaxation showed significant differences between the high pressure-exposed and the low pressure-exposed subclavian arteries. From the above results, we suggest that the contractility of vascular smooth muscle is unchanged by the elevated pressure per se. However, the endothelium-dependent relaxation to acetylcholine and the nitroprusside-induced relaxation are attenuated by pressure.

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죽력의 in vitro에서의 angiotensin-converting enzyme 저해효과와 마우스모델에서 혈행개선효과 (Effects of Bambusae Caulis in liquamen on inhibition of angiotensin-converting enzyme in vitro and blood flow in mouse model)

  • 김춘득;유민정;전형식;최근표;황권택
    • 한국식품저장유통학회지
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    • 제24권7호
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    • pp.992-999
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    • 2017
  • 대나무 죽력의 ACE 저해효과와 마우스모델에서의 혈행개선 효과를 보았다. 혈전용해능에서 청국장추출물은 2.56 unit, 미정제죽력에서 4.71 unit, 정제죽력에서 4.32 unit를 나타내어 모두가 plasmin 보다 유의하게 높은 활성이 높고, ACE 활성 저해 효과에서는 죽력 원액, 미정제 죽력과 정제 죽력에서 각각 70.25%, 69.01%, 68.23%로 대조군으로 사용된 청국장이 26.56%으로 나타나 높은 억제효과를 보였다. 마우스모델시험에서 고지방식이군과 함께 고지방식이군+정제죽력 0.01%와 0.05%를 투여, 혈청 중 지질변화에서 triglyceride의 함량은 고지방식이군이 일반식이군(271.1 mg/dL)에 비해 314.4 mg/dL로 증가하였고, 고지방식이+죽력 0.01%군은 301.5 mg/dL로 나타났으며, 고지방식이+죽력 0.05%군은 289.2 mg/dL으로 유의하게 중성지질이 감소를 나타내었고, total-cholesterol 함량은 327.2 mg/dL로 증가하였으며, 고지방식이+죽력 0.01%군은 311.9 mg/dL로 나타났으며, 고지방식이+죽력 0.05%군은 293.7 mg/dL로 고지방식이군에 비교, 유의하게 total-cholesterol이 감소세를 나타내었다. 한편 HDL-cholesterol은 일반식이군이 206.0 mg/dL로 가장 높은 값을 나타내었으며, 고지방식이+죽력 0.01%군 196.6 mg/dL, 고지방식이+죽력 0.05%군 189.2 mg/dL, 고지방식이군 162.2 mg/dL순으로 나타났고, 죽력첨가군 0.01%군과 0.05%군간의 유의성은 없었다. 혈류개선효과에서는 고지방식이에 비하여 고지방식이+죽력 0.05% 군이 고지방식이군, 고지방식이+죽력 0.01%군보다 모두 유의하게 빠르게 모세관을 통과하여 빠른 혈액 유동성을 나타내었다. 혈소판응집 억제능에서는 고지방식이군의 경우 대조군인 일반식이군에 비해 혈소판 응집이 증가한 반면 고지방식이+죽력 0.01%군과 고지방식이+죽력 0.05%군은 고지방식이군에 비해 혈소판응집이 억제되는 것으로 나타났다.

급속 진행성 사구체신염으로 시작된 현미경적 다발성 동맥염(Microscopic Polyangiitis) 환자의 7년간의 장기 추적관찰 1례 (Seven-Year Follow Up of Microscopic Polyangiitis Presenting with Rapidly Progressive Glomerulonephritis)

  • 오진원;김병길;이재승;정현주
    • Childhood Kidney Diseases
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    • 제12권1호
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    • pp.99-104
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    • 2008
  • 현미경적 다발성 동맥염은 폐출혈과 급속 진행성 사구체심염을 특징으로 하는 전신성 혈관염의 일종으로 소아에서는 매우 드문 질환이다. 저자들은 폐출혈과 급성 신부전을 동반한 7세 여아에서 신장조직검사와 p-ANCA 검사로 현미경적 다발성 동백염으로 진단 후 5년 뒤 2차 신장조직검사와 경구 ACE inhibitor, angiotensin II receptor blocker와 저용량의 cyclophosphamide를 투여 받은 환아를 7년간 추적관찰하였다. 발병당시에는 BUN 117 mg/dL, Cr 2.3 mg/dL이었으나, 퇴원시 BUN 20.8 mg/dL, Cr 1.6 mg/dL이었고, 최근 검사에서는 BUN 51.7 mg/dL, Cr 3.2 mg/dL으로 만성 신병증 소견을 보이고 있으며, 외래 추적 관찰 지속 중에 있다. 이에 문헌 고찰과 함께 증례 보고하는 바이다.

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Effects of Central Interleukin-1 on the Cardiovascular Response in Hemorrhaged Rats

  • Kang, Joon-Ho;Jang, Jae-Hee;Ahn, Dong-Kuk;Park, Jae-Sik
    • The Korean Journal of Physiology and Pharmacology
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    • 제8권2호
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    • pp.89-94
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    • 2004
  • The arterial pressure is regulated by the nervous and humoral mechanisms. The neuronal regulation is mostly carried out by the autonomic nervous system through the rostral ventrolateral medulla (RVLM), a key area for the cardiovascular regulation, and the humoral regulation is mediated by a number of substances, including the angiotensin (Ang) II and vasopressin. Recent studies suggest that central interleukin-1 (IL-1) activates the sympathetic nervous system and produces hypertension. The present study was undertaken to elucidate whether IL-1 and Ang II interact in the regulation of cardiovascular responses to the stress of hemorrhage. Thus, Sprague-Dawley rats were anesthetized and both femoral arteries were cannulated for direct measurement of arterial pressure and heart rate (HR) and for inducing hemorrhage. A guide cannula was placed into the lateral ventricle for injection of IL-1 $(0.1,\;1,\;10,\;20\;ng/2\;{\mu}l)$ or Ang II $(600\;ng/10\;{\mu}l)$. A glass microelectrode was inserted into the RVLM to record the single unit spike potential. Barosensitive neurons were identified by an increased number of single unit spikes in RVLM following intravenous injection of nitroprusside. I.c.v. $IL-1\;{\beta}$ increased mean arterial pressure (MAP) in a dose-dependent fashion, but HR in a dose-independent pattern. The baroreceptor reflex sensitivity was not affected by i.c.v. $IL-1\;{\beta}$. Both i.c.v. $IL-1\;{\alpha}\;and\;{\beta}$ produced similar increase in MAP and HR. When hemorrhage was induced after i.c.v. injection of $IL-1\;{\beta}$, the magnitude of MAP fall was not different from the control. The $IL-1\;{\beta}$ group showed a smaller decrease in HR and a lower spike potential count in RVLM than the control. MAP fall in response to hemorrhage after i.c.v. injection of Ang II was not different from the control. When both IL-1 and Ang II were simultaneously injected i.c.v., however, MAP fall was significantly smaller than the control, and HR was increased rather than decreased. These data suggest that IL-1, a defense immune mediator, manifests a hypertensive action in the central nervous system and attenuates the hypotensive response to hemorrhage by interaction with Ang II.

Renal fibrosis

  • Cho, Min-Hyun
    • Clinical and Experimental Pediatrics
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    • 제53권7호
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    • pp.735-740
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    • 2010
  • Renal fibrosis, characterized by tubulointerstitial fibrosis and glomerulosclerosis, is the final manifestation of chronic kidney disease. Renal fibrosis is characterized by an excessive accumulation and deposition of extracellular matrix components. This pathologic result usually originates from both underlying complicated cellular activities such as epithelial-to-mesenchymal transition, fibroblast activation, monocyte/macrophage infiltration, and cellular apoptosis and the activation of signaling molecules such as transforming growth factor beta and angiotensin II. However, because the pathogenesis of renal fibrosis is extremely complicated and our knowledge regarding this condition is still limited, further studies are needed.