• Title/Summary/Keyword: Angiotensin II receptor

Search Result 94, Processing Time 0.03 seconds

The Effects of Gypsum Fibrosum on Renal Functional and Histopathological Disorder in Chronic Renal Failure Rat Model (석고(石膏)가 만성 신부전 Rat의 신기능 보호 및 조직학적 변화에 미치는 영향)

  • Byun, Sang-Hyuk
    • The Journal of Internal Korean Medicine
    • /
    • v.29 no.4
    • /
    • pp.871-886
    • /
    • 2008
  • Objective : Gypsum fibrosum has been traditionally used in treatment of febrile diseases and recently been shown to have anti-inflammatory effect. Chronic renal failure has a serious clinical symptoms including proteinuria, azotemia, anemia, and hyperlipidemia and has characteristic histopathological changes, glomerular hypertrophy, infiltration of inflammatory cells, and crescentic sclerosis, We investigated the effects of gypsum fibrosum on renal functional and histopathological disorder in chronic renal failure rat model induced 5/6 nephrectomy. Methods : Using Sprague-Dawley rats, CRF was induced by 5/6 nephrectomy. The rats were divided into 3 groups, normal, conrol, and gypsum administered orally with gypsum fibrosum 500mg/kg/day. Body weight, 24 hr proteinuria, hematologic analysis, and histological morphologic changes were followed up after 8 weeks. The glomerular macrophage/monocyte infiltration, $TGF-{\beta}_1$, type IV collagen, and angiotensin II type1 receptor($AT_1$) were evaluated by immunohistochemistry. Resuls : In the CRF control group, functional parameters and histopathologic changes clearly indicated the development of CRF. 24 hr proteinuria significantly increased in the CRF control group over the normal group, and serum creatinine level was lower in the gypsum group than in the control group, LDL-cholesterol was significantly lower in the gypsum group than in the control group. Morphological investigations showed a variety of characteristic features of CRF, glomerular hypertrophy, increasing cellular density of glomerulus, deposition of extra-cellular matrix, fibrotic change, and glomerular sclerosis in the control group, but in the gypsum group, these features diminished significantly. In observation of renal type IV collagen and $AT_1$ expression, positive area significantly increased in the control group over the normal group, and it significantly decreased in the gypsum group compared to the control group. Conclusions : Our findings suggest that gypsum fibrosum inhibits $AT_1$ and type IV collagen expression in renal tissues and attenuates progression of glomerulosclerosis and interstitial fibrosis in chronic renal failure rats, which lead to amelioration of renal function. From these results, we suggest that gypsum fibrosum may have renoprotective effects and could be a useful remedy agent for treating chronic renal failure.

  • PDF

Pharmacological Profile of KR-31125, an Orally Active AT1 Receptor Antagonist (안지오텐신 수용체 리간드 KR-31125의 생체 내 활성에 관한 연구)

  • Lee, Sung-Hou
    • Journal of Life Science
    • /
    • v.20 no.7
    • /
    • pp.969-976
    • /
    • 2010
  • In vivo studies of KR-31125 (2-butyl-5-dimethoxymethyl-6-phenyl-7-methyl-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b]pyridine) were performed in pithed rats, conscious angiotensin II (AII) challenged normotensive rats, renal hypertensive rats (RHRs) and furosemide-treated beagle dogs. KR-31125 induced a non-parallel right shift in the dose-pressor response curve to AII ($ID_{50}$: 0.095 mg/kg) with a dose-dependent reduction in the maximum responses in pithed rats. Compared to losartan, this antagonistic effect was about 18 times more potent, presenting competitive antagonism. Other agonists such as norepinephrine and vasopressin did not alter the responses induced by KR-31125. Orally administered KR-31125 had no agonistic effect and dose-dependently inhibited the pressor response to AII with a slightly weaker potency ($ID_{50}$: 0.25 and 0.47 mg/kg, respectively) in the AII-challenged normotensive rat model, but with a more rapid onset of action than losartan (time to $E_{max}$: 30 min for KR-31125 and 6 hr for losartan). KR-31125 produced a dose-dependent antihypertensive effect with a higher potency than losartan in RHRs, and these effects were confirmed in furosemide-treated dogs where they presented a dose-dependent and long-lasting (>8 hr) antihypertensive effect with a rapid onset of action (time to $E_{max}$: 2-4 hr), as well as a 20-fold greater potency than losartan. These results suggest that KR-31125 is a potent, orally active $AT_1$ receptor antagonist that can be applied to the development of new diagnostic and research tools as an added exploratory potential of $AT_1$ receptor antagonist.

MYH9 nephropathy

  • Oh, Taehoon;Seo, Hyun Jung;Lee, Kyu Taek;Kim, Han Jo;Kim, Hwi Jun;Lee, Ji-Hye;Cheong, Hae Il;Lee, Eun Young
    • Kidney Research and Clinical Practice
    • /
    • v.34 no.1
    • /
    • pp.53-56
    • /
    • 2015
  • MYH9-related disorder is an autosomal dominant disease caused by a mutation in the MYH9 gene, which encodes nonmuscle myosin heavy chain IIA (NMMHC-IIA). This disease is characterized by giant platelets, thrombocytopenia, granulocyte inclusion bodies, proteinuria, and high-pitch sensorineural deafness. Nephropathy has been observed in 30% of patients with MYH9-related disorder. The characteristic features are early onset proteinuria and rapidly progressing renal disorder. However, the prognosis of MYH9 nephropathy remains unclear. Herein, we describe a 36-year-old woman who presented with proteinuria and was diagnosed with MYH9 nephropathy via renal biopsy and gene analysis. Her proteinuria improved after administration of an angiotensin II receptor blocker, but was aggravated after changing to a calcium channel blocker.

A novel blood pressure modulator C1q/TNF-α-related protein 1 (CTRP1)

  • Han, Sora;Yang, Young
    • BMB Reports
    • /
    • v.51 no.12
    • /
    • pp.611-612
    • /
    • 2018
  • $C1q/TNF-{\alpha}-Related$ Protein 1 (CTRP1) has recently been shown to act as a blood pressure regulator, as it induces vasoconstriction. In the aorta, CTRP1 facilitates recruitment of angiotensin II receptor 1 (AT1R) to plasma membrane, through activation of the AKT/AS160 signaling pathway. This leads to activation of the Ras homolog gene family (Rho)/Rho kinase (ROCK) signaling pathway, resulting in vasoconstriction. Accordingly, mice overexpressing Ctrp1 have hypertensive phenotype. Patients with hypertension also display higher circulating CTRP1 levels, compared to healthy individuals, indicating that excessive CTRP1 may affect development of hypertension. Conversely, CTRP1 is regarded as an 'innate blood pressure modulator' because CTRP1 increases blood pressure under dehydration to prevent hypotension. Mice lacking Ctrp1 fail to maintain normotension under dehydration conditions, resulting in hypotension, suggesting that CTRP1 is an essential protein for maintaining blood pressure homeostasis. In conclusion, CTRP1 is a novel, anti-hypotensive vasoconstrictor that increases blood pressure during dehydration-induced hypotension.

Efficacy and safety of losartan in childhood immunoglobulin A nephropathy: a prospective multicenter study

  • Hyesun Hyun;Yo Han Ahn;Eujin Park;Hyun Jin Choi;Kyoung Hee Han;Jung Won Lee;Su Young Kim;Eun Mi Yang;Jin Soon Suh;Jae Il Shin;Min Hyun Cho;Ja Wook Koo;Kee Hyuck Kim;Hye Won Park;Il Soo Ha;Hae Il Cheong;Hee Gyung Kang;Seong Heon Kim
    • Childhood Kidney Diseases
    • /
    • v.27 no.2
    • /
    • pp.97-104
    • /
    • 2023
  • Purpose: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) are frequently employed to counteract the detrimental effects of proteinuria on glomerular diseases. However, the effects of ARBs remain poorly examined in pediatric patients with immunoglobulin A (IgA) nephropathy. Herein, we evaluated the efficacy and safety of losartan, an ARB, in pediatric IgA nephropathy with proteinuria. Methods: This prospective, single-arm, multicenter study included children with IgA nephropathy exhibiting proteinuria. Changes in proteinuria, blood pressure, and kidney function were prospectively evaluated before and 4 and 24 weeks after losartan administration. The primary endpoint was the difference in proteinuria between baseline and 24 weeks. Results: In total, 29 patients were enrolled and received losartan treatment. The full analysis set included 28 patients who received losartan at least once and had pre- and post-urinary protein to creatinine ratio measurements (n=28). The per-protocol analysis group included 22 patients who completed all scheduled visits without any serious violations during the study period. In both groups, the mean log (urine protein to creatinine ratio) value decreased significantly at 6 months. After 24 weeks, the urinary protein to creatinine ratio decreased by more than 50% in approximately 40% of the patients. The glomerular filtration rate was not significantly altered during the observation period. Conclusions: Losartan decreased proteinuria without decreasing kidney function in patients with IgA nephropathy over 24 weeks. Losartan could be safely employed to reduce proteinuria in this patient population. ClinicalTrials.gov trial registration (NCT0223277)

Lifestyle intervention might easily improve blood pressure in hypertensive men with the C genotype of angiotensin II type 2 receptor gene

  • Kitaoka, Kaori;Kitade, Azusa;Nagaoka, Junko;Tsuzaki, Kokoro;Harada, Kiyomi;Aoi, Wataru;Wada, Sayori;Asano, Hiroaki;Sakane, Naoki;Higashi, Akane
    • Nutrition Research and Practice
    • /
    • v.9 no.4
    • /
    • pp.385-392
    • /
    • 2015
  • BACKGROUND/OBJECTIVES: Recent studies have reported an association of the angiotensin II type 2 receptor (AT2R) 3123Cytosine/Adenine (3123C/A) polymorphism with essential hypertension and cardiovascular diseases. The purpose of the study was to investigate whether the AT2R 3123C/A polymorphism affects blood pressure for free-living hypertensive men during a 5-month intervention period. SUBJECTS/METHODS: The subjects were free-living hypertensive Japanese men aged 40 to 75 years who agreed to intervention in the period from 2004 to 2011. Detection of the AT2R 3123C/A polymorphism was determined by polymerase chain reaction. The dietary intervention was designed to decrease salt level and to increase potassium level through cooking instructions and self-monitoring of the diet. The exercise session consisted of activities such as stretching, resistance training, and walking. Blood pressure, urinary sodium and potassium excretion, dietary and lifestyle data, and non-fasting venous blood sample were collected at baseline and after the intervention period. RESULTS: Thirty nine subjects were eligible for participation and the follow-up rate was 97.4%. The C allele proportion was 57.9%. AT2R 3123C/A polymorphism was X-chromosome-linked, therefore we analyzed the C and A genotypes. At baseline, no significant differences were observed between the genotype groups. After the intervention, there were no significant differences in lifestyle habit between the groups. Nevertheless, the estimated salt excretion (g/day) was significantly decreased only in the C genotype (13.0-10.3, P = 0.031). No significant change was observed in systolic blood pressure (SBP) (mmHg) in the A genotype, but a significant decrease was observed in the C genotype (150.0-141.5, P = 0.024). CONCLUSTIONS: In the C genotype, it might be easy to improve SBP through lifestyle intervention in free-living hypertensive Japanese men, however generalization could not be achieved by the small sample size.

Pharmacological Effects of ginseng Saponins on Receptor Stimulation-responses

  • Eiichi Tachikawa;Kenzo Kudo;Kazuho Harada;Takeshi Kashimoto;KatsuroFurumachi;Yoshikazu Miyate;Atsushi Kakizaki;Eiji Takahashi
    • Proceedings of the Ginseng society Conference
    • /
    • 1998.06a
    • /
    • pp.40-46
    • /
    • 1998
  • We investigated the influence of the root of Panax ginseng C. A. Meyer on the secretion of catecholamines from bovine adrenal chromaffin cells, which are used as a model of nervous systems. In two major parts extracted from the ginseng root, the crude saponin fraction, but not the non-saponin fraction, reduced the secretion from the cells, stimulated by acetylcholine (ACh). Ginseng saponins (ginsenosides) are classified into three groups, the panaxadiol, the panaxatriol and the oleanolic acid groups, on the basis of the chemical structures of their saponins. Both the panaxadiol and the panaxatriol saponins, excluding only one oleanolic acid saponin ginsenoside-Ro, generally reduced the ACh-evoked secretion. The inhibitory effects of the panaxatriol were much stronger than those of the panaxadiol. However, ginsenoside-Rg, and -Rh3 in the panaxadiol saponins were the potent inhibitors comparable to the panaxatriol saponins. Ginsenoside-Rg2 in the panaxatriol was the most effective. It is probable that the ginsenoside inhibition of the catecholamine secretion is due to the suppression of the function of the nicotinic ACh receptor-cation channels. On the other hand, ginsenoside-Rg2 did not affect the angiotensin II-, the bradykinin-, the histamine- and the neurotensin- induced catecholamine secretions from the chromaffin cells and the muscarine- and the histamine- induced contraction of the ileum in guinea-pigs. Ginsenoside-Rbl, a panaxadiol saponin, and ginsenoside-Ro had no or only a slight effect on them. On the contrary, ginsenoside-Rg3 not only competitively inhibited the muscarine-induced ileum contraction but also reduced the angiotensin R -, the bradykinin-, the histamine- and the neurotensin-induced catecholamine secretions. Thus, the ginseng root contains active ingredients, namely some ginsensides, which suppress the responses induced by receptor stimulation. The inhibitory effects of ginseng saponins may be one of the action mechanisms for the pharmacological effects of the Panax ginseng root.

  • PDF

Inhibitory Effects of Olmesartan on Catecholamine Secretion from the Perfused Rat Adrenal Medulla

  • Lim, Hyo-Jeong;Kim, Sang-Yong;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.14 no.4
    • /
    • pp.241-248
    • /
    • 2010
  • The present sutdy aimed to determine whether olmesartan, an angiotensin II (Ang II) type 1 ($AT_1$) receptor blocker, can influence the CA release from the isolated perfused model of the rat adrenal medulla. Olmesartan ($5{\sim}50{\mu}M$) perfused into an adrenal vein for 90 min produced dose- and time-dependent inhibition of the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM, a direct membrane-depolarizer), DMPP (100 ${\mu}M$) and McN-A-343 (100 ${\mu}M$). Olmesartan did not affect basal CA secretion. Also, in adrenal glands loaded with olmesartan (15 ${\mu}M$), the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}M$, an activator of voltage-dependent L-type $Ca^{2+}$ channels), cyclopiazonic acid (10 ${\mu}M$, an inhibitor of cytoplasmic $Ca^{2+}$-ATPase), veratridine (100 ${\mu}M$, an activator of voltage-dependent $Na^+$ channels), and Ang II (100 nM) were markedly inhibited. However, at high concentrations ($150{\sim}300{\mu}M$), olmesartan rather enhanced the ACh-evoked CA secretion. Taken together, these results show that olmesartan at low concentrations inhibits the CA secretion evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) as well as by direct membrane depolarization from the rat adrenal medulla, but at high concentrations it rather potentiates the ACh-evoked CA secretion. It seems that olmesartan has a dual action, acting as both agonist and antagonist at nicotinic receptors of the isolated perfused rat adrenal medulla, which might be dependent on the concentration. It is also thought that this inhibitory effect of olmesartan may be mediated by blocking the influx of both $Na^+$ and $Ca^{2+}$ into the rat adrenomedullary chromaffin cells as well as by inhibiting the $Ca^{2+}$ release from the cytoplasmic calcium store, which is thought to be relevant to the $AT_1$ receptor blockade, in addition to its enhancement on the CA secreton.

The Effects of Rehmannia on Nephrectomy-induced Chronic Renal Failure Rats (생지황(生地黃)이 신절제술로 유도된 만성신부전 Rat에 미치는 영향(影響))

  • Choe, Jong-Bae;Kim, Young-Seong;Han, Yang-Hee
    • The Journal of Internal Korean Medicine
    • /
    • v.29 no.4
    • /
    • pp.1100-1114
    • /
    • 2008
  • The aim of the study was to investigate recovery effects of Rehmannia, which has been used clinically for chronic renal failure therapy. Mice had 5/6 nephrectomy to induce chronic renal failure. The results were as follows: 1. The protein amount in urine per 24hrs of the Rehmannia-treated group was significantly reduced compared to the control. 2. The albumin amount in the blood of the Rehmannia-treated group significantly increased compared to the control. The creatinine. total-cholesterol, LDL-cholesterol and triglyceride levels in serum of the Rehmannia-treated group as compared to the control were significantly inhibited. 3. The structural change in kidney of the Rehrnannia-treated group was significantly inhibited compared to the control. 4. The factor (macrophage/monocyte antigen (ED-1), type IV collagen and angiotensin II type 1 ($AT_1$) receptor) of the Rehmanala-treated group was significantly inhibited compared to the control, which induced the structural change in kidneys. The above results suggest that Rehmannia partially improved kidney function.

  • PDF