WorldWideScience

Sample records for angiotensin ii-induced hypertension

  1. Central interactions of aldosterone and angiotensin II in aldosterone- and angiotensin II-induced hypertension.

    Science.gov (United States)

    Xue, Baojian; Beltz, Terry G; Yu, Yang; Guo, Fang; Gomez-Sanchez, Celso E; Hay, Meredith; Johnson, Alan Kim

    2011-02-01

    Many studies have implicated both angiotensin II (ANG II) and aldosterone (Aldo) in the pathogenesis of hypertension, the progression of renal injury, and cardiac remodeling after myocardial infarction. In several cases, ANG II and Aldo have been shown to have synergistic interactions in the periphery. In the present studies, we tested the hypothesis that ANG II and Aldo interact centrally in Aldo- and ANG II-induced hypertension in male rats. In rats with blood pressure (BP) and heart rate (HR) measured by DSI telemetry, intracerebroventricular (icv) infusions of the mineralocorticoid receptor (MR) antagonists spironolactone and RU28318 or the angiotensin type 1 receptor (AT1R) antagonist irbesartan significantly inhibited Aldo-induced hypertension. In ANG II-induced hypertension, icv infusion of RU28318 significantly reduced the increase in BP. Moreover, icv infusions of the reactive oxygen species (ROS) scavenger tempol or the NADPH oxidase inhibitor apocynin attenuated Aldo-induced hypertension. To confirm these effects of pharmacological antagonists, icv injections of either recombinant adeno-associated virus carrying siRNA silencers of AT1aR (AT1aR-siRNA) or MR (MR-siRNA) significantly attenuated the development of Aldo-induced hypertension. The immunohistochemical and Western blot analyses of AT1aR-siRNA- or MR-siRNA-injected rats showed a marked reduction in the expression of AT1R or MR in the paraventricular nucleus compared with scrambled siRNA rats. When animals from all studies underwent ganglionic blockade with hexamethonium, there was a smaller reduction in the fall of BP in animals receiving icv AT1R or MR antagonists. These results suggest that ANG II and Aldo interact in the brain in a mutually cooperative manner such that the functional integrity of both brain AT1R and MR are necessary for hypertension to be induced by either systemic ANG II or Aldo. The pressor effects produced by systemic ANG II or Aldo involve increased central ROS and

  2. NLRP3 Deficiency Improves Angiotensin II-Induced Hypertension But Not Fetal Growth Restriction During Pregnancy.

    Science.gov (United States)

    Shirasuna, Koumei; Karasawa, Tadayoshi; Usui, Fumitake; Kobayashi, Motoi; Komada, Tadanori; Kimura, Hiroaki; Kawashima, Akira; Ohkuchi, Akihide; Taniguchi, Shun'ichiro; Takahashi, Masafumi

    2015-11-01

    Preeclampsia is a pregnancy-specific syndrome characterized by elevated blood pressure, proteinuria, and intrauterine growth restriction (IUGR). Although sterile inflammation appears to be involved, its pathogenesis remains unclear. Recent evidence indicates that sterile inflammation is mediated through the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasomes, composed of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and caspase-1. Here we investigated the role of the NLRP3 inflammasomes in the pathogenesis of preeclampsia using Nlrp3(-/-) and Asc(-/-) (Nlrp3 and Asc deficient) pregnant mice. During pregnancy in mice, continuous infusion of high-dose angiotensin II (AngII) induced hypertension, proteinuria, and IUGR, whereas infusion of low-dose AngII caused hypertension alone. AngII-induced hypertension was prevented in Nlrp3(-/-) mice but not in Asc(-/-), indicating that NLRP3 contributes to gestational hypertension independently of ASC-mediated inflammasomes. Although NLRP3 deficiency had no effect on IUGR, it restored the IL-6 up-regulation in the placenta and kidney of AngII-infused mice. Furthermore, treatment with hydralazine prevented the development of gestational hypertension but not IUGR or IL-6 expression in the placenta and kidney. These findings demonstrate that NLRP3 contributes to the development of gestational hypertension independently of the inflammasomes and that IUGR and kidney injury can occur independent of blood pressure elevation during pregnancy.

  3. Role of α1D -adrenoceptors in vascular wall hypertrophy during angiotensin II-induced hypertension.

    Science.gov (United States)

    Gallardo-Ortíz, I A; Rodríguez-Hernández, S N; López-Guerrero, J J; Del Valle-Mondragón, L; López-Sánchez, P; Touyz, R M; Villalobos-Molina, R

    2015-09-01

    The in vivo effect of continuous angiotensin II (Ang II) infusion on arterial blood pressure, vascular hypertrophy and α1 -adrenoceptors (α1 -ARs) expression was explored. Alzet(®) minipumps filled with Ang II (200 ng kg(-1)  min(-1) ) were subcutaneously implanted in male Wistar rats (3 months-old). Groups of rats were also treated with losartan, an AT1 R antagonist, or with BMY 7378, a selective α1D -AR antagonist. Blood pressure was measured by tail-cuff; after 2 or 4 weeks of treatment, vessels were isolated for functional and structural analyses. Angiotensin II increased systolic blood pressure. Phenylephrine-induced contraction in aorta was greater (40% higher) in Ang II-treated rats than in the controls, and similar effect occurred with KCl 80 mm. Responses in tail arteries were not significantly different among the different groups. Angiotensin II decreased α1D -ARs without modifying the other α1 -ARs and induced an increase in media thickness (hypertrophy) in aorta, while no structural change occurred in tail artery. Losartan prevented and reversed hypertension and hypertrophy, while BMY 7378 prevented and reversed the aorta's hypertrophic response, without preventing or reversing hypertension. Findings indicate that Ang II-induced aortic hypertrophic response involves Ang II-AT1 Rs and α1D -ARs. Angiotensin II-induced α1D -AR-mediated vascular remodeling occurs independently of hypertension. Findings identify a α1D -AR-mediated process whereby Ang II influences aortic hypertrophy independently of blood pressure elevation.

  4. Estrogen regulation of the brain renin-angiotensin system in protection against angiotensin II-induced sensitization of hypertension.

    Science.gov (United States)

    Xue, Baojian; Zhang, Zhongming; Beltz, Terry G; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2014-07-15

    This study investigated sex differences in the sensitization of angiotensin (ANG) II-induced hypertension and the role of central estrogen and ANG-(1-7) in this process. Male and female rats were implanted for telemetered blood pressure (BP) recording. A subcutaneous subpressor dose of ANG II was given alone or concurrently with intracerebroventricular estrogen, ANG-(1-7), an ANG-(1-7) receptor antagonist A-779 or vehicle for 1 wk (induction). After a 1-wk rest (delay), a pressor dose of ANG II was given for 2 wk (expression). In males and ovariectomized females, subpressor ANG II had no sustained effect on BP during induction, but produced an enhanced hypertensive response to the subsequent pressor dose of ANG II during expression. Central administration of estrogen or ANG-(1-7) during induction blocked ANG II-induced sensitization. In intact females, subpressor ANG II treatment produced a decrease in BP during induction and delay, and subsequent pressor ANG II treatment given during expression produced only a slight but significant increase in BP. However, central blockade of ANG-(1-7) by intracerebroventricular infusion of A-779 during induction restored the decreased BP observed in females during induction and enhanced the pressor response to the ANG II treatment during expression. RT-PCR analyses indicated that estrogen given during induction upregulated mRNA expression of the renin-angiotensin system (RAS) antihypertensive components, whereas both central estrogen and ANG-(1-7) downregulated mRNA expression of RAS hypertensive components in the lamina terminalis. The results indicate that females are protected from ANG II-induced sensitization through central estrogen and its regulation of brain RAS.

  5. Sex differences in the development of angiotensin II-induced hypertension in conscious mice.

    Science.gov (United States)

    Xue, Baojian; Pamidimukkala, Jaya; Hay, Meredith

    2005-05-01

    Sex has an important influence on blood pressure (BP) regulation. There is increasing evidence that sex hormones interfere with the renin-angiotensin system. Thus the purpose of this study was to determine whether there are sex differences in the development of ANG II-induced hypertension in conscious male and female mice. We used telemetry implants to measure aortic BP and heart rate (HR) in conscious, freely moving animals. ANG II (800 ng.kg(-1).min(-1)) was delivered via an osmotic pump implanted subcutaneously. Our results showed baseline BP in male and female mice to be similar. Chronic systemic infusion of ANG II induced a greater increase in BP in male (35.1 +/- 5.7 mmHg) than in female mice (7.2 +/- 2.0 mmHg). Gonadectomy attenuated ANG II-induced hypertension in male mice (15.2 +/- 2.4 mmHg) and augmented it in female mice (23.1 +/- 1.0 mmHg). Baseline HR was significantly higher in females relative to males (630.1 +/- 7.9 vs. 544.8 +/- 16.2 beats/min). In females, ANG II infusion significantly decreased HR. However, the increase in BP with ANG II did not result in the expected decrease in HR in either intact male or gonadectomized mice. Moreover, the slope of the baroreflex bradycardia to phenylephrine was blunted in males (-5.6 +/- 0.3 to -2.9 +/- 0.5) but not in females (-6.5 +/- 0.5 to -5.6 +/- 0.3) during infusion of ANG II, suggesting that, in male mice, infusion of ANG II results in a resetting of the baroreflex control of HR. Ganglionic blockade resulted in greater reduction in BP on day 7 after ANG II infusion in males compared with females (-61.0 +/- 8.9 vs. -36.6 +/- 6.6 mmHg), suggesting an increased contribution of sympathetic nerve activity in arterial BP maintenance in male mice. Together, these data indicate that there are sex differences in the development of chronic ANG II-induced hypertension in conscious mice and that females may be protected from the increases in BP induced by ANG II.

  6. Transient Receptor Potential Melastatin 7 Cation Channel Kinase: New Player in Angiotensin II-Induced Hypertension.

    Science.gov (United States)

    Antunes, Tayze T; Callera, Glaucia E; He, Ying; Yogi, Alvaro; Ryazanov, Alexey G; Ryazanova, Lillia V; Zhai, Alexander; Stewart, Duncan J; Shrier, Alvin; Touyz, Rhian M

    2016-04-01

    Transient receptor potential melastatin 7 (TRPM7) is a bifunctional protein comprising a magnesium (Mg(2+))/cation channel and a kinase domain. We previously demonstrated that vasoactive agents regulate vascular TRPM7. Whether TRPM7 plays a role in the pathophysiology of hypertension and associated cardiovascular dysfunction is unknown. We studied TRPM7 kinase-deficient mice (TRPM7Δkinase; heterozygous for TRPM7 kinase) and wild-type (WT) mice infused with angiotensin II (Ang II; 400 ng/kg per minute, 4 weeks). TRPM7 kinase expression was lower in heart and aorta from TRPM7Δkinase versus WT mice, effects that were further reduced by Ang II infusion. Plasma Mg(2+) was lower in TRPM7Δkinase versus WT mice in basal and stimulated conditions. Ang II increased blood pressure in both strains with exaggerated responses in TRPM7Δkinase versus WT groups (Phypertension is exaggerated, cardiac remodeling and left ventricular dysfunction are amplified, and endothelial function is impaired. These processes are associated with hypomagnesemia, blunted TRPM7 kinase expression/signaling, endothelial nitric oxide synthase downregulation, and proinflammatory vascular responses. Our findings identify TRPM7 kinase as a novel player in Ang II-induced hypertension and associated vascular and target organ damage.

  7. Prolonged Subcutaneous Administration of Oxytocin Accelerates Angiotensin II-Induced Hypertension and Renal Damage in Male Rats.

    Directory of Open Access Journals (Sweden)

    James Phie

    Full Text Available Oxytocin and its receptor are synthesised in the heart and blood vessels but effects of chronic activation of this peripheral oxytocinergic system on cardiovascular function are not known. In acute studies, systemic administration of low dose oxytocin exerted a protective, preconditioning effect in experimental models of myocardial ischemia and infarction. In this study, we investigated the effects of chronic administration of low dose oxytocin following angiotensin II-induced hypertension, cardiac hypertrophy and renal damage. Angiotensin II (40 μg/Kg/h only, oxytocin only (20 or 100 ng/Kg/h, or angiotensin II combined with oxytocin (20 or 100 ng/Kg/h were infused subcutaneously in adult male Sprague-Dawley rats for 28 days. At day 7, oxytocin or angiotensin-II only did not change hemodynamic parameters, but animals that received a combination of oxytocin and angiotensin-II had significantly elevated systolic, diastolic and mean arterial pressure compared to controls (P < 0.01. Hemodynamic changes were accompanied by significant left ventricular cardiac hypertrophy and renal damage at day 28 in animals treated with angiotensin II (P < 0.05 or both oxytocin and angiotensin II, compared to controls (P < 0.01. Prolonged oxytocin administration did not affect plasma concentrations of renin and atrial natriuretic peptide, but was associated with the activation of calcium-dependent protein phosphatase calcineurin, a canonical signalling mechanism in pressure overload-induced cardiovascular disease. These data demonstrate that oxytocin accelerated angiotensin-II induced hypertension and end-organ renal damage, suggesting caution should be exercised in the chronic use of oxytocin in individuals with hypertension.

  8. Antihypertensive effect of gomisin A from Schisandra chinensis on angiotensin II-induced hypertension via preservation of nitric oxide bioavailability.

    Science.gov (United States)

    Young Park, Ji; Wook Yun, Jung; Whan Choi, Young; Ung Bae, Jin; Won Seo, Kyo; Jin Lee, Seung; Youn Park, So; Whan Hong, Ki; Kim, Chi Dae

    2012-09-01

    Gomisin A (GA) is a small molecular weight lignan present in Schisandra chinensis, and has been demonstrated to have vasodilatory activity. In the present study, we investigated the effect of GA on blood pressure (BP) in angiotensin II (Ang II)-induced hypertensive mice. C57/BL6 mice infused subcutaneously with Ang II (1 and 2 μg kg⁻¹ per min for 2 weeks) showed an increase in BP with a decrease in nitric oxide (NO) metabolites in plasma, and a negative correlation between these two parameters was demonstrated. In the thoracic aorta from Ang II-induced hypertensive mice, a decrease in vascular NO that was accompanied by a diminution of phosphorylated endothelial nitric oxide synthase (eNOS), as well as by increased reactive oxygen species (ROS) production, was demonstrated. These alterations in BP, eNOS phosphorylation and ROS production in the vasculature of Ang II-treated mice were markedly and dose-dependently reversed by simultaneous administration of GA (2 and 10 μg kg⁻¹ per min). In addition, Ang II-induced ROS production in cultured vascular cells such as endothelial cells and vascular smooth muscle cells was markedly attenuated by GA. These results suggested that GA attenuated the increase in BP via preservation of vascular NO bioavailability not only by inhibiting ROS production but also by preventing the impairment of eNOS function in the vasculature of Ang II-induced hypertensive mice.

  9. 6β-hydroxytestosterone, a cytochrome P450 1B1 metabolite of testosterone, contributes to angiotensin II-induced hypertension and its pathogenesis in male mice.

    Science.gov (United States)

    Pingili, Ajeeth K; Kara, Mehmet; Khan, Nayaab S; Estes, Anne M; Lin, Zongtao; Li, Wei; Gonzalez, Frank J; Malik, Kafait U

    2015-06-01

    Previously, we showed that Cyp1b1 gene disruption minimizes angiotensin II-induced hypertension and associated pathophysiological changes in male mice. This study was conducted to test the hypothesis that cytochrome P450 1B1-generated metabolites of testosterone, 6β-hydroxytestosterone and 16α-hydroxytestosterone, contribute to angiotensin II-induced hypertension and its pathogenesis. Angiotensin II infusion for 2 weeks increased cardiac cytochrome P450 1B1 activity and plasma levels of 6β-hydroxytestosterone, but not 16α-hydroxytestosterone, in Cyp1b1(+/+) mice without altering Cyp1b1 gene expression; these effects of angiotensin II were not observed in Cyp1b1(-/-) mice. Angiotensin II-induced increase in systolic blood pressure and associated cardiac hypertrophy, and fibrosis, measured by intracardiac accumulation of α-smooth muscle actin, collagen, and transforming growth factor-β, and increased nicotinamide adenine dinucleotide phosphate oxidase activity and production of reactive oxygen species; these changes were minimized in Cyp1b1(-/-) or castrated Cyp1b1(+/+) mice, and restored by treatment with 6β-hydroxytestoterone. In Cyp1b1(+/+) mice, 6β-hydroxytestosterone did not alter the angiotensin II-induced increase in systolic blood pressure; the basal systolic blood pressure was also not affected by this agent in either genotype. Angiotensin II or castration did not alter cardiac, angiotensin II type 1 receptor, angiotensin-converting enzyme, Mas receptor, or androgen receptor mRNA levels in Cyp1b1(+/+) or in Cyp1b1(-/-) mice. These data suggest that the testosterone metabolite, 6β-hydroxytestosterone, contributes to angiotensin II-induced hypertension and associated cardiac pathogenesis in male mice, most probably by acting as a permissive factor. Moreover, cytochrome P450 1B1 could serve as a novel target for developing agents for treating renin-angiotensin and testosterone-dependent hypertension and associated pathogenesis in males.

  10. Dimethylarginine dimethylaminohydrolase-1 mediates inhibitory effect of interleukin-10 on angiotensin II-induced hypertensive effects in vascular smooth muscle cells of spontaneously hypertensive rats.

    Science.gov (United States)

    Kim, Hye Young; Kim, Hee Sun

    2016-01-01

    In hypertension studies, anti-inflammatory cytokine interleukin-10 (IL-10) has been shown to prevent angiotensin II (Ang II)-induced vasoconstriction and regulate vascular function by down-regulating pro-inflammatory cytokine and superoxide production in vascular cells. However, little is known about the mechanism behind the down-regulatory effect of IL-10 on Ang II-induced hypertensive mediators. In this study, we demonstrated the effects of IL-10 on expression of dimethylarginine dimethylaminohydrolase (DDAH)-1, a regulator of NO bioavailability, as well as the down-regulatory mechanism of action of IL-10 in relation to Ang II-induced hypertensive mediator expression and cell proliferation in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR). IL-10 increased DDAH-1 but not DDAH-2 expression and increased DDAH activity. Additionally, IL-10 attenuated Ang II-induced DDAH-1 inhibition in SHR VSMCs. Increased DDAH activity due to IL-10 was mediated mainly through Ang II subtype II receptor (AT2 R) and AMP-activated protein kinase (AMPK) activation. DDAH-1 induced by IL-10 partially mediated the inhibitory action of IL-10 on Ang II-induced 12-lipoxygenase (LO) and endothelin (ET)-1 expression in SHR VSMCs. In addition, the inhibitory effect of IL-10 on proliferation of Ang II-induced VSMCs was mediated partially via DDAH-1 activity. These results suggest that DDAH-1 plays a potentially important role in the anti-hypertensive activity of IL-10 during Ang II-induced hypertension.

  11. Mitogen-activated protein kinase-activated protein kinase 2 in angiotensin II-induced inflammation and hypertension: regulation of oxidative stress.

    Science.gov (United States)

    Ebrahimian, Talin; Li, Melissa Wei; Lemarié, Catherine A; Simeone, Stefania M C; Pagano, Patrick J; Gaestel, Matthias; Paradis, Pierre; Wassmann, Sven; Schiffrin, Ernesto L

    2011-02-01

    Vascular oxidative stress and inflammation play an important role in angiotensin II-induced hypertension, and mitogen-activated protein kinases participate in these processes. We questioned whether mitogen-activated protein kinase-activated protein kinase 2 (MK2), a downstream target of p38 mitogen-activated protein kinase, is involved in angiotensin II-induced vascular responses. In vivo experiments were performed in wild-type and Mk2 knockout mice infused intravenously with angiotensin II. Angiotensin II induced a 30 mm Hg increase in mean blood pressure in wild-type that was delayed in Mk2 knockout mice. Angiotensin II increased superoxide production and vascular cell adhesion molecule-1 in blood vessels of wild-type but not in Mk2 knockout mice. Mk2 knockdown by small interfering RNA in mouse mesenteric vascular smooth muscle cells caused a 42% reduction in MK2 protein and blunted the angiotensin II-induced 40% increase of MK2 expression. Mk2 knockdown blunted angiotensin II-induced doubling of intracellular adhesion molecule-1 expression, 2.4-fold increase of nuclear p65, and 1.4-fold increase in Ets-1. Mk2 knockdown abrogated the angiotensin II-induced 4.7-fold and 1.3-fold increase of monocyte chemoattractant protein-1 mRNA and protein. Angiotensin II enhanced reactive oxygen species levels (by 29%) and nicotinamide adenine dinucleotide phosphate oxidase activity (by 48%), both abolished by Mk2 knockdown. Reduction of MK2 blocked angiotensin II-induced p47phox translocation to the membrane, associated with a 53% enhanced catalase expression. Angiotensin II-induced increase of MK2 was prevented by the nicotinamide adenine dinucleotide phosphate oxidase inhibitor Nox2ds-tat. Mk2 small interfering RNA prevented the angiotensin II-induced 30% increase of proliferation. In conclusion, MK2 plays a critical role in angiotensin II signaling, leading to hypertension, oxidative stress via activation of p47phox and inhibition of antioxidants, and vascular inflammation

  12. Preventive effect of gomisin J from Schisandra chinensis on angiotensin II-induced hypertension via an increased nitric oxide bioavailability.

    Science.gov (United States)

    Ye, Byeong Hyeok; Lee, Seung Jin; Choi, Young Whan; Park, So Youn; Kim, Chi Dae

    2015-03-01

    Gomisin J (GJ) is a small molecular weight lignan found in Schisandra chinensis and has been demonstrated to have vasodilatory activity. In this study, the authors investigated the effect of GJ on blood pressure (BP) in angiotensin II (Ang II)-induced hypertensive mice. In addition, we determined the relative potencies of gomisin A (GA) and GJ with respect to vasodilatory activity and antihypertensive effects. C57/BL6 mice infused s.c. with Ang II (2 μg kg(-1) min(-1) for 2 weeks) showed an increase in BP and a decrease in plasma nitric oxide (NO) metabolites. In the thoracic aortas of Ang II-induced hypertensive mice, a decrease in vascular NO was accompanied by an increase in reactive oxygen species (ROS) production. Furthermore, these alterations in BP, plasma concentrations of NO metabolites and in the vascular productions of NO and ROS in Ang II-treated mice were reversed by the co-administration of GJ (1 and 3 μg kg(-1) min(-1)). In in vitro studies, Ang II decreased the cellular concentration of NO, which was accompanied by a reduction in phosphorylated endothelial nitric oxide synthase (eNOS) and an increase in ROS production. These eNOS phosphorylation and ROS production changes in Ang II-treated cells were also reversed by GJ pretreatment (0-3 μg ml(-1)). Interestingly, the vasodilatory and antihypertensive effects of GJ were more prominent than those of GA. Collectively, an increase in BP in mice treated with Ang II was markedly attenuated by GJ, which was attributed to the preservations of vascular NO bioavailability and eNOS function, and to the inhibition of ROS production in Ang II-induced hypertensive mice.

  13. Collecting duct-specific knockout of renin attenuates angiotensin II-induced hypertension.

    Science.gov (United States)

    Ramkumar, Nirupama; Stuart, Deborah; Rees, Sara; Hoek, Alfred Van; Sigmund, Curt D; Kohan, Donald E

    2014-10-15

    The physiological and pathophysiological significance of collecting duct (CD)-derived renin, particularly as it relates to blood pressure (BP) regulation, is unknown. To address this question, we generated CD-specific renin knockout (KO) mice and examined BP and renal salt and water excretion. Mice containing loxP-flanked exon 1 of the renin gene were crossed with mice transgenic for aquaporin-2-Cre recombinase to achieve CD-specific renin KO. Compared with controls, CD renin KO mice had 70% lower medullary renin mRNA and 90% lower renin mRNA in microdissected cortical CD. Urinary renin levels were significantly lower in KO mice (45% of control levels) while plasma renin concentration was significantly higher in KO mice (63% higher than controls) during normal-Na intake. While no observable differences were noted in BP between the two groups with varying Na intake, infusion of angiotensin II at 400 ng·kg(-1)·min(-1) resulted in an attenuated hypertensive response in the KO mice (mean arterial pressure 111 ± 4 mmHg in KO vs. 128 ± 3 mmHg in controls). Urinary renin excretion and epithelial Na(+) channel (ENaC) remained significantly lower in the KO mice following ANG II infusion compared with controls. Furthermore, membrane-associated ENaC protein levels were significantly lower in KO mice following ANG II infusion. These findings suggest that CD renin modulates BP in ANG II-infused hypertension and these effects are associated with changes in ENaC expression.

  14. Effect of angiotensin II-induced arterial hypertension on the voltage-dependent contractions of mouse arteries.

    Science.gov (United States)

    Fransen, Paul; Van Hove, Cor E; Leloup, Arthur J A; Schrijvers, Dorien M; De Meyer, Guido R Y; De Keulenaer, Gilles W

    2016-02-01

    Arterial hypertension (AHT) affects the voltage dependency of L-type Ca(2+) channels in cardiomyocytes. We analyzed the effect of angiotensin II (AngII)-induced AHT on L-type Ca(2+) channel-mediated isometric contractions in conduit arteries. AHT was induced in C57Bl6 mice with AngII-filled osmotic mini-pumps (4 weeks). Normotensive mice treated with saline-filled osmotic mini-pumps were used for comparison. Voltage-dependent contractions mediated by L-type Ca(2+) channels were studied in vaso-reactive studies in vitro in isolated aortic and femoral arteries by using extracellular K(+) concentration-response (KDR) experiments. In aortic segments, AngII-induced AHT significantly sensitized isometric contractions induced by elevated extracellular K(+) and depolarization. This sensitization was partly prevented by normalizing blood pressure with hydralazine, suggesting that it was caused by AHT rather than by direct AngII effects on aortic smooth muscle cells. The EC50 for extracellular K(+) obtained in vitro correlated significantly with the rise in arterial blood pressure induced by AngII in vivo. The AHT-induced sensitization persisted when aortic segments were exposed to levcromakalim or to inhibitors of basal nitric oxide release. Consistent with these observations, AngII-treatment also sensitized the vaso-relaxing effects of the L-type Ca(2+) channel blocker diltiazem during K(+)-induced contractions. Unlike aorta, AngII-treatment desensitized the isometric contractions to depolarization in femoral arteries pointing to vascular bed specific responses of arteries to hypertension. AHT affects the voltage-dependent L-type Ca(2+) channel-mediated contraction of conduit arteries. This effect may contribute to the decreased vascular compliance in AHT and explain the efficacy of Ca(2+) channel blockers to reduce vascular stiffness and central blood pressure in AHT.

  15. Estrogen receptor-alpha mediates estrogen protection from angiotensin II-induced hypertension in conscious female mice.

    Science.gov (United States)

    Xue, Baojian; Pamidimukkala, Jaya; Lubahn, Dennis B; Hay, Meredith

    2007-04-01

    It has been shown that the female sex hormones have a protective role in the development of angiotensin II (ANG II)-induced hypertension. The present study tested the hypotheses that 1) the estrogen receptor-alpha (ERalpha) is involved in the protective effects of estrogen against ANG II-induced hypertension and 2) central ERs are involved. Blood pressure (BP) was measured in female mice with the use of telemetry implants. ANG II (800 ng.kg(-1).min(-1)) was administered subcutaneously via an osmotic pump. Baseline BP in the intact, ovariectomized (OVX) wild-type (WT) and ERalpha knockout (ERalphaKO) mice was similar; however, the increase in BP induced by ANG II was greater in OVX WT (23.0 +/- 1.0 mmHg) and ERalphaKO mice (23.8 +/- 2.5 mmHg) than in intact WT mice (10.1 +/- 4.5 mmHg). In OVX WT mice, central infusion of 17beta-estradiol (E(2); 30 microg.kg(-1).day(-1)) attenuated the pressor effect of ANG II (7.0 +/- 0.4 mmHg), and this protective effect of E(2) was prevented by coadministration of ICI-182,780 (ICI; 1.5 microg.kg(-1).day(-1), 18.8 +/- 1.5 mmHg), a nonselective ER antagonist. Furthermore, central, but not peripheral, infusions of ICI augmented the pressor effects of ANG II in intact WT mice (17.8 +/- 4.2 mmHg). In contrast, the pressor effect of ANG II was unchanged in either central E(2)-treated OVX ERalphaKO mice (19.0 +/- 1.1 mmHg) or central ICI-treated intact ERalphaKO mice (19.6 +/- 1.6 mmHg). Lastly, ganglionic blockade on day 7 after ANG II infusions resulted in a greater reduction in BP in OVX WT, central ER antagonist-treated intact WT, central E(2) + ICI-treated OVX WT, ERalphaKO, and central E(2)- or ICI-treated ERalphaKO mice compared with that in intact WT mice given just ANG II. Together, these data indicate that ERalpha, especially central expression of the ER, mediates the protective effects of estrogen against ANG II-induced hypertension.

  16. Protective actions of estrogen on angiotensin II-induced hypertension: role of central nitric oxide.

    Science.gov (United States)

    Xue, Baojian; Singh, Minati; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2009-11-01

    protective role against ANG II-induced hypertension in female mice.

  17. Reduced plasma noradrenaline during angiotensin II-induced acute hypertension in man

    DEFF Research Database (Denmark)

    Henriksen, J H; Kastrup, J; Christensen, N J

    1985-01-01

    1. Plasma noradrenaline and adrenaline concentrations were measured in ten subjects before, during and after intravenous infusion of angiotensin II (ANG II) in order to determine the sympathoadrenal response of ANG II challenge in man. In five subjects ganglionic blockade was additionally performed...... by intravenous infusion of trimethaphan. 2. During ANG II infusion mean arterial blood pressure increased by 30% (P adrenaline decreased less. 3. During ganglionic blockade plasma noradrenaline decreased significantly (P

  18. Chronic infusion of enalaprilat into hypothalamic paraventricular nucleus attenuates angiotensin II-induced hypertension and cardiac hypertrophy by restoring neurotransmitters and cytokines

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhang, Dong-Mei [Department of Physiology, Dalian Medical University, Dalian 116044 (China); Yu, Xiao-Jing; Yang, Qing; Qi, Jie; Su, Qing [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Suo, Yu-Ping [Department of Obstetrics and Gynecology, Shanxi Provincial People' s Hospital, Taiyuan 030012 (China); Yue, Li-Ying [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China)

    2014-02-01

    The renin–angiotensin system (RAS) in the brain is involved in the pathogenesis of hypertension. We hypothesized that inhibition of angiotensin-converting enzyme (ACE) in the hypothalamic paraventricular nucleus (PVN) attenuates angiotensin II (ANG II)-induced hypertension via restoring neurotransmitters and cytokines. Rats underwent subcutaneous infusions of ANG II or saline and bilateral PVN infusions of ACE inhibitor enalaprilat (ENL, 2.5 μg/h) or vehicle for 4 weeks. ANG II infusion resulted in higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, and mRNA expressions of cardiac atrial natriuretic peptide and beta-myosin heavy chain. These ANG II-infused rats had higher PVN levels of glutamate, norepinephrine, tyrosine hydroxylase, pro-inflammatory cytokines (PICs) and the chemokine monocyte chemoattractant protein-1, and lower PVN levels of gamma-aminobutyric acid, interleukin (IL)-10 and the 67-kDa isoform of glutamate decarboxylase (GAD67), and higher plasma levels of PICs, norepinephrine and aldosterone, and lower plasma IL-10, and higher renal sympathetic nerve activity. However, PVN treatment with ENL attenuated these changes. PVN microinjection of ANG II induced increases in IL-1β and IL-6, and a decrease in IL-10 in the PVN, and pretreatment with angiotensin II type 1 receptor (AT1-R) antagonist losartan attenuated these changes. These findings suggest that ANG II infusion induces an imbalance between excitatory and inhibitory neurotransmitters and an imbalance between pro- and anti-inflammatory cytokines in the PVN, and PVN inhibition of the RAS restores neurotransmitters and cytokines in the PVN, thereby attenuating ANG II-induced hypertension and cardiac hypertrophy. - Highlights: • Chronic ANG II infusion results in sympathetic hyperactivity and cardiac hypertrophy. • PVN inhibition of ACE

  19. An interaction of renin-angiotensin and kallikrein-kinin systems contributes to vascular hypertrophy in angiotensin II-induced hypertension: in vivo and in vitro studies.

    Directory of Open Access Journals (Sweden)

    Graziela S Ceravolo

    Full Text Available The kallikrein-kinin and renin-angiotensin systems interact at multiple levels. In the present study, we tested the hypothesis that the B1 kinin receptor (B1R contributes to vascular hypertrophy in angiotensin II (ANG II-induced hypertension, through a mechanism involving reactive oxygen species (ROS generation and extracellular signal-regulated kinase (ERK1/2 activation. Male Wistar rats were infused with vehicle (control rats, 400 ng/Kg/min ANG II (ANG II rats or 400 ng/Kg/min ANG II plus B1 receptor antagonist, 350 ng/Kg/min des-Arg(9-Leu(8-bradykinin (ANGII+DAL rats, via osmotic mini-pumps (14 days or received ANG II plus losartan (10 mg/Kg, 14 days, gavage - ANG II+LOS rats. After 14 days, ANG II rats exhibited increased systolic arterial pressure [(mmHg 184 ± 5.9 vs 115 ± 2.3], aortic hypertrophy; increased ROS generation [2-hydroxyethidium/dihydroethidium (EOH/DHE: 21.8 ± 2.7 vs 6.0 ± 1.8] and ERK1/2 phosphorylation (% of control: 218.3 ± 29.4 vs 100 ± 0.25]. B1R expression was increased in aortas from ANG II and ANG II+DAL rats than in aortas from the ANG II+LOS and control groups. B1R antagonism reduced aorta hypertrophy, prevented ROS generation (EOH/DHE: 9.17 ± 3.1 and ERK1/2 phosphorylation (137 ± 20.7% in ANG II rats. Cultured aortic vascular smooth muscle cells (VSMC stimulated with low concentrations (0.1 nM of ANG II plus B1R agonist exhibited increased ROS generation, ERK1/2 phosphorylation, proliferating-cell nuclear antigen expression and [H3]leucine incorporation. At this concentration, neither ANG II nor the B1R agonist produced any effects when tested individually. The ANG II/B1R agonist synergism was inhibited by losartan (AT1 blocker, 10 µM, B1R antagonist (10 µM and Tiron (superoxide anion scavenger, 10 mM. These data suggest that B1R activation contributes to ANG II-induced aortic hypertrophy. This is associated with activation of redox-regulated ERK1/2 pathway that controls aortic smooth muscle cells growth

  20. Contribution of renal purinergic receptors to renal vasoconstriction in angiotensin II-induced hypertensive rats.

    Science.gov (United States)

    Franco, Martha; Bautista, Rocio; Tapia, Edilia; Soto, Virgilia; Santamaría, José; Osorio, Horacio; Pacheco, Ursino; Sánchez-Lozada, L Gabriela; Kobori, Hiroyuki; Navar, L Gabriel

    2011-06-01

    To investigate the participation of purinergic P2 receptors in the regulation of renal function in ANG II-dependent hypertension, renal and glomerular hemodynamics were evaluated in chronic ANG II-infused (14 days) and Sham rats during acute blockade of P2 receptors with PPADS. In addition, P2X1 and P2Y1 protein and mRNA expression were compared in ANG II-infused and Sham rats. Chronic ANG II-infused rats exhibited increased afferent and efferent arteriolar resistances and reductions in glomerular blood flow, glomerular filtration rate (GFR), single-nephron GFR (SNGFR), and glomerular ultrafiltration coefficient. PPADS restored afferent and efferent resistances as well as glomerular blood flow and SNGFR, but did not ameliorate the elevated arterial blood pressure. In Sham rats, PPADS increased afferent and efferent arteriolar resistances and reduced GFR and SNGFR. Since purinergic blockade may influence nitric oxide (NO) release, we evaluated the role of NO in the response to PPADS. Acute blockade with N(ω)-nitro-l-arginine methyl ester (l-NAME) reversed the vasodilatory effects of PPADS and reduced urinary nitrate excretion (NO(2)(-)/NO(3)(-)) in ANG II-infused rats, indicating a NO-mediated vasodilation during PPADS treatment. In Sham rats, PPADS induced renal vasoconstriction which was not modified by l-NAME, suggesting blockade of a P2X receptor subtype linked to the NO pathway; the response was similar to that obtained with l-NAME alone. P2X1 receptor expression in the renal cortex was increased by chronic ANG II infusion, but there were no changes in P2Y1 receptor abundance. These findings indicate that there is an enhanced P2 receptor-mediated vasoconstriction of afferent and efferent arterioles in chronic ANG II-infused rats, which contributes to the increased renal vascular resistance observed in ANG II-dependent hypertension.

  1. Early interference with p44/42 mitogen-activated protein kinase signaling in hypothalamic paraventricular nucleus attenuates angiotensin II-induced hypertension.

    Science.gov (United States)

    Yu, Yang; Xue, Bao-Jian; Zhang, Zhi-Hua; Wei, Shun-Guang; Beltz, Terry G; Guo, Fang; Johnson, Alan Kim; Felder, Robert B

    2013-04-01

    Blood-borne angiotensin II (ANG II) can upregulate p44/42 mitogen-activated protein kinase (MAPK) signaling and ANG II type-1 receptors in the hypothalamic paraventricular nucleus (PVN), a critical cardiovascular and autonomic center. We tested the hypothesis that brain p44/42 MAPK signaling contributes to the development of ANG II-induced hypertension. The ANG II infusion (120 ng/kg per min, subcutaneously) induced increases in phosphorylated p44/42 MAPK and ANG II type-1 receptors in the PVN after 1 week, before the onset of hypertension, that were sustained as hypertension developed during a 2- or 3-week infusion protocol. Bilateral PVN microinjections of small interfering RNAs for p44/42 MAPK, at the onset of the ANG II infusion or 1 week later, prevented the early increase in p44/42 MAPK activity. The early treatment normalized ANG II type-1 receptor expression in the PVN and attenuated the hypertensive response to the 2-week infusion of ANG II. The later small interfering RNA microinjections had a transient effect on ANG II type-1 receptor expression in PVN and no effect on the hypertensive response to the 3-week infusion of ANG II. The early treatment also normalized the pressure response to ganglionic blockade. The ANG II infusion induced increases in mRNA for proinflammatory cytokines that were not affected by either small interfering RNA treatment. These results suggest that the full expression of ANG II-induced hypertension depends on p44/42 MAPK-mediated effects. A potential role for p44/42 MAPK in modulating the ANG II-induced central inflammatory response might also be considered. MAPK signaling in PVN may be a novel target for early intervention in the progression of ANG II-dependent hypertension.

  2. Central estrogen inhibition of angiotensin II-induced hypertension in male mice and the role of reactive oxygen species.

    Science.gov (United States)

    Xue, Baojian; Zhao, Yuanzi; Johnson, Alan Kim; Hay, Meredith

    2008-09-01

    It has been shown that reactive oxygen species (ROS) contribute to the central effect of ANG II on blood pressure (BP). Recent studies have implicated an antihypertensive action of estrogen in ANG II-infused female mice. The present study used in vivo telemetry recording and in vitro living mouse brain slices to test the hypothesis that the central activation of estrogen receptors in male mice inhibits ANG II-induced hypertension via the modulation of the central ROS production. In male wild-type mice, the systemic infusion of ANG II induced a significant increase in BP (Delta30.1 +/- 2.5 mmHg). Either central infusion of Tempol or 17beta-estradiol (E2) attenuated the pressor effect of ANG II (Delta10.9 +/- 2.3 and Delta4.5 +/- 1.4 mmHg), and the protective effect of E2 was prevented by the coadministration of an estrogen receptor, antagonist ICI-182780 (Delta23.6 +/- 3.1 mmHg). Moreover, the ganglionic blockade on day 7 after the start of ANG II infusions resulted in a smaller reduction of BP in central Tempol- and in central E2-treated males, suggesting that estrogen inhibits the central ANG II-induced increases in sympathetic outflow. In subfornical organ slices, the application of ANG II resulted in a 21.5 +/- 2.5% increase in ROS production. The coadministration of irbesartan, an ANG II type 1 receptor antagonist, or the preincubation of brain slices with Tempol blocked ANG II-induced increases in ROS production (-1.8 +/- 1.6% and -1.0 +/- 1.8%). The ROS response to ANG II was also blocked by E2 (-3.2 +/- 2.4%). The results suggest that the central actions of E2 are involved in the protection from ANG II-induced hypertension and that estrogen modulation of the ANG II-induced effects may involve interactions with ROS production.

  3. Role of the Na+/H+ exchanger 3 in angiotensin II-induced hypertension in NHE3-deficient mice with transgenic rescue of NHE3 in small intestines.

    Science.gov (United States)

    Li, Xiao C; Shull, Gary E; Miguel-Qin, Elisa; Chen, Fang; Zhuo, Jia L

    2015-11-01

    The role of Na(+/)H(+) exchanger 3 (NHE3) in the kidney in angiotensin II (ANG II)-induced hypertension remains unknown. The present study used global NHE3-deficient mice with transgenic rescue of the Nhe3 gene in small intestines (tgNhe3(-/-)) to test the hypothesis that genetic deletion of NHE3 selectively in the kidney attenuates ANG II-induced hypertension. Six groups of wild-type (tgNhe3(+/+)) and tgNhe3(-/-) mice were infused with either vehicle or ANG II (1.5 mg/kg/day, i.p., 2 weeks, or 10 nmol/min, i.v., 30 min), treated with or without losartan (20 mg/kg/day, p.o.) for 2 weeks. Basal systolic blood pressure (SBP) and mean intra-arterial blood pressure (MAP) were significantly lower in tgNhe3(-/-) mice (P excretion, urinary Na(+) excretion, urinary K(+) excretion, and urinary Cl(-) excretion were significantly lower in tgNhe3(-/-) mice (P < 0.01). These responses were associated with significantly elevated plasma ANG II and aldosterone levels, and marked upregulation in aquaporin 1, the Na(+)/HCO3 cotransporter, the α1 subunit isoform of Na(+)/K(+)-ATPase, protein kinase Cα, MAP kinases ERK1/2, and glycogen synthase kinase 3 α/β in the renal cortex of tgNhe3(-/-) mice (P < 0.01). ANG II infusion markedly increased SBP and MAP and renal cortical transporter and signaling proteins in tgNhe3(+/+), as expected, but all of these responses to ANG II were attenuated in tgNhe3(-/-) mice (P < 0.01). These results suggest that NHE3 in the kidney is necessary for maintaining normal blood pressure and fully developing ANG II-dependent hypertension.

  4. Perinatal 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure sensitizes offspring to angiotensin II-induced hypertension.

    Science.gov (United States)

    Aragon, Andrea C; Goens, M Beth; Carbett, Eleanor; Walker, Mary K

    2008-01-01

    In utero and lactational exposure of mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) leads to cardiac hypertrophy and hydronephrosis in adulthood. We tested the hypothesis that perinatal TCDD exposure increases the susceptibility to cardiovascular disease when offspring are exposed to a common cardiovascular disease risk factor, angiotensin II (Ang II). Pregnant C57BL/6N mice were exposed to corn oil (control) or 6.0 microg/kg TCDD on gestation day 14.5. Male offspring were then exposed to a subpressor (0.1 mg/kg/day) or pressor (0.7 mg/kg/day) dose of Ang II at 3.5 months and cardiac morphology and blood pressure analyzed, respectively. Perinatal TCDD exposure increased left ventricular cavity dilation during diastole, and wall thickness during diastole and systole. While Ang II stimulated an increase in wall thickness, the degree of increase was equivalent between control and TCDD offspring. In contrast, perinatal TCDD exposure did not alter basal blood pressure. However, Ang II increased systolic blood pressure more rapidly and to a greater degree in TCDD offspring. Further, Ang II stimulated renal myofibroblast differentiation and collagen deposition to a greater degree, and tended to increase procollagen I mRNA in TCDD offspring, compared to controls. These data suggest that perinatal TCDD exposure increases the susceptibility of offspring to renal fibrosis and hypertension in adulthood.

  5. Over-Expression of Copper/Zinc Superoxide Dismutase in the Median Preoptic Nucleus Attenuates Chronic Angiotensin II-Induced Hypertension in the Rat

    Directory of Open Access Journals (Sweden)

    John P. Collister

    2014-12-01

    Full Text Available The brain senses circulating levels of angiotensin II (AngII via circumventricular organs, such as the subfornical organ (SFO, and is thought to adjust sympathetic nervous system output accordingly via this neuro-hormonal communication. However, the cellular signaling mechanisms involved in these communications remain to be fully understood. Previous lesion studies of either the SFO, or the downstream median preoptic nucleus (MnPO have shown a diminution of the hypertensive effects of chronic AngII, without providing a clear explanation as to the intracellular signaling pathway(s involved. Additional studies have reported that over-expressing copper/zinc superoxide dismutase (CuZnSOD, an intracellular superoxide (O2·− scavenging enzyme, in the SFO attenuates chronic AngII-induced hypertension. Herein, we tested the hypothesis that overproduction of O2·− in the MnPO is an underlying mechanism in the long-term hypertensive effects of chronic AngII. Adenoviral vectors encoding human CuZnSOD (AdCuZnSOD or control vector (AdEmpty were injected directly into the MnPO of rats implanted with aortic telemetric transmitters for recording of arterial pressure. After a 3 day control period of saline infusion, rats were intravenously infused with AngII (10 ng/kg/min for ten days. Rats over-expressing CuZnSOD (n = 7 in the MnPO had a blood pressure increase of only 6 ± 2 mmHg after ten days of AngII infusion while blood pressure increased 21 ± 4 mmHg in AdEmpty-infected rats (n = 9. These results support the hypothesis that production of O2·− in the MnPO contributes to the development of chronic AngII-dependent hypertension.

  6. Exogenous administration of thiosulfate, a donor of hydrogen sulfide, attenuates angiotensin II-induced hypertensive heart disease in rats

    NARCIS (Netherlands)

    Snijder, P. M.; Frenay, A. R.; de Boer, R. A.; Pasch, A.; Hillebrands, J. L.; Leuvenink, H. G. D.; van Goor, H.

    2015-01-01

    BACKGROUND AND PURPOSE: Hypertension is an important mediator of cardiac damage and remodelling. Hydrogen sulfide (H2S) is an endogenously produced gasotransmitter with cardioprotective properties. However, it is not yet in clinical use. We, therefore, investigated the protective effects of sodium t

  7. Novel mechanism of intra‑renal angiotensin II-induced sodium/proton exchanger 3 expression by losartan in spontaneously hypertensive rats.

    Science.gov (United States)

    Fan, Xiaoqin; Liu, Kaishan; Cui, Wei; Huang, Jiongmei; Wang, Weina; Gao, Yuan

    2014-11-01

    The present study aimed to investigate the molecular pharmacodynamic mechanisms of losartan used in the treatment of hypertension. A total of 12 spontaneously hypertensive rats (SHR) were divided randomly into an SHR group treated with saline and LOS group treated with losartan. Six Wistar‑kyoto rats (WKY) were enrolled as the WKY group with saline in the study. The LOS group received 30 mg/kg/day losartan by intragastric injection, while the SHR and WKY were fed the same volume of saline. The dosage was modulated according to the weekly weight. Changes in blood pressure were measured by the indirect tail cuff method. Angiotensin (Ang) II production in the plasma and renal tissue was measured by an immunoradiometric method. Na+/H+ exchanger (NHE)3 and serum and glucocorticoid‑inducible kinase (SGK)1 were assessed by quantitative polymerase chain reaction (qPCR) and western blot analysis. When compared with the WKY group, the blood pressure of the SHR and LOS groups were higher prior to treatment with losartan. Following two weeks, blood pressure was reduced and the trend continued to decrease over the following six weeks. The plasma and renal tissue levels of Ang II in the SHR and LOS groups were significantly higher than those in the WKY group. NHE3 and SGK1 were increased at the mRNA and protein level in the SHR group, and losartan reduced the expression of both of them. The results suggested that in hypertensive rats, the circular and tissue renin angiotensin systems were activated, and the increased Ang II stimulated the expression of NHE3 and SGK1, which was reduced by losartan. Therefore, the effects of losartan in hypertension may be associated with the Ang II‑SGK1‑NHE3 of intra‑renal tissue.

  8. Angiotensin-(1-7) regulates Angiotensin II-induced VCAM-1 expression on vascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng [Department of Cardiology, Peking University People' s Hospital, Beijing (China); William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London (United Kingdom); Ren, Jingyi [Department of Cardiology, Peking University People' s Hospital, Beijing (China); Chan, Kenneth [William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London (United Kingdom); Chen, Hong, E-mail: chenhongbj@medmail.com.cn [Department of Cardiology, Peking University People' s Hospital, Beijing (China)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer We for the first time found that Ang-(1-7) inhibits Ang II-induced VCAM-1 expression. Black-Right-Pointing-Pointer The inhibitory effect of Ang-(1-7) on VCAM-1 is mediated by MAS receptor. Black-Right-Pointing-Pointer The effect of Ang-(1-7) is due to the suppression of NF-kappaB translocation. -- Abstract: Angiotensin II (Ang II) and Angiotensin-(1-7) (Ang-(1-7)) are key effector peptides in the renin-angiotensin system. Increased circulatory Ang II level is associated with the development of hypertension and atherosclerosis, whereas Ang-(1-7) is a counter-regulatory mediator of Ang II which appears to be protective against cardiovascular disease. However, whether Ang-(1-7) regulates the action of Ang II on vascular endothelial cells (EC) remains unclear. We investigated the effects of Ang II and Ang-(1-7) in the context of atherogenesis, specifically endothelial cell VCAM-1 expression that is implicated in early plaque formation. The results show that Ang II increased VCAM-1 mRNA expression and protein displayed on EC surface, while Ang-(1-7) alone exerted no effects. However, Ang-(1-7) significantly suppressed Ang II-induced VCAM-1 expression. Ang-(1-7) also inhibited the Ang II-induced VCAM-1 promoter activity driven by transcription factor NF-KappaB. Furthermore, immunofluorescence assay and ELISA showed that Ang II facilitated the nuclear translocation of NF-kappaB in ECs, and this was attenuated by the presence of Ang-(1-7). The inhibitory effects of Ang-(1-7) on Ang II-induced VCAM-1 promoter activity and NF-kappaB nuclear translocation were all reversed by the competitive antagonist of Ang-(1-7) at the Mas receptor. Our results suggest that Ang-(1-7) mediates its affects on ECs through the Mas receptor, and negatively regulates Ang II-induced VCAM-1 expression by attenuating nuclear translocation of NF-kappaB.

  9. TRPC6 enhances angiotensin II-induced albuminuria.

    LENUS (Irish Health Repository)

    Eckel, Jason

    2011-03-01

    Mutations in the canonical transient receptor potential cation channel 6 (TRPC6) are responsible for familial forms of adult onset focal segmental glomerulosclerosis (FSGS). The mechanisms by which TRPC6 mutations cause kidney disease are not well understood. We used TRPC6-deficient mice to examine the function of TRPC6 in the kidney. We found that adult TRPC6-deficient mice had BP and albumin excretion rates similar to wild-type animals. Glomerular histomorphology revealed no abnormalities on both light and electron microscopy. To determine whether the absence of TRPC6 would alter susceptibility to hypertension and renal injury, we infused mice with angiotensin II continuously for 28 days. Although both groups developed similar levels of hypertension, TRPC6-deficient mice had significantly less albuminuria, especially during the early phase of the infusion; this suggested that TRPC6 adversely influences the glomerular filter. We used whole-cell patch-clamp recording to measure cell-membrane currents in primary cultures of podocytes from both wild-type and TRPC6-deficient mice. In podocytes from wild-type mice, angiotensin II and a direct activator of TRPC6 both augmented cell-membrane currents; TRPC6 deficiency abrogated these increases in current magnitude. Our findings suggest that TRPC6 promotes albuminuria, perhaps by promoting angiotensin II-dependent increases in Ca(2+), suggesting that TRPC6 blockade may be therapeutically beneficial in proteinuric kidney disease.

  10. Nitrosonifedipine ameliorates angiotensin II-induced vascular remodeling via antioxidative effects.

    Science.gov (United States)

    Sakurada, Takumi; Ishizawa, Keisuke; Imanishi, Masaki; Izawa-Ishizawa, Yuki; Fujii, Shoko; Tominaga, Erika; Tsuneishi, Teppei; Horinouchi, Yuya; Kihira, Yoshitaka; Ikeda, Yasumasa; Tomita, Shuhei; Aihara, Ken-ichi; Minakuchi, Kazuo; Tsuchiya, Koichiro; Tamaki, Toshiaki

    2013-01-01

    Nifedipine is unstable under light and decomposes to a stable nitroso analog, nitrosonifedipine (NO-NIF). The ability of NO-NIF to block calcium channels is quite weak compared with that of nifedipine. Recently, we have demonstrated that NO-NIF reacts with unsaturated fatty acid leading to generate NO-NIF radical, which acquires radical scavenging activity. However, the effects of NO-NIF on the pathogenesis related with oxidative stress, such as atherosclerosis and hypertension, are unclear. In this study, we investigated the effects of NO-NIF on angiotensin II (Ang II)-induced vascular remodeling. Ang II-induced thickening and fibrosis of aorta were inhibited by NO-NIF in mice. NO-NIF decreased reactive oxygen species (ROS) in the aorta and urinary 8-hydroxy-20-deoxyguanosine. Ang II-stimulated mRNA expressions of p22(phox), CD68, F4/80, monocyte chemoattractant protein-1, and collagen I in the aorta were inhibited by NO-NIF. Moreover, NO-NIF inhibited Ang II-induced cell migration and proliferation of vascular smooth muscle cells (VSMCs). NO-NIF reduced Ang II-induced ROS to the control level detected by dihydroethidium staining and lucigenin chemiluminescence assay in VSMCs. NO-NIF suppressed phosphorylations of Akt and epidermal growth factor receptor induced by Ang II. However, NO-NIF had no effects on intracellular Ca(2+) increase and protein kinase C-δ phosphorylation induced by Ang II in VSMCs. The electron paramagnetic resonance spectra indicated the continuous generation of NO-NIF radical of reaction with cultured VSMCs. These findings suggest that NO-NIF improves Ang II-induced vascular remodeling via the attenuation of oxidative stress.

  11. Angiotensin II Induced Cardiac Dysfunction on a Chip.

    Directory of Open Access Journals (Sweden)

    Renita E Horton

    Full Text Available In vitro disease models offer the ability to study specific systemic features in isolation to better understand underlying mechanisms that lead to dysfunction. Here, we present a cardiac dysfunction model using angiotensin II (ANG II to elicit pathological responses in a heart-on-a-chip platform that recapitulates native laminar cardiac tissue structure. Our platform, composed of arrays of muscular thin films (MTF, allows for functional comparisons of healthy and diseased tissues by tracking film deflections resulting from contracting tissues. To test our model, we measured gene expression profiles, morphological remodeling, calcium transients, and contractile stress generation in response to ANG II exposure and compared against previous experimental and clinical results. We found that ANG II induced pathological gene expression profiles including over-expression of natriuretic peptide B, Rho GTPase 1, and T-type calcium channels. ANG II exposure also increased proarrhythmic early after depolarization events and significantly reduced peak systolic stresses. Although ANG II has been shown to induce structural remodeling, we control tissue architecture via microcontact printing, and show pathological genetic profiles and functional impairment precede significant morphological changes. We assert that our in vitro model is a useful tool for evaluating tissue health and can serve as a platform for studying disease mechanisms and identifying novel therapeutics.

  12. Angiotensin II Induced Cardiac Dysfunction on a Chip.

    Science.gov (United States)

    Horton, Renita E; Yadid, Moran; McCain, Megan L; Sheehy, Sean P; Pasqualini, Francesco S; Park, Sung-Jin; Cho, Alexander; Campbell, Patrick; Parker, Kevin Kit

    2016-01-01

    In vitro disease models offer the ability to study specific systemic features in isolation to better understand underlying mechanisms that lead to dysfunction. Here, we present a cardiac dysfunction model using angiotensin II (ANG II) to elicit pathological responses in a heart-on-a-chip platform that recapitulates native laminar cardiac tissue structure. Our platform, composed of arrays of muscular thin films (MTF), allows for functional comparisons of healthy and diseased tissues by tracking film deflections resulting from contracting tissues. To test our model, we measured gene expression profiles, morphological remodeling, calcium transients, and contractile stress generation in response to ANG II exposure and compared against previous experimental and clinical results. We found that ANG II induced pathological gene expression profiles including over-expression of natriuretic peptide B, Rho GTPase 1, and T-type calcium channels. ANG II exposure also increased proarrhythmic early after depolarization events and significantly reduced peak systolic stresses. Although ANG II has been shown to induce structural remodeling, we control tissue architecture via microcontact printing, and show pathological genetic profiles and functional impairment precede significant morphological changes. We assert that our in vitro model is a useful tool for evaluating tissue health and can serve as a platform for studying disease mechanisms and identifying novel therapeutics.

  13. Angiotensin II-induced cardiac hypertrophy and fibrosis are promoted in mice lacking Fgf16

    OpenAIRE

    Matsumoto, Emi; Sasaki, Sayaka; Kinoshita, Hideyuki; Kito, Takuya; Ohta, Hiroya; Konishi, Morichika; Kuwahara, Koichiro; Nakao, Kazuwa; Itoh, Nobuyuki

    2013-01-01

    Fibroblast growth factors (Fgfs) are pleiotropic proteins involved in development, repair and metabolism. Fgf16 is predominantly expressed in the heart. However, as the heart function is essentially normal in Fgf16 knockout mice, its role has remained unclear. To elucidate the pathophysiological role of Fgf16 in the heart, we examined angiotensin II-induced cardiac hypertrophy and fibrosis in Fgf16 knockout mice. Angiotensin II-induced cardiac hypertrophy and fibrosis were significantly promo...

  14. Angiotensin II induces differential insulin action in rat skeletal muscle.

    Science.gov (United States)

    Surapongchai, Juthamard; Prasannarong, Mujalin; Bupha-Intr, Tepmanas; Saengsirisuwan, Vitoon

    2017-03-01

    Angiotensin II (ANGII) is reportedly involved in the development of skeletal muscle insulin resistance. The present investigation evaluated the effects of two ANGII doses on the phenotypic characteristics of insulin resistance syndrome and insulin action and signaling in rat skeletal muscle. Male Sprague-Dawley rats were infused with either saline (SHAM) or ANGII at a commonly used pressor dose (100 ng/kg/min; ANGII-100) or a higher pressor dose (500 ng/kg/min; ANGII-500) via osmotic minipumps for 14 days. We demonstrated that ANGII-100-infused rats exhibited the phenotypic features of non-obese insulin resistance syndrome, including hypertension, impaired glucose tolerance and insulin resistance of glucose uptake in the soleus muscle, whereas ANGII-500-treated rats exhibited diabetes-like symptoms, such as post-prandial hyperglycemia, impaired insulin secretion and hypertriglyceridemia. At the cellular level, insulin-stimulated glucose uptake in the soleus muscle of the ANGII-100 group was 33% lower (P study demonstrates for the first time that chronic infusion with these two pressor doses of ANGII induced differential metabolic responses at both the systemic and skeletal muscle levels.

  15. Bcl10 mediates angiotensin II-induced cardiac damage and electrical remodeling.

    Science.gov (United States)

    Markó, Lajos; Henke, Norbert; Park, Joon-Keun; Spallek, Bastian; Qadri, Fatimunnisa; Balogh, András; Apel, Ingrid J; Oravecz-Wilson, Katherine I; Choi, Mira; Przybyl, Lukasz; Binger, Katrina J; Haase, Nadine; Wilck, Nicola; Heuser, Arnd; Fokuhl, Verena; Ruland, Jürgen; Lucas, Peter C; McAllister-Lucas, Linda M; Luft, Friedrich C; Dechend, Ralf; Müller, Dominik N

    2014-11-01

    Angiotensin (Ang) II is a potent mediator of both hypertension and cardiac damage; however, the mechanisms by which this occur remain unclear. B-cell lymphoma/leukemia 10 (Bcl10) is a member of the CBM signalosome, which links Ang II and nuclear factor-κB signaling. We hypothesized that Bcl10 is pivotal in the pathogenesis of Ang II-induced cardiac damage. Ang II infusion in mice lacking Bcl10 resulted in reduced cardiac fibrosis, less cellular infiltration, and improved arrhythmogenic electric remodeling, despite a similar degree of hypertension or cardiac hypertrophy. Adoptive transfer of bone marrow (BM), whereby Bcl10 knockout or wildtype BM was transferred to their opposite genotype recipients, revealed the dual importance of Bcl10 within both cardiac and immune cells. Loss of Bcl10 in cardiac cells resulted in reduced expression of genes important for the adhesion and recruitment of immune cells. In vitro experiments demonstrated that adhesion of monocytes to Ang II-treated endothelial cells also required Bcl10. Additionally, Bcl10 deficiency in macrophages reduced their intrinsic migratory ability. To address the role of BM-derived fibroblasts in the formation of cardiac fibrosis, we explored whether Bcl10 is also important for the infiltration of BM-derived (myo)fibroblasts into the heart. The transfer of green fluorescent protein positive wildtype BM into Bcl10 knockout recipient mice revealed a reduced number of noncardiac (myo)fibroblasts compared with those wildtype recipients. Our results demonstrate the significant role of Bcl10 in multiple cell types important for the generation of Ang II-induced cardiac damage and electric remodeling and may provide a new avenue for therapeutic intervention.

  16. Polychlorinated biphenyl 77 augments angiotensin II-induced atherosclerosis and abdominal aortic aneurysms in male apolipoprotein E deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Arsenescu, Violeta [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Arsenescu, Razvan [Digestive Diseases and Nutrition, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Parulkar, Madhura; Karounos, Michael [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Zhang, Xuan [Graduate Center for Toxicology, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Baker, Nicki [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Cassis, Lisa A., E-mail: lcassis@uky.edu [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States)

    2011-11-15

    Infusion of angiotensin II (AngII) to hyperlipidemic mice augments atherosclerosis and causes formation of abdominal aortic aneurysms (AAAs). Each of these AngII-induced vascular pathologies exhibit pronounced inflammation. Previous studies demonstrated that coplanar polychlorinated biphenyls (PCBs) promote inflammation in endothelial cells and adipocytes, two cell types implicated in AngII-induced vascular pathologies. The purpose of this study was to test the hypothesis that administration of PCB77 to male apolipoprotein E (ApoE) -/- mice promotes AngII-induced atherosclerosis and AAA formation. Male ApoE-/- mice were administered vehicle or PCB77 (49 mg/kg, i.p.) during week 1 and 4 (2 divided doses/week) of AngII infusion. Body weights and total serum cholesterol concentrations were not influenced by administration of PCB77. Systolic blood pressure was increased in AngII-infused mice administered PCB77 compared to vehicle (156 {+-} 6 vs 137 {+-} 5 mmHg, respectively). The percentage of aortic arch covered by atherosclerotic lesions was increased in AngII-infused mice administered PCB77 compared to vehicle (2.0 {+-} 0.4 vs 0.9 {+-} 0.1%, respectively). Lumen diameters of abdominal aortas determined by in vivo ultrasound and external diameters of excised suprarenal aortas were increased in AngII-infused mice administered PCB77 compared to vehicle. In addition, AAA incidence increased from 47 to 85% in AngII-infused mice administered PCB77. Adipose tissue in close proximity to AAAs from mice administered PCB77 exhibited increased mRNA abundance of proinflammatory cytokines and elevated expression of components of the renin-angiotensin system (angiotensinogen, angiotensin type 1a receptor (AT1aR)). These results demonstrate that PCB77 augments AngII-induced atherosclerosis and AAA formation. -- Highlights: Black-Right-Pointing-Pointer Polychlorinated biphenyl 77 (PCB77) promotes AngII-induced hypertension. Black-Right-Pointing-Pointer PCB77 augments AngII-induced

  17. EPOXYEICOSATRIENOIC ACID ANALOG ATTENUATES ANGIOTENSIN II HYPERTENSION AND KIDNEY INJURY

    Directory of Open Access Journals (Sweden)

    Md. Abdul Hye Khan

    2014-09-01

    Full Text Available Epoxyeicosatrienoic acids (EETs contribute to blood pressure regulation leading to the concept that EETs can be therapeutically targeted for hypertension and the associated end-organ damage. In the present study, we investigated anti-hypertensive and kidney protective actions of an EET analog, EET-B in angiotensin II (ANG II-induced hypertension. EET-B was administered in drinking water for 14 days (10mg/kg/d and resulted in a decreased blood pressure elevation in ANG II hypertension. At the end of the two-week period, blood pressure was 30 mmHg lower in EET analog-treated ANG II hypertensive rats. The vasodilation of mesenteric resistance arteries to acetylcholine was impaired in ANG II hypertension; however, it was improved with EET-B treatment. Further, EET-B protected the kidney in ANG II hypertension as evidenced by a marked 90% decrease in albuminuria and 54% decrease in nephrinuria. Kidney histology demonstrated a decrease in renal tubular cast formation in EET analog-treated hypertensive rats. In ANG II hypertension, EET-B treatment markedly lowered renal inflammation. Urinary monocyte chemoattractant protein-1 excretion was decreased by 55% and kidney macrophage infiltration was reduced by 52% with EET-B treatment. Overall, our results demonstrate that EET-B has anti-hypertensive properties, improves vascular function, and decreases renal inflammation and injury in ANG II hypertension.

  18. Epoxyeicosatrienoic acid analog attenuates angiotensin II hypertension and kidney injury.

    Science.gov (United States)

    Khan, Abdul Hye; Falck, John R; Manthati, Vijaya L; Campbell, William B; Imig, John D

    2014-01-01

    Epoxyeicosatrienoic acids (EETs) contribute to blood pressure regulation leading to the concept that EETs can be therapeutically targeted for hypertension and the associated end organ damage. In the present study, we investigated anti-hypertensive and kidney protective actions of an EET analog, EET-B in angiotensin II (ANG II)-induced hypertension. EET-B was administered in drinking water for 14 days (10 mg/kg/d) and resulted in a decreased blood pressure elevation in ANG II hypertension. At the end of the two-week period, blood pressure was 30 mmHg lower in EET analog-treated ANG II hypertensive rats. The vasodilation of mesenteric resistance arteries to acetylcholine was impaired in ANG II hypertension; however, it was improved with EET-B treatment. Further, EET-B protected the kidney in ANG II hypertension as evidenced by a marked 90% decrease in albuminuria and 54% decrease in nephrinuria. Kidney histology demonstrated a decrease in renal tubular cast formation in EET analog-treated hypertensive rats. In ANG II hypertension, EET-B treatment markedly lowered renal inflammation. Urinary monocyte chemoattractant protein-1 excretion was decreased by 55% and kidney macrophage infiltration was reduced by 52% with EET-B treatment. Overall, our results demonstrate that EET-B has anti-hypertensive properties, improves vascular function, and decreases renal inflammation and injury in ANG II hypertension.

  19. Metformin Inhibits Angiotensin II-Induced Differentiation of Cardiac Fibroblasts into Myofibroblasts

    OpenAIRE

    Jian Bai; Na Zhang; Ying Hua; Bingjian Wang; Lin Ling; Albert Ferro; Biao Xu

    2013-01-01

    Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that leads to pathological cardiac remodeling. Metformin, an antidiabetic agent, exhibits a number of cardioprotective properties. However, much less is known regarding the effect of metformin on cardiac fibroblast differentiation. Thus, in the present study, we examined the effect of metformin on angiotensin (Ang) II-induced differentiation of cardiac fibroblasts into myofibr...

  20. MiR-30-regulated autophagy mediates angiotensin II-induced myocardial hypertrophy.

    Science.gov (United States)

    Pan, Wei; Zhong, Yun; Cheng, Chuanfang; Liu, Benrong; Wang, Li; Li, Aiqun; Xiong, Longgen; Liu, Shiming

    2013-01-01

    Dysregulated autophagy may lead to the development of disease. Role of autophagy and the diagnostic potential of microRNAs that regulate the autophagy in cardiac hypertrophy have not been evaluated. A rat model of cardiac hypertrophy was established using transverse abdominal aortic constriction (operation group). Cardiomyocyte autophagy was enhanced in rats from the operation group, compared with those in the sham operation group. Moreover, the operation group showed up-regulation of beclin-1 (an autophagy-related gene), and down-regulation of miR-30 in cardiac tissue. The effects of inhibition and over-expression of the beclin-1 gene on the expression of hypertrophy-related genes and on autophagy were assessed. Angiotensin II-induced myocardial hypertrophy was found to be mediated by over-expression of the beclin-1 gene. A dual luciferase reporter assay confirmed that beclin-1 was a target gene of miR-30a. miR-30a induced alterations in beclin-1 gene expression and autophagy in cardiomyocytes. Treatment of cardiomyocytes with miR-30a mimic attenuated the Angiotensin II-induced up-regulation of hypertrophy-related genes and decreased in the cardiomyocyte surface area. Conversely, treatment with miR-30a inhibitor enhanced the up-regulation of hypertrophy-related genes and increased the surface area of cardiomyocytes induced by Angiotensin II. In addition, circulating miR-30 was elevated in patients with left ventricular hypertrophy, and circulating miR-30 was positively associated with left ventricular wall thickness. Collectively, these above-mentioned results suggest that Angiotensin II induces down-regulation of miR-30 in cardiomyocytes, which in turn promotes myocardial hypertrophy through excessive autophagy. Circulating miR-30 may be an important marker for the diagnosis of left ventricular hypertrophy.

  1. MiR-30-regulated autophagy mediates angiotensin II-induced myocardial hypertrophy.

    Directory of Open Access Journals (Sweden)

    Wei Pan

    Full Text Available Dysregulated autophagy may lead to the development of disease. Role of autophagy and the diagnostic potential of microRNAs that regulate the autophagy in cardiac hypertrophy have not been evaluated. A rat model of cardiac hypertrophy was established using transverse abdominal aortic constriction (operation group. Cardiomyocyte autophagy was enhanced in rats from the operation group, compared with those in the sham operation group. Moreover, the operation group showed up-regulation of beclin-1 (an autophagy-related gene, and down-regulation of miR-30 in cardiac tissue. The effects of inhibition and over-expression of the beclin-1 gene on the expression of hypertrophy-related genes and on autophagy were assessed. Angiotensin II-induced myocardial hypertrophy was found to be mediated by over-expression of the beclin-1 gene. A dual luciferase reporter assay confirmed that beclin-1 was a target gene of miR-30a. miR-30a induced alterations in beclin-1 gene expression and autophagy in cardiomyocytes. Treatment of cardiomyocytes with miR-30a mimic attenuated the Angiotensin II-induced up-regulation of hypertrophy-related genes and decreased in the cardiomyocyte surface area. Conversely, treatment with miR-30a inhibitor enhanced the up-regulation of hypertrophy-related genes and increased the surface area of cardiomyocytes induced by Angiotensin II. In addition, circulating miR-30 was elevated in patients with left ventricular hypertrophy, and circulating miR-30 was positively associated with left ventricular wall thickness. Collectively, these above-mentioned results suggest that Angiotensin II induces down-regulation of miR-30 in cardiomyocytes, which in turn promotes myocardial hypertrophy through excessive autophagy. Circulating miR-30 may be an important marker for the diagnosis of left ventricular hypertrophy.

  2. Statin treatment in hypercholesterolemic men does not attenuate angiotensin II-induced venoconstriction.

    Directory of Open Access Journals (Sweden)

    Christoph Schindler

    Full Text Available Experimental studies suggested that statins attenuate vascular AT1 receptor responsiveness. Moreover, the augmented excessive pressor response to systemic angiotensin II infusions in hypercholesterolemic patients was normalized with statin treatment. In 12 hypercholesterolemic patients, we tested the hypothesis that statin treatment attenuates angiotensin II-mediated vasoconstriction in hand veins assessed by a linear variable differential transducer. Subjects ingested daily doses of either atorvastatin (40 mg or positive control irbesartan (150 mg for 30 days in a randomized and cross-over fashion. Ang II-induced venoconstriction at minute 4 averaged 59%±10% before and 28%±9% after irbesartan (mean ± SEM; P<0.05 compared to 65%±11% before and 73%±11% after 30 days of atorvastatin treatment. Plasma angiotensin levels increased significantly after irbesartan treatment (Ang II: 17±22 before vs 52±40 pg/mL after [p = 0.048]; Ang-(1-7: 18±10 before vs 37±14 pg/mL after [p = 0.002] compared to atorvastatin treatment (Ang II: 9±4 vs 11±10 pg/mL [p = 0.40]; Ang-(1-7: 24±9 vs 32±8 pg/mL [p = 0.023]. Our study suggests that statin treatment does not elicit major changes in angiotensin II-mediated venoconstriction or in circulating angiotensin II levels whereas angiotensin-(1-7 levels increased modestly. The discrepancy between local vascular and systemic angiotensin II responses might suggest that statin treatment interferes with blood pressure buffering reflexes.ClinicalTrials.gov NCT00154024.

  3. Roles of Caveolin-1 in Angiotensin II-Induced Hypertrophy and Inward Remodeling of Cerebral Pial Arterioles.

    Science.gov (United States)

    Umesalma, Shaikamjad; Houwen, Frederick Keith; Baumbach, Gary L; Chan, Siu-Lung

    2016-03-01

    Angiotensin II (Ang II) is a major determinant of inward remodeling and hypertrophy in pial arterioles that may have an important role in stroke during chronic hypertension. Previously, we found that epidermal growth factor receptor is critical in Ang II-mediated hypertrophy that may involve caveolin-1 (Cav-1). In this study, we examined the effects of Cav-1 and matrix metalloproteinase-9 (MMP9) on Ang II-mediated structural changes in pial arterioles. Cav-1-deficient (Cav-1(-/-)), MMP9-deficient (MMP9(-/-)), and wild-type mice were infused with either Ang II (1000 ng/kg per minute) or saline via osmotic minipumps for 28 days (n=6-8 per group). Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of pial arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area of the wall was determined histologically in pressurized fixed pial arterioles. Expression of Cav-1, MMP9, phosphorylated epidermal growth factor receptor, and Akt was determined by Western blotting and immunohistochemistry. Deficiency of Cav-1 or MMP9 did not affect Ang II-induced hypertension. Ang II increased the expression of Cav-1, phosphorylated epidermal growth factor receptor, and Akt in wild-type mice, which was attenuated in Cav-1(-/-) mice. Ang II-induced hypertrophy, inward remodeling, and increased MMP9 expression in pial arterioles were prevented in Cav-1(-/-) mice. Ang II-mediated increases in MMP9 expression and inward remodeling, but not hypertrophy, were prevented in MMP9(-/-) mice. In conclusion, Cav-1 is essential in Ang II-mediated inward remodeling and hypertrophy in pial arterioles. Cav-1-induced MMP9 is exclusively involved in inward remodeling, not hypertrophy. Further studies are needed to determine the role of Akt in Ang II-mediated hypertrophy.

  4. Metformin inhibits angiotensin II-induced differentiation of cardiac fibroblasts into myofibroblasts.

    Science.gov (United States)

    Bai, Jian; Zhang, Na; Hua, Ying; Wang, Bingjian; Ling, Lin; Ferro, Albert; Xu, Biao

    2013-01-01

    Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that leads to pathological cardiac remodeling. Metformin, an antidiabetic agent, exhibits a number of cardioprotective properties. However, much less is known regarding the effect of metformin on cardiac fibroblast differentiation. Thus, in the present study, we examined the effect of metformin on angiotensin (Ang) II-induced differentiation of cardiac fibroblasts into myofibroblasts and its underlying mechanism. Adult rat cardiac fibroblasts were stimulated with Ang II (100 nM) in the presence or absence of metformin (10-200 µM). Ang II stimulation induced the differentiation of cardiac fibroblasts into myofibroblasts, as indicated by increased expression of α-smooth muscle actin (α-SMA) and collagen types I and III, and this effect of Ang II was inhibited by pretreatment of cardiac fibroblasts with metformin. Metformin also decreased Ang II-induced reactive oxygen species (ROS) generation in cardiac fibroblasts via inhibiting the activation of the PKC-NADPH oxidase pathway. Further experiments using PKC inhibitor calphostin C and NADPH oxidase inhibitor apocynin confirmed that inhibition of the PKC-NADPH oxidase pathway markedly attenuated Ang II-induced ROS generation and myofibroblast differentiation. These data indicate that metformin inhibits Ang II-induced myofibroblast differentiation by suppressing ROS generation via the inhibition of the PKC-NADPH oxidase pathway in adult rat cardiac fibroblasts. Our results provide new mechanistic insights regarding the cardioprotective effects of metformin and provide an efficient therapeutic strategy to attenuate cardiac fibrosis.

  5. Metformin inhibits angiotensin II-induced differentiation of cardiac fibroblasts into myofibroblasts.

    Directory of Open Access Journals (Sweden)

    Jian Bai

    Full Text Available Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that leads to pathological cardiac remodeling. Metformin, an antidiabetic agent, exhibits a number of cardioprotective properties. However, much less is known regarding the effect of metformin on cardiac fibroblast differentiation. Thus, in the present study, we examined the effect of metformin on angiotensin (Ang II-induced differentiation of cardiac fibroblasts into myofibroblasts and its underlying mechanism. Adult rat cardiac fibroblasts were stimulated with Ang II (100 nM in the presence or absence of metformin (10-200 µM. Ang II stimulation induced the differentiation of cardiac fibroblasts into myofibroblasts, as indicated by increased expression of α-smooth muscle actin (α-SMA and collagen types I and III, and this effect of Ang II was inhibited by pretreatment of cardiac fibroblasts with metformin. Metformin also decreased Ang II-induced reactive oxygen species (ROS generation in cardiac fibroblasts via inhibiting the activation of the PKC-NADPH oxidase pathway. Further experiments using PKC inhibitor calphostin C and NADPH oxidase inhibitor apocynin confirmed that inhibition of the PKC-NADPH oxidase pathway markedly attenuated Ang II-induced ROS generation and myofibroblast differentiation. These data indicate that metformin inhibits Ang II-induced myofibroblast differentiation by suppressing ROS generation via the inhibition of the PKC-NADPH oxidase pathway in adult rat cardiac fibroblasts. Our results provide new mechanistic insights regarding the cardioprotective effects of metformin and provide an efficient therapeutic strategy to attenuate cardiac fibrosis.

  6. Adiponectin attenuates angiotensin II-induced vascular smooth muscle cell remodeling through nitric oxide and the RhoA/ROCK pathway.

    Directory of Open Access Journals (Sweden)

    Wared eNour-Eldine

    2016-04-01

    Full Text Available INTRODUCTION: Adiponectin (APN, an adipocytokine, exerts protective effects on cardiac remodeling, while angiotensin II (Ang II induces hypertension and vascular remodeling. The potential protective role of APN on the vasculature during hypertension has not been fully elucidated yet. Here, we evaluate the molecular mechanisms of the protective role of APN in the physiological response of the vascular wall to Ang II.METHODS AND RESULTS: Rat aortic tissues were used to investigate the effect of APN on Ang II-induced vascular remodeling and hypertrophy. We investigated whether nitric oxide (NO, the RhoA/ROCK pathway, actin cytoskeleton remodeling, and reactive oxygen species (ROS mediate the anti-hypertrophic effect of APN. Ang II-induced protein synthesis was attenuated by pre-treatment with APN, NO donor (SNAP, or cGMP. The hypertrophic response to Ang II was associated with a significant increase in RhoA activation and vascular force production, which were prevented by APN and SNAP. NO was also associated with inhibition of Ang II-induced phosphorylation of cofilin. In addition, immunohistochemistry revealed that 24 hr Ang II treatment increased the F- to G-actin ratio, an effect that was inhibited by SNAP. Ang II-induced ROS formation and upregulation of p22phox mRNA expression were inhibited by APN and NO. Both compounds failed to inhibit Nox1 and p47phox expression. CONCLUSIONS: Our results suggest that the anti-hypertrophic effects of APN are due, in part, to NO-dependent inhibition of the RhoA/ROCK pathway and ROS formation.

  7. Tumor necrosis factor-α produced in the kidney contributes to angiotensin II-dependent hypertension.

    Science.gov (United States)

    Zhang, Jiandong; Patel, Mehul B; Griffiths, Robert; Mao, Alice; Song, Young-soo; Karlovich, Norah S; Sparks, Matthew A; Jin, Huixia; Wu, Min; Lin, Eugene E; Crowley, Steven D

    2014-12-01

    Immune system activation contributes to the pathogenesis of hypertension and the resulting progression of chronic kidney disease. In this regard, we recently identified a role for proinflammatory Th1 T-lymphocyte responses in hypertensive kidney injury. Because Th1 cells generate interferon-γ and tumor necrosis factor-α (TNF-α), we hypothesized that interferon-γ and TNF-α propagate renal damage during hypertension induced by activation of the renin-angiotensin system. Therefore, after confirming that mice genetically deficient of Th1 immunity were protected from kidney glomerular injury despite a preserved hypertensive response, we subjected mice lacking interferon-γ or TNF-α to our model of hypertensive chronic kidney disease. Interferon deficiency had no impact on blood pressure elevation or urinary albumin excretion during chronic angiotensin II infusion. By contrast, TNF-deficient (knockout) mice had blunted hypertensive responses and reduced end-organ damage in our model. As angiotensin II-infused TNF knockout mice had exaggerated endothelial nitric oxide synthase expression in the kidney and enhanced nitric oxide bioavailability, we examined the actions of TNF-α generated from renal parenchymal cells in hypertension by transplanting wild-type or TNF knockout kidneys into wild-type recipients before the induction of hypertension. Transplant recipients lacking TNF solely in the kidney had blunted hypertensive responses to angiotensin II and augmented renal endothelial nitric oxide synthase expression, confirming a role for kidney-derived TNF-α to promote angiotensin II-induced blood pressure elevation by limiting renal nitric oxide generation.

  8. Mechanism of angiotensin II-induced arachidonic acid metabolite release in aortic smooth muscle cells: involvement of phospholipase D.

    Science.gov (United States)

    Shinoda, J; Kozawa, O; Suzuki, A; Watanabe-Tomita, Y; Oiso, Y; Uematsu, T

    1997-02-01

    In a previous study, we have shown that angiotensin II (Ang II) activates phosphatidylcholine-hydrolyzing phospholipase D due to Ang II-induced Ca2+ influx from extracellular space in subcultured rat aortic smooth muscle cells. In the present study, we have investigated the role of phospholipase D in Ang II-induced arachidonic acid (AA) metabolite release and prostacyclin synthesis in subcultured rat aortic smooth muscle cells. Ang II significantly stimulated AA metabolite release in a concentration-dependent manner in the range between 1 nmol/I and 0.1 mumol/I. D.L.-Propranolol hydrochloride (propranolol), an inhibitor of phosphatidic acid phosphohydrolase, significantly inhibited the Ang II-induced release of AA metabolites. The Ang II-induced AA metabolite release was reduced by chelating extracellular Ca2+ with EGTA. Genistein, an inhibitor of protein tyrosine kinases, significantly suppressed the Ang II-induced AA metabolite release. 1,6-Bis-(cyclohexyloximinocarbonylamino)-hexane (RHC-80267), a potent and selective inhibitor of diacylglycerol lipase, significantly inhibited the Ang II-induced AA metabolite release. Both propranolol and RHC-80267 inhibited the Ang II-induced synthesis of 6-keto-prostaglandin F1 alpha, a stable metabolite of prostacyclin. The synthesis was suppressed by genistein. These results strongly suggest that the AA metabolite release induced by Ang II is mediated, at least in part, through phosphatidylcholine hydrolysis by phospholipase D activation in aortic smooth muscle cells.

  9. Central Renin-Angiotensin System Activation and Inflammation Induced by High-Fat Diet Sensitize Angiotensin II-Elicited Hypertension.

    Science.gov (United States)

    Xue, Baojian; Thunhorst, Robert L; Yu, Yang; Guo, Fang; Beltz, Terry G; Felder, Robert B; Johnson, Alan Kim

    2016-01-01

    Obesity has been shown to promote renin-angiotensin system activity and inflammation in the brain and to be accompanied by increased sympathetic activity and blood pressure. Our previous studies demonstrated that administration of a subpressor dose of angiotensin (Ang) II sensitizes subsequent Ang II-elicited hypertension. The present study tested whether high-fat diet (HFD) feeding also sensitizes the Ang II-elicited hypertensive response and whether HFD-induced sensitization is mediated by an increase in renin-angiotensin system activity and inflammatory mechanisms in the brain. HFD did not increase baseline blood pressure, but enhanced the hypertensive response to Ang II compared with a normal-fat diet. The sensitization produced by the HFD was abolished by concomitant central infusions of either a tumor necrosis factor-α synthesis inhibitor, pentoxifylline, an Ang II type 1 receptor blocker, irbesartan, or an inhibitor of microglial activation, minocycline. Furthermore, central pretreatment with tumor necrosis factor-α mimicked the sensitizing action of a central subpressor dose of Ang II, whereas central pentoxifylline or minocycline abolished this Ang II-induced sensitization. Real-time quantitative reverse transcription-polymerase chain reaction analysis of lamina terminalis tissue indicated that HFD feeding, central tumor necrosis factor-α, or a central subpressor dose of Ang II upregulated mRNA expression of several components of the renin-angiotensin system and proinflammatory cytokines, whereas inhibition of Ang II type 1 receptor and of inflammation reversed these changes. The results suggest that HFD-induced sensitization of Ang II-elicited hypertension is mediated by upregulation of the brain renin-angiotensin system and of central proinflammatory cytokines.

  10. Obligatory Role for B Cells in the Development of Angiotensin II-Dependent Hypertension.

    Science.gov (United States)

    Chan, Christopher T; Sobey, Christopher G; Lieu, Maggie; Ferens, Dorota; Kett, Michelle M; Diep, Henry; Kim, Hyun Ah; Krishnan, Shalini M; Lewis, Caitlin V; Salimova, Ekaterina; Tipping, Peter; Vinh, Antony; Samuel, Chrishan S; Peter, Karlheinz; Guzik, Tomasz J; Kyaw, Tin S; Toh, Ban-Hock; Bobik, Alexander; Drummond, Grant R

    2015-11-01

    Clinical hypertension is associated with raised serum IgG antibodies. However, whether antibodies are causative agents in hypertension remains unknown. We investigated whether hypertension in mice is associated with B-cell activation and IgG production and moreover whether B-cell/IgG deficiency affords protection against hypertension and vascular remodeling. Angiotensin II (Ang II) infusion (0.7 mg/kg per day; 28 days) was associated with (1) a 25% increase in the proportion of splenic B cells expressing the activation marker CD86, (2) an 80% increase in splenic plasma cell numbers, (3) a 500% increase in circulating IgG, and (4) marked IgG accumulation in the aortic adventitia. In B-cell-activating factor receptor-deficient (BAFF-R(-/-)) mice, which lack mature B cells, there was no evidence of Ang II-induced increases in serum IgG. Furthermore, the hypertensive response to Ang II was attenuated in BAFF-R(-/-) (Δ30±4 mm Hg) relative to wild-type (Δ41±5 mm Hg) mice, and this response was rescued by B-cell transfer. BAFF-R(-/-) mice displayed reduced IgG accumulation in the aorta, which was associated with 80% fewer aortic macrophages and a 70% reduction in transforming growth factor-β expression. BAFF-R(-/-) mice were also protected from Ang II-induced collagen deposition and aortic stiffening (assessed by pulse wave velocity analysis). Finally, like BAFF-R deficiency, pharmacological depletion of B cells with an anti-CD20 antibody attenuated Ang II-induced hypertension by ≈35%. Hence, these studies demonstrate that B cells/IgGs are crucial for the development of Ang II-induced hypertension and vessel remodeling in mice. Thus, B-cell-targeted therapies-currently used for autoimmune diseases-may hold promise as future treatments for hypertension.

  11. TRIF promotes angiotensin II-induced cross-talk between fibroblasts and macrophages in atrial fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiao-Qing; Zhang, Dao-Liang [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China); Zhang, Ming-Jian; Guo, Meng; Zhan, Yang-Yang; Liu, Fang [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Jiang, Wei-Feng; Zhou, Li [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China); Zhao, Liang, E-mail: zhaol_zg@163.com [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China); Wang, Quan-Xing, E-mail: wqxejd@126.com [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Liu, Xu, E-mail: liuxu_xk@163.com [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai (China)

    2015-08-14

    Aims: Atrial fibroblasts and macrophages have long been thought to participate in atrial fibrillation (AF). However, which specific mediator may regulate the interaction between them remains unclear. Methods and results: We provided the evidence for the involvement of Toll/IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF), an important inflammation-related molecule, in the pathophysiology of AF. Patients with AF showed higher levels of angiotensin II (AngII) and TRIF expression and larger number of macrophages infiltration in left atria appendage than individuals with sinus rhythm (SR). In the cell study, AngII induced chemokines expressions in mouse atrial fibroblasts and AngII-stimulated atrial fibroblasts induced the chemotaxis of macrophages, which were reduced by losartan and TRIF siRNA. Meanwhile, AngII-stimulated atrial fibroblasts proliferation was enhanced by macrophages. Conclusions: Our data demonstrated that TRIF may be a crucial factor promoting the interaction between atrial fibroblasts and macrophages, leading to atrial fibrosis. - Highlights: • Compared with SR, AF showed higher TRIF expression in left atrial appendage. • TRIF siRNA reversed macrophage chemotaxis induced by AngII-treated fibroblast. • TRIF siRNA reversed chemokines expressions induced by AngII in fibroblast. • AngII-stimulated atrial fibroblast proliferation was enhanced by macrophage.

  12. Sulforaphane Prevents Angiotensin II-Induced Testicular Cell Death via Activation of NRF2

    Science.gov (United States)

    Wang, Yonggang; Xin, Ying; Tan, Yi

    2017-01-01

    Although angiotensin II (Ang II) was reported to facilitate sperm motility and intratesticular sperm transport, recent findings shed light on the efficacy of Ang II in stimulating inflammatory events in testicular peritubular cells, effect of which may play a role in male infertility. It is still unknown whether Ang II can induce testicular apoptotic cell death, which may be a more direct action of Ang II in male infertility. Therefore, the present study aims to determine whether Ang II can induce testicular apoptotic cell death and whether this action can be prevented by sulforaphane (SFN) via activating nuclear factor (erythroid-derived 2)-like 2 (NRF2), the governor of antioxidant-redox signalling. Eight-week-old male C57BL/6J wild type (WT) and Nrf2 gene knockout mice were treated with Ang II, in the presence or absence of SFN. In WT mice, SFN activated testicular NRF2 expression and function, along with a marked attenuation in Ang II-induced testicular oxidative stress, inflammation, endoplasmic reticulum stress, and apoptotic cell death. Deletion of the Nrf2 gene led to a complete abolishment of these efficacies of SFN. The present study indicated that Ang II may result in testicular apoptotic cell death, which can be prevented by SFN via the activation of NRF2. PMID:28191275

  13. The Notch pathway mediates the angiotensin II-induced synthesis of extracellular matrix components in podocytes.

    Science.gov (United States)

    Yao, Min; Wang, Xiaomei; Wang, Xiaomeng; Zhang, Tao; Chi, Yanqing; Gao, Feng

    2015-07-01

    The Notch pathway is known to contribute to the development of glomerular disease. Angiotensin II (Ang II), an important member of the renin-angiotensin system, stimulates the accumulation of extracellular matrix components in glomerular disease; however, the exact mechanisms involved remain to be elucidated. In the present study, we aimed to investigate the effects of the Notch pathway on the synthesis of extracellular matrix components in Ang II-stimulated podocytes. Mouse podocytes were stimulated with Ang II (10-6 mol/l). The activation of the Notch pathway was inhibited by a vector carrying short hairpin RNA (shRNA) targeting Notch1 (sh-Notch1) or by γ-secretase inhibitor (GSI). The protein levels of Notch1, Notch intracellular domain 1 (NICD1), hairy and enhancer of split-1 (Hes1), matrix metalloproteinase (MMP)-2, MMP-9, transforming growth factor-β1 (TGF-β1), type IV collagen and laminin were determined by western blot analysis. The Notch1, Hes1, MMP-2, MMP-9, TGF-β1, type IV collagen and laminin mRNA levels were detected by RT-PCR. The MMP-2 and MMP-9 activity was measured using a cell active fluorescence assay kit. The levels of TGF-β1, type IV collagen and laminin were determined in the culture medium of the podocytes by enzyme-linked immunosorbent assay (ELISA). Our results revealed that Ang II upregulated Notch1, NICD1, Hes1, TGF-β1, type IV collagen and laminin expression and downregulated MMP-2 and MMP-9 expression in the cultured podocytes. The inhibition of the Notch pathway by sh-Notch1 or GSI increased MMP-2 and MMP-9 expression, decreased the TGF-β1 level and suppressed type IV collagen and laminin expression. The inhibition of the Notch pathway by sh-Notch1 or GSI also increased MMP-2 and MMP-9 activity, and decreased TGF-β1 levels, type IV collagen levels and laminin secretion. These findings indicate that the Notch pathway potentially mediates the Ang II-induced synthesis of extracellular matrix components in podocytes through the

  14. Melatonin attenuates angiotensin II-induced cardiomyocyte hypertrophy through the CyPA/CD147 signaling pathway.

    Science.gov (United States)

    Su, Hongyan; Li, Jingyuan; Chen, Tongshuai; Li, Na; Xiao, Jie; Wang, Shujian; Guo, Xiaobin; Yang, Yi; Bu, Peili

    2016-11-01

    Melatonin is well known for its cardioprotective effects; however, whether melatonin exerts therapeutic effects on cardiomyocyte hypertrophy remains to be investigated, as do the mechanisms underlying these effects, if they exist. Cyclophilin A (CyPA) and its corresponding receptor, CD147, which exists in a variety of cells, play crucial roles in modulating reactive oxygen species (ROS) production. In this study, we explored the role of the CyPA/CD147 signaling pathway in angiotensin II (Ang II)-induced cardiomyocyte hypertrophy and the protective effects exerted by melatonin against Ang II-induced injury in cultured H9C2 cells. Cyclosporine A, a specific CyPA/CD147 signaling pathway inhibitor, was used to manipulate CyPA/CD147 activity. H9C2 cells were then subjected to Ang II or CyPA treatment in either the absence or presence of melatonin. Our results indicate that Ang II induces cardiomyocyte hypertrophy through the CyPA/CD147 signaling pathway and promotes ROS production, which can be blocked by melatonin pretreatment in a concentration-dependent manner, in cultured H9C2 cells and that CyPA/CD147 signaling pathway inhibition protects against Ang II-induced cardiomyocyte hypertrophy. The protective effects of melatonin against Ang II-induced cardiomyocyte hypertrophy depend at least partially on CyPA/CD147 inhibition.

  15. Angiotensin-(1–7) abrogates angiotensin II-induced proliferation, migration and inflammation in VSMCs through inactivation of ROS-mediated PI3K/Akt and MAPK/ERK signaling pathways

    Science.gov (United States)

    Zhang, Feng; Ren, Xingsheng; Zhao, Mingxia; Zhou, Bing; Han, Ying

    2016-01-01

    The proliferation, migration and inflammation of vascular smooth muscle cells (VSMCs) contribute to the pathogenesis and progression of several cardiovascular diseases such as atherosclerosis and hypertension. Angiotensin (Ang)-(1–7) and Ang II are identified to be involved in regulating cardiovascular activity. The present study is designed to determine the interaction between Ang-(1–7) and Ang II on VSMCs proliferation, migration and inflammation as well as their underlying mechanisms. We found that Ang-(1–7) significantly suppressed the positive effects of Ang II on VSMCs proliferation, migration and inflammation, as well as on induction of the phosphorylation of Akt and ERK1/2 and increase of superoxide anion level and NAD(P)H oxidase activity in VSMCs, whereas Ang-(1–7) alone had no significant effects. This inhibitory effects of Ang-(1–7) were abolished by Mas receptor antagonist A-779. In addition, Ang II type 1 (AT1) receptor antagonist losartan, but not A-779, abolished Ang II induced VSMCs proliferation, migration and inflammation responses. Furthermore, superoxide anion scavenger N-acetyl-L-cysteine (NAC) or NAD(P)H oxidase inhibitor apocynin inhibited Ang II-induced activation of Akt and ERK1/2 signaling. These results indicate that Ang-(1–7) antagonizes the Ang II-induced VSMC proliferation, migration and inflammation through activation of Mas receptor and then suppression of ROS-dependent PI3K/Akt and MAPK/ERK signaling pathways. PMID:27687768

  16. Calpain-2 compensation promotes angiotensin II-induced ascending and abdominal aortic aneurysms in calpain-1 deficient mice.

    Directory of Open Access Journals (Sweden)

    Venkateswaran Subramanian

    Full Text Available Recently, we demonstrated that angiotensin II (AngII-infusion profoundly increased both aortic protein and activity of calpains, calcium-activated cysteine proteases, in mice. In addition, pharmacological inhibition of calpain attenuated AngII-induced abdominal aortic aneurysm (AA in mice. Recent studies have shown that AngII infusion into mice leads to aneurysmal formation localized to the ascending aorta. However, the precise functional contribution of calpain isoforms (-1 or -2 in AngII-induced abdominal AA formation is not known. Similarly, a functional role of calpain in AngII-induced ascending AA remains to be defined. Using BDA-410, an inhibitor of calpains, and calpain-1 genetic deficient mice, we examined the relative contribution of calpain isoforms in AngII-induced ascending and abdominal AA development.To investigate the relative contribution of calpain-1 and -2 in development of AngII-induced AAs, male LDLr -/- mice that were either calpain-1 +/+ or -/- were fed a saturated fat-enriched diet and infused with AngII (1,000 ng/kg/min for 4 weeks. Calpain-1 deficiency had no significant effect on body weight or blood pressure during AngII infusion. Moreover, calpain-1 deficiency showed no discernible effects on AngII-induced ascending and abdominal AAs. Interestingly, AngII infusion induced increased expression of calpain-2 protein, thus compensating for total calpain activity in aortas of calpain-1 deficient mice. Oral administration of BDA-410, a calpain inhibitor, along with AngII-infusion significantly attenuated AngII-induced ascending and abdominal AA formation in both calpain-1 +/+ and -/- mice as compared to vehicle administered mice. Furthermore, BDA-410 administration attenuated AngII-induced aortic medial hypertrophy and macrophage accumulation. Western blot and immunostaining analyses revealed BDA-410 administration attenuated AngII-induced C-terminal fragmentation of filamin A, an actin binding cytoskeletal protein in aorta

  17. Angiotensin II induces kidney inflammatory injury and fibrosis through binding to myeloid differentiation protein-2 (MD2)

    Science.gov (United States)

    Xu, Zheng; Li, Weixin; Han, Jibo; Zou, Chunpeng; Huang, Weijian; Yu, Weihui; Shan, Xiaoou; Lum, Hazel; Li, Xiaokun; Liang, Guang

    2017-01-01

    Growing evidence indicates that angiotensin II (Ang II), a potent biologically active product of RAS, is a key regulator of renal inflammation and fibrosis. In this study, we tested the hypothesis that Ang II induces renal inflammatory injury and fibrosis through interaction with myeloid differentiation protein-2 (MD2), the accessory protein of toll-like receptor 4 (TLR4) of the immune system. Results indicated that in MD2−/− mice, the Ang II-induced renal fibrosis, inflammation and kidney dysfunction were significantly reduced compared to control Ang II-infused wild-type mice. Similarly, in the presence of small molecule MD2 specific inhibitor L6H21 or siRNA-MD2, the Ang II-induced increases of pro-fibrotic and pro-inflammatory molecules were prevented in tubular NRK-52E cells. MD2 blockade also inhibited activation of NF-κB and ERK. Moreover, MD2 blockade prevented the Ang II-stimulated formation of the MD2/TLR4/MyD88 signaling complex, as well as the increased surface binding of Ang II in NRK-52E cells. In addition, Ang II directly bound recombinant MD2 protein, rather than TLR4 protein. We conclude that MD2 is a significant contributor in the Ang II-induced kidney inflammatory injury in chronic renal diseases. Furthermore, MD2 inhibition could be a new and important therapeutic strategy for preventing progression of chronic renal diseases.

  18. Ca2+ -regulated lysosome fusion mediates angiotensin II-induced lipid raft clustering in mesenteric endothelial cells.

    Science.gov (United States)

    Han, Wei-Qing; Chen, Wen-Dong; Zhang, Ke; Liu, Jian-Jun; Wu, Yong-Jie; Gao, Ping-Jin

    2016-04-01

    It has been reported that intracellular Ca2+ is involved in lysosome fusion and membrane repair in skeletal cells. Given that angiotensin II (Ang II) elicits an increase in intracellular Ca2+ and that lysosome fusion is a crucial mediator of lipid raft (LR) clustering, we hypothesized that Ang II induces lysosome fusion and activates LR formation in rat mesenteric endothelial cells (MECs). We found that Ang II acutely increased intracellular Ca2+ content, an effect that was inhibited by the extracellular Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) and the inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release inhibitor 2-aminoethoxydiphenyl borate (2-APB). Further study showed that EGTA almost completely blocked Ang II-induced lysosome fusion, the translocation of acid sphingomyelinase (ASMase) to LR clusters, ASMase activation and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activation. In contrast, 2-APB had a slight inhibitory effect. Functionally, both the lysosome inhibitor bafilomycin A1 and the ASMase inhibitor amitriptyline reversed Ang II-induced impairment of vasodilation. We conclude that Ca2+ -regulated lysosome fusion mediates the Ang II-induced regulation of the LR-redox signaling pathway and mesenteric endothelial dysfunction.

  19. Angiotensin II induced inflammation in the kidney and in the heart of double transgenic rats

    Directory of Open Access Journals (Sweden)

    Haller Hermann

    2002-01-01

    Full Text Available Abstract Background We are investigating a double transgenic rat (dTGR model, in which rats transgenic for the human angiotensinogen and renin genes are crossed. These rats develop moderately severe hypertension but die of end-organ cardiac and renal damage by week 7. The heart shows necrosis and fibrosis, whereas the kidneys resemble the hemolytic-uremic syndrome vasculopathy. Surface adhesion molecules (ICAM-1 and VCAM-1 are expressed early on the endothelium, while the corresponding ligands are found on circulating leukocytes. Leukocyte infiltration in the vascular wall accompanies PAI-1, MCP-1, iNOS and Tissue Factor expression. Furthermore we show evidence that Ang II causes the upregulation of NF-kB in our model. Methods We started PDTC-treatment on four weeks old dTGR (200 mg/kg sc and age-matched SD rats.. Blood-pressure- and albuminuria- measurements were monitored during the treatement period (four weeks. The seven weeks old animals were killed, hearts and kidneys were isolated and used for immunohistochemical-and electromobility shift assay analsis. Results Chronic treatment with the antioxidant PDTC decreased blood pressure (162 ± 8 vs. 190 ± 7 mm Hg, p = 0.02. Cardiac hypertrophy index was significantly reduced (4.90 ± 0.1 vs. 5.77 ± 0.1 mg/g, p Conclusion Our data show that inhibition of NF-κB by PDTC markedly reduces inflammation, iNOS expression in the dTGR most likely leading to decreased cytotoxicity, and cell proliferation. Thus, NF-κB activation plays an important role in ANG II-induced end-organ damage.

  20. Age determines the magnitudes of angiotensin II-induced contractions, mRNA, and protein expression of angiotensin type 1 receptors in rat carotid arteries.

    Science.gov (United States)

    Vamos, Zoltan; Cseplo, Peter; Ivic, Ivan; Matics, Robert; Hamar, Janos; Koller, Akos

    2014-05-01

    In this study, we hypothesized that aging alters angiotensin II (Ang II)-induced vasomotor responses and expression of vascular mRNA and protein angiotensin type 1 receptor (AT1R). Thus, carotid arteries were isolated from the following age groups of rats: 8 days, 2-9 months, 12-20 months, and 20-30 months, and their vasomotor responses were measured in a myograph after repeated administrations of Ang II. Vascular relative AT1R mRNA level was determined by quantitative reverse-transcriptase polymerase chain reaction and the AT1R protein density was measured by Western blot. Contractions to the first administration of Ang II increased from 8 days to 6 months and then they decreased to 30 months. In general, second administration of Ang II elicited reduced contractions, but they also increased from 8 days until 2 months and then they decreased to 30 months. Similarly the AT1R mRNA level increased from 8 days to 12 months and then decreased to 30 months. Similarly the AT1R protein density increased from 8 days until 16 months and then they decreased to 30 months. The pattern of these changes correlated with functional vasomotor data. We conclude that aging (newborn to senescence) has substantial effects on Ang II-induced vasomotor responses and AT1R signaling suggesting the importance of genetic programs.

  1. Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system and proinflammatory cytokines in hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Su, Qing [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China); Wang, Fu-Xin [Department of Neurology, The First Affiliated Hospital of Jiamusi University, Jiamusi 154002 (China); Ren, Jun [Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY 82071 (United States); Li, Hong-Bao; Zhang, Meng; Yang, Qing; Miao, Yu-Wang; Yu, Xiao-Jing; Qi, Jie [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhu, Zhiming [Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, The Third Military Medical University, Chongqing Institute of Hypertension, Chongqing 400042 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China)

    2014-04-15

    Aims: To explore whether reactive oxygen species (ROS) scavenger (tempol) in the hypothalamic paraventricular nucleus (PVN) attenuates renin–angiotensin system (RAS) and proinflammatory cytokines (PICs), and decreases the blood pressure and sympathetic activity in angiotensin II (ANG II)-induced hypertension. Methods and results: Male Sprague–Dawley rats were infused intravenously with ANG II (10 ng/kg per min) or normal saline (NS) for 4 weeks. These rats were treated with bilateral PVN infusion of oxygen free radical scavenger tempol (TEMP, 20 μg/h) or vehicle (artificial cerebrospinal fluid, aCSF) for 4 weeks. ANG II infusion resulted in increased mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA). These ANG II-infused rats also had higher levels of gp91{sup phox} (a subunit of NAD(P)H oxidase), angiotensin-converting enzyme (ACE), and interleukin-1beta (IL-1β) in the PVN than the control animals. Treatment with PVN infusion of TEMP attenuated the overexpression of gp91{sup phox}, ACE and IL-1β within the PVN, and decreased sympathetic activity and MAP in ANG II-infused rats. Conclusion: These findings suggest that ANG II infusion induces elevated PICs and oxidative stress in the PVN, which contribute to the sympathoexcitation in hypertension. Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system, proinflammatory cytokines and oxidative stress in ANG II-induced hypertension. - Highlights: • The effect of chronic inhibiting PVN superoxide on hypertension was investigated. • ANG II infusion induced increased proinflammatory cytokines and superoxide in PVN. • ANG II infusion resulted in oxidative stress, sympathoexcitation and hypertension. • Chronic inhibiting PVN superoxide attenuates RAS and cytokines in hypertension.

  2. Sex-specific T-cell regulation of angiotensin II-dependent hypertension.

    Science.gov (United States)

    Ji, Hong; Zheng, Wei; Li, Xiangjun; Liu, Jun; Wu, Xie; Zhang, Monan Angela; Umans, Jason G; Hay, Meredith; Speth, Robert C; Dunn, Shannon E; Sandberg, Kathryn

    2014-09-01

    Studies suggest T cells modulate arterial pressure. Because robust sex differences exist in the immune system and in hypertension, we investigated sex differences in T-cell modulation of angiotensin II-induced increases in mean arterial pressure in male (M) and female (F) wild-type and recombination-activating-gene-1-deficient (Rag1(-/-)) mice. Sex differences in peak mean arterial pressure in wild-type were lost in Rag1(-/-) mice (mm Hg: wild-type-F, 136±4.9 versus wild-type-M, 153±1.7; Phypertension are distinct between the sexes and need to be understood to improve therapeutics for hypertension-associated disease in both men and women.

  3. Sex differences in T-lymphocyte tissue infiltration and development of angiotensin II hypertension.

    Science.gov (United States)

    Pollow, Dennis P; Uhrlaub, Jennifer; Romero-Aleshire, Melissa J; Sandberg, Kathryn; Nikolich-Zugich, Janko; Brooks, Heddwen L; Hay, Meredith

    2014-08-01

    There is extensive evidence that activation of the immune system is both necessary and required for the development of angiotensin II (Ang II)-induced hypertension in males. The purpose of this study was to determine whether sex differences exist in the ability of the adaptive immune system to induce Ang II-dependent hypertension and whether central and renal T-cell infiltration during Ang II-induced hypertension is sex dependent. Recombinant activating gene-1 (Rag-1)(-/-) mice, lacking both T and B cells, were used. Male and female Rag-1(-/-) mice received adoptive transfer of male CD3(+) T cells 3 weeks before 14-day Ang II infusion (490 ng/kg per minute). Blood pressure was monitored via tail cuff. In the absence of T cells, systolic blood pressure responses to Ang II were similar between sexes (Δ22.1 mm Hg males versus Δ18 mm : Hg females). After adoptive transfer of male T cells, Ang II significantly increased systolic blood pressure in males (Δ37.7 mm : Hg; Phypertension when compared with their male counterparts, and this protection may involve sex differences in the magnitude of T-cell infiltration of the kidney and brain.

  4. High sodium augments angiotensin II-induced vascular smooth muscle cell proliferation through the ERK 1/2-dependent pathway.

    Science.gov (United States)

    Liu, Gang; Hitomi, Hirofumi; Rahman, Asadur; Nakano, Daisuke; Mori, Hirohito; Masaki, Tsutomu; Ma, Hong; Iwamoto, Takahiro; Kobori, Hiroyuki; Nishiyama, Akira

    2014-01-01

    Angiotensin II (Ang II)-induced vascular injury is exacerbated by high-salt diets. This study examined the effects of high-sodium level on Ang II-induced cell proliferation in rat vascular smooth muscle cells (VSMCs). The cells were cultured in a standard medium containing 137.5 mmol l(-1) of sodium. The high-sodium medium (140 mmol l(-1)) contained additional sodium chloride. Extracellular signal-regulated kinase (ERK) 1/2 phosphorylation was determined by western blot analysis. Cell proliferation was evaluated by [(3)H]-thymidine incorporation. Ang II (100 nmol l(-1)) significantly increased ERK 1/2 phosphorylation and cell proliferation in the both medium containing standard sodium and high sodium. High-sodium level augmented Ang II-induced ERK 1/2 phosphorylation and cell proliferation compared with standard sodium. Pre-treatment with candesartan (1 μmol l(-1), Ang II type 1 receptor blocker) or PD98095 (10 μmol l(-1), ERK kinase iinhibitor) abolished the proliferative effect induced by high sodium/Ang II. Pre-treatment with 5-N,N-hexamethylene amiloride (30 μmol l(-1), Na(+)/H(+) exchanger type 1 (NHE-1) inhibitor), but not SN-6 (10 μmol l(-1), Na(+)/Ca(2+) exchanger inhibitor) or ouabain (1 mmol l(-1), Na(+)/K(+)-ATPase inhibitor) attenuated ERK 1/2 phosphorylation or cell proliferation. Osmotic pressure or chloride had no effect on Ang II-induced proliferative changes. High-sodium level did not affect Ang II receptor expression. Ang II increased intracellular pH via NHE-1 activation, and high-sodium level augmented the pH increase induced by Ang II. These data suggest that high-sodium level directly augments Ang II-induced VSMC proliferation through NHE-1- and ERK 1/2-dependent pathways and may offer new insights into the mechanisms of vascular remodeling by high-sodium/Ang II.

  5. Rosuvastatin attenuates angiotensin II-induced neointimal formation after stent implantation in the rat

    NARCIS (Netherlands)

    van der Harst, Pim; Groenewegen, Hendrik C.; Roks, Anton J. M.; Buikema, Hendrik; Zijlstra, Felix; van Gilst, Wiek H.; de Smet, Bart J. G. L.

    2008-01-01

    Objective We investigated the efficacy of oral rosuvastatin treatment to reduce in-stent neointima formation, both in the absence and presence of high levels of the proproliferative substance angiotensin II (Ang II). Background Drawbacks of current drug-eluting stents include inhibition of reendothe

  6. Angiotensin-II-induced Muscle Wasting is Mediated by 25-Hydroxycholesterol via GSK3β Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Congcong Shen

    2017-02-01

    Full Text Available While angiotensin II (ang II has been implicated in the pathogenesis of cardiac cachexia (CC, the molecules that mediate ang II's wasting effect have not been identified. It is known TNF-α level is increased in patients with CC, and TNF-α release is triggered by ang II. We therefore hypothesized that ang II induced muscle wasting is mediated by TNF-α. Ang II infusion led to skeletal muscle wasting in wild type (WT but not in TNF alpha type 1 receptor knockout (TNFR1KO mice, suggesting that ang II induced muscle loss is mediated by TNF-α through its type 1 receptor. Microarray analysis identified cholesterol 25-hydroxylase (Ch25h as the down stream target of TNF-α. Intraperitoneal injection of 25-hydroxycholesterol (25-OHC, the product of Ch25h, resulted in muscle loss in C57BL/6 mice, accompanied by increased expression of atrogin-1, MuRF1 and suppression of IGF-1/Akt signaling pathway. The identification of 25-OHC as an inducer of muscle wasting has implications for the development of specific treatment strategies in preventing muscle loss.

  7. Aldosterone and angiotensin II induced protein aggregation in renal proximal tubules

    DEFF Research Database (Denmark)

    Cheema, Muhammad Umar; Poulsen, Ebbe Toftgaard; Enghild, Jan J;

    2013-01-01

    systems in the kidney from control rats and rats receiving aldosterone or angiotensin II treatment for 7 days. Control rats formed both aggresomes and autophagosomes specifically in the proximal tubules, indicating a need for these structures even under baseline conditions. Fluorescence sorted aggresomes...... contained various rat keratins known to be expressed in renal tubules as assessed by protein mass spectrometry. Aldosterone administration increased the abundance of the proximal tubular aggresomal protein keratin 5, the ribosomal protein RPL27, ataxin-3, and the chaperone heat shock protein 70...

  8. Allergic Lung Inflammation Aggravates Angiotensin II-Induced Abdominal Aortic Aneurysms in Mice

    DEFF Research Database (Denmark)

    Liu, Cong-Lin; Wang, Yi; Liao, Mengyang

    2016-01-01

    OBJECTIVE: Asthma and abdominal aortic aneurysms (AAA) both involve inflammation. Patients with asthma have an increased risk of developing AAA or experiencing aortic rupture. This study tests the development of one disease on the progression of the other. APPROACH AND RESULTS: Ovalbumin...... sensitization and challenge in mice led to the development of allergic lung inflammation (ALI). Subcutaneous infusion of angiotensin II into mice produced AAA. Simultaneous production of ALI in AAA mice doubled abdominal aortic diameter and increased macrophage and mast cell content, arterial media smooth...

  9. Mitogen-Activated Protein Kinase–Activated Protein Kinase 2 in Angiotensin II–Induced Inflammation and Hypertension

    Science.gov (United States)

    Ebrahimian, Talin; Li, Melissa Wei; Lemarié, Catherine A.; Simeone, Stefania M.C.; Pagano, Patrick J.; Gaestel, Matthias; Paradis, Pierre; Wassmann, Sven; Schiffrin, Ernesto L.

    2015-01-01

    Vascular oxidative stress and inflammation play an important role in angiotensin II–induced hypertension, and mitogen-activated protein kinases participate in these processes. We questioned whether mitogen-activated protein kinase–activated protein kinase 2 (MK2), a downstream target of p38 mitogen–activated protein kinase, is involved in angiotensin II–induced vascular responses. In vivo experiments were performed in wild-type and Mk2 knockout mice infused intravenously with angiotensin II. Angiotensin II induced a 30 mm Hg increase in mean blood pressure in wild-type that was delayed in Mk2 knockout mice. Angiotensin II increased superoxide production and vascular cell adhesion molecule-1 in blood vessels of wild-type but not in Mk2 knockout mice. Mk2 knockdown by small interfering RNA in mouse mesenteric vascular smooth muscle cells caused a 42% reduction in MK2 protein and blunted the angiotensin II–induced 40% increase of MK2 expression. Mk2 knockdown blunted angiotensin II–induced doubling of intracellular adhesion molecule-1 expression, 2.4-fold increase of nuclear p65, and 1.4-fold increase in Ets-1. Mk2 knockdown abrogated the angiotensin II–induced 4.7-fold and 1.3-fold increase of monocyte chemoattractant protein-1 mRNA and protein. Angiotensin II enhanced reactive oxygen species levels (by 29%) and nicotinamide adenine dinucleotide phosphate oxidase activity (by 48%), both abolished by Mk2 knockdown. Reduction of MK2 blocked angiotensin II–induced p47phox translocation to the membrane, associated with a 53% enhanced catalase expression. Angiotensin II–induced increase of MK2 was prevented by the nicotinamide adenine dinucleotide phosphate oxidase inhibitor Nox2ds-tat. Mk2 small interfering RNA prevented the angiotensin II–induced 30% increase of proliferation. In conclusion, MK2 plays a critical role in angiotensin II signaling, leading to hypertension, oxidative stress via activation of p47phox and inhibition of antioxidants, and

  10. African Americans,hypertension and the renin angiotensin system

    Institute of Scientific and Technical Information of China (English)

    Sandra; F; Williams; Susanne; B; Nicholas; Nosratola; D; Vaziri; Keith; C; Norris

    2014-01-01

    African Americans have exceptionally high rates of hypertension and hypertension related complications. It is commonly reported that the blood pressure lowering efficacy of renin angiotensin system(RAS) inhibitors is attenuated in African Americans due to a greater likelihood of having a low renin profile. Therefore these agents are often not recommended as initial therapy in African Americans with hypertension. However, the high prevalence of comorbid conditions, such as diabetes, cardiovascular and chronic kidney disease makes treatment with RAS inhibitors more compelling. Despite lower circulating renin levels and a less significant fall in blood pressure in response to RAS inhibitors in African Americans, numerous clinical trials support the efficacy of RAS inhibitors to improve clinical outcomes in this population, especially in those with hypertension and risk factors for cardiovascular and related diseases. Here, we discuss the rationale of RAS blockade as part of a comprehensive approach to attenuate the high rates of premature morbidity and mortality associated with hypertension among African Americans.

  11. Cooperative Role of Mineralocorticoid Receptor and Caveolin-1 in Regulating the Vascular Response to Low Nitric Oxide-High Angiotensin II-Induced Cardiovascular Injury.

    Science.gov (United States)

    Pojoga, Luminita H; Yao, Tham M; Opsasnick, Lauren A; Siddiqui, Waleed T; Reslan, Ossama M; Adler, Gail K; Williams, Gordon H; Khalil, Raouf A

    2015-10-01

    Aldosterone interacts with mineralocorticoid receptor (MR) to stimulate sodium reabsorption in renal tubules and may also affect the vasculature. Caveolin-1 (cav-1), an anchoring protein in plasmalemmal caveolae, binds steroid receptors and also endothelial nitric oxide synthase, thus limiting its translocation and activation. To test for potential MR/cav-1 interaction in the vasculature, we investigated if MR blockade in cav-1-replete or -deficient states would alter vascular function in a mouse model of low nitric oxide (NO)-high angiotensin II (AngII)-induced cardiovascular injury. Wild-type (WT) and cav-1 knockout mice (cav-1(-/-)) consuming a high salt diet (4% NaCl) received Nω-nitro-l-arginine methyl ester (L-NAME) (0.1-0.2 mg/ml in drinking water at days 1-11) plus AngII (0.7-2.8 mg/kg per day via an osmotic minipump at days 8-11) ± MR antagonist eplerenone (EPL) 100 mg/kg per day in food. In both genotypes, blood pressure increased with L-NAME + AngII. EPL minimally changed blood pressure, although its dose was sufficient to block MR and reverse cardiac expression of the injury markers cluster of differentiation 68 and plasminogen activator inhibitor-1 in L-NAME+AngII treated mice. In aortic rings, phenylephrine and KCl contraction was enhanced with EPL in L-NAME+AngII treated WT mice, but not cav-1(-/-) mice. AngII-induced contraction was not different, and angiotensin type 1 receptor expression was reduced in L-NAME + AngII treated WT and cav-1(-/-) mice. In WT mice, acetylcholine-induced relaxation was enhanced with L-NAME + AngII treatment and reversed with EPL. Acetylcholine relaxation in cav-1(-/-) mice was greater than in WT mice, not modified by L-NAME + AngII or EPL, and blocked by ex vivo L-NAME, 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ), or endothelium removal, suggesting the role of NO-cGMP. Cardiac endothelial NO synthase was increased in cav-1(-/-) versus WT mice, further increased with L-NAME + AngII, and not affected by EPL

  12. The murine angiotensin II-induced abdominal aortic aneurysm model: rupture risk and inflammatory progression patterns

    Directory of Open Access Journals (Sweden)

    Richard Y Cao

    2010-07-01

    Full Text Available An abdominal aortic aneurysm (AAA is an enlargement of the greatest artery in the body defined as an increase in diameter of 1.5-fold. AAAs are common in the elderly population and thousands die each year from their complications. The most commonly used mouse model to study the pathogenesis of AAA is the angiotensin II (Ang II infusion method delivered via osmotic mini-pump for 28 days. Here, we studied the site-specificity and onset of aortic rupture, characterized three-dimensional (3D images and flow patterns in developing AAAs by ultrasound imaging, and examined macrophage infiltration in the Ang II model using 65 apolipoprotein E deficient mice. Aortic rupture occurred in 16 mice (25 % and was nearly as prevalent at the aortic arch (44 % as it was in the suprarenal region (56 % and was most common within the first seven days after Ang II infusion (12 of 16; 75 %. Longitudinal ultrasound screening was found to correlate nicely with histological analysis and AAA volume renderings showed a significant relationship with AAA severity index. Aortic dissection preceded altered flow patterns and macrophage infiltration was a prominent characteristic of developing AAAs. Targeting the inflammatory component of AAA disease with novel therapeutics will hopefully lead to new strategies to attenuate aneurysm growth and aortic rupture.

  13. Adventitial gene transfer of catalase attenuates angiotensin II-induced vascular remodeling.

    Science.gov (United States)

    Liu, Cun-Fei; Zhang, Jia; Shen, Kai; Gao, Ping-Jin; Wang, Hai-Ya; Jin, Xin; Meng, Chao; Fang, Ning-Yuan

    2015-04-01

    Vascular adventitia and adventitia‑derived reactive oxygen species (ROS) contribute to vascular remodeling following vascular injury. A previous ex vivo study in adventitial fibroblasts showed that catalase, one of most important anti‑oxide enzymes, was downregulated by angiotensin II (AngII). The aim of the present study was to investigate whether adventitial gene transfer of catalase affects AngII‑induced vascular remodeling in vivo. Adenoviruses co‑expressing catalase and enhanced green fluorescent protein (eGFP) or expressing eGFP only were applied to the adventitial surface of common carotid arteries of Sprague‑Dawley rats. Alzet minipumps administering AngII (0.75 mg/kg/day) were then implanted subcutaneously for 14 days. Systolic blood pressure and biological parameters of vascular remodeling were measured in each group. Adventitial fibroblasts were cultured and p38 mitogen‑activated protein kinase (MAPK) phosphorylation was measured using western blot analysis. The results showed that adventitial gene transfer of catalase had no effect on AngII‑induced systolic blood pressure elevation. However, catalase adenovirus transfection significantly inhibited AngII‑induced media hypertrophy compared with that of the control virus (Pcatalase transfection significantly attenuated AngII‑induced ROS generation, macrophage infiltration, collagen deposition and adventitial α‑smooth muscle actin expression. Furthermore, catalase transfection significantly inhibited the AngII‑induced increase in p38MAPK phosphorylation. In conclusion, the results of the present study demonstrated that adventitial gene transfer of catalase significantly attenuated AngII‑induced vascular remodeling in rats via inhibition of adventitial p38MAPK phosphorylation.

  14. BMP type I receptor ALK2 is required for angiotensin II-induced cardiac hypertrophy.

    Science.gov (United States)

    Shahid, Mohd; Spagnolli, Ester; Ernande, Laura; Thoonen, Robrecht; Kolodziej, Starsha A; Leyton, Patricio A; Cheng, Juan; Tainsh, Robert E T; Mayeur, Claire; Rhee, David K; Wu, Mei X; Scherrer-Crosbie, Marielle; Buys, Emmanuel S; Zapol, Warren M; Bloch, Kenneth D; Bloch, Donald B

    2016-04-15

    Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.

  15. Role of Jagged1-Hey1 Signal in Angiotensin II-induced Impairment of Myocardial Angiogenesis

    Science.gov (United States)

    Guan, Ai-Li; He, Tao; Shao, Yi-Bing; Chi, Yi-Fan; Dai, Hong-Yan; Wang, Yan; Xu, Li; Yang, Xuan; Ding, Hua-Min; Cai, Shang-Lang

    2017-01-01

    Background: Angiotensin II (Ang II) is a major contributor to the development of heart failure. However, the molecular and cellular mechanisms that underlie this process remain elusive. Inadequate angiogenesis in the myocardium leads to a transition from cardiac hypertrophy to dysfunction, and our previous study showed that Ang II significantly impaired the angiogenesis response. The current study was designed to examine the role of Jagged1-Notch signaling in the effect of Ang II during impaired angiogenesis and cardiac hypertrophy. Methods: Ang II was subcutaneously infused into 8-week-old male C57BL/6 mice at a dose of 200 ng·kg−1·min−1 for 2 weeks using Alzet micro-osmotic pumps. N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine tert-butyl ester (DAPT), a γ-secretase inhibitor, was injected subcutaneously during Ang II infusion at a dose of 10.0 mg·kg−1·d−1. Forty mice were divided into four groups (n = 10 per group): control group; Ang II group, treated with Ang II; DAPT group, treated with DAPT; and Ang II + DAPT group, treated with both Ang II and DAPT. At the end of experiments, myocardial (left ventricle [LV]) tissue from each experimental group was evaluated using immunohistochemistry, Western blotting, and real-time polymerase chain reaction. Data were analyzed using one-way analysis of variance test followed by the least significant difference method or independent samples t-test. Results: Ang II treatment significantly induced cardiac hypertrophy and impaired the angiogenesis response compared to controls, as shown by hematoxylin and eosin (HE) staining and immunohistochemistry for CD31, a vascular marker (P < 0.05 for both). Meanwhile, Jagged1 protein was significantly increased, but gene expression for both Jag1 and Hey1 was decreased in the LV following Ang II treatment, compared to that in controls (relative ratio for Jag1 gene: 0.45 ± 0.13 vs. 0.84 ± 0.15; relative ratio for Hey1 gene: 0.51 ± 0.08 vs. 0.91 ± 0.09; P < 0

  16. Angiotensin receptor agonistic autoantibodies and hypertension: preeclampsia and beyond.

    Science.gov (United States)

    Xia, Yang; Kellems, Rodney E

    2013-06-21

    Hypertensive disorders are life-threatening diseases with high morbidity and mortality, affecting billions of individuals worldwide. A multitude of underlying conditions may contribute to hypertension, thus the need for a plethora of treatment options to identify the approach that best meets the needs of individual patients. A growing body of evidence indicates that (1) autoantibodies that bind to and activate the major angiotensin II type I (AT₁) receptor exist in the circulation of patients with hypertensive disorders, (2) these autoantibodies contribute to disease pathophysiology, (3) antibody titers correlate to the severity of the disease, and (4) efforts to block or remove these pathogenic autoantibodies have therapeutic potential. These autoantibodies, termed AT₁ agonistic autoantibodies have been extensively characterized in preeclampsia, a life-threatening hypertensive condition of pregnancy. As reviewed here, these autoantibodies cause symptoms of preeclampsia when injected into pregnant mice. Somewhat surprisingly, these auto antibodies also appear in 3 animal models of preeclampsia. However, the occurrence of AT₁ agonistic autoantibodies is not restricted to pregnancy. These autoantibodies are prevalent among kidney transplant recipients who develop severe transplant rejection and malignant hypertension during the first week after transplantation. AT₁ agonistic autoantibodies are also highly abundant among a group of patients with essential hypertension that are refractory to standard therapy. More recently these autoantibodies have been seen in patients with the autoimmune disease, systemic sclerosis. These 3 examples extend the clinical impact of AT₁ agonistic autoantibodies beyond pregnancy. Research reviewed here raises the intriguing possibility that preeclampsia and other hypertensive conditions are autoimmune diseases characterized by the presence of pathogenic autoantibodies that activate the major angiotensin receptor, AT₁. These

  17. Angiotensin II Induces C-Reactive Protein Expression via AT1-ROS-MAPK-NF-κB Signal Pathway in Hepatocytes

    Directory of Open Access Journals (Sweden)

    Jingjing Zhao

    2013-09-01

    Full Text Available Background: C-reactive protein (CRP participates in development of inflammatory diseases. Hepatocytes are a major contributor of circulating CRP. Although angiotensin II (Ang II is known to evoke inflammatory response, it remains unknown whether Ang II induces CRP expression in hepatocytes. The present study observed effect of Ang II on CRP expression and the related signal pathway in hepatocytes. Methods: mRNA and protein expressions in human hepatocytes were determined with RT-PCR and Western blot respectively. Reactive oxygen species (ROS was measured using a fluorescence probe. CRP in liver and serum of rats was determined by immunohistochemistry and ELISA respectively. Results: Ang II induced mRNA and protein expression of CRP in hepatocytes and increased CRP production in liver and CRP level in serum. Losartan reduced Ang II- induced CRP expression in hepatocytes. Losartan and thenoyltrifluoroacetone decreased Ang II-stimulated ROS production. N-acetylcysteine antagonized Ang II-induced CRP expression. Losartan and N-acetylcysteine inhibited Ang II-activated ERK1/2. Unlike ERK1/2, only losartan inhibited Ang II-activated JNK. Furthermore, pyrrolidine dithiocarbamate abolished Ang II-induced CRP expression. Conclusion: Ang II has ability to induce CRP expression in hepatocytes in vitro and in vivo through AT1 receptor followed by ROS, MAPK and NF-κB signal pathway.

  18. β-Carotene Attenuates Angiotensin II-Induced Aortic Aneurysm by Alleviating Macrophage Recruitment in Apoe(-/- Mice.

    Directory of Open Access Journals (Sweden)

    Kaliappan Gopal

    Full Text Available Abdominal aortic aneurysm (AAA is a common chronic degenerative disease characterized by progressive aortic dilation and rupture. The mechanisms underlying the role of α-tocopherol and β-carotene on AAA have not been comprehensively assessed. We investigated if α-tocopherol and β-carotene supplementation could attenuate AAA, and studied the underlying mechanisms utilized by the antioxidants to alleviate AAA. Four-months-old Apoe(-/- mice were used in the induction of aneurysm by infusion of angiotensin II (Ang II, and were orally administered with α-tocopherol and β-carotene enriched diet for 60 days. Significant increase of LDL, cholesterol, triglycerides and circulating inflammatory cells was observed in the Ang II-treated animals, and gene expression studies showed that ICAM-1, VCAM-1, MCP-1, M-CSF, MMP-2, MMP-9 and MMP-12 were upregulated in the aorta of aneurysm-induced mice. Extensive plaques, aneurysm and diffusion of inflammatory cells into the tunica intima were also noticed. The size of aorta was significantly (P = 0.0002 increased (2.24±0.20 mm in the aneurysm-induced animals as compared to control mice (1.17±0.06 mm. Interestingly, β-carotene dramatically controlled the diffusion of macrophages into the aortic tunica intima, and circulation. It also dissolved the formation of atheromatous plaque. Further, β-carotene significantly decreased the aortic diameter (1.33±0.12 mm in the aneurysm-induced mice (β-carotene, P = 0.0002. It also downregulated ICAM-1, VCAM-1, MCP-1, M-CSF, MMP-2, MMP-9, MMP-12, PPAR-α and PPAR-γ following treatment. Hence, dietary supplementation of β-carotene may have a protective function against Ang II-induced AAA by ameliorating macrophage recruitment in Apoe(-/- mice.

  19. Angiotensin and neurovascular coupling: beyond hypertension.

    Science.gov (United States)

    Bloch, Sherri; Obari, Dima; Girouard, Hélène

    2015-04-01

    Brain homeostasis is dependent upon the constant perfusion of oxygen and nutrients through CBF. The mechanism responsible to couple CBF to neuronal activity is termed NVC. Ang II, a key player in hypertension, impairs NVC and has been found to be of significant importance in neurodegenerative diseases, such as AD. The presence of Ang II and its metabolites, as well as their receptors have been detected in many areas of the brain. Findings indicate that disruption of NVC by Ang II is mediated by its AT1R and NADPH oxidase (NOX)-dependent ROS production independently of its effect on blood pressure. Although the process causing ROS to interfere with NVC has yet to be elucidated, data label peroxynitrite as the leading ROS to do so. The same common pathway is involved in NVC impairment in AD experimental models. This review investigates recent data concerning the effects of Ang II on NVC with the intent of exploring new treatment perspectives for neurodegenerative diseases such as AD.

  20. Angiotensin II-Induced Endothelial Dysfunction is Temporally Linked with Increases in Intereukin-6 and Vascular Macrophage Accumulation

    Directory of Open Access Journals (Sweden)

    Sean P Didion

    2014-10-01

    Full Text Available Angiotensin II (Ang II is associated with vascular hypertrophy, endothelial dysfunction and activation of a number of inflammatory molecules, however the linear events involved in the development of hypertension and endothelial dysfunction produced in response to Ang II are not well defined. The goal of this study was to examine the dose- and temporal-dependent development of endothelial dysfunction in response to Ang II. Blood pressure and responses of carotid arteries were examined in control (C57Bl/6 mice and in mice infused with 50, 100, 200, 400, or 1000 ng/kg/min Ang II for either 14 or 28 Days. Infusion of Ang II was associated with graded and marked increases in systolic blood pressure and plasma Ang II concentrations. While low doses of Ang II (ie, 50 and 100 ng/kg/min had little to no effect on blood pressure or endothelial function, high doses of Ang II (e.g., 1000 ng/kg/min were associated with large increases in arterial pressure and marked impairment of endothelial function. In contrast, intermediate doses of Ang II (200 and 400 ng/kg/min while initially having no effect on systolic blood pressure were associated with significant increases in pressure over time. Despite increasing blood pressure, 200 ng/kg/min had no effect on endothelial function, whereas 400 ng/kg/min produced modest impairment on Day 14 and marked impairment of endothelial function on Day 28. The degree of endothelial dysfunction produced by 400 and 1000 ng/kg/min Ang II was reflective of parallel increases in plasma IL-6 levels and vascular macrophage content, suggesting that increases in arterial blood pressure precede the development of endothelial dysfunction. These findings are important as they demonstrate that along with increases in arterial pressure that increases in IL-6 and vascular macrophage accumulation correlate with the impairment of endothelial function produced by Ang II.

  1. Inhibition of angiotensin II-induced contraction of human airway smooth muscle cells by angiotensin-(1-7) via downregulation of the RhoA/ROCK2 signaling pathway.

    Science.gov (United States)

    Li, Ning; Cai, Ruijun; Niu, Yi; Shen, Bin; Xu, Jian; Cheng, Yuanxiong

    2012-10-01

    Sustained renin-angiotensin system (RAS) activation in asthmatic patients plays a crucial role in airway hyperresponsiveness and airflow limitation. Angiotensin II (Ang II), as a key peptide of RAS, contributes to the contraction of human airway smooth muscle by activating the RhoA/Rho-associated coiled-coil containing protein kinase 2 (ROCK2) signaling pathway. Angiotensin-(1-7) [Ang-(1-7)], is a component of the angiotensin I converting enzyme 2 (ACE2)-Ang-(1-7)-Mas axis which counteracts the detrimental effects of the ACE- Ang II-angiotensin type 1 receptor (AT1R) axis in vivo; however, whether Ang-(1-7) can inhibit the effect of Ang II in the contraction of human airway smooth muscle cells (HASMCs) is unknown. In our study, collagen gel lattices and immunofluorescence were used to evaluate the contraction of HASMCs induced by Ang II. Real-time PCR and western blot analysis were performed to confirm the regulatory mechanism and the participating signaling pathway. Ang II caused the contraction of HASMCs; this effect was reversed by Ang‑(1‑7). In addition, irbesartan and A779, which are inhibitors of AT1R and Mas, respectively, attenuated the effect of Ang II and Ang-(1-7). Furthermore, Y-27632, an inhibitor of ROCK2, attenuated the Ang II-induced contraction of HASMCs by blocking the RhoA/ROCK2 signaling pathway which is involved in this contraction, and thus may be a major regulator involved in the basal maintenance of contractility in HASMCs. These data demonstrate that Ang II induces the contraction of HASMCs and that this effect can be reversed by Ang-(1-7), partially through the downregulation of of the RhoA/ROCK2 signaling pathway.

  2. H2S inhibits angiotensin II-induced atrial Kv1.5 upregulation by attenuating Nox4-mediated ROS generation during atrial fibrillation.

    Science.gov (United States)

    Lu, Guihua; Xu, Chenggui; Tang, Kaiyu; Zhang, Juhong; Li, Qinglang; Peng, Longyun; Wang, Yesong; Huang, Zhibin; Gao, Xiuren

    2017-01-29

    Our previous study demonstrated that angiotensin II (Ang II) upregulates the expression of Kv1.5, a promising target for atrial fibrillation (AF) therapy, by activating ROS-dependent P-Smad2/3 and P-ERK 1/2. A recent study showed that hydrogen sulfide (H2S) may modulate the effects of angiotensin II (Ang II) by inhibiting the NADPH oxidase 4 (Nox4)-ROS signaling in the heart. The present study aimed to determine whether H2S is involved in the regulation of atrial Kv1.5 via ROS-related mechanisms in AF. Cultured neonatal rat atrial myocytes and a beagle model of AF were used for this study. In the neonatal rat atrial myocytes, quantitative PCR and enzyme immunoassays revealed that the mRNA expression levels of angiotensinogen, angiotensin-converting enzyme, and Ang II type I receptor (AT1R) and the Ang II supernatant concentration were significantly increased by hydrogen peroxide (H2O2) incubation, and these H2O2-induced alterations were reversed by diphenyleneiodonium, apocynin and H2S supplementation. Flow cytometry and Western blotting revealed that blockade of H2S biosynthesis using dl-propargylglycine increased ROS production and the expression of Ang II and Kv1.5. Sodium hydrosulfide (an exogenous H2S donor) and Nox4 siRNA inhibited Ang II-induced ROS production and Ang II-induced expression of Kv1.5, P-Smad2/3, P-ERK 1/2. Sodium hydrosulfide suppressed the Ang II-induced upregulation of Nox4. In our beagle AF model, 24 h of rapid atrial pacing (RAP) increased the atrial Ang II concentration, ROS production and the protein expression of Nox4, Kv1.5, P-Smad2/3 and P-ERK 1/2. These RAP-induced changes were inhibited by H2S supplementation and losartan (an AT1R blocker) pretreatment. In conclusion, our study indicates that H2S downregulates Ang II-induced atrial Kv1.5 expression by attenuating Nox4-related ROS-triggered P-Smad2/3 and P-ERK 1/2 activation during AF. H2S supplementation would be beneficial for AF treatment via the suppression of atrial Kv1

  3. Lead, hypertension, and the renin-angiotensin system in rats

    Energy Technology Data Exchange (ETDEWEB)

    Victery, W.; Vander, A.J.; Shulak, J.M.; Schoeps, P.; Julius, S.

    1982-03-01

    Rats were exposed continuously to Pb in utero and after birth by giving their mothers, during pregnancy and lactation, drinking water containing 0, 100, or 500 ppm Pb (as Pb acetate) and then continuing this regimen after weaning. Male rats receiving 100 ppm developed a significant elevation of systolic blood pressure (152 +/- 3.7 mm Hg vs. 135 +/- 5.6 for controls) at 3 1/2 months and remained hypertensive until sacrifice at 6 months; 500 ppm rats remained normotensive. Both 100 ppm and 500 ppm females remained normotensive. At 6 months plasma renin activity (PRA) was significantly reduced in the 100 ppm male group but was normal in the 500 ppm group. There was dose-dependent decreases in the All/PRA ratio and in renal renin. Pulmonary converting enzyme activity was not changed by Pb exposure. Blood (Pb) was 40 and 71 ..mu..g/dl, respectively, and kidney (Pb) was 4.8 and 22.9 ..mu..g/gm. Renal histology was normal in the 100 ppm group. We conclude that doses of Pb which produce blood (Pb) seen in many people are capable of including modest hypertension in male rats; higher doses fail to do so. The hypertension is associated with a reduction in PRA and All and therefore is unlikely to be due to hyperactivity of the renin-angiotensin system (RAS).

  4. Plasma Angiotensin II Levels In Women With Type 2 Diabetes With Or Without Hypertension

    OpenAIRE

    Ariadno, Etra

    2013-01-01

    ABSTRACT Background. Hypertension is a major risk for the development and progressivity complication of macro and microvascular of diabetes mellitus. Renin-angiotensin-aldosteron system (RAAS), insulin resistance, endothelial dysfunction and autonomic nervous dysfunction play an important part in the pathogenesis of hypertension and type 2 diabetes mellitus. In RAAS, increased angiotensin II constricts arterioles, raises total peripheral resistance and blood volume. The rise in intravascular ...

  5. Puerarin-7-O-glucuronide, a water-soluble puerarin metabolite, prevents angiotensin II-induced cardiomyocyte hypertrophy by reducing oxidative stress.

    Science.gov (United States)

    Hou, Ning; Cai, Bin; Ou, Cai-Wen; Zhang, Zhen-Hui; Liu, Xia-Wen; Yuan, Mu; Zhao, Gan-Jian; Liu, Shi-Ming; Xiong, Long-Gen; Luo, Jian-Dong; Luo, Cheng-Feng; Chen, Min-Sheng

    2017-02-16

    This study aimed to investigate the anti-oxidant and anti-hypertrophic effects of puerarin-7-O-glucuronide, a water-soluble puerarin metabolite. The anti-oxidant effects of puerarin-7-O-glucuronide were assessed by measurement of intracellular superoxide levels, total superoxide dismutase (SOD) activity, total anti-oxidant capacity, and glutathione (GSH)/glutathione disulfide (GSSG) ratio in cultured neonatal rat cardiomyocytes (NRCMs) stimulated with the xanthine oxidase (XO)/xanthine (X) system or angiotensin II. The activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and expression of NADPH oxidase subunits p22(phox) and p47(phox) were determined. The anti-hypertrophic effects of puerarin-7-O-glucuronide in angiotensin II-challenged NRCMs were characterized by changes in cell morphology and expression of hypertrophic genes. In the pharmacokinetic study, the plasma concentration of puerarin-7-O-glucuronide was determined by rapid resolution-liquid chromatography-tandem mass spectrometry (RR-LC-MS/MS). Puerarin-7-O-glucuronide prevented XO/X-induced increase in intracellular superoxide production and decreases in total SOD activity, GSH/GSSG ratio, and total anti-oxidant capacity. Puerarin-7-O-glucuronide also reversed angiotensin II-induced increases in intracellular superoxide production and NADPH oxidase activity and decreases in total SOD activity. These anti-oxidant effects of puerarin-7-O-glucuronide were accompanied by downregulation of p22(phox) and p47(phox). Furthermore, puerarin-7-O-glucuronide prevented angiotensin II-induced increases in cell surface area and perimeter, as well as changes in Nppa, Myh7, and Myh6. In the pharmacokinetic study, puerarin-7-O-glucuronide was cleared with a half-life of 0.94 h after intravenous administration. Puerarin could be detected in rat plasma, albeit in low concentration, as early as 5 min after intravenous administration of puerarin-7-O-glucuronide. These anti-oxidant and anti

  6. Angiotensin-(1-7)-induced renal vasodilation in hypertensive humans is attenuated by low sodium intake and angiotensin II co-infusion.

    Science.gov (United States)

    van Twist, Daan J L; Houben, Alfons J H M; de Haan, Michiel W; Mostard, Guy J M; Kroon, Abraham A; de Leeuw, Peter W

    2013-10-01

    Current evidence suggests that angiotensin-(1-7) plays an important role in the regulation of tissue blood flow. This evidence, however, is restricted to studies in animals and human forearm. Therefore, we studied the effects of intrarenal angiotensin-(1-7) infusion on renal blood flow in hypertensive humans. To assess the influence of renin-angiotensin system activity, sodium intake was varied and co-infusion with angiotensin II was performed in a subgroup. In 57 hypertensive patients who were scheduled for renal angiography, renal blood flow was measured ((133)Xenon washout method) before and during intrarenal infusion of angiotensin-(1-7) (3 incremental doses: 0.27, 0.9, and 2.7 ng/kg per minute). Patients were randomized into low or high sodium intake. These 2 groups of patients received angiotensin-(1-7), with or without intrarenal co-infusion of angiotensin II (0.3 ng/kg per minute). Angiotensin-(1-7) infusion resulted in intrarenal vasodilation in patients adhering to a sodium-rich diet. This vasodilatory effect of angiotensin-(1-7) was clearly attenuated by low sodium intake, angiotensin II co-infusion, or both. Regression analyses showed that the prevailing renin concentration was the only independent predictor of angiotensin-(1-7)-induced renal vasodilation. In conclusion, angiotensin-(1-7) induces renal vasodilation in hypertensive humans, but the effect of angiotensin-(1-7) is clearly attenuated by low sodium intake and co-infusion of angiotensin II. This supports the hypothesis that angiotensin-(1-7) induced renal vasodilation depends on the degree of renin-angiotensin-system activation.

  7. Salvianolic acid A inhibits angiotensin II-induced proliferation of human umbilical vein endothelial cells by attenuating the production of ROS

    Science.gov (United States)

    Yang, Luan-luan; Li, Dong-ye; Zhang, Yan-bin; Zhu, Man-yi; Chen, Dan; Xu, Tong-da

    2012-01-01

    Aim: To investigate the action of salvianolic acid A (SalA) on angiotensin II (Ang II)-induced proliferation of human umbilical vein endothelial cells (HUVECs) and the possible signaling pathways mediating this action. Methods: Cell proliferation was examined with MTT assay. The expression levels of Src phosphorylation (phospho-Src), Akt phosphorylation (phospho-Akt), and NADPH oxidase 4 (Nox4) in HUVECs were determined by Western blot. The production of reactive oxygen species (ROS) was estimated using fluorescence-activated cell sorting (FACS). Results: SalA (6.25–50 μmol/L) did not affect the viability of HUVECs. Treatment of HUVECs with Ang II (1 μmol/L) markedly increased the cell viability; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) prevented Ang II-induced increase of the cell viability in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) markedly up-regulated the protein expression levels of phospho-Src, phospho-Akt (473) and Nox4; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked all the effects in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) dramatically increased ROS production in HUVECs; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked the ROS production in a concentration-dependent manner. Conclusion: SalA inhibits Ang II-induced proliferation of HUVECs via reducing the expression levels of phospho-Src and phospho-Akt (473), thereby attenuating the production of ROS. PMID:22101169

  8. Relative Atrial Natriuretic Peptide Deficiency and Inadequate Renin and Angiotensin II Suppression in Obese Hypertensive Men

    DEFF Research Database (Denmark)

    Asferg, Camilla L; Nielsen, Søren J; Andersen, Ulrik B;

    2013-01-01

    Obesity is a strong risk factor for hypertension, but the mechanisms by which obesity leads to hypertension are incompletely understood. On this background, we assessed dietary sodium intake, serum levels of natriuretic peptides (NPs), and the activity of the renin-angiotensin system in 63 obese...

  9. The neurogenic phase of angiotensin II-salt hypertension is prevented by chronic intracerebroventricular administration of benzamil.

    Science.gov (United States)

    Osborn, John W; Olson, Dalay M; Guzman, Pilar; Toney, Glenn M; Fink, Gregory D

    2014-02-01

    Hypertension induced by chronic administration of angiotensin II (AngII) is exacerbated by high-salt intake. Previous studies have demonstrated that this salt-sensitive component is due to increased activity of the sympathetic nervous system, suggesting an interaction of plasma AngII with sodium-sensitive regions of the brain. This study tested the hypothesis that the salt-sensitive component of AngII-induced hypertension would be prevented by intracerebroventricular (ICV) administration of the sodium channel/transporter blocker benzamil. Male Sprague Dawley rats were instrumented to measure mean arterial pressure (MAP) by radio telemetry and for ICV administration of benzamil or vehicle and placed in metabolic cages for measurement of sodium and water intake and excretion. In rats consuming a high-salt diet (2.0% NaCl) and treated with ICV vehicle, administration of AngII (150 ng/kg/min, sc) for 13 days increased MAP by ~30 mmHg. ICV administration of benzamil (16 nmol/day) had no effect during the first 5 days of AngII, but returned MAP to control levels by Day 13. There were minimal or no differences between ICV vehicle or benzamil groups in regards to sodium and water balance. A lower dose of ICV benzamil administered ICV at 8 nmol/day had no effect on the MAP response to AngII in rats on a high-salt diet. Finally, in contrast to rats on a high-salt diet, AngII had negligible effects on MAP in rats consuming a low-salt diet (0.1% NaCl) and there were no differences in any variable between ICV benzamil (16 nmol/day) and ICV vehicle-treated groups. We conclude that the salt-sensitive component of AngII-induced hypertension is dependent on benzamil blockable sodium channels or transporters in the brain.

  10. Protection of protease-activated receptor 2 mediated vasodilatation against angiotensin II-induced vascular dysfunction in mice

    OpenAIRE

    Chia, Elizabeth; Kagota, Satomi; Wijekoon, Enoka P; McGuire, John J

    2011-01-01

    Background Under conditions of cardiovascular dysfunction, protease-activated receptor 2 (PAR2) agonists maintain vasodilatation activity, which has been attributed to increased cyclooxygenase-2, nitric oxide synthase and calcium-activated potassium channel (SK3.1) activities. Protease-activated receptor 2 agonist mediated vasodilatation is unknown under conditions of dysfunction caused by angiotensin II. The main purpose of our study was to determine whether PAR2-induced vasodilatation of re...

  11. Development of nonfibrotic left ventricular hypertrophy in an ANG II-induced chronic ovine hypertension model

    DEFF Research Database (Denmark)

    Klatt, Niklas; Scherschel, Katharina; Schad, Claudia

    2016-01-01

    Hypertension is a major risk factor for many cardiovascular diseases and leads to subsequent concomitant pathologies such as left ventricular hypertrophy (LVH). Translational approaches using large animals get more important as they allow the use of standard clinical procedures in an experimental...

  12. Olmesartan inhibits angiotensin II-Induced migration of vascular smooth muscle cells through Src and mitogen-activated protein kinase pathways.

    Science.gov (United States)

    Kyotani, Yoji; Zhao, Jing; Tomita, Sayuko; Nakayama, Hitoshi; Isosaki, Minoru; Uno, Masayuki; Yoshizumi, Masanori

    2010-01-01

    Clinical studies have shown that angiotensin-receptor blockers (ARBs) reduce the risk of cardiovascular diseases in hypertensive patients. It is assumed that the reduction of the risk by ARBs may be attributed in part to the inhibition of angiotensin II (AII)-induced vascular smooth muscle cell (VSMC) migration associated with atherosclerosis. However, the effect of ARBs on AII-induced changes in intracellular signaling and resultant cell migration has not been well established. Here, we investigated the effect of olmesartan, an ARB, on AII-induced extracellular signal-regulated kinases 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) activation and rat aortic smooth muscle cell (RASMC) migration. Olmesartan inhibited AII-induced ERK1/2 and JNK activation at lower concentrations (10 nM). On the other hand, PP2, a Src tyrosine kinase inhibitor, also inhibited AII-induced ERK1/2 and JNK activation, but its effect on ERK1/2 was less pronounced than that of olmesartan. Olmesartan, U0126 (an ERK1/2 inhibitor), SP600125 (a JNK inhibitor), and PP2 potently inhibited AII-induced RASMC migration. From these findings, it was inferred that angiotensin-receptor blockade by olmesartan results in the inhibition of AII-induced activation of Src, ERK1/2, and JNK in RASMC. Olmesartan may be a potent inhibitor of AII-induced VSMC migration, which may be involved in the progression of atherosclerosis.

  13. Hemodynamic, morphometric and autonomic patterns in hypertensive rats - renin-angiotensin system modulation

    Directory of Open Access Journals (Sweden)

    Fernanda S. Zamo

    2010-01-01

    Full Text Available BACKGROUND: Spontaneously hypertensive rats develop left ventricular hypertrophy, increased blood pressure and blood pressure variability, which are important determinants of heart damage, like the activation of renin-angiotensin system. AIMS: To investigate the effects of the time-course of hypertension over 1 hemodynamic and autonomic patterns (blood pressure; blood pressure variability; heart rate; 2 left ventricular hypertrophy; and 3 local and systemic Renin-angiotensin system of the spontaneously hypertensive rats. METHODS: Male spontaneously hypertensive rats were randomized into two groups: young (n=13 and adult (n=12. Hemodynamic signals (blood pressure, heart rate, blood pressure variability (BPV and spectral analysis of the autonomic components of blood pressure were analyzed. LEFT ventricular hypertrophy was measured by the ratio of LV mass to body weight (mg/g, by myocyte diameter (μm and by relative fibrosis area (RFA, %. ACE and ACE2 activities were measured by fluorometry (UF/min, and plasma renin activity (PRA was assessed by a radioimmunoassay (ng/mL/h. Cardiac gene expressions of Agt, Ace and Ace2 were quantified by RT-PCR (AU. RESULTS: The time-course of hypertension in spontaneously hypertensive rats increased BPV and reduced the alpha index in adult spontaneously hypertensive rats. Adult rats showed increases in left ventricular hypertrophy and in RFA. Compared to young spontaneously hypertensive rats, adult spontaneously hypertensive rats had lower cardiac ACE and ACE2 activities, and high levels of PRA. No change was observed in gene expression of Renin-angiotensin system components. CONCLUSIONS: The observed autonomic dysfunction and modulation of Renin-angiotensin system activity are contributing factors to end-organ damage in hypertension and could be interacting. Our findings suggest that the management of hypertensive disease must start before blood pressure reaches the highest stable levels and the consequent

  14. The angiotensin-(1-7)/Mas axis reduces myonuclear apoptosis during recovery from angiotensin II-induced skeletal muscle atrophy in mice.

    Science.gov (United States)

    Meneses, Carla; Morales, María Gabriela; Abrigo, Johanna; Simon, Felipe; Brandan, Enrique; Cabello-Verrugio, Claudio

    2015-09-01

    Angiotensin-(1-7) [Ang (1-7)] is a peptide belonging to the non-classical renin-angiotensin system (RAS). Ang (1-7), through its receptor Mas, has an opposite action to angiotensin II (Ang II), the typical peptide of the classical RAS axis. Ang II produces skeletal muscle atrophy, a pathological condition characterised by the loss of strength and muscle mass. A feature of muscle atrophy is the decrease of the myofibrillar proteins produced by the activation of the ubiquitin-proteasome pathway (UPP), evidenced by the increase in the expression of two muscle-specific ubiquitin ligases: atrogin-1 and MuRF-1. In addition, it has been described that Ang II also induces myonuclear apoptosis during muscle atrophy. We assessed the effects of Ang (1-7) and Mas participation on myonuclear apoptosis during skeletal muscle atrophy induced by Ang II. Our results show that Ang (1-7), through Mas, prevents the effects induced by Ang II in the diaphragm muscles and decreases several events associated with apoptosis in the diaphragm (increased apoptotic nuclei, increased expression of caspase-8 and caspase-9, increased caspase-3 activity and increased Bax/Bcl-2 ratio). Concomitantly, Ang (1-7) also attenuates the decrease in fibre diameter and muscle strength, and prevents the increase in atrogin-1 and MuRF-1 during the muscle wasting induced by Ang II. Interestingly, these effects of Ang (1-7) are dependent on the Mas receptor. Thus, we demonstrated for the first time that Ang (1-7) prevents myonuclear apoptosis during the recovery of skeletal muscle atrophy induced by Ang II.

  15. HMG-CoA reductase inhibitors decrease angiotensin II-induced vascular fibrosis: role of RhoA/ROCK and MAPK pathways.

    Science.gov (United States)

    Rupérez, Mónica; Rodrigues-Díez, Raquel; Blanco-Colio, Luis Miguel; Sánchez-López, Elsa; Rodríguez-Vita, Juan; Esteban, Vanesa; Carvajal, Gisselle; Plaza, Juan José; Egido, Jesús; Ruiz-Ortega, Marta

    2007-08-01

    3-Hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) reductase inhibitors (statins) present beneficial effects in cardiovascular diseases. Angiotensin II (Ang II) contributes to cardiovascular damage through the production of profibrotic factors, such as connective tissue growth factor (CTGF). Our aim was to investigate whether HMG-CoA reductase inhibitors could modulate Ang II responses, evaluating CTGF expression and the mechanisms underlying this process. In cultured vascular smooth muscle cells (VSMCs) atorvastatin and simvastatin inhibited Ang II-induced CTGF production. The inhibitory effect of statins on CTGF upregulation was reversed by mevalonate and geranylgeranylpyrophosphate, suggesting that RhoA inhibition could be involved in this process. In VSMCs, statins inhibited Ang II-induced Rho membrane localization and activation. In these cells Ang II regulated CTGF via RhoA/Rho kinase activation, as shown by inhibition of Rho with C3 exoenzyme, RhoA dominant-negative overexpression, and Rho kinase inhibition. Furthermore, activation of p38MAPK and JNK, and redox process were also involved in Ang II-mediated CTGF upregulation, and were downregulated by statins. In rats infused with Ang II (100 ng/kg per minute) for 2 weeks, treatment with atorvastatin (5 mg/kg per day) diminished aortic CTGF and Rho activation without blood pressure modification. Rho kinase inhibition decreased CTGF upregulation in rat aorta, mimicking statin effect. CTGF is a vascular fibrosis mediator. Statins diminished extracellular matrix (ECM) overexpression caused by Ang II in vivo and in vitro. In summary, HMG-CoA reductase inhibitors inhibit several intracellular signaling systems activated by Ang II (RhoA/Rho kinase and MAPK pathways and redox process) involved in the regulation of CTGF. Our results may explain, at least in part, some beneficial effects of statins in cardiovascular diseases.

  16. Oxidative stress may explain how hypertension is maintained by normal levels of angiotensin II

    Directory of Open Access Journals (Sweden)

    J.C. Romero

    2000-06-01

    Full Text Available It is well known that essential hypertension evolves in most patients with "near normal" levels of plasma renin activity. However, these levels appear to be responsible for the high levels of arterial pressure because they are normalized by the administration of angiotensin II converting inhibitors or angiotensin receptor antagonist. In experimental animals, hypertension can be induced by the continuous intravenous infusion of small doses of angiotensin II that are not sufficient to evoke an immediate pressor response. However, this condition resembles the characteristics of essential hypertension because the high levels of blood pressure exist with normal plasma levels of angiotensin II. It is suggested that small amounts of angiotensin whose plasma levels are inappropriate for the existing size of extracellular volume stimulate oxidative stress which binds nitric oxide forming peroxynitrite. The latter compound oxidizes arachidonic acid producing isoprostaglandin F2a (an isoprostane which is characterized by a strong antinatriuretic vasoconstrictor renal effect. In this chain of reactions the vasoconstrictor effects derived from oxygen quenching of nitric oxide and increased isoprostane synthesis could explain how hypertension is maintained with normal plasma levels of renin.

  17. Angiotensin II induces an increase in MMP-2 expression in idiopathic ascending aortic aneurysm via AT1 receptor and JNK pathway.

    Science.gov (United States)

    Wang, Chunmao; Chang, Qian; Qian, Xiangyang; Tian, Chuan; Sun, Xiaogang

    2015-07-01

    The cellular and molecular mechanisms responsible for human idiopathic ascending aortic aneurysm (IAAA) remain unknown. Matrix metalloproteinase-2 (MMP-2) is a key enzyme for the degradation of extracellular matrix in aneurysmal walls. The aim of this study was to elucidate the role of the angiotensin II (Ang II) pathway in MMP-2 induction in IAAA aortic walls. Quantitative polymerase chain reaction and western blot analysis were used to compare the MMP-2 mRNA and protein levels in ascending aortic specimens with those in IAAA patients (n = 10) and heart transplant donors (n = 5) without any aortopathy. It was found that MMP-2 expression was significantly increased, which was associated with elastic lamellae disruption in IAAA walls. Additionally, the expression levels of angiotensinogen (AGT) and Ang II in the ascending aortic tissues from individuals with and without IAAAs were detected by western blot analysis and radioimmunoassay, respectively. The results demonstrated that the expressions of AGT and Ang II protein were significantly increased in the ascending aortic tissues of IAAA patients. Furthermore, whether Ang II induces MMP-2 expression was investigated using human IAAA walls ex vivo culture. It was found that exogenous Ang II increased the MMP-2 expression in a dose-dependent manner, which was completely inhibited by the Ang II type 1 receptor (AT1R) inhibitor candesartan and was mediated by c-Jun N-terminal kinase (JNK) activation. Taken together, these results indicate that Ang II can induce an increase of MMP-2 expression via AT1R and JNK in ex vivo cultured IAAA aortic walls, and suggest that angiotensin receptor blocker (ARB) drugs and JNK inhibitors have the potential in the prevention or treatment of IAAAs.

  18. Angiotensin II-induced Akt activation through the epidermal growth factor receptor in vascular smooth muscle cells is mediated by phospholipid metabolites derived by activation of phospholipase D.

    Science.gov (United States)

    Li, Fang; Malik, Kafait U

    2005-03-01

    Angiotensin II (Ang II) activates cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)), phospholipase D (PLD), p38 mitogen-activated protein kinase (MAPK), epidermal growth factor receptor (EGFR) and Akt in vascular smooth muscle cells (VSMC). This study was conducted to investigate the relationship between Akt activation by Ang II and other signaling molecules in rat VSMC. Ang II-induced Akt phosphorylation was significantly reduced by the PLD inhibitor 1-butanol, but not by its inactive analog 2-butanol, and by brefeldin A, an inhibitor of the PLD cofactor ADP-ribosylation factor, and in cells infected with retrovirus containing PLD(2) siRNA or transfected with PLD(2) antisense but not control LacZ or sense oligonucleotide. Diacylglycerol kinase inhibitor II diminished Ang II-induced and diC8-phosphatidic acid (PA)-increased Akt phosphorylation, suggesting that PLD-dependent Akt activation is mediated by PA. Ang II-induced EGFR phosphorylation was inhibited by 1-butanol and PLD(2) siRNA and also by cPLA(2) siRNA. In addition, the inhibitor of arachidonic acid (AA) metabolism 5,8,11,14-eicosatetraynoic acid (ETYA) reduced both Ang II- and AA-induced EGFR transactivation. Furthermore, ETYA, cPLA(2) antisense, and cPLA(2) siRNA attenuated Ang II-elicited PLD activation. p38 MAPK inhibitor SB202190 [4-(4-flurophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole] reduced PLD activity and EGFR and Akt phosphorylation elicited by Ang II. Pyrrolidine-1, a cPLA(2) inhibitor, and cPLA(2) siRNA decreased p38 MAPK activity. These data indicate that Ang II-stimulated Akt activity is mediated by cPLA(2)-dependent, p38 MAPK regulated PLD(2) activation and EGFR transactivation. We propose the following scheme of the sequence of events leading to activation of Akt in VSMC by Ang II: Ang II-->cPLA(2)-->AA-->p38 MAPK-->PLD(2)-->PA-->EGFR-->Akt.

  19. Radioimmunologic analysis of the state of the renin-angiotensin-aldosterone-system in arterial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Slavnov, V.N.; Yakovlev, A.A.; Gandzha, T.I.; Yugrinov, O.G. (AN Ukrainskoj SSR, Kiev)

    1985-01-01

    In 110 patients suffering from various forms of arterial hypertension (hypertension, aldosteronoma, phaeochromocytoma, corticosteroma) the parameters of the system renin-angiotensin-aldosterone were measured. Basal values of aldosterone, renin activity in blood as well as their concentration in blood taken from the vena cava inferior, renal and adrenal veins during selective renography were determined. The 24-hours rhythm of the hormones in the blood, the reaction of the glomerular zone of the adrenal cortex and the juxtaglomerular renal system under acute Lasix (furosemide) stress was evaluated. It was found, that the system renin-angiotensin-aldosterone is disturbed in all patients with arterial hypertension. This is indicated by changes of aldosterone concentration, renin activity in peripheral blood and in the blood from the vena cava inferior, renal and adrenal veins, the 24-hours rhythm of their concentrations in serum and the reaction to acute Lasix stress. The radioimmunoassays of quantitative parameters of the renin-angiotensin-aldosterone system are decisive for the differential diagnosis of hypertension and adrenal gland tumors connected with a hypertension syndrome. They facilitate a rational choice of the hypertension therapy and the daily distribution of the medications for patients with hypertension. The radioimmunoassays can be used for checking the efficiency of medications and surgery.

  20. Leptin Mediates High-Fat Diet Sensitization of Angiotensin II-Elicited Hypertension by Upregulating the Brain Renin-Angiotensin System and Inflammation.

    Science.gov (United States)

    Xue, Baojian; Yu, Yang; Zhang, Zhongming; Guo, Fang; Beltz, Terry G; Thunhorst, Robert L; Felder, Robert B; Johnson, Alan Kim

    2016-05-01

    Obesity is characterized by increased circulating levels of the adipocyte-derived hormone leptin, which can increase sympathetic nerve activity and raise blood pressure. A previous study revealed that rats fed a high-fat diet (HFD) have an enhanced hypertensive response to subsequent angiotensin II administration that is mediated at least, in part, by increased activity of brain renin-angiotensin system and proinflammatory cytokines. This study tested whether leptin mediates this HFD-induced sensitization of angiotensin II-elicited hypertension by interacting with brain renin-angiotensin system and proinflammatory cytokine mechanisms. Rats fed an HFD for 3 weeks had significant increases in white adipose tissue mass, plasma leptin levels, and mRNA expression of leptin and its receptors in the lamina terminalis and hypothalamic paraventricular nucleus. Central infusion of a leptin receptor antagonist during HFD feeding abolished HFD sensitization of angiotensin II-elicited hypertension. Furthermore, central infusion of leptin mimicked the sensitizing action of HFD. Concomitant central infusions of the angiotensin II type 1 receptor antagonist irbesartan, the tumor necrosis factor-α synthesis inhibitor pentoxifylline, or the inhibitor of microglial activation minocycline prevented the sensitization produced by central infusion of leptin. RT-PCR analysis indicated that either HFD or leptin administration upregulated mRNA expression of several components of the renin-angiotensin system and proinflammatory cytokines in the lamina terminalis and paraventricular nucleus. The leptin antagonist and the inhibitors of angiotensin II type 1 receptor, tumor necrosis factor-α synthesis, and microglial activation all reversed the expression of these genes. The results suggest that HFD-induced sensitization of angiotensin II-elicited hypertension is mediated by leptin through upregulation of central renin-angiotensin system and proinflammatory cytokines.

  1. Analysis of renin-angiotensin-aldosterone system gene polymorphisms in resistant hypertension

    Directory of Open Access Journals (Sweden)

    S.R.S. Freitas

    2007-03-01

    Full Text Available Essential hypertension is a disease multifactorially triggered by genetic and environmental factors. The contribution of genetic polymorphisms of the renin-angiotensin-aldosterone system and clinical risk factors to the development of resistant hypertension was evaluated in 90 hypertensive patients and in 115 normotensive controls living in Southwestern Brazil. Genotyping for insertion/deletion of angiotensin-converting enzyme, angiotensinogen M235T, angiotensin II type 1 receptor A1166C, aldosterone synthase C344T, and mineralocorticoid receptor A4582C polymorphisms was performed by PCR, with further restriction analysis when required. The influence of genetic polymorphisms on blood pressure variation was assessed by analysis of the odds ratio, while clinical risk factors were evaluated by logistic regression. Our analysis indicated that individuals who carry alleles 235-T, 1166-A, 344-T, or 4582-C had a significant risk of developing resistant hypertension (P < 0.05. Surprisingly, when we tested individuals who carried the presumed risk genotypes A1166C, C344T, and A4582C we found that these genotypes were not associated with resistant hypertension. However, a gradual increase in the risk to develop resistant hypertension was detected when the 235-MT and TT genotypes were combined with one, two or three of the supposedly more vulnerable genotypes - A1166C (AC/AA, C344T (TC/TT and A4582C (AC/CC. Analysis of clinical parameters indicated that age, body mass index and gender contribute to blood pressure increase (P < 0.05. These results suggest that unfavorable genetic renin-angiotensin-aldosterone system patterns and clinical risk variables may contribute to increasing the risk for the development of resistant hypertension in a sample of the Brazilian population.

  2. Angiotensin II clamp prevents the second step in renal apical NHE3 internalization during acute hypertension

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; McDonough, Alicia A

    2002-01-01

    Acute hypertension inhibits proximal tubule (PT) sodium reabsorption. The resultant increase in NaCl delivery to the macula densa suppresses renin release. We tested whether the sustained pressure-induced inhibition of PT sodium reabsorption requires a renin-mediated decrease in ANG II levels. Pl...... hypertension, including diuresis and redistribution of PT NHE3 into intracellular membranes, require a responsive renin-angiotensin system and that the responses may be induced by the sustained increase in NaCl delivery to the macula densa during acute hypertension....

  3. Protective effect of Boerhaavia diffusa L. against mitochondrial dysfunction in angiotensin II induced hypertrophy in H9c2 cardiomyoblast cells.

    Directory of Open Access Journals (Sweden)

    Ayyappan Prathapan

    Full Text Available Mitochondrial dysfunction plays a critical role in the development of cardiac hypertrophy and heart failure. So mitochondria are emerging as one of the important druggable targets in the management of cardiac hypertrophy and other associated complications. In the present study, effects of ethanolic extract of Boerhaavia diffusa (BDE, a green leafy vegetable against mitochondrial dysfunction in angiotensin II (Ang II induced hypertrophy in H9c2 cardiomyoblasts was evaluated. H9c2 cells challenged with Ang II exhibited pathological hypertrophic responses and mitochondrial dysfunction which was evident from increment in cell volume (49.09±1.13%, protein content (55.17±1.19%, LDH leakage (58.74±1.87%, increased intracellular ROS production (26.25±0.91%, mitochondrial superoxide generation (65.06±2.27%, alteration in mitochondrial transmembrane potential (ΔΨm, opening of mitochondrial permeability transition pore (mPTP and mitochondrial swelling. In addition, activities of mitochondrial respiratory chain complexes (I-IV, aconitase, NADPH oxidase, thioredoxin reductase, oxygen consumption rate and calcium homeostasis were evaluated. Treatment with BDE significantly prevented the generation of intracellular ROS and mitochondrial superoxide radicals and protected the mitochondria by preventing dissipation of ΔΨm, opening of mPTP, mitochondrial swelling and enhanced the activities of respiratory chain complexes and oxygen consumption rate in H9c2 cells. Activities of aconitase and thioredoxin reductase which was lowered (33.77±0.68% & 45.81±0.71% respectively due to hypertrophy, were increased in BDE treated cells (P≤0.05. Moreover, BDE also reduced the intracellular calcium overload in Ang II treated cells. Overall results revealed the protective effects of B. diffusa against mitochondrial dysfunction in hypertrophy in H9c2 cells and the present findings may shed new light on the therapeutic potential of B. diffusa in addition to its

  4. p38 MAPK Inhibition Improves Synaptic Plasticity and Memory in Angiotensin II-dependent Hypertensive Mice

    Science.gov (United States)

    Dai, Hai-long; Hu, Wei-yuan; Jiang, Li-hong; Li, Le; Gaung, Xue-feng; Xiao, Zhi-cheng

    2016-01-01

    The pathogenesis of hypertension-related cognitive impairment has not been sufficiently clarified, new molecular targets are needed. p38 MAPK pathway plays an important role in hypertensive target organ damage. Activated p38 MAPK was seen in AD brain tissue. In this study, we found that long-term potentiation (LTP) of hippocampal CA1 was decreased, the density of the dendritic spines on the CA1 pyramidal cells was reduced, the p-p38 protein expression in hippocampus was elevated, and cognitive function was impaired in angiotensin II-dependent hypertensive C57BL/6 mice. In vivo, using a p38 heterozygous knockdown mice (p38KI/+) model, we showed that knockdown of p38 MAPK in hippocampus leads to the improvement of cognitive function and hippocampal synaptic plasticity in angiotensin II-dependent p38KI/+ hypertensive mice. In vitro, LTP was improved in hippocampal slices from C57BL/6 hypertensive mice by treatment with p38MAPK inhibitor SKF86002. Our data demonstrated that p38 MAPK may be a potential therapeutic target for hypertension-related cognitive dysfunction. PMID:27283322

  5. Rationale for combination therapy in hypertension management: focus on angiotensin receptor blockers and thiazide diuretics.

    Science.gov (United States)

    Nash, David T

    2007-04-01

    Despite recognition that hypertension is a major risk factor for cardiovascular events and mortality, blood pressure control rates remain low in the US population. Reflecting clinical trial results, hypertension management guidelines assert the clinical benefit of achieving current blood pressure goals and indicate that most patients will require 2 or more drugs to reach goal. Well-designed drug combinations counter hypertension via complementary mechanisms that increase antihypertensive efficacy, potentially with lower rates of adverse events than higher dose monotherapy regimens. Lower adverse event rates, in turn, may contribute to greater adherence with treatment. The combination of a low-dose diuretic with agents that block the effects of the renin-angiotensin system (RAS), such as angiotensin receptor blockers, has been found in numerous clinical trials to be highly effective for lowering blood pressure in patients with uncomplicated as well as high-risk hypertension, with a comparable favorable side effect profile compared with monotherapy. Moreover, agents that block the RAS are associated with a lower risk of new-onset diabetes mellitus than other antihypertensive classes. Complementary combinations of antihypertensive agents provide an efficient and effective approach to hypertension management.

  6. Effects of Autoantibodies Against At1-receptor and Angiotensin II on Refractory Hypertension

    Institute of Scientific and Technical Information of China (English)

    廖玉华; 魏宇淼; 王敏; 董继华; 王朝晖; 苑海涛

    2001-01-01

    Objective The study will explore effects of the autoantibodies against AT1 receptor and angiotensin Ⅱ on the refractory hypertension. Methods Seventy-seven patients (46 men and 31 women) with essential hypertension were divided into groups of refractory hypertension (RH) and hypertension (HT) according to the 1999 WHO -ISH Guidelines for the Management of Hypertension. Forty normotensives (22 men) were recruited as controls.The mean age was 54. 3 ± 13 years old in RH group,53.5±9 years old in HT group and 51.2±11.9years old in normotensives (NT) group. The mean blood pressure was 154.2 ± 9.4/98.4 ± 8.2 mmHg in RH group and 130.1 ±7.6/80.5 ±6.7 mmHg in HT group after combination drug therapy of hypertension for 4 weeks. Blood pressure in NT group was 120. 8 ± 11.7/76. 4 ± 7.2 mmHg. The epitope of the 2nd extracellular loops of AT1 receptor was synthesized and used as antigens to screen the autoantibodies by ELISA. Plasma angiotensin (Ang) Ⅱ were examined by a radioimmunoassay. Results The autoantibodies against AT1 receptor were positive in 18 (46. 15% ) patients with RH, in 4 (10. 5 % ) hypertension and in 3 (7.5 % ) normotensives, P < 0.01. Ang Ⅱwas 57.01 ± 52.63 pmol/L in patients with RH. Both the autoantibodies positive and the Ang Ⅱ increasing were 4 (10. 3 %) cases, both normal were 7 (17.9% ) cases, the autoantibodies positive or Ang Ⅱ in creasing was all of 14 (35.9 % ) cases (χ2 =0. 09,P > 0. 05) There was no relationship between the autoantibodies against AT1 receptor and the angiotensin Ⅱ in refractory hypertension. Conclusion The autoantibodies against AT1 receptor and Ang Ⅱ might be two independent factors in developing of refractory hypertension. The findings suggest that AT1 receptor antagnist used in the treatment of refractory hypertension might have an important value.

  7. Polymorphisms of Renin-angiotensin System in Essential Hypertension in Chinese Tibetans

    Institute of Scientific and Technical Information of China (English)

    BEI SUN; TSERING DRONMA; WEI-JUN QIN; CHAO-YING CUI; DAN TSE; TASHI PINGTSO; YING LIU; CHANG-CHUN QIU

    2004-01-01

    Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensinⅡtype 1 receptor gene for essential hypertension in Tibetan. Methods A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension. Results As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20.1) times higher than those with TT genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect. Conclusion Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.

  8. A Study on Renin-Angiotensin System and Total Exchangeable Sodium in Hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Kang Won; Park, Jung Sik; Lee, Jung Sang; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1976-03-15

    The etiologic role of renin-angiotensin system and sodium-volume status in the pathophysiology of various forms of hypertension was investigated. Plasma renin activity (PRA) was measured by radioimmunoassay, while sodium-volume status was evaluated by the determination of total exchangeable sodium(NaE) using isotope dilution method. The subjects consisted of 25 controls, 24 patients with essential hypertension, 22 patients with chronic renal failure (13 with hypertension, 9 without hypertension) and 14 patients with malignant hypertension. The results were as follows: 1) An inverse correlation between NaE and PRA was noted in control subjects (r=-0.598, p<0.001) and normal renin essential hypertension(r=-0.551, p<0.05) and the chronic renal failure with hypertension. (r=-0.790, P<0.001) 2) NaE increased markedly the in chronic renal failure with hypertension (66.9+-8.69 mEq/kg of LBM, p<0.001) and the chronic renal failure without hypertension (54.9+-9.28 mEq/kg of LBM, p<0.05), while mild increase was noted in malignant hypertension (51.7+-6.24 mEq/kg of LBM, 0.05hypertension as a whole (50.1+-7.24 mEq) as well as in its renin subgroups.(p>0.1) 3) Absolute value of PRA was not deviated significantly from control group (2.53+-1.416 ng/ml/hr) except in malignant hypertension (6.09+-2.042, p<0.001). But PRA was inappropriately high in relation to prevailing NaE in the chronic renal failure with hypertension (eleven of thirteen patients) and malignant hypertension (ten of fourteen patients), while PRA variatiation was within physiologic range in the chronic renal failure without hypertension. 4) The NaE-PRA product was markedly increased in the chronic renal failure with hypertension (514.4+-42.10, p<0.001) and in malignant hypertension (442.7+-55.03, p<0.001), while moderately increased NaE-PRA product was noted in the chronic renal failure without hypertension (402.6+-59.67, p<0

  9. Reciprocal roles of angiotensin II and Angiotensin II Receptors Blockade (ARB) in regulating Cbfa1/RANKL via cAMP signaling pathway: possible mechanism for hypertension-related osteoporosis and antagonistic effect of ARB on hypertension-related osteoporosis.

    Science.gov (United States)

    Guan, Xiao-Xu; Zhou, Yi; Li, Ji-Yao

    2011-01-01

    Hypertension is a risk factor for osteoporosis. Animal and epidemiological studies demonstrate that high blood pressure is associated with increased calcium loss, elevated parathyroid hormone, and increased calcium movement from bone. However, the mechanism responsible for hypertension-related osteoporosis remains elusive. Recent epidemiological studies indicate the benefits of Angiotensin II Receptors Blockade (ARB) on decreasing fracture risks. Since receptors for angiotensin II, the targets of ARB, are expressed in both osteoblasts and osteoclasts, we postulated that angiotensin II plays an important role in hypertension-related osteoporosis. Cbfa1 and RANKL, the important factors for maintaining bone homeostasis and key mediators in controlling osteoblast and osteoclast differentiation, are both regulated by cAMP-dependent signaling. Angiotensin II along with factors such as LDL, HDL, NO and homocysteine that are commonly altered both in hypertension and osteoporosis, can down-regulate the expression of Cbfa1 but up-regulate RANKL expression via the cAMP signaling pathway. We thus hypothesized that, by altering the ratio of Cbfa1/RANKL expression via the cAMP-dependent pathway, angiotensin II differently regulates osteoblast and osteoclast differentiation leading to enhanced bone resorption and reduced bone formation. Since ARB can antagonize the adverse effect of angiotensin II on bone by lowering cAMP levels and modifying other downstream targets, including LDL, HDL, NO and Cbfa1/RANKL, we propose the hypothesis that the antagonistic effects of ARB may also be exerted via cAMP signaling pathway.

  10. New drug therapies interfering with the renin-angiotensin-aldosterone system for resistant hypertension.

    Science.gov (United States)

    Monge, Matthieu; Lorthioir, Aurélien; Bobrie, Guillaume; Azizi, Michel

    2013-12-01

    There is a persistent need for the development of new antihypertensive drugs, because the control of blood pressure is still not achievable in a significant proportion of hypertensive patients. Since the approval in 2007 of aliskiren, no other new antihypertensive based on new mechanism(s) of action have been approved. In fact, the development of promising novel drugs has been stopped for safety, efficacy or marketing reasons. Despite these difficulties, the pipeline is not dry and different new antihypertensive strategies targeting the renin-angiotensin-aldosterone pathway, are in clinical development stage. The dual angiotensin II receptor-neprilysin inhibitor LCZ696, a single molecule synthetized by cocrystallisation of valsartan and the neprilysin inhibitor prodrug AHU377 is in development for resistant hypertension and for heart failure. Daglutril is a dual neprylisin-endothelin converting enzyme inhibitor which was shown to decrease BP in patients with type 2 diabetic nephropathy. Aldosterone synthase inhibitors and the third and fourth generation non-steroidal dihydropyridine based mineralocorticoid receptors blockers are new ways to target the multiple noxious effects of aldosterone in the kidney, vessels and heart. Centrally acting aminopeptidase A inhibitors block brain angiotensin III formation, one of the main effector peptides of the brain renin angiotensin system. However, a long time will be still necessary to evaluate extensively the efficacy and safety of these new approaches. In the mean time, using appropriate and personalized daily doses of available drugs, decreasing physician inertia, improving treatment adherence, improving access to healthcare and reducing treatment costs remain major objectives to reduce the incidence of resistant hypertension.

  11. The renin-angiotensin system and hypertension in autosomal recessive polycystic kidney disease.

    Science.gov (United States)

    Goto, Miwa; Hoxha, Nita; Osman, Rania; Dell, Katherine Macrae

    2010-12-01

    Hypertension is a well-recognized complication of autosomal recessive polycystic kidney disease (ARPKD). The renin-angiotensin system (RAS) is a key regulator of blood pressure; however, data on the RAS in ARPKD are limited and conflicting, showing both up- and down-regulation. In the current study, we characterized intrarenal and systemic RAS activation in relationship to hypertension and progressive cystic kidney disease in the ARPKD orthologous polycystic kidney (PCK) rat. Clinical and histological measures of kidney disease, kidney RAS gene expression by quantitative real-time PCR, angiotensin II (Ang II) immunohistochemistry, and systemic Ang I and II levels were assessed in 2-, 4-, and 6-month-old cystic PCK and age-matched normal rats. PCK rats developed hypertension and progressive cystic kidney disease without significant worsening of renal function or relative kidney size. Intrarenal renin, ACE and Ang II expression was increased significantly in cystic kidneys; angiotensinogen and Ang II Type I receptor were unchanged. Systemic Ang I and II levels did not differ. This study demonstrates that intrarenal, but not systemic, RAS activation is a prominent feature of ARPKD. These findings help reconcile previous conflicting reports and suggest that intrarenal renin and ACE gene upregulation may represent a novel mechanism for hypertension development or exacerbation in ARPKD.

  12. POLYMORPHISM OF ANGIOTENSIN Ⅱ TYPE 1 RECEPTOR GENE IN ELDERLY PATIENTS WITH ESSENTIAL HYPERTENSION

    Institute of Scientific and Technical Information of China (English)

    方宁远; 张怡; 陆惠华; 郑迪辉; 邬亦贤; 郑道声

    2003-01-01

    Objective To detect the A/C1166 polymorphism of angiotensin Ⅱ type-1 receptor (AT1 R) gene in essential hypertensive elderly.MethodsThe A/C1166 polymorphism of AT1 R gene was assessed by polymerase chain reaction restriction fragment length polymorphism (PCR RFLP) in a case control study of 87 essential hypertensive elders (EH) and 55 normotensive elders (NT).ResultsThe genotype frequencies of AA, AC, CC were 0.805, 0.161, 0.034 in EH group and 0.927, 0.073, 0.000 in NT group respectively. The frequency of C1166 allele was higher in EH group (0.115) than in NT group (0.036)(P<0.05).ConclusionThe results indicate that A/C1166 polymorphism of AT1 R gene may be associated with essential hypertension in elderly.

  13. The impact of telmisartan on angiotensin converting enzyme 2 mRNA expression in monocyte-derived macrophages of diabetic hypertensive patients

    Institute of Scientific and Technical Information of China (English)

    李永勤

    2013-01-01

    Objective To investigate the effects of telmisartan on the expression of angiotensin converting enzyme 2(ACE2) mRNA in monocyte-derived macrophages of hypertensive patients accompanied with diabetes. Methods 62 essential hypertensive patients accompanied with

  14. Liberación de endotelina-1 por angiotensina ll en miocitos cardíacos aislados Angiotensin II-induced endothelin-1 release in cardiac myocytes

    Directory of Open Access Journals (Sweden)

    María C. Villa-Abrille

    2006-06-01

    + exchanger (NCX blockade or by ROS scavenging. Ang II 100 nM increases SS by 70.5±7.6% (p<0.05. This PIE was completely abolished by AT1 receptors blockade and were partially bocked by ET-1 receptors blockade, by NHE inhibition, by reverse mode NCX blockade or by ROS scavenging. Ang II increased preproET-1 mRNA, effect that was blunted by AT1 receptors blockade. We conclude that Ang II induces (through its AT1 receptor release/formation of ET-1, which acting in autocrine fashion on ET receptors of the isolated myocytes increases inotropism through NHE stimulation and NCX reverse mode activation. The participation of ROS is involved is this chain of events.

  15. Synthesis and evaluation of novel angiotensin II receptor 1 antagonists as anti-hypertension drugs.

    Science.gov (United States)

    Bao, Xiaolu; Zhu, Weibo; Zhang, Ruijing; Wen, Caihong; Wang, Li; Yan, Yijia; Tang, Hesheng; Chen, Zhilong

    2016-05-01

    Three new angiotensin II receptor 1 antagonists, 1, 2 and 3 were designed, synthesized and evaluated. The AT1 receptor-binding assays in vitro showed that all the synthesized compounds had nanomolar affinity for the AT1 receptor. From which compound 3 was found to be the most potent ligands with an IC50 value of 2.67±0.23 nM. Biological evaluation in vivo revealed that all the compounds could cause significant decrease on MBP in a dose dependent manner in spontaneously hypertensive rats, and compound 3 especially showed an efficient and long-lasting effect in reducing blood pressure, whose maximal response lowered 41 mmHg of MBP at 10mg/kg and 62 mmHg at 15 mg/kg after oral administration, the significant anti-hypertensive effect lasted beyond 12 h, which is better than the reference compound losartan. The pharmacokinetic experiments showed that compound 3 could be absorbed efficiently and metabolized smoothly both in blood and in tissues in Wistar rats. The acute toxicity assay suggested that it has low toxicity with the LD50 value of 2974.35 mg/kg. These results demonstrate that compound 3 is a potent angiotensin AT1 receptor antagonist which could be considered as a novel anti-hypertension candidate and deserved for further investigation.

  16. Renin-Angiotensin System Genes Polymorphisms and Essential Hypertension in Burkina Faso, West Africa

    Directory of Open Access Journals (Sweden)

    Daméhan Tchelougou

    2015-01-01

    Full Text Available Objective. This study aimed to investigate the association between three polymorphisms of renin-angiotensin system and the essential hypertension in the population of Burkina Faso. Methodology. This was a case-control study including 202 cases and 204 matched controls subjects. The polymorphisms were identified by a classical and a real-time PCR. Results. The AGT 235M/T and AT1R 1166A/C polymorphisms were not associated with the hypertension while the genotype frequencies of the ACE I/D polymorphism between patients and controls (DD: 66.83% and 35.78%, ID: 28.22% and 50.98%, II: 4.95% and 13.24%, resp. were significantly different (p < 10−4. The genotype DD of ACE gene (OR = 3.40, p < 0.0001, the increasing age (OR = 3.83, p < 0.0001, obesity (OR = 4.84, p < 0.0001, dyslipidemia (OR = 3.43, p = 0.021, and alcohol intake (OR = 2.76, p < 0.0001 were identified as the independent risk factors for hypertension by multinomial logistic regression. Conclusion. The DD genotype of the ACE gene is involved in susceptibility to hypertension. Further investigations are needed to better monitor and provide individualized care for hypertensive patients.

  17. Renin-Angiotensin System Genes Polymorphisms and Essential Hypertension in Burkina Faso, West Africa

    Science.gov (United States)

    Tchelougou, Daméhan; Kologo, Jonas K.; Karou, Simplice D.; Yaméogo, Valentin N.; Bisseye, Cyrille; Djigma, Florencia W.; Ouermi, Djeneba; Compaoré, Tegwindé R.; Assih, Maléki; Pietra, Virginio; Zabsonré, Patrice; Simpore, Jacques

    2015-01-01

    Objective. This study aimed to investigate the association between three polymorphisms of renin-angiotensin system and the essential hypertension in the population of Burkina Faso. Methodology. This was a case-control study including 202 cases and 204 matched controls subjects. The polymorphisms were identified by a classical and a real-time PCR. Results. The AGT 235M/T and AT1R 1166A/C polymorphisms were not associated with the hypertension while the genotype frequencies of the ACE I/D polymorphism between patients and controls (DD: 66.83% and 35.78%, ID: 28.22% and 50.98%, II: 4.95% and 13.24%, resp.) were significantly different (p < 10−4). The genotype DD of ACE gene (OR = 3.40, p < 0.0001), the increasing age (OR = 3.83, p < 0.0001), obesity (OR = 4.84, p < 0.0001), dyslipidemia (OR = 3.43, p = 0.021), and alcohol intake (OR = 2.76, p < 0.0001) were identified as the independent risk factors for hypertension by multinomial logistic regression. Conclusion. The DD genotype of the ACE gene is involved in susceptibility to hypertension. Further investigations are needed to better monitor and provide individualized care for hypertensive patients. PMID:26351579

  18. Different reactivity to angiotensin II of peripheral and renal arteries in spontaneously hypertensive rats: effect of acute and chronic angiotensin converting enzyme inhibition

    Science.gov (United States)

    Guidi, E.; Hollenberg, N. K.

    1986-01-01

    We assessed renal blood flow and pressor responses to graded angiotensin II doses in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats ingesting a diet containing 1.6% sodium basally and after acute and chronic angiotensin converting enzyme (ACE) inhibition with captopril. In the basal state the pressor response to angiotensin II was enhanced (Prenal vascular response was blunted (Pacute captopril administration the pressor response was enhanced in both strains, and the difference between them was maintained, while the renal vascular response was enhanced in both, but more in SHR, so that the renal vascular response in the SHR became larger than in WKY (Prenal responses in WKY rats, but only the pressor response in SHR. The renal vessels of SHR seem to be different from those of WKY rats in reaction to exogenous angiotensin II, and in response to both acute administration of captopril (probably acting through blockade of angiotensin II production) and chronic administration of captopril (probably acting mainly through accumulation of kinin or production of prostaglandins).

  19. Angiotensin II induces hypertrophy of human airway smooth muscle cells: expression of transcription factors and transforming growth factor-beta1

    NARCIS (Netherlands)

    S. McKay (Sue); J.C. de Jongste (Johan); P.R. Saxena (Pramod Ranjan); H.S. Sharma (Hari)

    1998-01-01

    textabstractIncreased smooth muscle mass due to hyperplasia and hypertrophy of airway smooth muscle (ASM) cells is a common feature in asthma. Angiotensin II (Ang II), a potent vasoconstrictor and mitogen for a wide variety of cells, has recently been implicated in bron

  20. Angiotensin II induces reorganization of the actin cytoskeleton and myosin light-chain phosphorylation in podocytes through rho/ROCK-signaling pathway

    NARCIS (Netherlands)

    Wang, Siyuan; Chen, Cheng; Su, Ke; Zha, Dongqing; Liang, Wei; Hillebrands, J L; van Goor, Harry; Ding, Guohua

    2016-01-01

    Aims In the present study, we have evaluated the effect of angiotensin II (Ang II) on actin cytoskeleton reorganization and myosin light-chain (MLC) phosphorylation in podocytes to demonstrate whether the Rho/Rho-associated coiled kinase (ROCK) pathway is involved podocyte injury. Methods Eighteen m

  1. Renin-angiotensin-aldosterone system in the elderly: rational use of aliskiren in managing hypertension

    Directory of Open Access Journals (Sweden)

    Karl Andersen

    2009-03-01

    Full Text Available Karl AndersenDepartment of Medicine, Division of Cardiology, Landspitali University Hospital, University of Iceland, Reykjavik, IcelandAbstract: The overall purpose of hypertension treatment is 2-fold. First, patients often have symptoms that are related to their high blood pressure and although subtle in many instances may be improved dramatically by blood pressure control. The main reason for blood pressure treatment, however, is to reduce the burden of cardiovascular complications and end organ damage related to the condition. This may be considered the ultimate goal of blood pressure treatment. In this respect, actual blood pressure measurements may be seen as surrogate end points as the organ protective effects of two antihypertensive agents may differ significantly even though their blood pressure lowering effects are similar. Thus beta-blockers, once seen as first-line treatment of hypertension for most patients, now are considered as third- or fourth-line agents according to the latest NICE guidelines (National Institute for Health and Clinical Excellence, www.nice.org.uk/CG034. On the other hand, agents that inhibit the activity of the renin-angiotensin-aldosterone system (RAAS are being established as safe, effective and end organ protective in numerous clinical trials, resulting in their general acceptance as first-line treatment in most patients with stage 2 hypertension. This shift in emphasis from beta-blockers and thiazide diuretics is supported by numerous clinical trials and has proven safe and well tolerated by patients. The impact of this paradigm shift will have to be established in future long-term randomized clinical trials. The optimal combination treatment with respect to end organ protection has yet to be determined. Most combinations will include either a RAAS active agent and calcium channel blocker or two separate RAAS active agents working at different levels of the cascade. In this respect direct renin inhibitors

  2. Intrarenal alterations of the angiotensin-converting enzyme type 2/angiotensin 1-7 complex of the renin-angiotensin system do not alter the course of malignant hypertension in Cyp1a1-Ren-2 transgenic rats.

    Science.gov (United States)

    Husková, Zuzana; Kopkan, Libor; Červenková, Lenka; Doleželová, Šárka; Vaňourková, Zdeňka; Škaroupková, Petra; Nishiyama, Akira; Kompanowska-Jezierska, Elzbieta; Sadowski, Janusz; Kramer, Herbert J; Červenka, Luděk

    2016-04-01

    The role of the intrarenal renin-angiotensin system (RAS) in the pathophysiology of malignant hypertension is not fully understood. Accumulating evidence indicates that the recently discovered vasodilator axis of the RAS, angiotensin-converting enzyme (ACE) type 2 (ACE2)/angiotensin 1-7 (ANG 1-7), constitutes an endogenous system counterbalancing the hypertensiogenic axis, ACE/angiotensin II (ANG II)/AT1 receptor. This study aimed to evaluate the role of the intrarenal vasodilator RAS axis in the pathophysiology of ANG II-dependent malignant hypertension in Cyp1a1-Ren-2 transgenic rats. ANG II-dependent malignant hypertension was induced by 13 days' dietary administration of indole-3-carbinol (I3C), a natural xenobiotic that activates the mouse renin gene in Cyp1a1-Ren-2 transgenic rats. It was hypothesized that pharmacologically-induced inhibition of the ACE2/ANG 1-7 complex should aggravate, and activation of this axis should attenuate, the course of ANG II-dependent malignant hypertension. Blood pressure (BP) was monitored by radiotelemetry. ACE2 inhibitor (DX 600, 0.2 μg/day) and ACE2 activator (DIZE, 1 mg/day) were administrated via osmotic minipumps. Even though ACE2 inhibitor significantly decreased and ACE2 activator increased intrarenal ANG 1-7 concentrations, the course of BP, as well as of albuminuria, cardiac hypertrophy and renal glomerular damage, were not altered. It was shown that intrarenal alterations in the ACE2/ANG 1-7 complex did not significantly modify the course of malignant hypertension in I3C-induced Cyp1a1-Ren-2 transgenic rats. Thus, in our experimental setting alterations of this intrarenal vasodilator complex of the RAS do not significantly modify the form of malignant hypertension that clearly depends on the inappropriately increased activity of the ACE/ANG II/AT1 receptor axis.

  3. Low-Salt Diet and Circadian Dysfunction Synergize to Induce Angiotensin II-Dependent Hypertension in Mice.

    Science.gov (United States)

    Pati, Paramita; Fulton, David J R; Bagi, Zsolt; Chen, Feng; Wang, Yusi; Kitchens, Julia; Cassis, Lisa A; Stepp, David W; Rudic, R Daniel

    2016-03-01

    Blood pressure exhibits a robust circadian rhythm in health. In hypertension, sleep apnea, and even shift work, this balanced rhythm is perturbed via elevations in night-time blood pressure, inflicting silent damage to the vasculature and body organs. Herein, we examined the influence of circadian dysfunction during experimental hypertension in mice. Using radiotelemetry to measure ambulatory blood pressure and activity, the effects of angiotensin II administration were studied in wild-type (WT) and period isoform knockout (KO) mice (Per2-KO, Per2, 3-KO, and Per1, 2, 3-KO/Per triple KO [TKO] mice). On a normal diet, administration of angiotensin II caused nondipping blood pressure and exacerbated vascular hypertrophy in the Period isoform KO mice relative to WT mice. To study the endogenous effects of angiotensin II stimulation, we then administered a low-salt diet to the mice, which does stimulate endogenous angiotensin II in addition to lowering blood pressure. A low-salt diet decreased blood pressure in wild-type mice. In contrast, Period isoform KO mice lost their circadian rhythm in blood pressure on a low-salt diet, because of an increase in resting blood pressure, which was restorable to rhythmicity by the angiotensin receptor blocker losartan. Chronic administration of low salt caused vascular hypertrophy in Period isoform KO mice, which also exhibited increased renin levels and altered angiotensin 1 receptor expression. These data suggest that circadian clock genes may act to inhibit or control renin/angiotensin signaling. Moreover, circadian disorders such as sleep apnea and shift work may alter the homeostatic responses to sodium restriction to potentially influence nocturnal hypertension.

  4. Successful pregnancy with scleroderma renal disease and pulmonary hypertension in a patient using angiotensin converting enzyme inhibitors.

    OpenAIRE

    Baethge, B A; Wolf, R E

    1989-01-01

    A patient with scleroderma renal disease and pulmonary hypertension who had a successful pregnancy with the use of angiotensin converting enzyme inhibitors is presented. The routine use of these inhibitors during pregnancy is not recommended, however, owing to the reported potential risks to the fetus.

  5. Endogenous angiotensin II modulates nNOS expression in renovascular hypertension

    Directory of Open Access Journals (Sweden)

    T.M.C. Pereira

    2009-07-01

    Full Text Available Nitric oxide (NO influences renal blood flow mainly as a result of neuronal nitric oxide synthase (nNOS. Nevertheless, it is unclear how nNOS expression is modulated by endogenous angiotensin II, an inhibitor of NO function. We tested the hypothesis that the angiotensin II AT1 receptor and oxidative stress mediated by NADPH oxidase contribute to the modulation of renal nNOS expression in two-kidney, one-clip (2K1C hypertensive rats. Experiments were performed on male Wistar rats (150 to 170 g body weight divided into 2K1C (N = 19 and sham-operated (N = 19 groups. nNOS expression in kidneys of 2K1C hypertensive rats (N = 9 was compared by Western blotting to that of 2K1C rats treated with low doses of the AT1 antagonist losartan (10 mg·kg-1·day-1; N = 5 or the superoxide scavenger tempol (0.2 mmol·kg-1·day-1; N = 5, which still remain hypertensive. After 28 days, nNOS expression was significantly increased by 1.7-fold in the clipped kidneys of 2K1C rats and by 3-fold in the non-clipped kidneys of 2K1C rats compared with sham rats, but was normalized by losartan. With tempol treatment, nNOS expression increased 2-fold in the clipped kidneys and 1.4-fold in the non-clipped kidneys compared with sham rats. The changes in nNOS expression were not followed by changes in the enzyme activity, as measured indirectly by the cGMP method. In conclusion, AT1 receptors and oxidative stress seem to be primary stimuli for increased nNOS expression, but this up-regulation does not result in higher enzyme activity.

  6. Alterations in circulatory and renal angiotensin-converting enzyme and angiotensin-converting enzyme 2 in fetal programmed hypertension.

    Science.gov (United States)

    Shaltout, Hossam A; Figueroa, Jorge P; Rose, James C; Diz, Debra I; Chappell, Mark C

    2009-02-01

    Antenatal betamethasone treatment is a widely accepted therapy to accelerate lung development and improve survival in preterm infants. However, there are reports that infants who receive antenatal glucocorticoids exhibit higher systolic blood pressure in their early adolescent years. We have developed an experimental model of programming whereby the offspring of pregnant sheep administered clinically relevant doses of betamethasone exhibit elevated blood pressure. We tested the hypothesis as to whether alterations in angiotensin-converting enzyme (ACE), ACE2, and neprilysin in serum, urine, and proximal tubules are associated with this increase in mean arterial pressure. Male sheep were administered betamethasone (2 doses of 0.17 mg/kg, 24 hours apart) or vehicle at the 80th day of gestation and delivered at term. Sheep were instrumented at adulthood (1.8 years) for direct conscious recording of mean arterial pressure. Serum and urine were collected and proximal tubules isolated from the renal cortex. Betamethasone-treated animals had elevated mean arterial pressure (97+/-3 versus 83+/-2 mm Hg; P<0.05) and a 25% increase in serum ACE activity (48.4+/-7.0 versus 36.0+/-2.7 fmol/mL per minute) but a 40% reduction in serum ACE2 activity (18.8+/-1.2 versus 31.4+/-4.4 fmol/mL per minute). In isolated proximal tubules, ACE2 activity and expression were 50% lower in the treated sheep with no significant change in ACE or neprilysin activities. We conclude that antenatal steroid treatment results in the chronic alteration of ACE and ACE2 in the circulatory and tubular compartments, which may contribute to the higher blood pressure in this model of fetal programming-induced hypertension.

  7. Carotid remodeling of hypertensive subjects and polymorphism of the angiotensin-converting enzyme gene

    Institute of Scientific and Technical Information of China (English)

    李世军; 孙宁玲; 周素敏

    2004-01-01

    Background This study was designed to investigate the relationships between changes in the structure and function of carotid arteries and angiotensin converting enzyme (ACE) gene polymorphism in Chinese hypertensive subjects. Methods Multiplex polymerase chain reaction amplification was used to evaluate the ACE gene insertion/deletion (I/D) polymorphism. High-resolution B-mode ultrasound examinations were performed to detect parameters of carotid artery remodeling. Results Intima-media thickness (IMT) was significantly different among the DD, ID and II genotypes of ACE (DD>ID>II, P0.05) in hypertensive subjects. The frequency of the DD gene and D allele of ACE were higher in patients with thickening carotid than in patients with normal carotid (70.4% vs 24.1%, and 79.5% vs 40.5%, respectively, P<0.001). In multiple stepwise regression analysis, independent risk factors for increased carotid IMT in hypertensive subjects were ACE genotypes (P<0.001), age (P<0.001) and carotid internal diameter (P=0.032). Moreover, triglycerides and total cholesterol were higher in patients with the DD genotype than in those with the II genotype (P<0.05). Conclusions The I/D polymorphism of the ACE gene was related to IMT, but not to internal diameter, distensibility and stiffness of the carotid in Chinese hypertensive subjects. ACE gene polymorphism was a main risk factor for increased carotid IMT. These results may imply that there is a link between lipid metabolism and ACE genotype polymorphism in Chinese hypertensive subjects.

  8. Mitochondrial aldehyde dehydrogenase prevents ROS-induced vascular contraction in angiotensin-II hypertensive mice.

    Science.gov (United States)

    Choi, Hyehun; Tostes, Rita C; Webb, R Clinton

    2011-01-01

    Mitochondrial aldehyde dehydrogenase (ALDH2) is an enzyme that detoxifies aldehydes to carboxylic acids. ALDH2 deficiency is known to increase oxidative stress, which is the imbalance between reactive oxygen species (ROS) generation and antioxidant defense activity. Increased ROS contribute to vascular dysfunction and structural remodeling in hypertension. We hypothesized that ALDH2 plays a protective role to reduce vascular contraction in angiotensin-II (AngII) hypertensive mice. Endothelium-denuded aortic rings from C57BL6 mice, treated with AngII (3.6 μg/kg/min, 14 days), were used to measure isometric force development. Rings treated with daidzin (10 μmol/L), an ALDH2 inhibitor, potentiated contractile responses to phenylephrine (PE) in AngII mice. Tempol (1 mmol/L) and catalase (600 U/mL) attenuated the augmented contractile effect of daidzin. In normotensive mice, contraction to PE in the presence of the daidzin was not different from control, untreated values. AngII aortic rings transfected with ALDH2 recombinant protein decreased contractile responses to PE compared with control. These data suggest that ALDH2 reduces vascular contraction in AngII hypertensive mice. Because tempol and catalase blocked the contractile response of the ALDH2 inhibitor, ROS generation by AngII may be decreased by ALDH2, thereby preventing ROS-induced contraction.

  9. Brain-targeted angiotensin-converting enzyme 2 overexpression attenuates neurogenic hypertension by inhibiting cyclooxygenase-mediated inflammation.

    Science.gov (United States)

    Sriramula, Srinivas; Xia, Huijing; Xu, Ping; Lazartigues, Eric

    2015-03-01

    Overactivity of the renin-angiotensin system, oxidative stress, and cyclooxygenases (COX) in the brain are implicated in the pathogenesis of hypertension. We previously reported that angiotensin-converting enzyme 2 (ACE2) overexpression in the brain attenuates the development of deoxycorticosterone acetate-salt hypertension, a neurogenic hypertension model with enhanced brain renin-angiotensin system and sympathetic activity. To elucidate the mechanisms involved, we investigated whether oxidative stress, mitogen-activated protein kinase signaling and cyclooxygenase (COX) activation in the brain are modulated by ACE2 in neurogenic hypertension. Deoxycorticosterone acetate-salt hypertension significantly increased expression of Nox-2 (+61±5%), Nox-4 (+50±13%), and nitrotyrosine (+89±32%) and reduced activity of the antioxidant enzymes, catalase (-29±4%) and superoxide dismutase (-31±7%), indicating increased oxidative stress in the brain of nontransgenic mice. This increased oxidative stress was attenuated in transgenic mice overexpressing ACE2 in the brain. Deoxycorticosterone acetate-salt-induced reduction of neuronal nitric oxide synthase expression (-26±7%) and phosphorylated endothelial nitric oxide synthase/total endothelial nitric oxide synthase (-30±3%), and enhanced phosphorylation of protein kinase B and extracellular signal-regulated kinase 1/2 in the paraventricular nucleus, were reversed by ACE2 overexpression. In addition, ACE2 overexpression blunted the hypertension-mediated increase in gene and protein expression of COX-1 and COX-2 in the paraventricular nucleus. Furthermore, gene silencing of either COX-1 or COX-2 in the brain, reduced microglial activation and accompanied neuroinflammation, ultimately attenuating Deoxycorticosterone acetate-salt hypertension. Together, these data provide evidence that brain ACE2 overexpression reduces oxidative stress and COX-mediated neuroinflammation, improves antioxidant and nitric oxide signaling, and

  10. Cost effectiveness of angiotensin receptor blocker monotherapy in patients with hypertension in the Netherlands : a comparative analysis using clinical trial and drug utilization data

    NARCIS (Netherlands)

    Boersma, C.; Voors, A.A.; Visser, Sipke; de Jong-van den Berg, L.T.W.; Postma, M.J.

    2010-01-01

    Background and Objective: Health gains and related cost savings achieved by optimizing treatment in hypertensive patients is highly important. The aim of this study was to evaluate the costs and cost effectiveness of treatment with angiotensin II receptor antagonists (angiotensin II receptor blocker

  11. Insertion/deletion polymorphism of the angiotensin-converting enzyme gene and the risk of hypertension among residents of two cities, South-South Nigeria

    Directory of Open Access Journals (Sweden)

    Mary Esien Kooffreh

    2014-01-01

    Conclusion: The I/D polymorphism of the angiotensin-converting enzyme gene was a risk factor for hypertension in the sample population of Calabar and Uyo. This research will form baseline information for subsequent molecular studies in this population.

  12. Patients With Newly Diagnosed Hypertension Treated With the Renin Angiotensin Receptor Blocker Azilsartan Medoxomil vs Angiotensin-Converting Enzyme Inhibitors: The Prospective EARLY Registry.

    Science.gov (United States)

    Schmieder, Roland E; Potthoff, Sebastian A; Bramlage, Peter; Baumgart, Peter; Mahfoud, Felix; Buhck, Hartmut; Ouarrak, Taoufik; Ehmen, Martina; Senges, Jochen; Gitt, Anselm K

    2015-12-01

    For patients with newly diagnosed hypertension, angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are usually the first-line therapies. There is, however, no real-life data regarding the relative clinical effectiveness and tolerability of either drug class. The prospective registry, Treatment With Azilsartan Compared to ACE Inhibitors in Antihypertensive Therapy (EARLY), was conducted to evaluate the effectiveness of the ARB azilsartan medoxomil (AZL-M) vs ACE inhibitors in real-world patients. Of the 1153 patients with newly diagnosed hypertension who were included in the registry, 789 were prescribed AZL-M and 364 were prescribed an ACE inhibitor. After multivariate adjustment, AZL-M was found to provide superior blood pressure reduction and better target blood pressure (<140/90 mm Hg) achievement. The proportion of patients with adverse events was not statistically different between groups. The authors conclude that in newly diagnosed hypertensive patients, AZL-M provides superior blood pressure control with a similar safety profile compared with ACE inhibitors.

  13. THE GENDER FEATURES OF THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM IN HYPERTENSIVE PATIENTS

    Directory of Open Access Journals (Sweden)

    V. I. Podzolkov

    2010-01-01

    Full Text Available Aim. To study the correlation of the renin-angiotensin-aldosterone system (RAAS activity with the female sex hormone levels and markers of target organ damage in patients with arterial hypertension (HT.Material and methods. Patients with HT (20 men and 39 postmenopausal women were involved into the study. The dynamic renal angioscintigraphy and echocardiography were performed, plasma rennin activity (PRA, levels of aldosterone, estradiole and 17-hydroxiprogesterone were determined by radioimmunoassay.Results. Higher aldosterone level was found in women in comparison with men (212,5±123,9 pg/ml and 148,9±82,5 pg/m, respectively, р=0,03. Negative relations between aldosterone and estradiol levels (r=-0,3; p=0,04, and between aldosterone and 17-hydroxyprogesterone levels (r=-0,318; p=0,04, and positive relations between aldosterone concentration and PRA (r=0,555; p=0,04 was found in women. Besides, correlation between levels of female sex hormones, aldosterone and renal blood flow indicators, glomerular filtration rate, left ventricular mass index (LVMI were found in women. These correlations were not found in men.Conclusion. The gender differences of RAAS activity were revealed with higher aldosterone level in postmenopausal hypertensive women in comparison with men. Relationships between PRA, levels of aldosterone and female sex hormones and renal blood flow indices, LVMI were also found in women.

  14. Vascular hyporeactivity to angiotensin II induced by Escherichia coli endotoxin is reversed by Nω-Nitro-L-Arginine, an inhibitor of nitric oxide synthase

    Directory of Open Access Journals (Sweden)

    L. A. RODRIGUES

    2009-01-01

    Full Text Available

    Septic shock or sepsis is reported to be one of the major causes of death when followed by systemic infectious trauma in humans and other mammals. Its development leads to a large drop in blood pressure and a reduction in vascular responsiveness to physiological vasoconstrictors which, if not contained, can lead to death. It is proposed that this vascular response is due to the action of bacterial cell wall products released into the bloodstream by the vascular endothelium and is considered a normal response of the body`s defenses against infection. A reduction in vascular reactivity to epinephrine and norepinephrine is observed under these conditions. In the present study in rats, the aim was to assess whether those effects of hypotension and hyporeactivity are also related to another endogenous vasoconstrictor, angiotensin II (AII. We evaluated the variation in the power of this vasoconstrictor over the mean arterial pressure in anesthetized rats, before and after the establishment of hypotension by Escherichia coli endotoxin (Etx. Our results show that in this model of septic shock, there is a reduction in vascular reactivity to AII and this reduction can be reversed by the inhibitor of nitric oxide synthase, Nω-Nitro-L-Arginine (NωNLA. Our results also suggest that other endogenous factors (not yet fully known are involved in the protection of rats against septic shock, in addition to the L-arginine NO pathway. Keywords: vascular hyporeactivity; NO; rat; angiotensin II; NωNLA Escherichia coli endotoxin.

  15. Dysregulated renin-angiotensin-aldosterone system contributes to pulmonary arterial hypertension

    Science.gov (United States)

    De Man, Frances; Tu, Ly; Handoko, Louis; Rain, Silvia; Ruiter, Gerrina; François, Charlène; Schalij, Ingrid; Dorfmüller, Peter; Simonneau, Gérald; Fadel, Elie; Perros, Frederic; Boonstra, Anco; Postmus, Piet; Van Der Velden, Jolanda; Vonk-Noordegraaf, Anton; Humbert, Marc; Eddahibi, Saadia; Guignabert, Christophe

    2012-01-01

    Rationale Patients with idiopathic pulmonary arterial hypertension (iPAH) often have a low cardiac output. To compensate, neurohormonal systems like renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system are upregulated but this may have long-term negative effects on the progression of iPAH. Objectives Assess systemic and pulmonary RAAS-activity in iPAH-patients and determine the efficacy of chronic RAAS-inhibition in experimental PAH. Measurements and Main Results We collected 79 blood samples from 58 iPAH-patients in the VU University Medical Center Amsterdam (between 2004–2010), to determine systemic RAAS-activity. We observed increased levels of renin, angiotensin (Ang) I and AngII, which was associated with disease progression (p<0.05) and mortality (p<0.05). To determine pulmonary RAAS-activity, lung specimens were obtained from iPAH-patients (during lung transplantation, n=13) and controls (during lobectomy or pneumonectomy for cancer, n=14). Local RAAS-activity in pulmonary arteries of iPAH-patients was increased, demonstrated by elevated ACE-activity in pulmonary endothelial cells and increased AngII type 1 (AT1) receptor expression and signaling. In addition, local RAAS- upregulation was associated with increased pulmonary artery smooth muscle cell proliferation via enhanced AT1-receptor signaling in iPAH-patients compared to controls. Finally, to determine the therapeutic potential of RAAS-activity, we assessed the chronic effects of an AT1-receptor antagonist (losartan) in the monocrotaline PAH-rat model (60 mg/kg). Losartan delayed disease progression, decreased RV afterload and pulmonary vascular remodeling and restored right ventricular-arterial coupling in PAH-rats. Conclusions Systemic and pulmonary RAAS-activities are increased in iPAH-patients and associated with increased pulmonary vascular remodeling. Chronic inhibition of RAAS by losartan is beneficial in experimental PAH. PMID:22859525

  16. Circulating angiotensin II gains access to the hypothalamus and brain stem during hypertension via breakdown of the blood-brain barrier.

    Science.gov (United States)

    Biancardi, Vinicia Campana; Son, Sook Jin; Ahmadi, Sahra; Filosa, Jessica A; Stern, Javier E

    2014-03-01

    Angiotensin II-mediated vascular brain inflammation emerged as a novel pathophysiological mechanism in neurogenic hypertension. However, the precise underlying mechanisms and functional consequences in relation to blood-brain barrier (BBB) integrity and central angiotensin II actions mediating neurohumoral activation in hypertension are poorly understood. Here, we aimed to determine whether BBB permeability within critical hypothalamic and brain stem regions involved in neurohumoral regulation was altered during hypertension. Using digital imaging quantification after intravascularly injected fluorescent dyes and immunohistochemistry, we found increased BBB permeability, along with altered key BBB protein constituents, in spontaneously hypertensive rats within the hypothalamic paraventricular nucleus, the nucleus of the solitary tract, and the rostral ventrolateral medulla, all critical brain regions known to contribute to neurohumoral activation during hypertension. BBB disruption, including increased permeability and downregulation of constituent proteins, was prevented in spontaneously hypertensive rats treated with the AT1 receptor antagonist losartan, but not with hydralazine, a direct vasodilator. Importantly, we found circulating angiotensin II to extravasate into these brain regions, colocalizing with neurons and microglial cells. Taken together, our studies reveal a novel angiotensin II-mediated feed-forward mechanism during hypertension, by which circulating angiotensin II evokes increased BBB permeability, facilitating in turn its access to critical brain regions known to participate in blood pressure regulation.

  17. Salvianolic Acid A Attenuates Cell Apoptosis, Oxidative Stress, Akt and NF-κB Activation in Angiotensin-II Induced Murine Peritoneal Macrophages.

    Science.gov (United States)

    Li, Ling; Xu, Tongda; Du, Yinping; Pan, Defeng; Wu, Wanling; Zhu, Hong; Zhang, Yanbin; Li, Dongye

    2016-01-01

    We discuss the role of Salvianolic acid A(SAA), one of the main effective components in Salvia Miltiorrhiza (known as 'Danshen' in traditional Chinese medicine), in apoptotic factors, the production of oxidative products, and the expression of Akt and NF-κB in angiotensin II (Ang II)-mediated murine macrophages. In the present study, Ang II was added to mice abdominal macrophages with or without addition of SAA. After cell identification, apoptosis was measured by DNA strand break level with TdT-mediated dUTP nick-end labeling (TUNEL) staining, and the expression of Bcl-2 and Bax. Intracellular concentrations of superoxide dismutase (SOD) and malondialdehyde (MDA) were also measured. Western blotting determined the expression of Akt, p-Akt, NF-κB and p-NF-κB. Ly294002 (the inhibitor of PI3K) was used to determine the mechanism of SAA. Ang II (1 µM) significantly increased the number of TUNEL-positive cells and Bax expression, but reduced Bcl-2 expression. These effects were antagonized when the cells were pretreated with SAA. SAA decreased MDA, but increased SOD in the cell lysis solution treated with Ang II. It markedly reduced the level of p-NF-κB, as also p-Akt, which was partly blocked by Ly294002. SAA prevents Ang IIinduced apoptosis, oxidative stress and related protein expression in the macrophages. It also inhibits the activation of Akt.

  18. Target Organ Protection from a Novel Angiotensin Ⅱ Receptor (AT1) Vaccine ATR12181 in Spontaneously Hypertensive Rats

    Institute of Scientific and Technical Information of China (English)

    Feng Zhu; Yuhua Liao; Liudong Li; Min Cheng; Fen Wei; Yumiao Wei; Ming Wang

    2006-01-01

    Hypertension produces pathophysiological changes that are often responsible for the mortality associated with the disease. It is evident that overactive renin-angiotensin systems play a central role in the development of hypertension and target organ damage associated with hypertension. We have previously found that a novel angiotensin Ⅱ receptor (AT1) vaccine-ATR12181 attenuated the development of high blood pressure (BP) in spontaneously hypertensive rat (SHR) model of human essential hypertension. Our objective was to determine whether this attenuation of high BP is associated with prevention of target organ damage induced by hypertensive state. SHRs were immunized against a peptide (coded ATR12181) from the extracelluar portion of the AT1A receptor by repeated subcutaneous injections of peptide-tetanus-toxoid complex in combination with Freund's adjuvant. A 64 weeks long-term observation was performed. Repeated vaccinations resulted in the induction of anti-ATR12181 antibodies. At the end of observation, vaccinated SHRs manifested lower BP, decreased cardiac hypertrophy and attenuation of kidney injuries. mRNA levels of c-fos and c-jun in heart and kidneys were decreased in vaccinated SHRs. Since a self antigen was used, safety of vaccine was concerned. However, the signs of autoimmune diseases were not observed in the sections of heart and kidney. These data demonstrated that repeated immunization against a domain of the extracellular portion of the AT1 receptor was able to cause a target organ protection against hypertension. Active immunization against the AT1 receptor may be considered as a promising new strategy in the treatment of hypertension.

  19. The changes of serum nitric oxide, angiotensin Ⅱ and superoxide anion in renal artery hypertension rat

    Institute of Scientific and Technical Information of China (English)

    马向红; 杨万松; 黄体钢; 周丽娟; 倪燕平; 樊振旺

    2003-01-01

    Objectives To study the changes of nitric oxide, angiotensin Ⅱ and superoxide anion in renal artery hypertension pathogenesis. Methods Male Wistar rats weighing 256 -285g were divided into 5 groups randomly, 10 rats of each group. Control group:false operation was made and routine diet was given; Ligature group: left renal artery was ligatured uncompletely and routine diet was given; Ligature + Losartan group:left renal artery was ligatured uncompletely and Losartan ture + L -Arg group: left renal artery was ligatured undrinking water; Ligature + L - Arg + Losartan group: left the drinking water. Blood pressure and heart rate were measured before and at the end of the experiment. One week after ligature, blood was drawn to determine angiotensin Ⅱ, cGMP, nitric oxide, nitric oxide synthase (NOS), O2-, superoxide dismutase (SOD). Results Systolic blood pressure was higher in ligature group than that in control group (p<0.05), systolic blood pressure was much lower in ligature + Losartan group than that in ligature group. Heart rate did not change significantly after experiment (p > 0. 05 ). AngⅡ was higher in ligature group than that in control group, even much higher in ligature + Losartan group (p < 0. 01 ). There was no difference of cGMP in each group (p > 0. 05 ). The concentration of NO was lower in ligature group (p < 0. 05 ), NO was higher in ligature + L - Arg + Losartan group than that in ligature group (p < 0. 05). O2' was higher in ligature group and ligature + L - Arg group than that in control group (p < 0. 05), O2- was lower in ligature + Losartan group than that in ligature group (p <0. 05). The level of SOD was lower in ligature group than that in control group (p < 0.05), higher in ligature + L - Arg group and ligature + L - Arg + Losartan group than that in ligature group (p <0.05). Conclusions AnglⅡ,O2- and NO imbalance play an important role in hypertension pathogenesis, L-Arg and losartan may have protective effect.

  20. Palmitoylethanolamide treatment reduces blood pressure in spontaneously hypertensive rats: involvement of cytochrome p450-derived eicosanoids and renin angiotensin system.

    Science.gov (United States)

    Mattace Raso, Giuseppina; Pirozzi, Claudio; d'Emmanuele di Villa Bianca, Roberta; Simeoli, Raffaele; Santoro, Anna; Lama, Adriano; Di Guida, Francesca; Russo, Roberto; De Caro, Carmen; Sorrentino, Raffaella; Calignano, Antonio; Meli, Rosaria

    2015-01-01

    Palmitoylethanolamide (PEA), a peroxisome proliferator-activated receptor-α agonist, has been demonstrated to reduce blood pressure and kidney damage secondary to hypertension in spontaneously hypertensive rat (SHR). Currently, no information is available concerning the putative effect of PEA on modulating vascular tone. Here, we investigate the mechanisms underpinning PEA blood pressure lowering effect, exploring the contribution of epoxyeicosatrienoic acids, CYP-dependent arachidonic acid metabolites, as endothelium-derived hyperpolarizing factors (EDHF), and renin angiotensin system (RAS) modulation. To achieve this aim SHR and Wistar-Kyoto rats were treated with PEA (30 mg/kg/day) for five weeks. Functional evaluations on mesenteric bed were performed to analyze EDHF-mediated vasodilation. Moreover, mesenteric bed and carotid were harvested to measure CYP2C23 and CYP2J2, the key isoenzymes in the formation of epoxyeicosatrienoic acids, and the soluble epoxide hydrolase, which is responsible for their degradation in the corresponding diols. Effect of PEA on RAS modulation was investigated by analyzing angiotensin converting enzyme and angiotensin receptor 1 expression. Here, we showed that EDHF-mediated dilation in response to acetylcholine was increased in mesenteric beds of PEA-treated SHR. Western blot analysis revealed that the increase in CYP2C23 and CYP2J2 observed in SHR was significantly attenuated in mesenteric beds of PEA-treated SHR, but unchanged in the carotids. Interestingly, in both vascular tissues, PEA significantly decreased the soluble epoxide hydrolase protein level, accompanied by a reduced serum concentration of its metabolite 14-15 dihydroxyeicosatrienoic acid, implying a reduction in epoxyeicosatrienoic acid hydrolisis. Moreover, PEA treatment down-regulated angiotensin receptor 1 and angiotensin converting enzyme expression, indicating a reduction in angiotensin II-mediated effects. Consistently, a damping of the activation of

  1. Palmitoylethanolamide treatment reduces blood pressure in spontaneously hypertensive rats: involvement of cytochrome p450-derived eicosanoids and renin angiotensin system.

    Directory of Open Access Journals (Sweden)

    Giuseppina Mattace Raso

    Full Text Available Palmitoylethanolamide (PEA, a peroxisome proliferator-activated receptor-α agonist, has been demonstrated to reduce blood pressure and kidney damage secondary to hypertension in spontaneously hypertensive rat (SHR. Currently, no information is available concerning the putative effect of PEA on modulating vascular tone. Here, we investigate the mechanisms underpinning PEA blood pressure lowering effect, exploring the contribution of epoxyeicosatrienoic acids, CYP-dependent arachidonic acid metabolites, as endothelium-derived hyperpolarizing factors (EDHF, and renin angiotensin system (RAS modulation. To achieve this aim SHR and Wistar-Kyoto rats were treated with PEA (30 mg/kg/day for five weeks. Functional evaluations on mesenteric bed were performed to analyze EDHF-mediated vasodilation. Moreover, mesenteric bed and carotid were harvested to measure CYP2C23 and CYP2J2, the key isoenzymes in the formation of epoxyeicosatrienoic acids, and the soluble epoxide hydrolase, which is responsible for their degradation in the corresponding diols. Effect of PEA on RAS modulation was investigated by analyzing angiotensin converting enzyme and angiotensin receptor 1 expression. Here, we showed that EDHF-mediated dilation in response to acetylcholine was increased in mesenteric beds of PEA-treated SHR. Western blot analysis revealed that the increase in CYP2C23 and CYP2J2 observed in SHR was significantly attenuated in mesenteric beds of PEA-treated SHR, but unchanged in the carotids. Interestingly, in both vascular tissues, PEA significantly decreased the soluble epoxide hydrolase protein level, accompanied by a reduced serum concentration of its metabolite 14-15 dihydroxyeicosatrienoic acid, implying a reduction in epoxyeicosatrienoic acid hydrolisis. Moreover, PEA treatment down-regulated angiotensin receptor 1 and angiotensin converting enzyme expression, indicating a reduction in angiotensin II-mediated effects. Consistently, a damping of the

  2. Toll-like receptor 4 upregulation by angiotensin II contributes to hypertension and vascular dysfunction through reactive oxygen species production.

    Directory of Open Access Journals (Sweden)

    Priscila R De Batista

    Full Text Available Hypertension is considered as a low-grade inflammatory disease, with adaptive immunity being an important mediator of this pathology. TLR4 may have a role in the development of several cardiovascular diseases; however, little is known about its participation in hypertension. We aimed to investigate whether TLR4 activation due to increased activity of the renin-angiotensin system (RAS contributes to hypertension and its associated endothelial dysfunction. For this, we used aortic segments from Wistar rats treated with a non-specific IgG (1 µg/day and SHRs treated with losartan (15 mg/kg·day, the non-specific IgG or the neutralizing antibody anti-TLR4 (1 µg/day, as well as cultured vascular smooth muscle cells (VSMC from Wistar and SHRs. TLR4 mRNA levels were greater in the VSMC and aortas from SHRs compared with Wistar rats; losartan treatment reduced those levels in the SHRs. Treatment of the SHRs with the anti-TLR4 antibody: 1 reduced the increased blood pressure, heart rate and phenylephrine-induced contraction while it improved the impaired acetylcholine-induced relaxation; 2 increased the potentiation of phenylephrine contraction after endothelium removal; and 3 abolished the inhibitory effects of tiron, apocynin and catalase on the phenylephrine-induced response as well as its enhancing effect of acetylcholine-induced relaxation. In SHR VSMCs, angiotensin II increased TLR4 mRNA levels, and losartan reduced that increase. CLI-095, a TLR4 inhibitor, mitigated the increases in NAD(PH oxidase activity, superoxide anion production, migration and proliferation that were induced by angiotensin II. In conclusion, TLR4 pathway activation due to increased RAS activity is involved in hypertension, and by inducing oxidative stress, this pathway contributes to the endothelial dysfunction associated with this pathology. These results suggest that TLR4 and innate immunity may play a role in hypertension and its associated end-organ damage.

  3. Effects of Antihypertensive Agents on Intestinal Contractility in the Spontaneously Hypertensive Rat: Angiotensin Receptor System Downregulation by Losartan

    Science.gov (United States)

    Abeywardena, Mahinda Yapa

    2017-01-01

    Hypertension is an inflammatory condition controlled by the renin angiotensin system and is linked to kidney disease, diabetes mellitus, and recently to dysfunction of the gut. The aim of this study was to determine what effect antihypertensive drug treatments may have on intestinal function of the spontaneously hypertensive rat (SHR). In the first experiment, SHRs were treated with enalapril, hydralazine, or with no treatment as a control. In the second experiment, SHRs were treated with losartan or with no treatment as a control. All drug treatments led to significant lowering of blood pressure after 16 weeks. At termination, intact tissue sections of the ileum and colon were induced to contract ex vivo by KCl; electrical stimulation; and agonists carbachol, angiotensin II, and prostaglandin E2 (PGE2). There were no differences in ileal or colonic contractility due to hydralazine or enalapril compared with no-treatment SHR control. However, for the ileum, the losartan group responded significantly more to KCl and carbachol while responding less to angiotensin II, with no difference for PGE2 compared with the no-treatment SHR control. In contrast, the colon responded similarly to KCl, electrical stimulation, and PGE2 but responded significantly less to angiotensin II. These results demonstrate that the ileum responds differently (with KCl and carbachol as agonists) to the colon after losartan treatment, whereas there is a reduced contractile response in both the ileum and colon following losartan treatment. Although there are few well documented major contraindications for angiotensin receptor blockers, the modulation of gut contractility by losartan may have wider implications for bowel health. PMID:27903643

  4. Angiotensin-receptor blockers as therapy for mildto- moderate hypertension-associated non-alcoholic steatohepatitis

    Institute of Scientific and Technical Information of China (English)

    Eugen Florin Georgescu; Reanina Ionescu; Mihaela Niculescu; Laurentiu Mogoanta; Liliana Vancica

    2009-01-01

    AIM: To evaluate insulin resistance, cytolysis and nonalcoholic steatohepatitis (NASH) score (NAS) using the Kleiner and Brunt criteria in 54 patients with NASH and mild-to-moderate hypertension, treated with telmisartan vs valsartan for 20 mo. METHODS: All patients met the NCEP-ATP Ⅲ criteria for metabolic syndrome. Histology confirmed steatohepatitis, defined as a NAS greater than five up to 3 wk prior inclusion, using the current criteria. Patients with viral hepatitis, chronic alcohol intake, drug abuse or other significant immune or metabolic hepatic pathology were excluded. Subjects were randomly as -signed either to the valsartan (V) group (standard dose 80 mg o.d., n = 26), or to the telmisartan (T) group (standard dose 20 mg o.d., n = 28). Treatment had to be taken daily at the same hour with no concomitant medication or alcohol consumption allowed. Neither the patient nor the medical staff was aware of treatment group allocation. Paired liver biopsies obtained at inclusion (visit 1) and end of treatment (EOT) were assessed by a single blinded pathologist, not aware of patient or treatment group. Blood pressure, BMI, ALT, AST, HOMA-IR, plasma triglycerides (TG) and total cholesterol (TC) were evaluated at inclusion and every 4 mo until EOT (visit 6). RESULTS: At EOT we noticed a significant decrease in ALT levels vs inclusion in all patients and this decrease did not differ significantly in group T vs group V. HOMA-IR significantly decreased at EOT vs inclusion in all patients but in group T, the mean HOMA-IR decrease per month was higher than in group V. NAS significantly diminished at EOT in all patients with a higher decrease in group T vs group V. CONCLUSION: Angiotensin receptor blockers seem to be efficient in hypertension-associated NASH. Telmisartan showed a higher efficacy regarding insulin resistance and histology, perhaps because of its specific PPAR-gamma ligand effect.

  5. Central endogenous angiotensin-(1-7) protects against aldosterone/NaCl-induced hypertension in female rats.

    Science.gov (United States)

    Xue, Baojian; Zhang, Zhongming; Johnson, Ralph F; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2013-09-01

    In comparison to male rodents, females are protected against angiotensin (ANG) II- and aldosterone (Aldo)-induced hypertension. However, the mechanisms underlying this protective effect are not well understood. ANG-(1-7) is formed from ANG II by angiotensin-converting enzyme 2 (ACE2) and has an antihypertensive effect in the central nervous system (CNS). The present study tested the hypothesis that central ANG-(1-7) plays an important protective role in attenuating the development of Aldo/NaCl-hypertension in female rats. Systemic infusion of Aldo into intact female rats with 1% NaCl as their sole drinking fluid resulted in a slight increase in blood pressure (BP). Intracerebroventricular (icv) infusion of A-779, an ANG-(1-7) receptor (Mas-R) antagonist, significantly augmented the pressor effects of Aldo/NaCl. In contrast, systemic Aldo/NaCl induced a significant increase in BP in ovariectomized (OVX) female rats, and central infusion of ANG-(1-7) significantly attenuated this Aldo/NaCl pressor effect. The inhibitory effect of ANG-(1-7) on the Aldo/NaCl pressor effect was abolished by concurrent infusion of A-779. RT-PCR analyses showed that there was a corresponding change in mRNA expression of several renin-angiotensin system components, estrogen receptors and an NADPH oxidase subunit in the lamina terminalis. Taken together these results suggest that female sex hormones regulate an antihypertensive axis of the brain renin-angiotensin system involving ACE2/ANG-(1-7)/Mas-R that plays an important counterregulatory role in protecting against the development of Aldo/NaCl-induced hypertension.

  6. Inhibitory effect of antisense oligodeoxynucleotide to p44/p42 MAPK on angiotensin II-induced hypertrophic response in cultured neonatal rat cardiac myocyte

    Institute of Scientific and Technical Information of China (English)

    Shi-qinZHANG; BoDING; Zhao-guiGUO; Yun-xiaLI

    2004-01-01

    AIM: To explore the inhibitory effect of antisense oligonucleotide (ODN) to mitogen activated protein kinase(MAPK) on cardiomyocyte hypertrophy induced by angiotensin Ⅱ (Ang Ⅱ). METHODS: A 17-mer phosphorothioate-protected antisense ODN directed against the initiation of translation sites of the p42 and p44 MAPK isoforms byliposomal transfection was applied to inhibit the translation of p44/p42 MAPK mRNA. The sense and random ODNs to p44/p42MAPK were used as sequence controls. Neonatal cardiac myocytes were exposed to Ang Ⅱ (10nmol/L) for 5 min and then harvested in lysis buffer for the measurement of the activity and the phosphorylated protein content of p44/p42MAPK that were tested by P-81 phosphocellulose filter paper method and Western blotting, respectively. The rate of protein synthesis by [3H]leucine incorporation and the diameter of cell were measured after exposure to Ang Ⅱ for 24 h and 72 h, respectively. RESULTS: In cardiac myocyte Ang Ⅱ increased p44/p42MAPK activity and phosphorylated protein content by 140 % and 699 %, and also increased [3H]leucine incorporation and cell diameter by 40 % and 27 %. c-fos and c-myc mRNAs were induced significantly after exposure to Ang Ⅱ. Antisense ODN to p44/p42MAPK (0.2 μmol/L) reduced Ang Ⅱ-induced MAPK activity by 30 %,and phophorylated MAPK protein expression by 59 % in cardiac myocyte, and inhibited c-fos and c-myc mRNA expression induced by Ang Ⅱ by 44 % and 43 %, respectively. The diameter and the rate of protein synthesis of cardiac myocyte induced by Ang Ⅱ were decreased by 16 % and 22 % after pretreatment with antisense ODN to p44/p42MAPK. CONCLUSION: Antisense ODN to p44/p42 MAPK inhibited the increase of rate of protein synthesis,and the augmentation of cell diameter and expression of c-fos and c-myc mRNA induced by Ang Ⅱ in culturedcardiac myocytes, p44/p42 MAPK played a critical role in the hypertrophic response induced by Ang Ⅱ in cultured neonatal rat cardiac myocytes.

  7. Angiotensin II induces apoptosis of human pulmonary microvascular endothelial cells in acute aortic dissection complicated with lung injury patients through modulating the expression of monocyte chemoattractant protein-1.

    Science.gov (United States)

    Wu, Zhiyong; Dai, Feifeng; Ren, Wei; Liu, Huagang; Li, Bowen; Chang, Jinxing

    2016-01-01

    Patients with acute aortic dissection (AAD) usually showed acute lung injury (ALI). However, its pathogenesis is still not well defined. Apoptosis of pulmonary microvascular endothelial cells (PMVECs) is closely related to the alveolus-capillary barrier injury and the increased vascular permeability. In this study, we aim to investigate the human PMVECs (hPMVECs) apoptosis induced by angiotensin II (AngII) and monocyte chemoattractant protein-1 (MCP-1) and their potential interaction in the pathogenesis of AAD complicated with ALI. Fifty-eight newly diagnosed AAD, 12 matched healthy individuals were included. Pulmonary tissues of AAD complicated with lung injury were obtained from 2 cadavers to determine the levels of AngII type 1 receptor (AT1-R) and MCP-1. Serum AngII was measured using commercial ELISA kit. H&E staining and immunohistostaining were performed to determine the expression of AT1-R and MCP-1. For the in vitro experiment, hPMVECs were divided into control, AngII group, AngII+Bindarit group and Bindarit group, respectively. Flow cytometry was performed to analyze the apoptosis in each group. Reverse transcription-polymerase chain reaction was performed to determine the mRNA expression of MCP-1. Western blot analysis was performed to evaluate the expression of MCP-1 and apoptosis related protein. Apoptosis of hPMVECs was observed in the lung tissues in the cadavers with AAD complicated with ALI. Besides, the expression of AT1-R and MCP-1 was remarkably elevated. Compared with normal individuals and the non-lung injury AAD patients, the expression of serum AngII was remarkably elevated in AAD patients complicated with ALI. In vitro experiments showed AngII contributed to the apoptosis and elevation of MCP1 in hPMVECs. Besides, it involved in the down-regulation of Bcl-2 protein, and up-regulation of Bax and Caspase-3. Such phenomenon was completely reversed after administration of MCP-1 inhibitor (Bindarit). The production of MCP-1 and cellular

  8. Angiotensin II type 1 receptor antagonists in the treatment of hypertension in elderly patients: focus on patient outcomes

    Directory of Open Access Journals (Sweden)

    Artavazd Tadevosyan

    2011-01-01

    Full Text Available Artavazd Tadevosyan1, Eric J MacLaughlin2, Vardan T Karamyan31Departments of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, QC, Canada; 2Department of Pharmacy Practice, 3Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, USAAbstract: Hypertension in the elderly is one of the main risk factors of cardiovascular and cerebrovascular diseases. Knowledge regarding the mechanisms of hypertension and specific considerations in managing hypertensive elderly through pharmacological intervention(s is fundamental to improving clinical outcomes. Recent clinical studies in the elderly have provided evidence that angiotensin II type 1 (AT1 receptor antagonists can improve clinical outcomes to a similar or, in certain populations, an even greater extent than other classical arterial blood pressure-lowering agents. This newer class of antihypertensive agents presents several benefits, including potential for improved adherence, excellent tolerability profile with minimal first-dose hypotension, and a low incidence of adverse effects. Thus, AT1 receptor antagonists represent an appropriate option for many elderly patients with hypertension, type 2 diabetes, heart failure, and/or left ventricular dysfunction.Keywords: angiotensin II, ARB, cardiovascular disease, antihypertensive therapy, elderly

  9. Effect of exercise on plasma concentrations of arginine vasopressin, angiotensin II and aldosterone in hypertensive and normotensive renal transplant recipients.

    Science.gov (United States)

    Pedersen, E B; Danielsen, H; Nielsen, A H; Knudsen, F; Jensen, T; Kornerup, H J; Madsen, M

    1986-04-01

    Plasma concentrations of angiotensin II (A II), aldosterone (Aldo) and arginine vasopressin (AVP), and serum osmolality (Sosm) were determined before and after gradually increasing exercise loads on a bicycle ergometer in 10 hypertensive (group I) and 10 normotensive renal transplant recipients (group II), and in 15 healthy control subjects (group III). Working capacity was reduced in groups I and II. The A II, Aldo, AVP, Sosm increased in all groups after exercise. The A II was higher in group I than II and the percentage changes were significantly lower in groups I and II than in group III. There were no significant differences in Aldo between the groups either before or after exercise. The AVP was the same in groups I and II, and AVP in these groups was higher than in group III. The Sosm and AVP were significantly correlated in all groups. Neither A II, Aldo nor AVP were significantly correlated to systolic blood pressure (BP). Alterations in AVP, but not in A II or Aldo, were correlated to the degree of exercise load. It can be concluded that the renin-angiotensin-aldosterone system and the osmoregulatory system are stimulated during exercise in renal transplant recipients. The A II is elevated in post-renal transplant hypertension, but the responsiveness is reduced in both hypertensive and normotensive recipients. The alterations in AVP are probably secondary to changes in Sosm, and the higher AVP levels in recipients could be due to a decreased responsiveness of the renal tubules to AVP. Our findings are in good agreement with the hypothesis that hypertension after renal transplantation is angiotensin II-dependent.

  10. Histone acetylation is essential for ANG-II-induced IGF-IIR gene expression in H9c2 cardiomyoblast cells and pathologically hypertensive rat heart.

    Science.gov (United States)

    Chu, Chun-Hsien; Lo, Jeng-Fan; Hu, Wei-Syun; Lu, Ru-Band; Chang, Mu-Hsin; Tsai, Fuu-Jen; Tsai, Chang-Hai; Weng, Yueh-Shan; Tzang, Bor-Show; Huang, Chih-Yang

    2012-01-01

    The IGF-II/mannose 6-phosphate receptor (IGF-IIR/Man-6-P) up-regulation correlates with heart disease progression and its signaling cascades directly trigger pathological cardiac hypertrophy, fibrosis, and cardiomyocytes apoptosis. IGF-IIR gene expression/ suppression is able to prevent myocardial remodeling. However, the regulating mechanisms for the IGF-IIR gene remain unclear. This study performed reverse transcriptase PCR (RT-PCR) and methylation-specific PCR (MS-PCR) to detect expression and DNA methylation of CpG islands within the IGF-IIR genomic DNA region. Our finding revealed that the IGF-IIR gene was up-regulated both in H9c2 cells treated with tumor necrosis factor-alpha (TNF-α), lipopolysaccharide (LPS), angiotensin II (ANGII) and inomycin, and age-dependently in spontaneously hypertensive rat (SHR) heart. For the DNA methylation study, although there were four CpG islands within IGF-IIR genomic regions, the DNA methylation distribution showed no change either in cells treated with ANGII or in the SHR heart. Using chemical inhibitors to individually block histone acetyltransferase (HAT) and histone deacetylase (HDAC) activity, we found that histone acetylation was essential for ANGII-induced IGF-IIR gene expression using RT-PCR and luciferase assay. The Chromatin immuno-precipitation assay indicated that acetyl-Histone H3 and acetyl-Histone H4 associated with the IGF-IIR promoter increased in the presence of ANGII, otherwise methyl-CpG binding domain protein 2 (MeCP2) is disassociated with this. Taken together, this study demonstrates that histone acetylation plays a critical role in IGF-IIR up-regulation during pathological cardiac diseases and might provide a targeting gene in transcriptional therapies for the failing heart.

  11. Oligoclonal CD8+ T cells play a critical role in the development of hypertension.

    Science.gov (United States)

    Trott, Daniel W; Thabet, Salim R; Kirabo, Annet; Saleh, Mohamed A; Itani, Hana; Norlander, Allison E; Wu, Jing; Goldstein, Anna; Arendshorst, William J; Madhur, Meena S; Chen, Wei; Li, Chung-I; Shyr, Yu; Harrison, David G

    2014-11-01

    Recent studies have emphasized a role of adaptive immunity, and particularly T cells, in the genesis of hypertension. We sought to determine the T-cell subtypes that contribute to hypertension and renal inflammation in angiotensin II-induced hypertension. Using T-cell receptor spectratyping to examine T-cell receptor usage, we demonstrated that CD8(+) cells, but not CD4(+) cells, in the kidney exhibited altered T-cell receptor transcript lengths in Vβ3, 8.1, and 17 families in response to angiotensin II-induced hypertension. Clonality was not observed in other organs. The hypertension caused by angiotensin II in CD4(-/-) and MHCII(-/-) mice was similar to that observed in wild-type mice, whereas CD8(-/-) mice and OT1xRAG-1(-/-) mice, which have only 1 T-cell receptor, exhibited a blunted hypertensive response to angiotensin II. Adoptive transfer of pan T cells and CD8(+) T cells but not CD4(+)/CD25(-) cells conferred hypertension to RAG-1(-/-) mice. In contrast, transfer of CD4(+)/CD25(+) cells to wild-type mice receiving angiotensin II decreased blood pressure. Mice treated with angiotensin II exhibited increased numbers of kidney CD4(+) and CD8(+) T cells. In response to a sodium/volume challenge, wild-type and CD4(-/-) mice infused with angiotensin II retained water and sodium, whereas CD8(-/-) mice did not. CD8(-/-) mice were also protected against angiotensin-induced endothelial dysfunction and vascular remodeling in the kidney. These data suggest that in the development of hypertension, an oligoclonal population of CD8(+) cells accumulates in the kidney and likely contributes to hypertension by contributing to sodium and volume retention and vascular rarefaction.

  12. Role of extracellular superoxide dismutase in hypertension.

    Science.gov (United States)

    Gongora, Maria Carolina; Qin, Zhenyu; Laude, Karine; Kim, Ha Won; McCann, Louise; Folz, J Rodney; Dikalov, Sergey; Fukai, Tohru; Harrison, David G

    2006-09-01

    We previously found that angiotensin II-induced hypertension increases vascular extracellular superoxide dismutase (ecSOD), and proposed that this is a compensatory mechanism that blunts the hypertensive response and preserves endothelium-dependent vasodilatation. To test this hypothesis, we studied ecSOD-deficient mice. ecSOD(-/-) and C57Blk/6 mice had similar blood pressure at baseline; however, the hypertension caused by angiotensin II was greater in ecSOD(-/-) compared with wild-type mice (168 versus 147 mm Hg, respectively; P<0.01). In keeping with this, angiotensin II increased superoxide and reduced endothelium-dependent vasodilatation in small mesenteric arterioles to a greater extent in ecSOD(-/-) than in wild-type mice. In contrast to these findings in resistance vessels, angiotensin II paradoxically improved endothelium-dependent vasodilatation, reduced intracellular and extracellular superoxide, and increased NO production in aortas of ecSOD(-/-) mice. Whereas aortic expression of endothelial NO synthase, Cu/ZnSOD, and MnSOD were not altered in ecSOD(-/-) mice, the activity of Cu/ZnSOD was increased by 80% after angiotensin II infusion. This was associated with a concomitant increase in expression of the copper chaperone for Cu/ZnSOD in the aorta but not in the mesenteric arteries. Moreover, the angiotensin II-induced increase in aortic reduced nicotinamide-adenine dinucleotide phosphate oxidase activity was diminished in ecSOD(-/-) mice as compared with controls. Thus, during angiotensin II infusion, ecSOD reduces hypertension, minimizes vascular superoxide production, and preserves endothelial function in resistance arterioles. We also identified novel compensatory mechanisms involving upregulation of copper chaperone for Cu/ZnSOD, increased Cu/ZnSOD activity, and decreased reduced nicotinamide-adenine dinucleotide phosphate oxidase activity in larger vessels. These compensatory mechanisms preserve large vessel function when ecSOD is absent in

  13. Role of angiotensin II type 1 receptor antagonists in the treatment of hypertension in patients aged >or=65 years.

    Science.gov (United States)

    Gradman, Alan H

    2009-01-01

    Systolic blood pressure (SBP) increases with age, and hypertension affects approximately two-thirds of adults in the US aged >60 years. Blood pressure (BP) increases as a consequence of age-related structural changes in large arteries, which lead to loss of elasticity and reduced vascular compliance. Increased pulse wave velocity augments SBP, resulting in a high prevalence of isolated systolic hypertension. Because age itself elevates cardiovascular risk, effective treatment of hypertension in an older (aged >or=65 years) patient population prevents many more events per 1000 patients treated than treatment of younger hypertensive patients. Recommendations for treating hypertension are similar in older patients compared with the general population. The Seventh Report of the Joint National Committee on Detection, Prevention, Evaluation, and Treatment of High Blood Pressure recommends target BP goals of heart failure. Randomized clinical trials have demonstrated the efficacy of calcium channel antagonists (calcium channel blockers [CCBs]), low-dose diuretics, ACE inhibitors and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) in reducing the risk of stroke and other adverse cardiovascular outcomes in older patients; beta-adrenoceptor antagonists are less effective in terms of endpoint reduction. The majority of older patients require two or more drugs to achieve BP goals. Despite active treatment, half of these patients do not achieve target BP, in part because of the reluctance of physicians to intensify treatment, a phenomenon referred to as 'clinical inertia'. ARBs are effective antihypertensive agents in older patients and have been shown to reduce cardiovascular endpoints in patients with hypertension, diabetic nephropathy, cerebrovascular disease and heart failure. ARBs produce additive BP reduction when combined with diuretics or CCBs. They also have the advantage of placebo-like tolerability, and this contributes favourably to

  14. The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome.

    Science.gov (United States)

    Putnam, Kelly; Shoemaker, Robin; Yiannikouris, Frederique; Cassis, Lisa A

    2012-03-15

    The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment.

  15. Long-Term Reduction of High Blood Pressure by Angiotensin II DNA Vaccine in Spontaneously Hypertensive Rats.

    Science.gov (United States)

    Koriyama, Hiroshi; Nakagami, Hironori; Nakagami, Futoshi; Osako, Mariana Kiomy; Kyutoku, Mariko; Shimamura, Munehisa; Kurinami, Hitomi; Katsuya, Tomohiro; Rakugi, Hiromi; Morishita, Ryuichi

    2015-07-01

    Recent research on vaccination has extended its scope from infectious diseases to chronic diseases, including Alzheimer disease, dyslipidemia, and hypertension. The aim of this study was to design DNA vaccines for high blood pressure and eventually develop human vaccine therapy to treat hypertension. Plasmid vector encoding hepatitis B core-angiotensin II (Ang II) fusion protein was injected into spontaneously hypertensive rats using needleless injection system. Anti-Ang II antibody was successfully produced in hepatitis B core-Ang II group, and antibody response against Ang II was sustained for at least 6 months. Systolic blood pressure was consistently lower in hepatitis B core-Ang II group after immunization, whereas blood pressure reduction was continued for at least 6 months. Perivascular fibrosis in heart tissue was also significantly decreased in hepatitis B core-Ang II group. Survival rate was significantly improved in hepatitis B core-Ang II group. This study demonstrated that Ang II DNA vaccine to spontaneously hypertensive rats significantly lowered high blood pressure for at least 6 months. In addition, Ang II DNA vaccines induced an adequate humoral immune response while avoiding the activation of self-reactive T cells, assessed by ELISPOT assay. Future development of DNA vaccine to treat hypertension may provide a new therapeutic option to treat hypertension.

  16. Calcium channel blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors: Effectiveness in combination with diuretics or β-blockers for treating hypertension

    Science.gov (United States)

    Bisognano, John D; McLaughlin, Trent; Roberts, Craig S; Tang, Simon SK

    2007-01-01

    This retrospective database analysis compared the effectiveness of dihydropyridine calcium channel blockers (DHPs), angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs) added to diuretics or β-blockers. Adults with hypertension treated with diuretic or β-blocker monotherapy between 1998 and 2001 were identified from a large US electronic medical records database of primary care practices. Patients were required to have a baseline blood pressure (BP) ≥140/90 mmHg (≥130/80 mmHg for diabetes mellitus) and recorded BP measurements within 6 months before and 1–12 months following index date. Patients were matched 1:1:1 by propensity score to correct for differences in baseline characteristics. 1875 patients met study criteria and 660 (220 in each cohort) were matched based on propensity scores. Matched cohorts had no significant differences in baseline characteristics. Mean changes in systolic/diastolic BP were −17.5/−8.8, −15.7/−6.3, and −13.0/−8.0 mmHg with DHPs, ACE inhibitors, and ARBs, respectively. Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High BP 6/7 goal attainment for each regimen was 47.3%, 40.0%, and 32.2%, respectively. DHPs, ACE inhibitors, and ARBs improved BP when added to patients’ β-blocker or diuretic therapy. The greatest benefits were observed with DHPs, followed by ACE inhibitors, then ARBs. PMID:18078009

  17. Angiotensin converting enzymes from human urine of mild hypertensive untreated patients resemble the N-terminal fragment of human angiotensin I-converting enzyme.

    Science.gov (United States)

    Casarini, D E; Plavinik, F L; Zanella, M T; Marson, O; Krieger, J E; Hirata, I Y; Stella, R C

    2001-01-01

    Angiotensin I-converting enzyme (ACE) activity was analyzed in human urine collected from mild hypertensive untreated patients. DEAE-cellulose chromatography using linear gradient elution revealed two forms of angiotensin I-converting enzyme, eluted in the conductivity of 0.75 and 1.25 mS. The fractions of each conductivity were pooled and submitted to direct gel filtration in an AcA-34 column, and the apparent molecular weights of urinary ACEs were estimated as 90 kDa (for ACE eluted in 0.75 mS) and 65 kDa (for ACE eluted in 1.25 mS). Both enzymes have a K(i) of the order of 10(-7) M for the specific inhibitors studied, and are able to hydrolyze luteinizing hormone-releasing hormone and N-acetyl-Ser-Asp-Lys-Pro as described for N-domain ACE. By Western blot analysis, both peaks were recognized by ACE-specific antibody Y4, confirming the molecular weight already described. A plate precipitation assay using monoclonal antibodies to the N-domain of ACE showed that both forms of ACE binds with all monoclonal antibodies to the active N-domain ACE, suggesting that these forms of human urine ACEs resemble the N-fragment of ACE. The HP2 ACE (65 kDa) is similar to low molecular weight (LMW) ACE from normal subjects, and the HP2 ACE (90 kDa) is different from high molecular weight (190 kDa) and LMW (65 kDa) normal ACEs. The 90 kDa ACE could have an important role in development of hypertension. It will be fundamental to elucidate the molecular mechanism responsible for the genesis of this isoform.

  18. Calcium channel blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors: Effectiveness in combination with diuretics or β-blockers for treating hypertension

    Directory of Open Access Journals (Sweden)

    John D Bisognano

    2007-11-01

    Full Text Available John D Bisognano1, Trent McLaughlin2, Craig S Roberts3, Simon SK Tang31Internal Medicine Department, Cardiology Division, the University of Rochester Medical Center, Rochester, NY, USA; 2NDC Health, Phoenix, Arizona, USA; 3Pfizer Inc, New York, NY, USAAbstract: This retrospective database analysis compared the effectiveness of dihydropyridine calcium channel blockers (DHPs, angiotensin-converting enzyme (ACE inhibitors, and angiotensin receptor blockers (ARBs added to diuretics or β-blockers. Adults with hypertension treated with diuretic or β-blocker monotherapy between 1998 and 2001 were identified from a large US electronic medical records database of primary care practices. Patients were required to have a baseline blood pressure (BP ≥140/90 mmHg (≥130/80 mmHg for diabetes mellitus and recorded BP measurements within 6 months before and 1–12 months following index date. Patients were matched 1:1:1 by propensity score to correct for differences in baseline characteristics. 1875 patients met study criteria and 660 (220 in each cohort were matched based on propensity scores. Matched cohorts had no significant differences in baseline characteristics. Mean changes in systolic/diastolic BP were –17.5/–8.8, –15.7/–6.3, and –13.0/–8.0 mmHg with DHPs, ACE inhibitors, and ARBs, respectively. Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High BP 6/7 goal attainment for each regimen was 47.3%, 40.0%, and 32.2%, respectively. DHPs, ACE inhibitors, and ARBs improved BP when added to patients’ β-blocker or diuretic therapy. The greatest benefits were observed with DHPs, followed by ACE inhibitors, then ARBs.Keywords: hypertension, amlodipine besylate, lisinopril, valsartan, Joint National Committee (JNC 6 and 7

  19. The Renal Protective Effect of Jiangya Tongluo Formula, through Regulation of Adrenomedullin and Angiotensin II, in Rats with Hypertensive Nephrosclerosis

    Directory of Open Access Journals (Sweden)

    Lin Han

    2015-01-01

    Full Text Available We investigated the effect of Jiangya Tongluo (JYTL formula on renal function in rats with hypertensive nephrosclerosis. A total of 21 spontaneously hypertensive rats (SHRs were randomized into 3 groups: valsartan (10 mg/kg/d valsartan, JYTL (14.2 g/kg/d JYTL, and a model group (5 mL/kg/d distilled water; Wistar Kyoto rats comprised the control group (n = 7, 5 mL/kg/d distilled water. Treatments were administered by gavage every day for 8 weeks. Blood pressure, 24-h urine protein, pathological changes in the kidney, serum creatinine, and blood urea nitrogen (BUN levels were estimated. The contents of adrenomedullin (ADM and angiotensin II (Ang II in both the kidney and plasma were evaluated. JYTL lowered BP, 24-h urine protein, serum creatinine, and BUN. ADM content in kidneys increased and negatively correlated with BP, while Ang II decreased and negatively correlated with ADM, but there was no statistically significant difference of plasma ADM between the model and the treatment groups. Possibly, activated intrarenal renin-angiotensin system (RAS plays an important role in hypertensive nephrosclerosis and the protective function of ADM via local paracrine. JYTL may upregulate endogenous ADM level in the kidneys and antagonize Ang II during vascular injury by dilating renal blood vessels.

  20. Plant Flavonoids as Angiotensin Converting Enzyme Inhibitors in Regulation of Hypertension

    Directory of Open Access Journals (Sweden)

    H.P. Vasantha Rupasinghe

    2011-05-01

    Full Text Available Background: Angiotensin converting enzyme (ACE is a key component in the renin angiotensin aldosterone system (RAAS which regulates blood pressure. As the over expression of RAAS is associated with vascular hypertension, ACE inhibition has become a major target control for hypertension. The research on potential ACE inhibitors is expanding broadly and most are focused on natural product derivatives such as peptides, polyphenolics, and terpenes. Plant polyphenolics are antioxidant molecules with various beneficial pharmacological properties. The current study is focused on investigating and reviewing the ACE inhibitory property of fruit flavonoids. An apple skin extract (ASE rich in flavonoids, the major constituents of the extract and their selected metabolites were assessed for the ACE inhibitory property in vitro. It is important to investigate the metabolites along with the flavonoids as they are the constituents active inside the human body.Objective: To investigate whether flavonoids, flavonoid rich apple extracts and their metabolites could inhibit ACE in vitro.Method: The samples were incubated with sodium borate buffer (30 μL, pH 8.3, 150 μL of substrate (Hip-His-Liu and ACE (30 μL at 37 oC for 1 h. The reaction was stopped by addition of 150 μL of 0.3M NaOH. The enzyme cleaved substrate was detected by making a fluorimetricadduct by adding 100 μL of o-phthaladehyde for 10 min at room temperature. Reaction wasstopped by adding 50 μL of 3M HCl. Fluorescence was measured by using a FluoStar Optimaplate reader at excitation of 350 nm and emission of 500 nm.Results: The extract and the compounds showed a concentration dependant enzyme inhibition.Increasing concentrations from 0.001 ppm to 100 ppm of ASE showed an increment of 29% to64% ACE inhibition. The IC50 (concentration of test compound which gives 50% enzymeinhibition values of ASE, quercetin, quercetin-3-glucoside, quercetin-3-galactoside, cyanidin-3-galactoside were 49

  1. Vasoconstricting effect of angiotensin II in human hand veins: influence of aging, diabetes mellitus and hypertension.

    Science.gov (United States)

    Harada, Kazuhiro; Ohmori, Masami; Fujimura, Akio

    2002-09-01

    We examined human hand veins to determine whether venoconstricting response to angiotensin II (Ang II) and noradrenaline (NA) was influenced by aging or such diseases as diabetes mellitus (DM) and hypertension (HT). Twenty healthy male subjects (20-73 years), and 8 male patients with non-insulin-dependent DM and 8 male patients with essential HT were included in this study. A constant dose (50 ng/min) of Ang II or increasing dose (2-256 ng/min) of NA was infused into the dorsal hand vein and its diameter was measured using a linear variable differential transformer. The constant infusion of Ang II caused rapid desensitization or tachyphylaxis. The venoconstriction by Ang II in the 8 elderly subjects (58 to 73 years) was significantly (p<0.05) larger than that in the 8 young subjects (20 to 36 years) from 6 to 18 min after the start of the infusion (after 6 min: 63.6+/-11.6 (mean+/-SD)% vs. 39.9+/-20.8%, 12 min: 34.0+/-11.9% vs. 12.0+/-12.0%). However, the venoconstriction by Ang II in the patients with DM or HT was not significantly different from that in the 9 age-matched control subjects. No significant difference in venoconstrictor response to NA was observed between the young and elderly subjects, nor between the control subjects and the patients with DM or HT. These findings indicated that venoconstrictor response to Ang II might be greater in the elderly but might not be influenced by DM nor HT.

  2. Effects of nabumetone, celecoxib, and ibuprofen on blood pressure control in hypertensive patients on angiotensin converting enzyme inhibitors.

    Science.gov (United States)

    Palmer, Robert; Weiss, Robert; Zusman, Randall M; Haig, Ann; Flavin, Susan; MacDonald, Brian

    2003-02-01

    Nonsteroidal anti-inflammatory drugs interfere with certain antihypertensive therapies. In a double-blind study, 385 hypertensive patients stabilized on an angiotensin converting enzyme inhibitor were treated with nabumetone, celecoxib, ibuprofen, or placebo for 4 weeks. Ibuprofen caused significantly greater increases in systolic (P nabumetone or celecoxib. The proportion of patients with systolic BP increases of clinical concern at end point was significantly higher (P nabumetone group (5.5%; 5 of 91) or the celecoxib group (4.6%; 4 of 87) compared to the placebo group (1.1%; 1 of 91).

  3. The blockade of renin-angiotensin-aldosterone system in hemodialysis patients to control hypertension and prevent cardiovascular disease: optimal pharmacotherapy.

    Science.gov (United States)

    Morishita, Yoshiyuki; Kusano, Eiji

    2011-10-01

    Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in hemodialysis (HD) patients. Hypertension (HT) is a major risk factor for CVD. The renin-angiotensin-aldosterone system (RAAS) plays pivotal roles in the pathogenesis of HT in HD patients. Previous studies suggested that the blockade of RAAS may be effective to control blood pressure (BP) and to prevent CVD in HD patients. A certain level of preventive effects against CVD by RAAS blockade in HD patients has been reported independently from a BP lowering effect. This review focuses on the effect of blocking RAAS in HD patients for the control of HT and the prevention of CVD.

  4. How should we manage heart failure developing in patients already treated with angiotensin-converting enzyme inhibitors and beta-blockers for hypertension, diabetes or coronary disease?

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Segura, Julian; Ruilope, Luis M

    2010-01-01

    An increasing number of patients in the community are being treated with angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and beta-blockers for hypertension, coronary disease or diabetic renal and vascular complications. Some of these patients will develop heart...... failure despite such treatment. Based on data from hypertension trials it can be estimated that approximately 5% of treated patients will develop heart failure over 5 years. It is unclear whether patients developing heart failure on and off ACE-inhibitors or beta-blockers, respectively, at the time...

  5. Sequential activation of the intrarenal renin-angiotensin system in the progression of hypertensive nephropathy in Goldblatt rats.

    Science.gov (United States)

    Kim, Yang Gyun; Lee, Sang Ho; Kim, Se-Yun; Lee, Arah; Moon, Ju Young; Jeong, Kyung-Hwan; Lee, Tae Won; Lim, Sung Jig; Sohn, Il Suk; Ihm, Chun-Gyoo

    2016-07-01

    The intrarenal renin-angiotensin system (RAS) has an important role in generating and maintaining hypertension in two-kidney, one-clip (2K1C) rats. This study evaluated how various intrarenal RAS components contributed to hypertension not only in the maintenance period (5w; 5 wk after operation) but also earlier (2w; 2 wk after operation). We inserted a 2.5-mm clip into the left renal artery of Sprague-Dawley rats and euthanized them at 2w and 5w following the operation. Systolic blood pressure increased within 1 wk after the operation, and left ventricular hypertrophy occurred in 2K1C rats. At 2w, juxtaglomerular apparatus (JGA) and collecting duct (CD) renin increased in clipped kidney (CK) of 2K1C rats. The tubular angiotensin I-converting enzyme (ACE) was not changed, but peritubular ACE2 decreased in nonclipped kidney (NCK) and CK of 2K1C rats. At 5w, ACE and CD renin were enhanced, and ACE2 was still lessened in both kidneys of 2K1C rats. However, plasma renin activity (PRA) was not different from that in sham rats. In proximal tubules of CK, the ANG II type 1 receptor (AT1R) was not suppressed, but the Mas receptor (MasR) was reduced; thus the AT1R/MasR ratio was elevated. Although hypoxic change in CK could not be excluded, the JGA renin of CK and CD renin in both kidneys was highly expressed independent of time. Peritubular ACE2 changed in the earlier period, and uninhibited AT1R in proximal tubules of CK was presented in the maintenance period. In 2K1C rats, attenuated ACE2 seems to contribute to initiating hypertension while upregulated ACE in combination with unsuppressed AT1R may have a key role in maintaining hypertension.

  6. Effects of angiotensin converting enzyme inhibitor: ramipril on different biochemical parameters in essential hypertensive patients

    Directory of Open Access Journals (Sweden)

    Pratibha S. Salve

    2016-06-01

    Conclusions: Ramipril has beneficial effects on RAS (Renin angiotensin system and kinin system or both may contribute to the improvement in different biochemical parameters by ramipril. [Int J Res Med Sci 2016; 4(6.000: 2288-2291

  7. Effect of angiotensin converting enzyme inhibition after acute myocardial infarction in patients with arterial hypertension. TRACE Study Group, Trandolapril Cardiac Event

    DEFF Research Database (Denmark)

    Gustafsson, F; Torp-Pedersen, C; Køber, L;

    1997-01-01

    OBJECTIVE: To evaluate the influence of a history of arterial hypertension on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril in patients with acute myocardial infarction (AMI) and left ventricular dysfunction. METHODS: A retrospective analysis of data from...... to patients with a history of arterial hypertension. ACE inhibition might be of particular importance in this group of patients but further studies to establish the clinical impact are necessary....

  8. Clinical study on the influence of phloroglucinol on plasma angiotensin II and D-Dimer index in patients with severe pregnancy-induced hypertension.

    Science.gov (United States)

    Ai, Liang; Lan, Xinzhi; Wang, Limin; Xu, Yanjie; Zhang, Bin

    2016-07-01

    To observe the effect of phloroglucinol on plasma angiotensin II and D-dimer index when it was applied to patients with severe pregnancy-induced hypertension. 212 cases of severe pregnancy-induced hypertension patients diagnosed clinically were selected to be randomly divided into the research group and the control group. The research groups were given phloroglucinol, while the control groups were given magnesium sulfate. The plasma angiotensin II and D-dimer index in patients were detected before treatment and after 7 days respectively with statistical analysis of results. The diffidence after treatment was statistically significant (P0.05). It showed that the research group could reduce the plasma D-dimer and angiotensin II index in severe pregnancy-induced hypertension patients, and its effect was significantly better than the control group according to the plasma D-dimer and angiotensin II index changes in patients, it indicated that it was effective of phloroglucinol treatment for patients with pregnancy-induced hypertension disease and superior to the western medicine conventional treatment, worth clinical promotion.

  9. Angiotensin converting enzyme inhibition induces alterations to hippuran renography despite unchanged ipsilateral renal blood flow in conscious two-kidney, one clip Goldblatt hypertensive dogs

    NARCIS (Netherlands)

    Jonker, G J; de Zeeuw, D; Huisman, R M; van der Hem, G K

    1988-01-01

    We performed experiments in the two-kidney, one clip Goldblatt hypertensive dog to see whether angiotensin converting enzyme (ACE) inhibition could improve the sensitivity of hippurate renography in detecting renal artery stenosis. Ten dogs on a sodium-restricted diet were studied before and after i

  10. ADVANTAGES OF COMBINATION THERAPY OF HYPERTENSION WITH CALCIUM CHANNEL BLOCKER AND ANGIOTENSIN-CONVERTING ENZYME INHIBITOR IN PATIENTS WITH IMPAIRED RENAL FUNCTION

    Directory of Open Access Journals (Sweden)

    N. A. Dzhaiani

    2014-01-01

    Full Text Available Up-to-date data on combination therapy of arterial hypertension in patients with chronic kidney disease are presented. Special attention is paid to the fixed combination of calcium antagonist lercanidipine and angiotensin-converting enzyme inhibitor enalapril.

  11. Tacrolimus-induced hypertension and nephrotoxicity in Fawn-Hooded rats are attenuated by dual inhibition of renin-angiotensin system

    NARCIS (Netherlands)

    Hoskova, Lenka; Malek, Ivan; Kautzner, Josef; Honsova, Eva; van Dokkum, Richard P. E.; Huskova, Zuzana; Vojtiskova, Alzbeta; Varcabova, Sarka; Cervenka, Ludek; Kopkan, Libor

    2014-01-01

    Chronic immunosuppressive therapy is often complicated by the development of both arterial hypertension and renal dysfunction. The principal aim of this study was to assess the effects of dual inhibition of renin-angiotensin system (RAS) and other antihypertensive treatment on blood pressure and ren

  12. Altered functioning of both renal dopamine D1 and angiotensin II type 1 receptors causes hypertension in old rats.

    Science.gov (United States)

    Chugh, Gaurav; Lokhandwala, Mustafa F; Asghar, Mohammad

    2012-05-01

    Activation of renal dopamine D1 (D1R) and angiotensin II type 1 receptors (AT(1)Rs) influences the activity of proximal tubular sodium transporter Na,K-ATPase and maintains sodium homeostasis and blood pressure. We reported recently that diminished D1R and exaggerated AT(1)R functions are associated with hypertension in old Fischer 344 × Brown Norway F1 (FBN) rats, and oxidative stress plays a central role in this phenomenon. Here we studied the mechanisms of age-associated increase in oxidative stress on diminished D1R and exaggerated AT(1)R functions in the renal proximal tubules of control and antioxidant Tempol-treated adult and old FBN rats. Although D1R numbers and D1R agonist SKF38393-mediated stimulation of [(35)S]-GTPγS binding (index of D1R activation) were lower, G protein-coupled receptor kinase 4 (kinase that uncouples D1R) levels were higher in old FBN rats. Tempol treatment restored D1R numbers and G protein coupling and reduced G protein-coupled receptor kinase 4 levels in old FBN rats. Angiotensin II-mediated stimulation of [(35)S]-GTPγS binding and Na,K-ATPase activity were higher in old FBN rats, which were also restored with Tempol treatment. We also measured renal AT(1)R function in adult and old Fischer 344 (F344) rats, which, despite exhibiting an age-related increase in oxidative stress and diminished renal D1R function, are normotensive. We found that diuretic and natriuretic responses to candesartan (indices of AT(1)R function) were similar in F344 rats, a likely explanation for the absence of age-associated hypertension in these rats. Perhaps, alterations in both D1R (diminished) and AT(1)R (exaggerated) functions are necessary for the development of age-associated hypertension, as seen in old FBN rats.

  13. An Ongoing Role of α-Calcitonin Gene–Related Peptide as Part of a Protective Network Against Hypertension, Vascular Hypertrophy, and Oxidative Stress

    DEFF Research Database (Denmark)

    Smillie, Sarah-Jane; King, Ross; Kodji, Xenia;

    2014-01-01

    α-Calcitonin gene-related peptide (αCGRP) is a vasodilator, but there is limited knowledge of its long-term cardiovascular protective influence. We hypothesized that αCGRP protects against the onset and development of angiotensin II-induced hypertension and have identified protective mechanisms...

  14. Renin-angiotensin system activity in vitamin D deficient, obese individuals with hypertension: An urban Indian study

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Kota

    2011-01-01

    Full Text Available Background: Elevated renin-angiotensin-aldosterone system (RAAS activity is an important mechanism in the development of hypertension. Both obesity and 25-hydroxy vitamin D [25(OHD] deficiency have been associated with hypertension and augmented renin-angiotensin system (RAS activity. We tried to test the hypothesis that vitamin D deficiency and obesity are associated with increased RAS activity in Indian patients with hypertension. Materials and Methods: Fifty newly detected hypertensive patients were screened. Patients with secondary hypertension, chronic kidney disease, or coronary artery disease were excluded. Patients underwent measurement of vitamin D and plasma renin and plasma aldosterone concentrations. They were divided into three groups according to their baseline body mass index (BMI; normal <25 kg/m 2 , overweight 25-29.9 kg/m 2 and obese ≥30 kg/m 2 and 25(OHD levels (deficient <20 ng/ml, insufficient 20-29 ng/ml and optimal ≥30 ng/ml. Results: A total of 50 (male:female = 32:18 patients were included, with a mean age of 49.5 ± 7.8 years, mean BMI of 28.3 ± 3.4 kg/m 2 and a mean 25(OHD concentration of 18.5 ± 6.4 ng/ml. Mean systolic blood pressure (SBP was 162.4 ± 20.2 mm Hg and mean diastolic blood pressure (DBP was 100.2 ± 11.2 mm Hg. All the three blood pressure parameters [SBP, DBP and mean arterial pressure (MAP] were significantly higher among individuals with lower 25(OHD levels. The P values for trends in SBP, DBP and MAP were 0.009, 0.01 and 0.007, respectively. Though all the three blood pressure parameters (SBP, DBP and MAP were higher among individuals with higher BMIs, they were not achieving statistical significance. Increasing trends in PRA and PAC were noticed with lower 25(OHD and higher BMI levels. Conclusion: Vitamin D deficiency and obesity are associated with stimulation of RAAS activity. Vitamin D supplementation along with weight loss may be studied as a therapeutic strategy to reduce tissue RAS

  15. Green asparagus (Asparagus officinalis) prevented hypertension by an inhibitory effect on angiotensin-converting enzyme activity in the kidney of spontaneously hypertensive rats.

    Science.gov (United States)

    Sanae, Matsuda; Yasuo, Aoyagi

    2013-06-12

    Green asparagus (Asparagus officinalis) is known to be rich in functional components. In the present study, spontaneously hypertensive rats (SHR) were used to clarify whether green asparagus prevents hypertension by inhibition of angiotensin-converting enzyme (ACE) activity. Six-week-old male SHR were fed a diet with (AD group) or without (ND group) 5% asparagus for 10 weeks. Systolic blood pressure (SBP) (AD: 159 ± 4.8 mmHg, ND: 192 ± 14.7 mmHg), urinary protein excretion/creatinine excretion, and ACE activity in the kidney were significantly lower in the AD group compared with the ND group. Creatinine clearance was significantly higher in the AD group compared with the ND group. In addition, ACE inhibitory activity was observed in a boiling water extract of asparagus. The ACE inhibitor purified and isolated from asparagus was identified as 2″-hydroxynicotianamine. In conclusion, 2″-hydroxynicotianamine in asparagus may be one of the factors inhibiting ACE activity in the kidney, thus preventing hypertension and preserving renal function.

  16. Brain Angiotensin II Type 1 Receptor Blockade Improves Dairy Blood Pressure Variability via Sympathoinhibition in Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Takuya Kishi

    2015-01-01

    Full Text Available Abnormal blood pressure (BP elevation in early morning is known to cause cardiovascular events. Previous studies have suggested that one of the reasons in abnormal dairy BP variability is sympathoexcitation. We have demonstrated that brain angiotensin II type 1 receptor (AT1R causes sympathoexcitation. The aim of the present study was to investigate whether central AT1R blockade attenuates the excess BP elevation in rest-to-active phase in hypertensive rats or not. Stroke-prone spontaneously hypertensive rats (SHRSP were treated with intracerebroventricular infusion (ICV of AT1R receptor blocker (ARB, oral administration of hydralazine (HYD, or ICV of vehicle (VEH. Telemetric averaged mean BP (MBP was measured at early morning (EM, after morning (AM, and night (NT. At EM, MBP was significantly lower in ARB to a greater extent than in HYD compared to VEH, though MBP at AM was the same in ARB and HYD. At NT, MBP was also significantly lower in ARB than in HYD. These results in MBP were compatible to those in sympathoexcitation and suggest that central AT1R blockade attenuates excess BP elevation in early active phase and continuous BP elevation during rest phase independent of depressor response in hypertensive rats.

  17. Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension.

    Science.gov (United States)

    Muñoz-Durango, Natalia; Fuentes, Cristóbal A; Castillo, Andrés E; González-Gómez, Luis Martín; Vecchiola, Andrea; Fardella, Carlos E; Kalergis, Alexis M

    2016-06-23

    Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage.

  18. EGF receptor transactivation in angiotensin II and endothelin control of vascular protein synthesis in vivo.

    Science.gov (United States)

    Beaucage, Pierre; Moreau, Pierre

    2004-11-01

    Endothelin represents a necessary intermediate of angiotensin II-induced resistance artery remodeling in hypertension. Recent data suggest that epidermal growth factor receptors are rapidly transactivated by angiotensin II stimulation to mediate its growth-promoting effects. Because endothelin also transactivates epidermal growth factor receptors in vitro, we studied the contribution of epidermal growth factor receptor transactivation in the in vivo trophic actions of the upstream effector angiotensin II and its downstream mediator endothelin in rat mesenteric arteries. Twenty-six-hour infusion of angiotensin II (400 ng/kg per min) or endothelin (5 pmol/kg per min) via osmotic pumps significantly enhanced vascular protein synthesis. With angiotensin II, treatment with the inhibitor of epidermal growth factor receptor transactivation (AG1478, 0.5 mg/kg) produced a significant attenuation (P < 0.05) of protein synthesis. In contrast, AG1478 did not abrogate the elevation of protein synthesis induced by endothelin. In conclusion, angiotensin II-induced epidermal growth factor receptor transactivation seems to be involved in the recruitment of endothelin in the cascade leading to vascular protein synthesis, rather than in the effect of endothelin on small artery remodeling.

  19. Activation of thiazide-sensitive co-transport by angiotensin II in the cyp1a1-Ren2 hypertensive rat.

    Directory of Open Access Journals (Sweden)

    Ali Ashek

    Full Text Available Transgenic rats with inducible expression of the mouse Ren2 gene were used to elucidate mechanisms leading to the development of hypertension and renal injury. Ren2 transgene activation was induced by administration of a naturally occurring aryl hydrocarbon, indole-3-carbinol (100 mg/kg/day by gastric gavage. Blood pressure and renal parameters were recorded in both conscious and anesthetized (butabarbital sodium; 120 mg/kg IP rats at selected time-points during the development of hypertension. Hypertension was evident by the second day of treatment, being preceded by reduced renal sodium excretion due to activation of the thiazide-sensitive sodium-chloride co-transporter. Renal injury was evident after the first day of transgene induction, being initially limited to the pre-glomerular vasculature. Mircoalbuminuria and tubuloinsterstitial injury developed once hypertension was established. Chronic treatment with either hydrochlorothiazide or an AT1 receptor antagonist normalized sodium reabsorption, significantly blunted hypertension and prevented renal injury. Urinary aldosterone excretion was increased ≈ 20 fold, but chronic mineralocorticoid receptor antagonism with spironolactone neither restored natriuretic capacity nor prevented hypertension. Spironolactone nevertheless ameliorated vascular damage and prevented albuminuria. This study finds activation of sodium-chloride co-transport to be a key mechanism in angiotensin II-dependent hypertension. Furthermore, renal vascular injury in this setting reflects both barotrauma and pressure-independent pathways associated with direct detrimental effects of angiotensin II and aldosterone.

  20. Is there a place for combining angiotensin-converting enzyme inhibitors and angiotensin-receptor antagonists in the treatment of hypertension, renal disease or congestive heart failure?

    Science.gov (United States)

    Taylor, A A

    2001-09-01

    Angiotensin-converting enzyme inhibitors and angiotensin II receptor subtype 1 antagonists have proven to be effective and well tolerated antihypertensive agents. They also exhibit unique cardioprotective and renoprotective properties in patients with comorbid conditions such as congestive heart failure and proteinuria or renal insufficiency. This benefit is observed most dramatically in diabetic persons. Although inconclusive, the results of a limited number of clinical trials support the notion that additive antihypertensive, cardioprotective, and renoprotective effects may be obtained with combined used of angiotensin-converting enzyme inhibitors and angiotensin II receptor subtype 1 antagonists in some patients. More studies are needed to confirm the findings of these preliminary studies, and to define more clearly those subsets of patients who might derive the greatest benefit from angiotensin-converting enzyme inhibitor-angiotensin II receptor subtype 1 antagonist combination therapy.

  1. Recombinant adeno-associated virus-mediated delivery of antisense angiotensin Ⅱ receptor 1 gene attenuates hypertension development

    Institute of Scientific and Technical Information of China (English)

    Xu-guang LI; Jiang-tao YAN; Xi-zheng XU; Jia-ning WANG; Li-ming CHENG; Tao WANG; Ping ZUO; Dao-wen WANG

    2007-01-01

    Aim:The renin-angiotensin system plays a crucial role in the development and establishment of hypertension,and the pharmacological blockade of the system results in a reduction in blood pressure. In the present study,we investigated whether the effects of a novel,double-stranded,recombinant adeno-associated virus vector (rAAV)-mediated antisense angiotensin Ⅱ receptor l (AT1R) gene efficiently prevents the development of hypertension induced by a high-salt diet in adult,male Sprague-Dawley (SD) rats. Methods:A rAAV was prepared with a cassette containing a cytomegalovirus promoter and partial cDNA (660 base pairs) for the AT1R inserted in the antisense direction (rAAV-AT1AS). A single tail vein injection of the rAAV-AT1-AS or rAAV-GFP (green fluorescent protein,a reporter gene) was performed in adult,male SD rats. Two weeks after injection,the animals were fed a diet containing 8% NaCI,and the systolic blood pressure was measured weekly using the tail-cuff method for 12 weeks. Results:The high-salt diet induced a significant rise in systolic blood pressure in the rAAV-GFP-treated animals;however,the rAAV-AT:AS treatment attenuated the rise in blood pressure (142.7±4.5 mmHg vs 117±3.8 mmHg,P<0.01),and the hypotensive effect was maintained until the experiments ended at 12 weeks. In the rAAV-GFP-treated animals AT1 was overexpressed in various tissues,especially in the aorta and kidney at mRNA levels;in contrast,rAAV-AT:AS treatment markedly attenuated AT1 expression. Furthermore,rAAV-AT:AS treatment prevented target organ damages from hypertension,including cardiac dysfunction and renal injury compared to the rAAV-GFP group. Conclusion:These results suggest that rAAVmediated anti-AT1 delivery attenuates the development of hypertension and protects against renal injury and cardiac remodeling.

  2. Effect of angiotensin Ⅱ type Ⅰ receptor blocker losartan on bone deterioration in orchiectomized male hypertensive and normotensive rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-feng; QIN Ling; Timothy CY Kwok; Benson HY Yeung; LI Guo-dong; LIU Fan

    2013-01-01

    Background Epidemiological study showed that the use of angiotensin-converting enzyme inhibitors was associated with higher bone mineral density (BMD) in older people,especially male subjects,which suggested that angiotensin Ⅱ may have a detrimental effect on bone.Therefore,blocking its effect may have a beneficial effect on bone health.Methods Six-month-old male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) were used.Animals of each model were randomly assigned to the following four groups:Group 1,SHAM operated+vehicle;Group 2,orchidectomy (ORX)+vehicle; Group 3,ORX+low-dose losartan (10 mg.kg-1·d-1); and Group 4,ORX+high-dose losartan (25 mg.kg-1.d-1).Blood pressure was recorded weekly.SHAM and ORX operations were performed,followed by daily losartan and vehicle treatment from day 4 after operation for 16 weeks.Serum and 24-hour urine samples were collected for measurement of bone turnover markers before euthanasia and then the left femur was collected for measurements of BMD and microarchitecture before mechanical test.Results Urine deoxypyridinoline/urine creatinine (DPD/Cr) ratio was significantly higher in SHR than in WKY.BMD and microarchitecture parameters also showed bone deterioration in SHR.After ORX,serum osteocalcin concentration decreased and urine DPD/Cr ratio increased significantly accompanied by a significant decrease in cortical and trabecular BMD and cortical bone thickness in both WKY and SHR.High-dose losartan significantly increased DPD in urine in both SHR and WKY.Apart from marginal favorable changes in bone architecture in WKY treated with high-dose losartan,losartan did not show significant effect on BMD,bone area,bone microarchitecture,and mechanical properties in both SHR and WKY.Conclusion Angiotensin Ⅱ type Ⅰ receptor blocker losartan was not able to demonstrate significant effect on ORX-induced bone deterioration in both hypertensive and normotensive rats.

  3. Opposing tissue-specific roles of angiotensin in the pathogenesis of obesity, and implications for obesity-related hypertension.

    Science.gov (United States)

    Littlejohn, Nicole K; Grobe, Justin L

    2015-12-15

    Metabolic disease, specifically obesity, has now become the greatest challenge to improving cardiovascular health. The renin-angiotensin system (RAS) exists as both a circulating hormone system and as a local paracrine signaling mechanism within various tissues including the brain, kidney, and adipose, and this system is strongly implicated in cardiovascular health and disease. Growing evidence also implicates the RAS in the control of energy balance, supporting the concept that the RAS may be mechanistically involved in the pathogenesis of obesity and obesity hypertension. Here, we review the involvement of the RAS in the entire spectrum of whole organism energy balance mechanisms, including behaviors (food ingestion and spontaneous physical activity) and biological processes (digestive efficiency and both aerobic and nonaerobic resting metabolic rates). We hypothesize that opposing, tissue-specific effects of the RAS to modulate these various components of energy balance can explain the apparently paradoxical results reported by energy-balance studies that involve stimulating, versus disrupting, the RAS. We propose a model in which such opposing and tissue-specific effects of the RAS can explain the failure of simple, global RAS blockade to result in weight loss in humans, and hypothesize that obesity-mediated uncoupling of endogenous metabolic rate control mechanisms can explain the phenomenon of obesity-related hypertension.

  4. Comparative Analysis of Renin-Angiotensin System (RAS)-Related Gene Expression Between Hypertensive and Normotensive Rats

    Science.gov (United States)

    Williamson, Chad R.; Khurana, Sandhya; Nguyen, Phong; Byrne, Collin J.; Tai, T.C.

    2017-01-01

    Background The renal renin-angiotensin system (RAS) is physiologically important for blood pressure regulation. Altered regulation of RAS-related genes has been observed in an animal model of hypertension (spontaneously hypertensive rats – SHRs). The current understanding of certain RAS-related gene expression differences between Wistar-Kyoto rats (WKYs) and SHRs is either limited or has not been compared. The purpose of this study was to compare the regulation of key RAS-related genes in the kidneys of adult WKYs and SHRs. Material/Methods Coronal sections were dissected through the hilus of kidneys from 16-week-old male WKYs and SHRs. RT-PCR analysis was performed for Ace, Ace2, Agt, Agtr1a, Agtr1b, Agtr2, Atp6ap2 (PRR), Mas1, Ren, Rnls, and Slc12a3 (NCC). Results Increased mRNA expression was observed for Ace, Ace2, Agt, Agtr1a, Agtr1b, and Atp6ap2 in SHRs compared to WKYs. Mas1, Ren, Slc12a3, and Rnls showed no difference in expression between animal types. Conclusions This study shows that the upregulation of several key RAS-related genes in the kidney may account for the increased blood pressure of adult SHRs. PMID:28138124

  5. Insights into the Hypertensive Effects of Tityus serrulatus Scorpion Venom: Purification of an Angiotensin-Converting Enzyme-Like Peptidase

    Directory of Open Access Journals (Sweden)

    Daniela Cajado-Carvalho

    2016-11-01

    Full Text Available The number of cases of envenomation by scorpions has grown significantly in Brazil since 2007, with the most severe cases being caused by the Tityus serrulatus scorpion. Although envenomed patients mostly suffer neurotoxic manifestations, other symptoms, such as hypertension, cannot be exclusively attributed to neurotoxins. Omics analyses have detected plentiful amounts of metalloproteases in T. serrulatus venom. However, the roles played by these enzymes in envenomation are still unclear. Endeavoring to investigate the functions of scorpion venom proteases, we describe here for the first time an Angiotensin I-Converting Enzyme-like peptidase (ACE-like purified from T. serrulatus venom. The crude venom cleaved natural and fluorescent substrates and these activities were inhibited by captopril. Regarding the serum neutralization, the scorpion antivenom was more effective at blocking the ACE-like activity than arachnid antivenom, although neither completely inhibited the venom cleavage action, even at higher doses. ACE-like was purified from the venom after three chromatographic steps and its identity was confirmed by mass spectrometric and transcriptomic analyses. Bioinformatics analysis showed homology between the ACE-like transcript sequences from Tityus spp. and human testis ACE. These findings advance our understanding of T. serrulatus venom components and may improve treatment of envenomation victims, as ACE-like may contribute to envenomation symptoms, especially the resulting hypertension.

  6. Insights into the Hypertensive Effects of Tityus serrulatus Scorpion Venom: Purification of an Angiotensin-Converting Enzyme-Like Peptidase

    Science.gov (United States)

    Cajado-Carvalho, Daniela; Kuniyoshi, Alexandre Kazuo; Duzzi, Bruno; Iwai, Leo Kei; de Oliveira, Úrsula Castro; Junqueira de Azevedo, Inácio de Loiola Meirelles; Kodama, Roberto Tadashi; Portaro, Fernanda Vieira

    2016-01-01

    The number of cases of envenomation by scorpions has grown significantly in Brazil since 2007, with the most severe cases being caused by the Tityus serrulatus scorpion. Although envenomed patients mostly suffer neurotoxic manifestations, other symptoms, such as hypertension, cannot be exclusively attributed to neurotoxins. Omics analyses have detected plentiful amounts of metalloproteases in T. serrulatus venom. However, the roles played by these enzymes in envenomation are still unclear. Endeavoring to investigate the functions of scorpion venom proteases, we describe here for the first time an Angiotensin I-Converting Enzyme-like peptidase (ACE-like) purified from T. serrulatus venom. The crude venom cleaved natural and fluorescent substrates and these activities were inhibited by captopril. Regarding the serum neutralization, the scorpion antivenom was more effective at blocking the ACE-like activity than arachnid antivenom, although neither completely inhibited the venom cleavage action, even at higher doses. ACE-like was purified from the venom after three chromatographic steps and its identity was confirmed by mass spectrometric and transcriptomic analyses. Bioinformatics analysis showed homology between the ACE-like transcript sequences from Tityus spp. and human testis ACE. These findings advance our understanding of T. serrulatus venom components and may improve treatment of envenomation victims, as ACE-like may contribute to envenomation symptoms, especially the resulting hypertension. PMID:27886129

  7. Assessment of Effect of Angiotensin Ⅱ Receptor Antagonist Losartan on Aortic Distensibility in Patients With Essential Hypertension by Echocardiography

    Institute of Scientific and Technical Information of China (English)

    杨好意; 邓又斌; 黎春蕾; 毕小军; 潘敏; 常青

    2002-01-01

    Summary: The effects of angiotensin Ⅱ receptor antagonist losartan on elastic properties of aorta in patients with mild to moderate essential hypertension were assessed. The ascending aortic distensibili-ty in 26 patients (48± 3 years) with mild to moderate essential hypertension before and after 12 weeks of treatment with losartan (50 mg/day) was evaluated by using two-dimensional echocardio graphy. M-mode measurements of aortic systolic (Ds) and diastolic diameter (Dd) were taken at a level approximately 3 cm above the aortic valve. Simultaneously, cuff brachial artery systolic (SBP)and diastolic(DBP) pressures were measured. Aortic pressure-strain elastic modulus (Ep) was calcu lated as Dd × (SBP-DBP)/(Ds-Dd) × 1333 and stiffness index beta (β) was defined as Dd × Ln (SBP/DBP)/(Ds-Dd). Blood pressure significantly decreased from 148±13/95±9 mmHg to 138± 12/88±8 mmHg (systolic blood pressure, P=0. 001; diastolic blood pressure, P=0. 003). Therewas no significant difference in pulse pressure before and after treatment with losartan (53±10 mmHg vs 50± 7 mmHg). The distensibility of ascending aorta increased significantly as showed by the significant decrease in pressure-strain elastic modulus from 4.42± 5.79 × 106 dynes/cm2 to 1.99 ± 1.49 × 106 dynes/cm2 (P=0. 02) and stiffness index beta from 27.4 ± 32.9 to 13.3 ± 9.9 (P = 0. 02). Although there was a weak correlation between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in diastolic blood pressure after losartan treatment (r= 0. 40, P = 0. 04 and r = 0.55, P = 0. 004, respectively), no correlation was found between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in systolic blood pressure (r = 0. 04, P = 0. 8 and r = 0. 24, P = 0. 2, respectively). Our study demonstrated that angiotensin Ⅱ receptor antagonist losartan has a beneficial effect on aortic distensibility in patients with mild to moderate essential

  8. Angiotensin II induced venoconstriction in normotensive and hypertensive rats: study of action mechanisms, localization and expression of AT1 and AT2 receptors.

    OpenAIRE

    Rodrigo Azevedo Loiola

    2007-01-01

    Neste estudo, avaliamos e caracterizamos o efeito de Ang II em leito venular mesentérico (LVM) e anéis de veia porta (AVP) de wistar e SHR. A reatividade vascular para Ang II foi estudada na presença e ausência de diferentes antagonistas para elucidar os mecanismos envolvidos na venoconstrição induzida por Ang II. Nossos resultados sugerem que a Ang II induz venoconstrição através da ativação de receptores AT1 e AT2 em Wistar e receptor AT1 em SHR. Essa venoconstrição parece ser contrabalanc...

  9. Calcium Channel Blockers, More than Diuretics, Enhance Vascular Protective Effects of Angiotensin Receptor Blockers in Salt-Loaded Hypertensive Rats

    Science.gov (United States)

    Yamamoto, Eiichiro; Kataoka, Keiichiro; Dong, Yi-Fei; Koibuchi, Nobutaka; Toyama, Kensuke; Sueta, Daisuke; Katayama, Tetsuji; Yasuda, Osamu; Ogawa, Hisao; Kim-Mitsuyama, Shokei

    2012-01-01

    The combination therapy of an angiotensin receptor blocker (ARB) with a calcium channel blocker (CCB) or with a diuretic is favorably recommended for the treatment of hypertension. However, the difference between these two combination therapies is unclear. The present work was undertaken to examine the possible difference between the two combination therapies in vascular protection. Salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP) were divided into 6 groups, and they were orally administered (1) vehicle, (2) olmesartan, an ARB, (3) azelnidipine, a CCB, (4) hydrochlorothiazide, a diuretic, (5) olmesartan combined with azelnidipine, or (6) olmesartan combined with hydrochlorothiazide. Olmesartan combined with either azelnidipine or hydrochlorothiazide ameliorated vascular endothelial dysfunction and remodeling in SHRSP more than did monotherapy with either agent. However, despite a comparable blood pressure lowering effect between the two treatments, azelnidipine enhanced the amelioration of vascular endothelial dysfunction and remodeling by olmesartan to a greater extent than did hydrochlorothiazide in salt-loaded SHRSP. The increased enhancement by azelnidipine of olmesartan-induced vascular protection than by hydrochlorothiazide was associated with a greater amelioration of vascular nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, superoxide, mitogen-activated protein kinase activation, and with a greater activation of the Akt/endothelial nitric oxide synthase (eNOS) pathway. These results provided the first evidence that a CCB potentiates the vascular protective effects of an ARB in salt-sensitive hypertension, compared with a diuretic, and provided a novel rationale explaining the benefit of the combination therapy with an ARB and a CCB. PMID:22720058

  10. Calcium channel blockers, more than diuretics, enhance vascular protective effects of angiotensin receptor blockers in salt-loaded hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Eiichiro Yamamoto

    Full Text Available The combination therapy of an angiotensin receptor blocker (ARB with a calcium channel blocker (CCB or with a diuretic is favorably recommended for the treatment of hypertension. However, the difference between these two combination therapies is unclear. The present work was undertaken to examine the possible difference between the two combination therapies in vascular protection. Salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP were divided into 6 groups, and they were orally administered (1 vehicle, (2 olmesartan, an ARB, (3 azelnidipine, a CCB, (4 hydrochlorothiazide, a diuretic, (5 olmesartan combined with azelnidipine, or (6 olmesartan combined with hydrochlorothiazide. Olmesartan combined with either azelnidipine or hydrochlorothiazide ameliorated vascular endothelial dysfunction and remodeling in SHRSP more than did monotherapy with either agent. However, despite a comparable blood pressure lowering effect between the two treatments, azelnidipine enhanced the amelioration of vascular endothelial dysfunction and remodeling by olmesartan to a greater extent than did hydrochlorothiazide in salt-loaded SHRSP. The increased enhancement by azelnidipine of olmesartan-induced vascular protection than by hydrochlorothiazide was associated with a greater amelioration of vascular nicotinamide adenine dinucleotide phosphate (NADPH oxidase activation, superoxide, mitogen-activated protein kinase activation, and with a greater activation of the Akt/endothelial nitric oxide synthase (eNOS pathway. These results provided the first evidence that a CCB potentiates the vascular protective effects of an ARB in salt-sensitive hypertension, compared with a diuretic, and provided a novel rationale explaining the benefit of the combination therapy with an ARB and a CCB.

  11. How should we manage heart failure developing in patients already treated with angiotensin-converting enzyme inhibitors and beta-blockers for hypertension, diabetes or coronary disease?

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Segura, Julian; Ruilope, Luis M

    2010-01-01

    An increasing number of patients in the community are being treated with angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and beta-blockers for hypertension, coronary disease or diabetic renal and vascular complications. Some of these patients will develop heart...... failure despite such treatment. Based on data from hypertension trials it can be estimated that approximately 5% of treated patients will develop heart failure over 5 years. It is unclear whether patients developing heart failure on and off ACE-inhibitors or beta-blockers, respectively, at the time...... of heart failure diagnosis have similar prognosis.Treatment options for patients developing heart failure while already treated with ACE inhibitors/ARBs and beta-blockers are very limited if current heart failure guidelines are followed. In this review possible strategies are outlined and important areas...

  12. Angiotensin-converting enzyme 2 activation protects against pulmonary arterial hypertension through improving early endothelial function and mediating cytokines levels

    Institute of Scientific and Technical Information of China (English)

    LI Gang; XU Yu-lin; LING Feng; LIU Ai-jun; WANG Dong; WANG Qiang; LIU Ying-long

    2012-01-01

    Background Increasing evidences indicate that an activated renin-angiotensin system (RAS) causes an imbalance between the vasoconstrictive and vasodilator mechanisms involving the pulmonary circulation leading to the development of pulmonary arterial hypertension (PAH).Angiotensin-converting enzyme 2 (ACE2),a primary component of the vasoprotective axis in RAS,is recently identified that it has regulatory actions in lung pathophysiology,but the mechanism in these processes is uncertain yet.Methods Severe PAH was induced by monocrotaline injection one week following pneumonectomy in rats.The activation of ACE2 by continuous injection of resorcinolnaphthalein was studied by real time-polymerase chain reaction (RT-PCR),Western blotting and fluorogenic peptide assay.Endothelial functions were evaluated by the response to acetylcholine and cytokines were measured by RT-PCR seven days after monocrotaline injection.The PAH-related hemodynamics and pathological changes were examined at day 21 when severe PAH was completely established.Results Resorcinolnaphthalein caused significant activation of ACE2 in both normal and diseased rats in 7 days after treatment.The pulmonary arterial pressure (PAP) started to increase at least 7 days after monocrotaline injection,and the rats developed severe PAH in 21 days with high PAP,right ventricular hypertrophy and neointimal formation.Treatment with resorcinolnaphthalein prevented these features.Resorcinolnaphthalein caused an improved endothelia-dependent vasorelaxation and decrease in proinflammatory cytokines (tumor necrosis factor (TNF)-α,monocyte chemoattractant protein-1 (MCP-1),interleukin (IL)-6) and increase in anti-inflammatory cytokine IL-10 in the early stage of the pathogenesis.Conclusions These results demonstrated that activation of ACE2 by continuous injection of resorcinolnaphthalein prevented the development of PAH through improving early endothelial dysfunction and mediating the level of proinflammatory and anti

  13. Diuretic response to acute hypertension is blunted during angiotensin II clamp

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Zhang, Yibin; Yang, Li E;

    2002-01-01

    ("ANG II clamp"). When blood pressure was acutely increased 50-60 mmHg by arterial constriction without ANG II clamp, urine output and endogenous lithium clearance increased 4.0- and 6.7-fold, respectively. With ANG II clamp, the effects of acute hypertension were reduced 50%: urine output...... and endogenous lithium clearance increased two- and threefold, respectively. We conclude that HOE-140, an inhibitor of the B(2) receptor, potentiates the sensitivity of arterial pressure to ANG II and that clamping systemic ANG II levels during acute hypertension blunts the magnitude of the pressure diuretic...

  14. Sex differences in NMDA GluN1 plasticity in rostral ventrolateral medulla neurons containing corticotropin-releasing factor type 1 receptor following slow-pressor angiotensin II hypertension.

    Science.gov (United States)

    Van Kempen, T A; Dodos, M; Woods, C; Marques-Lopes, J; Justice, N J; Iadecola, C; Pickel, V M; Glass, M J; Milner, T A

    2015-10-29

    AngII-induced hypertension is reflected by NMDA receptor trafficking in presumptive sympathoexcitatory neurons in the RVLM.

  15. Renal dopamine and angiotensin II receptor signaling in age-related hypertension.

    Science.gov (United States)

    Chugh, Gaurav; Pokkunuri, Indira; Asghar, Mohammad

    2013-01-01

    Kidneys play a vital role in long-term regulation of blood pressure. This is achieved by actions of many renal and nonrenal factors acting on the kidney that help maintain the body's water and electrolyte balance and thus control blood pressure. Several endogenously formed or circulating hormones/peptides, by acting within the kidney, regulate fluid and water homeostasis and blood pressure. Dopamine and angiotensin II are the two key renal factors that, via acting on their receptors and counterregulating each other's function, maintain water and sodium balance. In this review, we provide recent advances in the signaling cascades of these renal receptors, especially at the level of their cross talk, and discuss their roles in blood pressure regulation in the aging process.

  16. Imaging the renin-angiotensin system: an important target of anti-hypertensive therapy.

    Science.gov (United States)

    Kang, Jung Julie; Toma, Ildikó; Sipos, Arnold; McCulloch, Fiona; Peti-Peterdi, János

    2006-09-15

    Multiphoton fluorescence microscopy allows visualization, manipulation, and quantification of the structure-function relationships between pharmacological interventions and their physiological effects. The application of these methods to live animals permits direct observation of acute physical responses that lack chemically detectable signals in the blood or urine and would otherwise remain unknown. With the use of special fluorescent dyes, chemical/hormonal responses may also be detected. The delivery and site-specific effects of drugs can be monitored in real-time. The capacity to simultaneously visualize both proximal and distal segments of the nephron permits observation of the dynamic processes within the living kidney and a quantitative assessment of the various operations. Consequently, a clinically valuable and pending application for multi-photon microscopy will be to provide real-time, quantitative imaging of basic organ functions and their responses to therapeutic intervention. Imaging of the intra-renal renin content and enzymatic activity of renin in situ and in real-time is a new, more informative measure of RAS activity. Direct visualization of the molecular and cellular components of renin release signals and the interactions between the vascular endothelium, tubular epithelium, local mediators, and the renin producing cells provides great insight for drug development. Examples of how the effects of various RAS inhibitors can be visualized in the intact kidney are provided: including angiotensin converting enzyme inhibition (captopril), angiotensin II type 1 receptor blockade (olmesartan), and renin inhibition (aliskiren). The site-specific actions of diuretics, like furosemide, have also been visualized. Quantitative imaging of basic renal functions in health and disease can provide key information to assess the delivery and effects of pharmaceutical interventions.

  17. Central angiotensin-(1-7) improves vagal function independent of blood pressure in hypertensive (mRen2)27 rats.

    Science.gov (United States)

    Nautiyal, Manisha; Shaltout, Hossam A; de Lima, Daniel C; do Nascimento, Kenia; Chappell, Mark C; Diz, Debra I

    2012-11-01

    Hypertensive transgenic (mRen2)27 rats with overexpression of the mRen2 gene have impaired baroreflex sensitivity for heart rate control and high nicotinamide adenine dinucleotide phosphate oxidase and kinase-to-phosphatase signaling activity in medullary tissue compared with normotensive Hannover Sprague-Dawley control rats. They also exhibit insulin resistance at a young age. To determine whether blocking angiotensin II actions, supplementing angiotensin-(1-7), or scavenging reactive oxygen species in brain differentially alters mean arterial pressure, baroreflex sensitivity, or metabolic function, while altering medullary signaling pathways in these animals, we compared intracerebroventricular infusions of the angiotensin II type 1 receptor antagonist candesartan (4 μg/5 μL/h), angiotensin-(1-7) (0.1 μg/5 μL/h), a reactive oxygen species scavenger tempol (25 μg/5 μL/h), or artificial cerebrospinal fluid (5 μL/h) for 2 weeks. Mean arterial pressure was reduced in candesartan-treated rats without significantly improving the vagal components of baroreflex function or heart rate variability. In contrast, angiotensin-(1-7) treatment significantly improved the vagal components of baroreflex function and heart rate variability at a dose that did not significantly lower mean arterial pressure. Tempol significantly reduced nicotinamide adenine dinucleotide phosphate oxidase activity in brain dorsal medullary tissue but had no effect on mean arterial pressure or autonomic function. Candesartan tended to reduce fat mass, but none of the treatments significantly altered indices of metabolic function or mitogen-activated protein kinase signaling pathways in dorsal medulla. Although additional dose response studies are necessary to determine the potential maximal effectiveness of each treatment, the current findings demonstrate that blood pressure and baroreflex function can be essentially normalized independently of medullary nicotinamide adenine dinucleotide

  18. The Prognostic Role of Angiotensin II Type 1 Receptor Autoantibody in Non-Gravid Hypertension and Pre-eclampsia: A Meta-analysis and Our Studies.

    Science.gov (United States)

    Lei, Jinghui; Li, Yafeng; Zhang, Suli; Wu, Ye; Wang, Pengli; Liu, Huirong

    2016-04-01

    Angiotensin II type 1 receptor autoantibody (AT1-AA) is found in patients with non-gravid hypertension or pre-eclampsia, but the relationship is uncertain.The aim of the present study was to assess the association between AT1-AA and high blood pressure using meta-analysis, and to evaluate the prognosis value of AT1-AA for hypertensive diseases.Literature search from PubMed, Embase, and Cochrane databases were conducted using keywords "hypertension" or "pre-eclampsia," "angiotensin II receptor type 1 autoantibody," and its aliases from April 1999 to December 2015.Studies evaluating the association between AT1-AA and non-gravid hypertension or pre-eclampsia were included in this analysis. The quality of the eligible studies was assessed based on the Newcastle-Ottawa Scale with some modifications.Two researchers then independently reviewed all included studies and extracted all relevant data. Association between AT1-AA and hypertension was tested with pooled odds ratios (ORs) and 95% confidence intervals (CIs). Finally, we evaluated whether AT1-AA predicted the prognosis of hypertension by using a summary receiver-operating characteristic (ROC) curve and sensitivity analysis.Ten studies were finally included in this meta-analysis. AT1-AA showed more significant association with pre-eclampsia than that with non-gravid hypertension (pooled OR 32.84, 95% CI 17.19-62.74; and pooled OR 4.18, 95% CI 2.20-7.98, respectively). Heterogeneity among studies was also detected probably due to different hypertensive subtypes and AT1-AA measuring methods. Area under summary ROC curve (AUC) of pre-eclampsia was 0.92 (sensitivity 0.76; specificity 0.86). Area under the ROC curve of overall hypertensive diseases or non-gravid hypertension was lower than that of pre-eclampsia (0.86 and 0.72, respectively) with lower sensitivities (0.46 and 0.26, respectively).The major limitation of this analysis was the publication bias due to lack of unpublished data and the language limitation during

  19. Angiotensin I converting enzyme inhibitory activity and antihypertensive effect in spontaneously hypertensive rats of cobia (Rachycentron canadum) head papain hydrolysate.

    Science.gov (United States)

    Yang, Ping; Jiang, Yuchuan; Hong, Pengzhi; Cao, Wenhong

    2013-06-01

    Cobia head protein hydrolysate (CHPH) with angiotensin I converting enzyme (ACE) inhibitory activity was prepared with papain. The 3 kDa ultrafiltration filtrate CHPH-IV of the hydrolysate exerted a potent ACE inhibitory activity with IC50 being 0.24 mg/mL. The fractions with molecular weight located between 1749 Da and 173 Da represented up 66.96% of CHPH-IV, and those between 494 Da and 173 Da represented up 31.37% of CHPH-IV. It was found that the ACE inhibitory activity of CHPH-IV was intensified from IC50 0.24 mg/mL to 0.17 mg/mL after incubation with gastrointestinal proteases. The CHPH-IV significantly decreased the systolic blood pressure in a dose-dependent manner after oral administration to spontaneously hypertensive rats (SHR) at dose of 150 mg/kg, 600 mg/kg and 1200 mg/kg body weight. These results suggested that CHPH-IV from cobia head protein hydrolysate by papain could serve as a source of peptides with antihypertensive activity in functional food industry.

  20. Plasma Molecular Signatures in Hypertensive Patients With Renin-Angiotensin System Suppression: New Predictors of Renal Damage and De Novo Albuminuria Indicators.

    Science.gov (United States)

    Baldan-Martin, Montserrat; Mourino-Alvarez, Laura; Gonzalez-Calero, Laura; Moreno-Luna, Rafael; Sastre-Oliva, Tamara; Ruiz-Hurtado, Gema; Segura, Julian; Lopez, Juan Antonio; Vazquez, Jesus; Vivanco, Fernando; Alvarez-Llamas, Gloria; Ruilope, Luis M; de la Cuesta, Fernando; Barderas, Maria G

    2016-07-01

    Albuminuria is a risk factor strongly associated with cardiovascular disease, the first cause of death in the general population. It is well established that renin-angiotensin system suppressors prevent the development of new-onset albuminuria in naïf hypertensive patients and diminish its excretion, but we cannot forget the percentage of hypertensive patients who develop de novo albuminuria. Here, we applied multiple proteomic strategy with the purpose to elucidate specific molecular pathways involved in the pathogenesis and provide predictors and chronic organ damage indicators. Briefly, 1143 patients were followed up for a minimum period of 3 years. One hundred and twenty-nine hypertensive patients chronically renin-angiotensin system suppressed were recruited, classified in 3 different groups depending on their albuminuria levels (normoalbuminuria, de novo albuminuria, and sustained albuminuria), and investigated by multiple proteomic strategies. Our strategy allowed us to perform one of the deepest plasma proteomic analysis to date, which has shown 2 proteomic signatures: (1) with predictive value of de novo albuminuria and (2) sustained albuminuria indicator proteins. These proteins are involved in inflammation, immune as well as in the proteasome activation occurring in situations of endoplasmic reticulum stress. Furthermore, these results open the possibility of a future strategy based on anti-immune therapy to treat hypertension which could help to prevent the development of albuminuria and, hence, the progression of kidney damage.

  1. Mechanisms responsible for postmenopausal hypertension in a rat model: Roles of the renal sympathetic nervous system and the renin-angiotensin system.

    Science.gov (United States)

    Maranon, Rodrigo O; Reckelhoff, Jane F

    2016-02-01

    Hypertension in postmenopausal women is less well controlled than in age-matched men. The aging female SHR is a model of postmenopausal hypertension that is mediated in part by activation of the renin-angiotensin system (RAS) and by the renal sympathetic nervous system. In this study, the hypothesis was tested that renal denervation would lower the blood pressure in old female SHR and would attenuate the antihypertensive effects of AT1 receptor antagonism. Retired breeder female SHR were subjected to right uninephrectomy (UNX) and left renal denervation (RD) or UNX and sham, and 2 weeks later, baseline mean arterial pressure (MAP; radiotelemetry) was measured for 4 days, and then rats were treated with angiotensin (AT1) receptor antagonist, losartan (40 mg/kg/day po) for 6 days. Renal denervation reduced MAP in old females compared to sham (172 ± 6 vs. 193 ± 6 mm Hg; P system and the RAS have independent effects to control the blood pressure in old female SHR. Since the denervated rats treated with losartan remained hypertensive, the data also suggest that other mechanisms than the RAS and renal sympathetic nervous system contribute to the hypertension in old female SHR. The data also suggest that multiple mechanisms may mediate the elevated blood pressure in postmenopausal women.

  2. Influence of a history of arterial hypertension and pretreatment blood pressure on the effect of angiotensin converting enzyme inhibition after acute myocardial infarction. Trandolapril Cardiac Evaluation Study

    DEFF Research Database (Denmark)

    Gustafsson, F; Køber, L; Torp-Pedersen, C

    1998-01-01

    inhibition after AMI complicated by left ventricular dysfunction may be of particular importance in patients with a history of arterial hypertension or a relatively high pretreatment blood pressure. However, further investigations are necessary to establish the clinical impact of these results.......OBJECTIVE: To evaluate the influence of a history of arterial hypertension and the level of pretreatment blood pressure on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril on mortality and morbidity in patients with acute myocardial infarction (AMI) and left...... for a broad spectrum of potential confounders. Also, benefit from ACE inhibition increased with increasing blood pressure at the time of randomization. Significant interactions between benefit from ACE inhibition and hypertension history, and systolic and diastolic blood pressure were found. CONCLUSION: ACE...

  3. High fat diet confers vascular hyper-contractility against angiotensin II through upregulation of MLCK and CPI-17

    Science.gov (United States)

    2017-01-01

    Obesity is a critical risk factor for the hypertension. Although angiotensin II (Ang II) in obese individuals is known to be upregulated in obesity-induced hypertension, direct evidence that explains the underlying mechanism for increased vascular tone and consequent increase in blood pressure (BP) is largely unknown. The purpose of this study is to investigate the novel mechanism underlying Ang II-induced hyper-contractility and hypertension in obese rats. Eight-week old male Sprague-Dawley rats were fed with 60% fat diet or normal diet for 4 months. Body weight, plasma lipid profile, plasma Ang II level, BP, Ang II-induced vascular contraction, and expression of regulatory proteins modulating vascular contraction with/without Ang II stimulation were measured. As a result, high fat diet (HFD) accelerated age-dependent body weight gaining along with increased plasma Ang II concentration. It also increased BP and Ang II-induced aortic contraction. Basal expression of p-CPI-17 and myosin light chain (MLC) kinase was increased by HFD along with increased phosphorylation of MLC. Ang II-induced phosphorylation of CPI-17 and MLC were also higher in HFD group than control group. In conclusion HFD-induced hypertension is through at least in part by increased vascular contractility via increased expression and activation of contractile proteins and subsequent MLC phosphorylation induced by increased Ang II. PMID:28066146

  4. Exercise testing in hypertensive patients taking different angiotensin-converting enzyme inhibitors

    Directory of Open Access Journals (Sweden)

    Maria Angela M. Q. Carreira

    2003-02-01

    Full Text Available OBJECTIVE: To compare blood pressure response to dynamic exercise in hypertensive patients taking trandolapril or captopril. METHODS: We carried out a prospective, randomized, blinded study with 40 patients with primary hypertension and no other associated disease. The patients were divided into 2 groups (n=20, paired by age, sex, race, and body mass index, and underwent 2 symptom-limited exercise tests on a treadmill before and after 30 days of treatment with captopril (75 to 150 mg/day or trandolapril (2 to 4 mg/day. RESULTS: The groups were similar prior to treatment (p<0.05, and both drugs reduced blood pressure at rest (p<0.001. During treatment, trandolapril caused a greater increase in functional capacity (+31% than captopril (+17%; p=0.01 did, and provided better blood pressure control during exercise, observed as a reduction in the variation of systolic blood pressure/MET (trandolapril: 10.7±1.9 mmHg/U vs 7.4±1.2 mmHg/U, p=0.02; captopril: 9.1±1.4 mmHg/U vs 11.4±2.5 mmHg/U, p=0.35, a reduction in peak diastolic blood pressure (trandolapril: 116.8±3.1 mmHg vs 108.1±2.5 mmHg, p=0.003; captopril: 118.2±3.1 mmHg vs 115.8±3.3 mmHg, p=0.35, and a reduction in the interruption of the tests due to excessive elevation in blood pressure (trandolapril: 50% vs 15%, p=0.009; captopril: 50% vs 45%, p=0.32. CONCLUSION: Monotherapy with trandolapril is more effective than that with captopril to control blood pressure during exercise in hypertensive patients.

  5. Polymorphisms of angiotensin-converting enzyme (ACE) and ACE2 are not associated with orthostatic blood pressure dysregulation in hypertensive patients

    Institute of Scientific and Technical Information of China (English)

    Xiaohan FAN; Yi-bo WANG; Hu WANG; Kai SUN; Wei-li ZHANG; Xiao-dong SONG; Jing-zhou CHENG; Hai-ying WU; Xiang-liang ZHOU; Ru-tai HUI

    2009-01-01

    Aim: The genetic background of orthostatic blood pressure dysregulation remains poorly understood. Since the renin-angiotensin sys-tem plays an important role in blood pressure regulation and response to position change, we hypothesized that angiotensin-convert-ing enzyme (ACE) and ACE2 genetic polymorphisms might contribute, at least partially, to orthostatic blood pressure dysregulation in hypertensive patients. Methods: Two tag single nucleotide polymorphisms (SNPs) of ACE2 and ACE I/D were genotyped in 3630 untreated hypertensive patients and 826 normotensive subjects. Orthostatic hypertension was defined as an increase in systolic blood pressure of 20 mmHg or more and orthostatic hypotension as a drop in blood pressure of 20/10 mmHg or more within three minutes of assumption of upright posture. Results: Female and male patients had similar rates of orthostatic hypertension (16.5% vs 15.3%) and hypotension (22.5% vs 23.8%). No significant differences were detected in the minor allele frequency of ACE2 rs2106809, rs2285666, or ACE I/D in either female or male patients with orthostatic hypertension (15.1%, 22.7%, 19.6%, respectively), hypotension (13.8%, 25%, 16.5%), or normal ortho-static blood pressure response (14.4%, 21.9%, 15.8%) in additive, dominant or recessive models after adjustment for confounders (all P>0.05). The orthostatic changes in systolic and diastolic blood pressure were also comparable among patients carrying different genotypes. Similar results were observed in normotensive subjects. Conclusion: These data provide no support for the involvement of ACE or ACE2 in the genetic predisposition to orthostatic hypotension or hypertension.

  6. Renal Inhibition of Heme Oxygenase-1 Increases Blood Pressure in Angiotensin II-Dependent Hypertension

    Directory of Open Access Journals (Sweden)

    Eva Csongradi

    2012-01-01

    Full Text Available The goal of this study was to test the hypothesis that renal medullary heme oxygenase (HO acts as a buffer against Ang-II dependent hypertension. To test this hypothesis, renal medullary HO activity was blocked using QC-13, an imidazole-dioxolane HO-1 inhibitor, or SnMP, a classical porphyrin based HO inhibitor. HO inhibitors were infused via IRMI catheters throughout the study starting 3 days prior to implantation of an osmotic minipump which delivered Ang II or saline vehicle. MAP was increased by Ang II infusion and further increased by IRMI infusion of QC-13 or SnMP. MAP averaged 113±3, 120±7, 141±2, 153±2, and 154±3 mmHg in vehicle, vehicle + IRMI QC-13, Ang II, Ang II + IRMI QC-13, and Ang II + IRMI SnMP treated mice, respectively (n=6. Inhibition of renal medullary HO activity with QC-13 in Ang II infused mice was also associated with a significant increase in superoxide production as well as significant decreases in antioxidant enzymes catalase and MnSOD. These results demonstrate that renal inhibition of HO exacerbates Ang II dependent hypertension through a mechanism which is associated with increases in superoxide production and decreases in antioxidant enzymes.

  7. Antithrombotic effects of losartan in patients with hypertension complicated by atrial fibrillation: 4A (Angiotensin II Antagonist of platelet Aggregation in patients with Atrial fibrillation), a pilot study.

    Science.gov (United States)

    Sakamoto, Tomohiro; Kudoh, Takashi; Sakamoto, Kenji; Matsui, Kunihiko; Ogawa, Hisao

    2014-06-01

    Angiotensin receptor blockers (ARBs) are widely used for the treatment of hypertension. It has been reported that the ARB losartan has antiplatelet, anticoagulant and profibrinolytic effects experimentally. These properties could be desirable to treat hypertensive patients with high atherothrombotic and/or thromboembolic risk. To examine the antithrombotic effects of losartan in hypertension, 20 consecutive patients with hypertension complicated by atrial fibrillation (AF) were enrolled in this study. The patients were treated with losartan 50 mg for 8 weeks followed by 100 mg for 4 weeks. Blood samples were obtained from each patient at 0 (pretreatment), 8 and 12 weeks after initiating treatment. Platelet aggregability, plasma levels of tissue factor (TF) and type 1 plasminogen activator inhibitor (PAI-1) activity levels were measured. The area under the curve for small platelet aggregability decreased from 100 to 42.8% at 12 weeks (PLosartan inhibited platelet activity and coagulation factors in a dose- and time-dependent manner in patients with hypertension complicated by AF, whereas the fibrinolytic capacity was increased. The use of losartan could be advantageous in the treatment of hypertensive patients with high atherothrombotic risk.

  8. Long-term renin-angiotensin blocking therapy in hypertensive patients with normal aorta may attenuate the formation of abdominal aortic aneurysms.

    Science.gov (United States)

    Silverberg, Daniel; Younis, Anan; Savion, Naphtali; Harari, Gil; Yakubovitch, Dmitry; Sheick Yousif, Basheer; Halak, Moshe; Grossman, Ehud; Schneiderman, Jacob

    2014-08-01

    Renin-angiotensin system (RAS) has been implicated in the pathogenesis of abdominal aortic aneurysm (AAA). Angiotensin II type 1 receptor blocker (ARB), when given with angiotensin II prevents AAA formation in mice, but found ineffective in attenuating the progression of preexisting AAA. This study was designed to evaluate the effect of chronic RAS blockers on abdominal aortic diameter in hypertensive patients without known aortic aneurysm. Consecutive hypertensive outpatients (n = 122) were stratified according to antihypertensive therapy they received for 12 months or more, consisting of ARB (n = 45), angiotensin converting enzyme inhibitor (ACE-I; n = 45), or nonARB/nonACE-I (control therapy; n = 32). Abdominal ultrasonography was performed to measure maximal subrenal aortic diameter. Eighty-four patients were reexamined by ultrasonography 8 months later. The correlation between the different antihypertensive therapies and aortic diameter was examined. Aortic diameters were significantly smaller in ARB than in control patients in the baseline and follow-up measurements (P = .004; P = .0004, respectively). Risk factor adjusted covariance analysis showed significant differences between ARB or ACE-I treated groups and controls (P = .006 or P = .046, respectively). Ultrasound that was performed 8 months later showed smaller increases in mean aortic diameters of the ARB and ACE-I groups than in controls. Both ARB and ACE-I therapy attenuated expansion of nonaneurysmal abdominal aorta in humans. These results indicate that RAS blockade given before advancement of aortic medial remodeling may slow down the development of AAA.

  9. Human GRK4γ142V Variant Promotes Angiotensin II Type I Receptor-Mediated Hypertension via Renal Histone Deacetylase Type 1 Inhibition.

    Science.gov (United States)

    Wang, Zheng; Zeng, Chunyu; Villar, Van Anthony M; Chen, Shi-You; Konkalmatt, Prasad; Wang, Xiaoyan; Asico, Laureano D; Jones, John E; Yang, Yu; Sanada, Hironobu; Felder, Robin A; Eisner, Gilbert M; Weir, Matthew R; Armando, Ines; Jose, Pedro A

    2016-02-01

    The influence of a single gene on the pathogenesis of essential hypertension may be difficult to ascertain, unless the gene interacts with other genes that are germane to blood pressure regulation. G-protein-coupled receptor kinase type 4 (GRK4) is one such gene. We have reported that the expression of its variant hGRK4γ(142V) in mice results in hypertension because of impaired dopamine D1 receptor. Signaling through dopamine D1 receptor and angiotensin II type I receptor (AT1R) reciprocally modulates renal sodium excretion and blood pressure. Here, we demonstrate the ability of the hGRK4γ(142V) to increase the expression and activity of the AT1R. We show that hGRK4γ(142V) phosphorylates histone deacetylase type 1 and promotes its nuclear export to the cytoplasm, resulting in increased AT1R expression and greater pressor response to angiotensin II. AT1R blockade and the deletion of the Agtr1a gene normalize the hypertension in hGRK4γ(142V) mice. These findings illustrate the unique role of GRK4 by targeting receptors with opposite physiological activity for the same goal of maintaining blood pressure homeostasis, and thus making the GRK4 a relevant therapeutic target to control blood pressure.

  10. Association of exercise training and angiotensin-converting enzyme 2 activator improves baroreflex sensitivity of spontaneously hypertensive rats.

    Science.gov (United States)

    Lopes, P R; Moreira, M C S; Marques, S M; Pinto, I S J; Macedo, L M; Silva, C C; Freiria-Oliveira, A H; Rebelo, A C S; Reis, A A S; Rosa, D A; Ferreira-Neto, M L; Castro, C H; Pedrino, G R

    2016-08-01

    The present study sought to determine cardiovascular effects of aerobic training associated with diminazene aceturate (DIZE), an activator of the angiotensin converting enzyme 2, in spontaneously hypertensive rats (SHRs). Male SHRs (280-350 g) were either subjected to exercise training or not (sedentary group). The trained group was subjected to 8 weeks of aerobic training on a treadmill (five times a week, lasting 60 min at an intensity of 50-60% of maximum aerobic speed). In the last 15 days of the experimental protocol, these groups were redistributed into four groups: i) sedentary SHRs with daily treatment of 1 mg/kg DIZE (S+D1); ii) trained SHRs with daily treatment of 1 mg/kg DIZE (T+D1); iii) sedentary SHRs with daily treatment of vehicle (S+V); and iv) trained SHRs with daily treatment of vehicle (T+V). After treatment, SHRs were anesthetized and subjected to artery and femoral vein cannulation prior to the implantation of ECG electrode. After 24 h, mean arterial pressure (MAP) and heart rate (HR) were recorded; the baroreflex sensitivity and the effect of double autonomic blockade (DAB) were evaluated in non-anesthetized SHRs. DIZE treatment improved baroreflex sensitivity in the T+D1 group as compared with the T+V and S+D1 groups. The intrinsic heart rate (IHR) and MAP were reduced in T+D1 group as compared with T+V and S+D1 groups. Hence, we conclude that the association of exercise training with DIZE treatment improved baroreflex function and cardiovascular regulation.

  11. A PROSPECTIVE STUDY OF EFFECT OF TELMISARTAN (ANGIOTENSIN II RECEPTOR BLOCKER ON METABOLIC PARAMETERS IN HYPERTENSIVE PATIENTS WITH METABOLIC SYNDROME

    Directory of Open Access Journals (Sweden)

    Somesekhar

    2016-04-01

    Full Text Available BACKGROUND The metabolic syndrome is currently a major worldwide epidemic. It strongly associates with obesity, insulin resistance, type 2 diabetes, and cardiovascular diseases, which are major pathologies contributing to mortality and morbidity worldwide. The effect of PPAR-y on metabolic syndrome is significant it is critical regulator of adipogenesis the gain in PPAR-y is resulted in obesity but loss of PPAR–y by mutation is associated with loss of weight and insulin resistance. Telmisartan is an orally active, long-acting, non-peptide angiotensin type 1 (ATI receptor blocker. In addition to this, it has been identified as partial agonist/selective modulator of the nuclear hormone receptor PPAR-y. MATERIAL AND METHOD This is a prospective, randomised and open labelled 16 weeks study conducted in the Dept. of General Medicine, Konaseema Institute of Medical Science, Amalapuram. Present study is designed to study the effect of telmisartan on various metabolic parameters in hypertensive patients who fulfilled the criteria of metabolic syndrome. RESULT There was statistically significant change in all parameters most important was lipid profile; LDL concentration was decreased from 139.2 mg/dL to 120.2 mg/dL. Baseline triglyceride concentration was 161.0 mg/dL which was changed 152.8 mg/dL Total cholesterol was decreased from 203.2 to 193.8 mg/dL. CONCLUSION In our study, we have also found that use of telmisartan is associated with decrease in lipid concentration in addition to its effect on blood pressure regulation. But a long term study with high dose required of this drug is required because safety profile of this drug is better than thiazolidinedione. Financial part of this study is our limitation.

  12. Interaction and Relationship Between Angiotensin Converting Enzyme Gene and Environmental Factors Predisposing to Essential Hypertension in Mongolian Population of China

    Institute of Scientific and Technical Information of China (English)

    QUN XU; HUA FENG; SHUANG-LIAN BAI; HAI-HUA PANG; GUI-RONG HUANG; MING-WU FANG; YONG-HONG ZHANG; ZHENG-LAI WU; CHANG-CHUN QIU; YAN-HUA WANG; WEI-JUN TONG; MING-LIANG GU; GANG WU; BATU BUREN; YONG-YUE LIU; JIAN WANG; YONG-SHAN LI

    2004-01-01

    Objective To investigate the association of specific functional gene ACE (I/D) variants of the renin-angiotensin system with essential hypertension (EH) and interaction between ACE (I/D) gene and risk factors for EH in a genetically homogenous Mongolia rural population of China. Methods Individuals (n=1099) were recruited from general population of Kezuohouqi Banner in Inner Mongolian Autonomous Region. Results The association was found between ACE genotype DD plus ID and EH, with an interaction between ACE genotype DD plus ID and cigarette smoking in an additive model. Cigarette smoking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 7.10 to 1.16. Interaction between ACE genotype DD plus ID and alcohol drinking on EH appeared an additive model. Alcohol drinking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 1.66 to 1.09. BMI and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 6.15 to 2.49. Interactions between ACE genotype and WHR on EH showed a multiplicative model. In a short, there was an interaction between ACE gene and cigarette smoking, alcohol drinking and BMI on EH, especially in a low dose-exposure effect. Conclusion It is important for individuals who carry ACE D allele gene to prevent EH, and furthermore, to prevent and control coronary heart disease, in a view of population-based prevention.

  13. Increasing the doses of both diuretics and angiotensin receptor blockers is beneficial in subjects with uncontrolled systolic hypertension

    Science.gov (United States)

    Lacourcière, Yves; Poirier, Luc; Lefebvre, Jean; Ross, Stuart A; Leenen, Frans H

    2010-01-01

    BACKGROUND: Blood pressure (BP) control is frequently difficult to achieve in patients with predominantly elevated systolic BP. Consequently, these patients frequently require combination therapy including a thiazide diuretic such as hydrochlorothiazide (HCTZ) and an agent blocking the renin-angiotensin-aldosterone system. Current clinical practice usually limits the daily dose of HCTZ to 25 mg. This often leads to the necessity of using additional antihypertensive agents to control BP in a high proportion of patients. OBJECTIVES: To compare the efficacy of two doses of losartan (LOS)/HCTZ combinations in patients with uncontrolled ambulatory systolic hypertension after six weeks of treatment with LOS 100 mg/HCTZ 25 mg (LOS100/HCTZ25). METHODS: Following a two- to four-week washout period, subjects with a mean clinic sitting systolic BP of 160 mmHg or higher and a mean ambulatory daytime systolic BP (MDSBP) of 135 mmHg or higher on LOS100/HCTZ25 (n=105; 33 women and 72 men) were randomly assigned to receive LOS 150 mg/HCTZ 25 mg (group 1; n=53) or LOS 150 mg/HCTZ 37.5 mg (LOS150/HCTZ37.5, group 2; n=52). The primary end point was the difference in MDSBP reductions. RESULTS: At the end of the six-week treatment period, the respective additional decreases in MDSBP were 1.2 mmHg (P=0.335) on LOS 150 mg/HCTZ 25 mg and 5.6 mmHg (P<0.0001) on LOS150/HCTZ37.5 (difference of 4.4 mmHg; P=0.011). Daytime systolic ambulatory BP goal (lower than 130 mmHg) achievement tended to be higher (25% versus 17%; P=0.313) with LOS150/HCTZ37.5, while it was significantly higher (65% versus 43%; P=0.024) for mean daytime diastolic BP (lower than 80 mmHg). No deleterious metabolic changes were observed. CONCLUSIONS: In patients with uncontrolled systolic ambulatory hypertension receiving LOS100/HCTZ25, increasing both HCTZ and LOS dosages simultaneously to LOS150/HCTZ37.5 may be an effective strategy that does not affect metabolic parameters. PMID:20931100

  14. Renin-Angiotensin System Genes and Exercise Training-Induced Changes in Sodium Excretion in African American Hypertensives

    Science.gov (United States)

    Jones, Jennifer M.; Park, Jung-Jun; Johnson, Jennifer; Vizcaino, Dave; Hand, Brian; Ferrell, Robert; Weir, Matthew; Dowling, Thomas; Obisesan, Thomas; Brown, Michael

    2008-01-01

    Objective To determine whether angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) genotypes could predict changes in urinary sodium excretion in response to short-term aerobic exercise training (AEX). Design Longitudinal intervention. Setting The study was conducted at the University of Maryland at College Park and at Baltimore, and the University of Pittsburgh General Clinical Research Center. Participants 31 (age 53 ± 2 years) sedentary, hypertensive (146 ± 2/88 ± 2 mm Hg) African Americans. Intervention Aerobic exercise training (AEX) consisted of seven or eight consecutive days, 50 minutes per day, at 65% of heart rate reserve. Participants underwent a 24-hour period of ambulatory blood pressure (BP) monitoring and urine collection at baseline and 14–18 hours after the last exercise session. Main Outcome Measures Angiotensiongen (AGT) M235T and ACE I/D genotype and sodium excretion and ambulatory BP. Results Average sodium excretion for the entire group independent of genotype increased after AEX (108 ± 9 vs 143 ± 12 mEq/day, P=.003). Sodium excretion significantly increased after exercise training in the ACE II (114 ± 22 vs 169 ± 39 mEq/day, P=.04), but not in the ID (100 ± 8 vs 133 ± 17 mEq/day, P=.12) or DD (113 ± 18 vs 138 ± 11 mEq/day, P=.13) genotype groups. In the II genotype group, the increase in sodium excretion was significantly and inversely correlated with decreases in 24-hour diastolic (r=−.88, P=.02) and mean (r=−.95, P=.004) BP. The AGT TT and MT+MM genotype groups similarly increased their sodium excretion by 34 ± 16 (P=.05) and 37 ± 17 (P=.05) mEq/day respectively. Conclusions These results suggest that African American hypertensives with the ACE II genotype may be more susceptible to sodium balance and BP changes with exercise training compared with those with the ID and DD genotypes. PMID:16937603

  15. Construction, expression and immunogenicity of a novel anti-hypertension angiotensin II vaccine based on hepatitis A virus-like particle.

    Science.gov (United States)

    Ou, Xia; Guo, Lili; Wu, Jinyuan; Mi, Kai; Yin, Na; Zhang, Guangming; Li, Hongjun; Sun, Maosheng

    2013-06-01

    Hypertension is a serious worldwide public health problem. The aim of this study is to design anti-hypertension angiotensin II (Ang II) vaccine using molecular biology and immunological method. This novel anti-hypertension vaccine, which is a chimeric protein named pHAV-4Ang IIs, presents four successive repeated Ang IIs as the functional epitope on the surface of the hepatitis A virus-like particle(HAVLP). In this study, pHAV-4Ang IIs was expressed using Bac-to-Bac Baculovirus Expression System. With the RT-PCR analysis, SDS-PAGE, western blot, IFA, electron microscope methods for identification of expression products, these results confirmed that stable expression of pHAV-4Ang IIs can be effectively achieved in infected sf9 cells. Spontaneous hypertensive rats (SHRs) were immunized with pHAV-4Ang IIs to test immunogenicity and pharmacodynamic action. The results showed that this anti-hypertension vaccine can induce high titer Ang II -specific IgG antibody for almost 10 weeks. When antibody titer reached the peak at 8th week, the mean systolic blood pressure (SBP) degraded approximately 23 mmHg compared with the PBS control group, and the mean diastolic blood pressure (DBP) degraded approximately 12 mmHg compared with the PBS control group. These results suggest that this anti-hypertension vaccine has good immunogenicity and good effect on reduction of blood pressure in SHRs, which provide reliable base for large-scale preparation of this hypertension vaccine in the future, and a new direction of exploration for the development of anti-hypertension therapeutic vaccine.

  16. Improving BP control with combined renin-angiotensin system blockade and thiazide diuretics in hypertensive patients with diabetes mellitus or kidney disease.

    Science.gov (United States)

    Palmer, Biff F

    2008-01-01

    Most hypertensive patients will require more than one antihypertensive drug to lower BP below target levels. The combination of diuretics with renin-angiotensin system (RAS) antagonists offers several advantages to include additive BP-lowering efficacy and enhanced reductions in urinary protein excretion. Thiazide diuretics are associated with metabolic complications that are particularly evident when used in high doses. When used in combination with RAS blockade, metabolic complications such as hypokalemia are minimized. The avoidance of hypokalemia has been linked to less thiazide-induced glucose intolerance. Patient persistence on therapy is dependent on well tolerated drug combinations.

  17. The combination of amlodipine and angiotensin receptor blocker or diuretics in high-risk hypertensive patients: rationale, design and baseline characteristics

    Science.gov (United States)

    Wang, W; Ma, L; Zhang, Y; Deng, Q; Liu, M; Liu, L

    2011-01-01

    The Chinese Hypertension Intervention Efficacy Study (CHIEF) is a multi-centre randomized controlled clinical trial comparing the effects of amlodipine+angiotensin II receptor blocker and amlodipine+diuretics on the incidence of cardiovascular events, represented as a composite of non-fatal stroke, non-fatal myocardial infarction and cardiovascular death events in high-risk Chinese hypertensive patients. The study also evaluates the long-term effects of lipid-lowering treatment and lifestyle modification. From October 2007 to October 2008, 13 542 patients were enrolled into the study in 180 centres in China. Patients will be followed up for 4 years. There was no difference in baseline characteristics between the two blood pressure arms. PMID:20445570

  18. Deletion of the angiotensin II type 1 receptor–associated protein enhances renal sodium reabsorption and exacerbates angiotensin II–mediated hypertension

    OpenAIRE

    Ohsawa, Masato; Tamura, Kouichi; Wakui, Hiromichi; Maeda, Akinobu; Dejima, Toru; Kanaoka, Tomohiko; Azushima, Kengo; Uneda, Kazushi; Tsurumi-Ikeya, Yuko; Kobayashi, Ryu; Matsuda, Miyuki; Uchida, Shinichi; Toya, Yoshiyuki; Kobori, Hiroyuki; Nishiyama, Akira

    2014-01-01

    Angiotensin II type 1 receptor (AT1R)–associated protein (ATRAP) promotes AT1R internalization along with suppression of pathological activation of tissue AT1R signaling. However, the functional significance of ATRAP in renal sodium handling and blood pressure regulation under pathological stimuli is not fully resolved. Here we show the blood pressure of mice with a gene-targeted disruption of ATRAP was comparable to that of wild-type mice at baseline. However, in ATRAP-knockout mice, angiote...

  19. Magnetic resonance imaging left ventricular mass reduction with fixed-dose angiotensin-converting enzyme inhibitor-based regimens in patients with high-risk hypertension.

    Science.gov (United States)

    Reichek, Nathaniel; Devereux, Richard B; Rocha, Ricardo A; Hilkert, Robert; Hall, Donna; Purkayastha, Das; Pitt, Bertram

    2009-10-01

    Left ventricular hypertrophy, a major cardiovascular risk factor for morbidity and mortality, is commonly caused by arterial hypertension. The renin-angiotensin-aldosterone system may contribute to the pathogenesis of left ventricular hypertrophy. The Assessment of Lotrel in Left Ventricular Hypertrophy and Hypertension Study compared a single-pill combination of amlodipine/benazepril at doses 5.0/20.0 mg, 5.0/40.0 mg, and 10.0/40.0 mg with hydrochlorothiazide/benazepril at doses 12.5/20.0 mg, 12.5/40.0 mg, and 25.0/40.0 mg on the reduction of left ventricular mass index measured by cardiac MRI in stage 2 hypertensive patients over 52 weeks of treatment in a randomized clinical trial. A total of 125 male and female patients, > or =55 years of age, with echocardiographic left ventricular hypertrophy and high-risk hypertension defined as blood pressure > or =160/100 mm Hg or current antihypertensive treatment were enrolled. After 52 weeks of treatment, left ventricular mass index was significantly reduced from baseline with amlodipine/benazepril (mean: 10.16 g/m(2)) or hydrochlorothiazide/benazepril (mean: 6.74 g/m(2); both Pamlodipine/benazepril (P=0.02). Both treatments were well tolerated.

  20. Association of Angiotensin Converting Enzyme Insertion-Deletion Polymorphism with Hypertension in Emiratis with Type 2 Diabetes Mellitus and Its Interaction with Obesity Status

    Directory of Open Access Journals (Sweden)

    Habiba Alsafar

    2015-01-01

    Full Text Available The association of Angiotensin Converting Enzyme (ACE insertion-deletion (I/D polymorphism with Type 2 Diabetes Mellitus (T2DM and hypertension has been extensively studied throughout various ethnic populations but largely with inconsistent findings. We investigated these associations in Emirati population and their interaction with obesity status. Saliva samples were collected from a total of 564 Emiratis (277 T2DM and 297 healthy. DNA was extracted and the samples were genotyped for ACE I/D polymorphism by a PCR based method followed by gel electrophoresis. Upon evaluation of the ACE I/D polymorphism amongst all T2DM, hypertensive patients, and respective controls regardless of obesity status, ACE DD genotype was not found to be associated with either T2DM [odds ratio (OR = 1.34, p=0.086] or hypertension [odd ratio (OR = 1.02, p=0.93]. When the genetic variants amongst the nonobese and obese population were analyzed separately, the risk genotype ACE DD conferred significantly increased risk of hypertension in nonobese population [odds ratio (OR = 1.80, p=0.02] but was found to be protective against the hypertension in the obese group ((OR = 0.54, p=0.01. However, there was no effect of obesity status on the association of ACE genotypes with T2DM. The risk of hypertension associated with ACE DD is modulated by obesity status and hence future genetic association studies should take obesity into account for the interpretation of data. We also confirmed that ACE I/D polymorphism is not associated with T2DM risk in Emirati population.

  1. Association of Angiotensin Converting Enzyme Insertion-Deletion Polymorphism with Hypertension in Emiratis with Type 2 Diabetes Mellitus and Its Interaction with Obesity Status.

    Science.gov (United States)

    Alsafar, Habiba; Hassoun, Ahmed; Almazrouei, Shaikha; Kamal, Wala; Almaini, Mustafa; Odama, Unini; Rais, Naushad

    2015-01-01

    The association of Angiotensin Converting Enzyme (ACE) insertion-deletion (I/D) polymorphism with Type 2 Diabetes Mellitus (T2DM) and hypertension has been extensively studied throughout various ethnic populations but largely with inconsistent findings. We investigated these associations in Emirati population and their interaction with obesity status. Saliva samples were collected from a total of 564 Emiratis (277 T2DM and 297 healthy). DNA was extracted and the samples were genotyped for ACE I/D polymorphism by a PCR based method followed by gel electrophoresis. Upon evaluation of the ACE I/D polymorphism amongst all T2DM, hypertensive patients, and respective controls regardless of obesity status, ACE DD genotype was not found to be associated with either T2DM [odds ratio (OR) = 1.34, p = 0.086] or hypertension [odd ratio (OR) = 1.02, p = 0.93]. When the genetic variants amongst the nonobese and obese population were analyzed separately, the risk genotype ACE DD conferred significantly increased risk of hypertension in nonobese population [odds ratio (OR) = 1.80, p = 0.02] but was found to be protective against the hypertension in the obese group ((OR) = 0.54, p = 0.01). However, there was no effect of obesity status on the association of ACE genotypes with T2DM. The risk of hypertension associated with ACE DD is modulated by obesity status and hence future genetic association studies should take obesity into account for the interpretation of data. We also confirmed that ACE I/D polymorphism is not associated with T2DM risk in Emirati population.

  2. Platelet-localized FXI promotes a vascular coagulation-inflammatory circuit in arterial hypertension.

    Science.gov (United States)

    Kossmann, Sabine; Lagrange, Jeremy; Jäckel, Sven; Jurk, Kerstin; Ehlken, Moritz; Schönfelder, Tanja; Weihert, Yvonne; Knorr, Maike; Brandt, Moritz; Xia, Ning; Li, Huige; Daiber, Andreas; Oelze, Matthias; Reinhardt, Christoph; Lackner, Karl; Gruber, Andras; Monia, Brett; Karbach, Susanne H; Walter, Ulrich; Ruggeri, Zaverio M; Renné, Thomas; Ruf, Wolfram; Münzel, Thomas; Wenzel, Philip

    2017-02-01

    Multicellular interactions of platelets, leukocytes, and the blood vessel wall support coagulation and precipitate arterial and venous thrombosis. High levels of angiotensin II cause arterial hypertension by a complex vascular inflammatory pathway that requires leukocyte recruitment and reactive oxygen species production and is followed by vascular dysfunction. We delineate a previously undescribed, proinflammatory coagulation-vascular circuit that is a major regulator of vascular tone, blood pressure, and endothelial function. In mice with angiotensin II-induced hypertension, tissue factor was up-regulated, as was thrombin-dependent endothelial cell vascular cellular adhesion molecule 1 expression and integrin αMβ2- and platelet-dependent leukocyte adhesion to arterial vessels. The resulting vascular inflammation and dysfunction was mediated by activation of thrombin-driven factor XI (FXI) feedback, independent of factor XII. The FXI receptor glycoprotein Ibα on platelets was required for this thrombin feedback activation in angiotensin II-infused mice. Inhibition of FXI synthesis with an antisense oligonucleotide was sufficient to prevent thrombin propagation on platelets, vascular leukocyte infiltration, angiotensin II-induced endothelial dysfunction, and arterial hypertension in mice and rats. Antisense oligonucleotide against FXI also reduced the increased blood pressure and attenuated vascular and kidney dysfunction in rats with established arterial hypertension. Further, platelet-localized thrombin generation was amplified in an FXI-dependent manner in patients with uncontrolled arterial hypertension, suggesting that platelet-localized thrombin generation may serve as an inflammatory marker of high blood pressure. Our results outline a coagulation-inflammation circuit that promotes vascular dysfunction, and highlight the possible utility of FXI-targeted anticoagulants in treating hypertension, beyond their application as antithrombotic agents in

  3. PERK介导的内质网应激参与血管紧张素Ⅱ诱导心肌肥大的机制%PERK-mediated endoplasmic reticulum stress is involved in angiotensin II-induced myocardial hypertrophy

    Institute of Scientific and Technical Information of China (English)

    吕振嵘; 王晓礽; 李玉珍; 王琛; 刘秀华

    2012-01-01

    目的:研究蛋白激酶R样内质网激酶(PERK)介导的内质网应激(ERS)反应在血管紧张素Ⅱ(AngⅡ)诱导心肌细胞肥大中的作用.方法:在AngⅡ诱导原代培养的乳大鼠心肌细胞肥大模型上,采用[3H]-亮氨酸掺入、心肌细胞表面积测定等评估心肌细胞肥大程度;以实时定量PCR、RT-PCR和Western blotting检测ERS标志性分子葡萄糖调节蛋白78(GRP78)、钙网蛋白(CRT)、蛋白激酶R样内质网激酶(PERK)、真核细胞翻译起始因子2α(eIF2α)和C/EBP同源蛋白(CHOP)mRNA和蛋白表达变化.结果:与正常对照组比较,AngⅡ组CRT mRNA和蛋白表达分别高146.4%和125.3%(P<0.05),GRP78 mRNA和蛋白的表达分别高84.0%和77.6% (P<0.05),PERK mRNA和蛋白表达分别高165.4%和132.1%(P<0.05),eIF2α mRNA和蛋白表达分别高110.9%和46.5%(P<0.05),CHOP mRNA和蛋白表达分别高117.7%和63.3%(P<0.05).结论:PERK介导的内质网应激反应参与了AngⅡ诱导的心肌细胞肥大.%AIM: To investigate the role of protein kinase R - like endoplasmic reticulum kinase ( PERK ) -mediated endoplasmic reticulum stress ( ERS ) in angiotensin II ( Ang II ) — induced myocardial hypertrophy. METHODS : In the hypertrophy model of Ang II — induced cardiomyocytes isolated from neonatal Sprague — Dawley rats, the methods of morphological observation, [ 3 H ] - leucine incorporation and surface area measurement were employed to assess the cardiomyocyte hypertrophy. Real -time PCR, RT-PCR and Western blotting were used to detected the expression of glucose — regulated protein 78 ( GRP78 ), calreticulin ( CRT ), PERK, eukaryotic initiation factor 2α ( eIF2α ) and C/EBP homologous protein ( CHOP ) at mRNA and protein levels. RESULTS: Compared with control group, Ang II - treated cardiomyocytes showed that the mRNA and protein expression of CRT increased by 146. 4% and 125. 3% , respectively ( P < 0. 05 ). The mRNA and protein expression of GRP78 increased by 84. 0% and 77. 6

  4. Comparative Effects of Direct Renin Inhibitor and Angiotensin Receptor Blocker on Albuminuria in Hypertensive Patients with Type 2 Diabetes. A Randomized Controlled Trial

    Science.gov (United States)

    Uzu, Takashi; Araki, Shin-ichi; Kashiwagi, Atsunori; Haneda, Masakazu; Koya, Daisuke; Yokoyama, Hiroki; Kida, Yasuo; Ikebuchi, Motoyoshi; Nakamura, Takaaki; Nishimura, Masataka; Takahara, Noriko; Obata, Toshiyuki; Omichi, Nobuyuki; Sakamoto, Katsuhiko; Shingu, Ryosuke; Taki, Hideki; Nagai, Yoshio; Tokuda, Hiroaki; Kitada, Munehiro; Misawa, Miwa; Nishiyama, Akira; Kobori, Hiroyuki; Maegawa, Hiroshi

    2016-01-01

    Background In patients with diabetes, albuminuria is a risk marker of end-stage renal disease and cardiovascular events. An increased renin-angiotensin system activity has been reported to play an important role in the pathological processes in these conditions. We compared the effect of aliskiren, a direct renin inhibitor (DRI), with that of angiotensin receptor blockers (ARBs) on albuminuria and urinary excretion of angiotensinogen, a marker of intrarenal renin-angiotensin system activity. Methods We randomly assigned 237 type 2 diabetic patients with high-normal albuminuria (10 to <30 mg/g of albumin-to-creatinine ratio) or microalbuminuria (30 to <300 mg/g) to the DRI group or ARB group (any ARB) with a target blood pressure of <130/80 mmHg. The primary endpoint was a reduction in albuminuria. Results Twelve patients dropped out during the observation period, and a total of 225 patients were analyzed. During the study period, the systolic and diastolic blood pressures were not different between the groups. The changes in the urinary albumin-to-creatinine ratio from baseline to the end of the treatment period in the DRI and ARB groups were similar (-5.5% and -6.7%, respectively). In contrast, a significant reduction in the urinary excretion of angiotensinogen was observed in the ARB group but not in the DRI group. In the subgroup analysis, a significant reduction in the albuminuria was observed in the ARB group but not in the DRI group among high-normal albuminuria patients. Conclusion DRI and ARB reduced albuminuria in hypertensive patients with type 2 diabetes. In addition, ARB, but not DRI, reduced albuminuria even in patients with normal albuminuria. DRI is not superior to ARB in the reduction of urinary excretion of albumin and angiotensinogen. PMID:28033332

  5. Angiotensin-converting enzyme inhibition-induced changes in hippurate renography and renal function in renovascular hypertension

    NARCIS (Netherlands)

    Visscher, C.A; de Zeeuw, D; de Jong, P.E; Piers, D.A; Beekhuis, H; Groothuis, Geny; Huisman, R.M

    1996-01-01

    We studied the mechanism of angiotensin-converting enzyme (ACE) inhibition-induced changes in hippurate renography of the poststenotic kidney. Methods: Ten male mongrel dogs, six with unilateral and four with bilateral renal artery stenosis, were equipped with renal artery blood flow probes and cath

  6. Isolation of an Angiotensin I-Converting Enzyme Inhibitory Protein with Antihypertensive Effect in Spontaneously Hypertensive Rats from the Edible Wild Mushroom Leucopaxillus tricolor

    Directory of Open Access Journals (Sweden)

    Xueran Geng

    2015-06-01

    Full Text Available An 86-kDa homodimeric angiotensin I-converting enzyme (ACE inhibitory protein designated as LTP was isolated from fruit bodies of the mushroom Leucopaxillus tricolor. The isolation procedure involved ultrafiltration through a membrane with a molecular weight cutoff of 10-kDa, ion exchange chromatography on Q-Sepharose, and finally fast protein liquid chromatography-gel filtration on Superdex 75. LTP exhibited an IC50 value of 1.64 mg∙mL−1 for its ACE inhibitory activity. The unique N-terminal amino acid sequence of LTP was disclosed by Edman degradation to be DGPTMHRQAVADFKQ. In addition, seven internal sequences of LTP were elucidated by liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis. Results of the Lineweaver-Burk plot suggested that LTP competitively inhibited ACE. Both LTP and the water extract of L. tricolor exhibited a clear antihypertensive effect on spontaneously hypertensive rats.

  7. Post-renal-transplant hypertension. Urine volume, free water clearance and plasma concentrations of arginine vasopressin, angiotensin II and aldosterone before and after oral water loading in hypertensive and normotensive renal transplant recipients.

    Science.gov (United States)

    Pedersen, E B; Danielsen, H; Knudsen, F; Nielsen, A H; Jensen, T; Kornerup, H J; Madsen, M

    1986-09-01

    Urine volume (V), free water clearance (CH2O) and plasma concentrations of arginine vasopressin (AVP), angiotensin II (A II) and aldosterone (Aldo) were determined before and three times during the first 5 h after an oral water load of 20 ml/kg body wt in 19 patients with post-renal-transplant hypertension (group I), in 13 normotensive renal transplant recipients (group II) and in 20 control subjects (group III). Both V and CH2O increased significantly in all groups, but considerably less in groups I and II than in group III. When CH2O was related to glomerular filtration rate no differences existed between patients and control subjects. Basal AVP was the same in groups I (3.3 pmol/l, median) and II (3.0 pmol/l), but significantly (p less than 0.01) higher than in group III (1.9 pmol/l). Basal A II was significantly (p less than 0.01) elevated in group I (18 pmol/l) when compared to both groups II (10 pmol/l) and III (11 pmol/l), and the level was independent of the presence of native kidneys. Basal Aldo was the same in all groups. During loading, AVP was reduced in all groups, A II was almost unchanged, and Aldo was increased in groups I and II and reduced in group III depending on alterations in serum potassium. Thus urinary diluting ability is reduced in renal transplant recipients due to a reduced glomerular filtration rate. The enhanced A II in hypertensive renal transplant recipients gives further evidence for the point of view that hypertension is angiotensin-dependent in most of these patients.

  8. Aldosterone synthase C-344T, angiotensin II type 1 receptor A1166C and 11- hydroxysteroid dehydrogenase G534A gene polymorphisms and essential hypertension in the population of Odisha, India

    Indian Academy of Sciences (India)

    Manisha Patnaik; Pallabi Pati; Surendra N. Swain; Manoj K. Mohapatra; Bhagirathi Dwibedi; Shantanu K. Kar; Manoranjan Ranjit

    2014-12-01

    Essential hypertension which accounts 90–95% of the total hypertension cases is affected by both genetic and environmental factors. This study was undertaken to investigate the association of aldosterone synthase C-344T, angiotensin II type I receptor A1166C and 11- hydroxysteroid dehydrogenase type 2 G534A polymorphisms with essential hypertension in the population of Odisha, India. A total of 246 hypertensive subjects (males, 159; females, 87) and 274 normal healthy individuals (males, 158; females, 116) were enrolled in this study based on the inclusion and exclusion criteria. Analysis of genetic and biochemical data revealed that in this population the CT and TT genotypes of aldosterone synthase C-344T polymorphism, frequency of alcohol consumption and aldosterone levels were significantly high among the total as well as male hypertensives, while the AC and CC genotypes of angiotensin II type I receptor A1166C polymorphism were significantly high among the total as well as female hypertensives. High density lipoprotein levels were higher in male hypertensives.

  9. Aldosterone synthase C-344T, angiotensin II type 1 receptor A1166C and 11- hydroxysteroid dehydrogenase G534A gene polymorphisms and essential hypertension in the population of Odisha, India

    Indian Academy of Sciences (India)

    Manisha Patnaik; Pallabi Pati; Surendra N. Swain; Manoj K. Mohapatra; Bhagirathi Dwibedi; Shantanu K. Kar; Manoranjan Ranjit

    2015-06-01

    Essential hypertension which accounts 90–95% of the total hypertension cases is affected by both genetic and environmental factors. This study was undertaken to investigate the association of aldosterone synthase C-344T, angiotensin II type I receptor A1166C and 11- hydroxysteroid dehydrogenase type 2 G534A polymorphisms with essential hypertension in the population of Odisha, India. A total of 246 hypertensive subjects (males, 159; females, 87) and 274 normal healthy individuals (males, 158; females, 116) were enrolled in this study based on the inclusion and exclusion criteria. Analysis of genetic and biochemical data revealed that in this population the CT and TT genotypes of aldosterone synthase C-344T polymorphism, frequency of alcohol consumption and aldosterone levels were significantly high among the total as well as male hypertensives, while the AC and CC genotypes of angiotensin II type I receptor A1166C polymorphism were significantly high among the total as well as female hypertensives. High density lipoprotein levels were higher in male hypertensives.

  10. The chronic blockade of angiotensin I-converting enzyme eliminates the sex differences of serum cytokine levels of spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Dalpiaz, P.L.M.; Lamas, A.Z.; Caliman, I.F. [Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Medeiros, A.R.S. [Ciências Biológicas e da Saúde, Instituto Federal do Espírito Santo, Vitória, ES (Brazil); Abreu, G.R.; Moysés, M.R. [Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Andrade, T.U. [Departamento de Farmácia, Centro Universitário de Vila Velha, Vila Velha, ES (Brazil); Alves, M.F.; Carmona, A.K. [Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Bissoli, N.S. [Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, ES (Brazil)

    2013-02-01

    Sex hormones modulate the action of both cytokines and the renin-angiotensin system. However, the effects of angiotensin I-converting enzyme (ACE) on the proinflammatory and anti-inflammatory cytokine levels in male and female spontaneously hypertensive rats (SHR) are unclear. We determined the relationship between ACE activity, cytokine levels and sex differences in SHR. Female (F) and male (M) SHR were divided into 4 experimental groups each (n = 7): sham + vehicle (SV), sham + enalapril (10 mg/kg body weight by gavage), castrated + vehicle, and castrated + enalapril. Treatment began 21 days after castration and continued for 30 days. Serum cytokine levels (ELISA) and ACE activity (fluorimetry) were measured. Male rats exhibited a higher serum ACE activity than female rats. Castration reduced serum ACE in males but did not affect it in females. Enalapril reduced serum ACE in all groups. IL-10 (FSV = 16.4 ± 1.1 pg/mL; MSV = 12.8 ± 1.2 pg/mL), TNF-α (FSV = 16.6 ± 1.2 pg/mL; MSV = 12.8 ± 1 pg/mL) and IL-6 (FSV = 10.3 ± 0.2 pg/mL; MSV = 7.2 ± 0.2 pg/mL) levels were higher in females than in males. Ovariectomy reduced all cytokine levels and orchiectomy reduced IL-6 but increased IL-10 concentrations in males. Castration eliminated the differences in all inflammatory cytokine levels (IL-6 and TNF-α) between males and females. Enalapril increased IL-10 in all groups and reduced IL-6 in SV rats. In conclusion, serum ACE inhibition by enalapril eliminated the sexual dimorphisms of cytokine levels in SV animals, which suggests that enalapril exerts systemic anti-inflammatory and anti-hypertensive effects.

  11. Local and systemic renin-angiotensin system participates in cardiopulmonary-renal interactions in monocrotaline-induced pulmonary hypertension in the rat.

    Science.gov (United States)

    Malikova, Eva; Galkova, Kristina; Vavrinec, Peter; Vavrincova-Yaghi, Diana; Kmecova, Zuzana; Krenek, Peter; Klimas, Jan

    2016-07-01

    Renin-angiotensin system (RAS) is one of the pathophysiological mechanisms in heart failure. Recently, involvement of the kidney in the disease progression has been proposed in patients with pulmonary arterial hypertension (PAH). We hypothesized that local and systemic RAS could be the central regulators of cardiopulmonary-renal interactions in experimental monocrotaline-induced pulmonary hypertension (PH) in rats. Male 12-week-old Wistar rats were injected subcutaneously with monocrotaline (60 mg/kg). The experiment was terminated 4 weeks after monocrotaline administration. Using RT-PCR, we measured the expression of RAS-related genes in right and left ventricles, lungs and kidneys, together with indicators of renal dysfunction and damage. We observed a significantly elevated expression of angiotensin-converting enzyme (ACE) in both left and right ventricles and kidneys (P < 0.05), but a significantly decreased ACE in the lungs (P < 0.05). Kidneys showed a significant 2.5-fold increase in renin mRNA (P < 0.05) along with erythropoietin, TGFβ1, COX-2, NOS-1 and nephrin. Expression of erythropoietin correlated inversely with hemoglobin oxygen saturation and positively with renin expression. In conclusion, monocrotaline-induced PH exhibited similar alterations of ACE expression in the left and right ventricles, and in the kidney, in contrast to the lungs. Increased renal renin was likely a consequence of renal hypoxia/hypoperfusion, as was increased renal erythropoietin expression. Alterations in RAS in the monocrotaline model are probably a result of hypoxic state, and while they could serve as a compensatory mechanism at a late stage of the disease, they could be viewed also as an indicator of multiorgan failure in PAH.

  12. Alpinate Oxyphyllae Fructus Inhibits IGFII-Related Signaling Pathway to Attenuate Ang II-Induced Pathological Hypertrophy in H9c2 Cardiomyoblasts.

    Science.gov (United States)

    Tsai, Chuan-Te; Chang, Yung-Ming; Lin, Shu-Luan; Chen, Yueh-Sheng; Yeh, Yu-Lan; Padma, Viswanadha Vijaya; Tsai, Chin-Chuan; Chen, Ray-Jade; Ho, Tsung-Jung; Huang, Chih-Yang

    2016-03-01

    Angiotensin II (Ang II) is a very important cardiovascular disease inducer and may cause cardiac pathological hypertrophy and remodeling. We evaluated a Chinese traditional medicine, alpinate oxyphyllae fructus (AOF), for therapeutic efficacy for treating Ang II-induced cardiac hypertrophy. AOF has been used to treat patients with various symptoms accompanying hypertension and cerebrovascular disorders in Korea. We investigated its protective effect against Ang II-induced cytoskeletal change and hypertrophy in H9c2 cells. The results showed that treating cells with Ang II resulted in pathological hypertrophy, such as increased expression of transcription factors NFAT-3/p-NFAT-3, hypertrophic response genes (atrial natriuretic peptide [ANP] and b-type natriuretic peptide [BNP]), and Gαq down-stream effectors (PLCβ3 and calcineurin). Pretreatment with AOF (60-100 μg/mL) led to significantly reduced hypertrophy. We also found that AOF pretreatment significantly suppressed the cardiac remodeling proteins, metalloproteinase (MMP9 and MMP2), and tissue plasminogen activator (tPA), induced by Ang II challenge. In conclusion, we provide evidence that AOF protects against Ang II-induced pathological hypertrophy by specifically inhibiting the insulin-like growth factor (IGF) II/IIR-related signaling pathway in H9c2 cells. AOF might be a candidate for cardiac hypertrophy and ventricular remodeling prevention in chronic cardiovascular diseases.

  13. Effects of valsartan with or without benazepril on blood pressure,angiotensin Ⅱ,and endoxin in patients with essential hypertension

    Institute of Scientific and Technical Information of China (English)

    KEYong-Sheng; TAOYue-Yu; 等

    2003-01-01

    AIM:To eveluate the effects of valsartan(Val)with or without benazepril(Ben)on blood pressure and plasma levels of angiotensin(Ang Ⅱ)and digoxin-immunoreactive factors(endoxin)in patients with essential hypertension. METHODS:Ninety patients with essential hypertension were randomly divided into 3 groups(n=30 per group):Ben group(Ben 10 mg/d,po);Val group(Val 80mg/d,po);combination drug therapy group(Val 80mg/d+Ben 10mg/d,po);all patients were treated for 12 weeks.Age and sex-matched 20 normal subjects were served as control group.RESULTS:The levels of plasma endoxin and ang Ⅱ in patients with essential hypertension were remarkably higher than those in normal subjects.The levels of plasma ang Ⅱ and endoxin were all obvious positive correlation with systolic blood pressure(SBP)and diastolic blood pressure(DBP)(Ang Ⅱ:r=0.5151,0.7978;endoxin:r= 0.4706,0.7274,respectively),within 6 weeks of drug intervene,SBP and DBP were remarkably decreased in 3 groups.After 6 weeks,SBP and DBP were continuously decreased in Ben group and Val+Ben group,but not in Val group.Level of plasma AngⅡ was remarkably decreased as SBP and DBP decreased in Ben group and Val+Ben group;level of plasma AngⅡ was remarkably increased in Val group.CONCLUSION:Val with or without Ben remarkably decreased SBP and DBP in patients with essential hypertension within 6 weeks.Antihypertensive efficacy was weakened after long-term use of Val alone.The antihypertensive effect of Val+Ben group was the most remarkable among 3 groups and could avoid the side effects of high plasma AngⅡ.

  14. Blockade of the renin-angiotensin system

    OpenAIRE

    Cheung, BMY.

    2002-01-01

    The renin-angiotensin-aldosterone system plays a key role in the regulation of fluid and electrolyte balance. Angiotensin-converting enzyme inhibitors inhibit angiotensin-converting enzyme and have been shown to be effective in many cardiovascular diseases. They should be considered for the treatment of hypertension in patients with heart failure, previous myocardial infarction, diabetes, or proteinuria. There are a number of side-effects associated with angiotensin-converting enzyme inhibito...

  15. Renoprotective Effect of the Combination of Renin-angiotensin System Inhibitor and Calcium Channel Blocker in Patients with Hypertension and Chronic Kidney Disease

    Institute of Scientific and Technical Information of China (English)

    Rong-Shuang Huang; Yi-Ming Cheng; Xiao-Xi Zeng; Sehee Kim; Ping Fu

    2016-01-01

    Background:Renin-angiotensin system inhibitor and calcium channel blocker (CCB) are widely used in controlling blood pressure (BP) in patients with chronic kidney disease (CKD).We carried out a meta-analysis to compare the renoprotective effect of the combination of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) and CCB (i.e.,ACEI/ARB + CCB) with ACEI/ ARB monotherapy in patients with hypertension and CKD.Methods:Publications were identified from PubMed,Embase,Medline,and Cochrane databases.Only randomized controlled trials (RCTs) of BP lowering treatment for patients with hypertension and CKD were considered.The outcomes of end-stage renal disease (ESRD),cardiovascular events,BP,urinary protein measures,estimated glomerular filtration rate (GFR),and adverse events were extracted.Results:Based on seven RCTs with 628 patients,ACEI/ARB + CCB did not show additional benefit for the incidence of ESRD (risk ratio [RR] =0.84;95% confidence interval [CI]:0.52-1.33) and cardiovascular events (RR =0.58;95% CI:0.21-1.63) significantly,compared with ACEI/ARB monotherapy.There were no significant differences in change from baseline to the end points in diastolic BP (weighted mean difference [WMD] =-1.28 mmHg;95% CI:-3.18 to-0.62),proteinuria (standard mean difference =-0.55;95% CI:-1.41 to-0.30),GFR (WMD =-0.32 ml/min;95% CI:-1.53 to-0.89),and occurrence of adverse events (RR =1.05;95% CI:0.72-1.53).However,ACEI/ARB + CCB showed a greater reduction in systolic BP (WMD =-4.46 mmHg;95% CI:-6.95 to-1.97),compared with ACEI/ARB monotherapy.Conclusion:ACEI/ARB + CCB had no additional renoprotective benefit beyond than what could be achieved with ACEI/ARB monotherapy.

  16. 肾素-血管紧张素系统与肺动脉高压%Renin-angiotensin system and pulmonary hypertension

    Institute of Scientific and Technical Information of China (English)

    张云霞; 李积凤; 王辰

    2015-01-01

    Pulmonary hypertension (PH ) is characterized by sustained increase of pulmonary arterial pressure and eventually leading to right heart failure.PH is caused by heterogeneous diseases and different pathogenesis.PH is still incurable and fatal,although current treatments alleviated some symptoms and prolonged survival.Therefore,it is urgent to discover novel targets for safe and effective therapy.The renin-angiotensin system (RAS ) is mainly composed by the vaso-constrictive and proliferative axis called as ACE-AngⅡ-AT1R,and the vaso-protective and anti-proliferative axis called as ACE2-Ang-(1-7)-Mas.The dysfunction ACE-AngⅡ-AT1R axis,has been implicated as a causative factor in the pathogenesis of PH.While because it can antagonize the function of ACE-AngⅡ-AT1R axis,ACE2-Ang-(1-7)-Mas axis may be a novel target in PH treatment.%肺动脉高压(pulmonary hypertension,PH)是一种由异源性疾病和不同发病机制引起的,以肺动脉压力增高为表现的疾病状态,严重者可出现右心衰竭。目前的治疗方式虽然可缓解 PH 患者的部分症状,并在一定程度上延长患者的寿命,但 PH 仍然是一种死亡率极高的疾病,所以亟需发现新的安全有效的治疗方法。研究表明,肾素-血管紧张素系统(renin-angiotensin system,RAS)参与了 PH 的发病过程。该系统由促进血管收缩及增殖的血管紧张素转换酶-血管紧张素Ⅱ-血管紧张素Ⅱ受体1(angiotensin converting enzyme-angiotensinⅡ-angiotensinⅡ receptor 1,ACE-AngⅡ-AT1R)轴与抗血管收缩及增殖的血管紧张素转换酶2-血管紧张素(1-7)-Mas[angiotensin converting enzyme 2-angiotensin (1-7)-Mas,ACE2-Ang-(1-7)-Mas]轴组成。ACE-AngⅡ-AT1R 轴是促进 PH 病情发展的重要机制,而ACE2-Ang-(1-7)-Mas 轴因可以拮抗 ACE-AngⅡ-AT1R 轴的作用,成为 PH 治疗的研究热点。

  17. Changes in Plasma Angiotensin II and Circadian Rhythm of Blood Pressure in Hypertensive Patients with Sleep Apnea Syndrome Before and After Treatment

    Institute of Scientific and Technical Information of China (English)

    Hai-ling Wang; Qing-zeng Liu; Yu Wang; Ying Zhang; Yun-dai Chen; Xin-chun Wang; Zhi-xuan Liu; Guo-li Jing; Hai-feng Tong; Yuan Tian

    2011-01-01

    Objective To explore the changes in plasma angiotensin Ⅱ (Ang Ⅱ) and circadian rhythm of blood pressure among hypertensive patients with sleep apnea syndrome (SAS) before and after continuous positive airway pressure (CPAP) or surgical treatment. Methods A total of 180 essential hypertension patients were enrolled in our study. The determination of plasma Ang Ⅱ concentration, ambulatory blood pressure (ABP), and polysomnography (PSG) monitoring were performed before and 3 months after CPAP or surgical treatment.Results Patients were dassified into three groups by their apnea-hypopnea index (AHI): essential hypertension group (EH group, n=72; AHI<5), essential hypertension with mild SAS group (EH+mild SAS group, n=60, 5≤AHI<20), and essential hypertension with moderate and severe SAS group (EH+moderate-severe SAS group, n=48, AHI≥20). The concentrations of plasma Ang Ⅱ in the above three groups were 13.42±3.27, 16.17±3.82, and 18.73±4.05 ng/mL respectively before treatment, and AngⅡ concentration in EH patients combined with SAS was significantly higher than that in EH group (all P<O.05).After treatment the values in the latter two groups significantly decreased to 14.67±2.56 and 15.03±3.41 ng/mL respectively (P<0.05). The incidence of non-dipper blood pressure curve in EH patients was 31.9%,and those in hypertensive patients with mild SAS and moderate-severe SAS were 51.7% and 58.3%, respectively before treatment. The incidence of non-dipper blood pressure curve in the EH patients with mild SAS was significantly higher than that of patients with EH alone (P<0.05). After CPAP treatment or surgery, the incidence of non-dipper blood pressure curve in the two SAS groups was significantly decreased to 38.3% and 39.6%, respectively (P<0.05).Condusions Ang Ⅱ might phy a role in blood pressure variability in patients with obstructive SAS. CPAP or surgical treatment can improve blood pressure disorder and decrease plasma Ang

  18. Losartan/Hydrochlorothiazide Combination Therapy Surpasses High-dose Angiotensin Receptor Blocker in the Reduction of Morning Home Blood Pressure in Patients with Morning Hypertension

    Directory of Open Access Journals (Sweden)

    Nakamura,Yoshio

    2012-12-01

    Full Text Available Angiotensin receptor blockers (ARBs are the first-line antihypertensive agents. In clinical practice, it is often difficult to achieve the recommended blood pressure level by ARBs in their ordinal dosages alone. This study examined the practical efficacy of a combination therapy of ARB with thiazide diuretics for lowering morning home blood pressure (MHBP in comparison to high-dose ARB therapy in patients with morning hypertension administered an ordinal dosage of ARB. This study was performed in a prospective, randomized, open-labeled and blind-endpoint fashion. Patients were considered to have morning hypertension when their self-measured systolic MHBPs were 135mmHg or higher, irrespective of their diastolic MHBP and office blood pressures (OBPs. Forty-eight outpatients with morning hypertension receiving the ordinal dosage of ARB were given either losartan/hydrochlorothiazide (n=26 or high-dose ARB (n=22 in place of their previously prescribed ARB. No change in any medication was permitted during this period. Decreases of both systolic and diastolic MHBP after 3 months of treatment were significantly greater in the losartan/hydrochlorothiazide group than in the high-dose ARB group (p<0.05, respectively. The ratio of adverse events was somewhat high (23.1% in the losartan/hydrochlorothiazide group, 9.1% in the high-dose ARB group, respectively. However, there were no significant differences in any particular adverse event between groups. This study suggested losartan/hydrochlorothiazide might be superior to high-dose ARB for reducing morning home blood pressure.

  19. Effect of active immunization against angiotensin II type 1 (AT1) receptor on hypertension & arterial remodelling in spontaneously hypertensive rats (SHR)

    OpenAIRE

    Liu-Dong Li; Miao Tian; Yu-Hua Liao; Zi-Hua Zhou; Fen Wei; Feng Zhu; Min Wang; Bin Wang; Yu-Miao Wei

    2014-01-01

    Background & objectives: a0 ngiotensin II receptor type 1 (AT1) is known to be involved in the pathogenesis of hypertension. t0 his study was undertaken to explore the effect of active immunization against AT1 receptor on blood pressure and small artery remodelling in spontaneously hypertensive rat (SHR). Methods: Male SHR and Wistar rats aged two months were actively immunized with different peptides (ATR12185ͱͲATR10014 and ATR12181) corresponding to particular sequences of rat AT1 recep...

  20. Angiotensin II (de)sensitization: Fluid intake studies with implications for cardiovascular control.

    Science.gov (United States)

    Daniels, Derek

    2016-08-01

    Cardiovascular disease is the leading cause of death worldwide and hypertension is the most common risk factor for death. Although many anti-hypertensive pharmacotherapies are approved for use in the United States, rates of hypertension have increased over the past decade. This review article summarizes a presentation given at the 2015 meeting of the Society for the Study of Ingestive Behavior. The presentation described work performed in our laboratory that uses angiotensin II-induced drinking as a model system to study behavioral and cardiovascular effects of the renin-angiotensin system, a key component of blood pressure regulation, and a common target of anti-hypertensives. Angiotensin II (AngII) is a potent dipsogen, but the drinking response shows a rapid desensitization after repeated injections of AngII. This desensitization appears to be dependent upon the timing of the injections, requires activation of the AngII type 1 (AT1) receptor, requires activation of mitogen-activated protein (MAP) kinase family members, and involves the anteroventral third ventricle (AV3V) region as a critical site of action. Moreover, the response does not appear to be the result of a more general suppression of behavior, a sensitized pressor response to AngII, or an aversive state generated by the treatment. More recent studies suggest that the treatment regimen used to produce desensitization in our laboratory also prevents the sensitization that occurs after daily bolus injections of AngII. Our hope is that these findings can be used to support future basic research on the topic that could lead to new developments in treatments for hypertension.

  1. Loss of collectrin, an angiotensin-converting enzyme 2 homolog, uncouples endothelial nitric oxide synthase and causes hypertension and vascular dysfunction

    DEFF Research Database (Denmark)

    Cechova, Sylvia; Zeng, Qing; Billaud, Marie;

    2013-01-01

    Collectrin is an orphan member of the renin-angiotensin system and is a homolog of angiotensin-converting enzyme 2, sharing ≈50% sequence identity. Unlike angiotensin-converting enzyme 2, collectrin lacks any catalytic domain. Collectrin has been shown to function as a chaperone of amino acid tra...

  2. Comparative effect of angiotensin II type I receptor blockers and calcium channel blockers on laboratory parameters in hypertensive patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Nishida Yayoi

    2012-05-01

    Full Text Available Abstract Background Both angiotensin II type I receptor blockers (ARBs and calcium channel blockers (CCBs are widely used antihypertensive drugs. Many clinical studies have demonstrated and compared the organ-protection effects and adverse events of these drugs. However, few large-scale studies have focused on the effect of these drugs as monotherapy on laboratory parameters. We evaluated and compared the effects of ARB and CCB monotherapy on clinical laboratory parameters in patients with concomitant hypertension and type 2 diabetes mellitus. Methods We used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2011, to identify cohorts of new ARB users (n = 601 and propensity-score matched new CCB users (n = 601, with concomitant mild to moderate hypertension and type 2 diabetes mellitus. We used a multivariate-adjusted regression model to adjust for differences between ARB and CCB users, and compared laboratory parameters including serum levels of triglyceride (TG, total cholesterol (TC, non-fasting blood glucose, hemoglobin A1c (HbA1c, sodium, potassium, creatinine, alanine aminotransferase (ALT, aspartate aminotransferase (AST, gamma-glutamyltransferase (GGT, hemoglobin and hematocrit, and white blood cell (WBC, red blood cell (RBC and platelet (PLT counts up to 12 months after the start of ARB or CCB monotherapy. Results We found a significant reduction of serum TC, HbA1c, hemoglobin and hematocrit and RBC count and a significant increase of serum potassium in ARB users, and a reduction of serum TC and hemoglobin in CCB users, from the baseline period to the exposure period. The reductions of RBC count, hemoglobin and hematocrit in ARB users were significantly greater than those in CCB users. The increase of serum potassium in ARB users was significantly greater than that in CCB users. Conclusions Our study suggested that hematological adverse effects and

  3. Efficacy and Safety of Combination Therapy Consisting of Angiotensin II Type 1 Receptor Blocker, Calcium Channel Blocker and Hydrochlorothiazide in Patients With Hypertension

    Science.gov (United States)

    Shiga, Yuhei; Miura, Shin-ichiro; Motozato, Kota; Yoshimine, Yuka; Norimatsu, Kenji; Arimura, Tadaaki; Koyoshi, Rie; Morii, Joji; Kuwano, Takashi; Inoue, Ken; Shirotani, Tetsuro; Fujisawa, Kazuaki; Matsunaga, Eiyu; Saku, Keijiro

    2017-01-01

    Background Many patients continue to have high blood pressure (BP) even after treatment with high-dose (H)-angiotensin II type 1 receptor blocker (ARB)/calcium channel blocker (CCB) or middle-dose (M)-ARB/CCB/hydrochlorothiazide (HCTZ). Methods Thirty-two hypertensive patients who had the use of H-ARB/CCB or M-ARB/CCB/HCTZ were enrolled in this study. We applied a changeover with a switch to H-ARB (telmisartan 80 mg/day)/CCB (amlodipine 5 mg/day or nifedipine CR 40 mg/day)/HCTZ (12.5 mg/day). Results Systolic BP (SBP) and diastolic BP (DBP) were significantly decreased in all patients and in the H-ARB/CCB and M-ARB/CCB/HCTZ groups after 3 months. Percentage (%) of patients who reached the target BP after 3 months (72%) in all patients was significantly higher than that at 0 months (19%). There were no serious adverse effects in any of the patients. Conclusions Combination therapy with H-ARB/CCB/HCTZ was associated with a significant reduction of BP. PMID:28090225

  4. Altered expression of renal bumetanide-sensitive sodium-pota-ssium-2 chloride cotransporter and Cl- channel -K2 gene in angiotensin Ⅱ-infused hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    YE Tao; LIU Zhi-quan; SUN Chao-feng; ZHENG Yong; MA Ai-qun; FANG Yuan

    2005-01-01

    Background Little information is available regarding the effect of angiotensin Ⅱ (Ang Ⅱ) on the bumetanide-sensitive sodium-potassium-2 chloride cotransporter (NKCC2), the thiazide-sensitive sodium-chloride cotransporter (NCC), and the Cl- channel (CLC)-K2 at both mRNA and protein expression level in Ang Ⅱ-induced hypertensive rats. This study was conducted to investigate the influence of Ang Ⅱ with chronic subpressor infusion on nephron-specific gene expression of NKCC2, NCC and CLC-K2. Results Ang Ⅱ significantly increased blood pressure and up-regulated NKCC2 mRNA and protein expression in the kidney. Expression of CLC-K2 mRNA in the kidney increased 1.6 fold (P<0.05).There were no changes in NCC mRNA or protein expression in AngII-treated rats versus control. Conclusions Chronic subpressor Ang Ⅱ infusion can significantly alter NKCC2 and CLC-K2 mRNA expression in the kidney, and protein abundance of NKCC2 in kidney is positively regulated by Ang Ⅱ. These effects may contribute to enhanced renal Na+ and Cl- reabsorption in response to Ang Ⅱ.

  5. Angiotensin II type 1 receptor antagonists in the treatment of hypertension in elderly patients: focus on patient outcomes

    OpenAIRE

    Artavazd Tadevosyan; MacLaughlin, Eric J; Karamyan, Vardan T

    2011-01-01

    Artavazd Tadevosyan1, Eric J MacLaughlin2, Vardan T Karamyan31Departments of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, QC, Canada; 2Department of Pharmacy Practice, 3Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, USAAbstract: Hypertension in the elderly is one of the main risk factors of cardiovascular and cerebrovascular diseases. Knowledge regarding the mechanisms of ...

  6. The evolution of renin-angiotensin blockade: angiotensin-converting enzyme inhibitors as the starting point.

    Science.gov (United States)

    Sica, Domenic A

    2010-04-01

    The renin-angiotensin system has been a target in the treatment of hypertension for close to three decades. Several medication classes that block specific aspects of this system have emerged as useful therapies, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and, most recently, direct renin inhibitors. There has been a natural history to the development of each of these three drug classes, starting with their use as antihypertensive agents; thereafter, in each case they have been employed as end-organ protective agents. To date, there has been scant evidence to favor angiotensin receptor blockers or direct renin inhibitors over angiotensin-converting enzyme inhibitors in treating hypertension or in affording end-organ protection; thus, angiotensin-converting enzyme inhibitors remain the standard of care when renin-angiotensin system blockade is warranted.

  7. Hypertension and hypertensive encephalopathy.

    Science.gov (United States)

    Price, Raymond S; Kasner, Scott E

    2014-01-01

    The definition of hypertension has continuously evolved over the last 50 years. Hypertension is currently defined as a blood pressure greater than 140/90mmHg. One in every four people in the US has been diagnosed with hypertension. The prevalence of hypertension increases further with age, affecting 75% of people over the age of 70. Hypertension is by far the most common risk factor identified in stroke patients. Hypertension causes pathologic changes in the walls of small (diameter<300 microns) arteries and arterioles usually at short branches of major arteries, which may result in either ischemic stroke or intracerebral hemorrhage. Reduction of blood pressure with diuretics, β-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors have all been shown to markedly reduce the incidence of stroke. Hypertensive emergency is defined as a blood pressure greater than 180/120mmHg with end organ dysfunction, such as chest pain, shortness of breath, encephalopathy, or focal neurologic deficits. Hypertensive encephalopathy is believed to be caused by acute failure of cerebrovascular autoregulation. Hypertensive emergency is treated with intravenous antihypertensive agents to reduce blood pressure by 25% within the first hour. Selective inhibition of cerebrovascular blood vessel permeability for the treatment of hypertensive emergency is beginning early clinical trials.

  8. Cost-utility of angiotensin-converting enzyme inhibitor-based treatment compared with thiazide diuretic-based treatment for hypertension in elderly Australians considering diabetes as comorbidity.

    Science.gov (United States)

    Chowdhury, Enayet K; Ademi, Zanfina; Moss, John R; Wing, Lindon M H; Reid, Christopher M

    2015-03-01

    The objective of this study was to examine the cost-effectiveness of angiotensin-converting enzyme inhibitor (ACEI)-based treatment compared with thiazide diuretic-based treatment for hypertension in elderly Australians considering diabetes as an outcome along with cardiovascular outcomes from the Australian government's perspective.We used a cost-utility analysis to estimate the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) gained. Data on cardiovascular events and new onset of diabetes were used from the Second Australian National Blood Pressure Study, a randomized clinical trial comparing diuretic-based (hydrochlorothiazide) versus ACEI-based (enalapril) treatment in 6083 elderly (age ≥65 years) hypertensive patients over a median 4.1-year period. For this economic analysis, the total study population was stratified into 2 groups. Group A was restricted to participants diabetes free at baseline (n = 5642); group B was restricted to participants with preexisting diabetes mellitus (type 1 or type 2) at baseline (n = 441). Data on utility scores for different events were used from available published literatures; whereas, treatment and adverse event management costs were calculated from direct health care costs available from Australian government reimbursement data. Costs and QALYs were discounted at 5% per annum. One-way and probabilistic sensitivity analyses were performed to assess the uncertainty around utilities and cost data.After a treatment period of 5 years, for group A, the ICER was Australian dollars (AUD) 27,698 (&OV0556; 18,004; AUD 1-&OV0556; 0.65) per QALY gained comparing ACEI-based treatment with diuretic-based treatment (sensitive to the utility value for new-onset diabetes). In group B, ACEI-based treatment was a dominant strategy (both more effective and cost-saving). On probabilistic sensitivity analysis, the ICERs per QALY gained were always below AUD 50,000 for group B; whereas for group A, the

  9. Effects of Qindan Capsule(芩丹胶囊) on Blood Pressure,Endothelin, Calcitonin Gene-related Peptide and Angiotensin-Ⅱ in Spontaneous Hypertensive Rats

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To observe the hypotensive effects of Qindan Capsule (芩丹胶囊, QC) on spontaneous hypertensive rats (SHR) and its effect on the contents of endothelin (ET), calcitonin gene-related peptide (CGRP) and angiotensin-Ⅱ (Ang-Ⅱ ) in plasma and vascular tissues, and to investigate the possible mechanism of QC in lowering blood pressure. Methods: Forty SHRs were divided into 5 groups: the high dosage QC group [QCHD, 750 mg/(kg·d)], the low dosage QC group [QCLD, 150 mg/(kg·d)], the Niuhuang Jiangya Pill group [牛黄降压丸, NJP, 200 mg/(kg·d)], the Captopril group [ 15 mg/(kg·d)]and the model group, 8 in each group. Meanwhile, a normal control group consisting of 8 Wistar-Kyoto (WKY) rats was set up also. All the rats were administered with medicine through gastrogavage. Systolic blood pressure (SBP),level of ET, CGRP and Ang-Ⅱ in plasma and Ang-Ⅱ in tissues of mesenteric artery were detected in all the rats after 12 weeks of treatment. Results: The level of SBP after treatment in the QCHD group was lower than that in the model group ( P<0.01 ), but with no significant difference as compared with that in the Captopril group and the NJP group (P>0.05). After treatment, the plasma level of ET was lower and CGRP higher than those in the model group (both P<0.05), and also higher than those in the NJP and Captopril group (both P<0.05). As for the content of Ang- Ⅱ, in mesenteric arterial tissues, it was lower in the QCHD group than that in the model group ( P<0.05), but in plasma, it showed no significant difference between the two groups (P>0.05). Conclusion: QC has a satisfactory hypotensive action on SHR rats, and its mechanism may be associated with the regulation on plasma vasoactive peptide and regional renin-angiotensin system.

  10. Differential baseline expression and angiotensin II stimulation of leukemia-associated RhoGEF in vascular smooth muscle cells of spontaneously hypertensive rats

    Directory of Open Access Journals (Sweden)

    Chiu WC

    2012-12-01

    Full Text Available Wei-Chiao Chiu,1 Jyh-ming Juang,1,2 Shen-nan Chang,2 Cho-kai Wu,2 Chia-ti Tsai,2 Chuen-den Tseng,2 Yung-zu Tseng,1,2 Ming-Jai Su,3 Fu-tien Chiang1,2,41Graduate Institute of Physiology, National Taiwan University College of Medicine, 2Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, 3Graduate Institute of Pharmacology, National Taiwan University College of Medicine, 4Department of Laboratory Medicine, National Taiwan University College of Medicine, Taipei, Taiwan, Republic of ChinaPurpose: Studies to explore angiotensin II (Ang II and its downstream signaling pathways via Rho guanine nucleotide exchange factors (RhoGEFs and RhoA signaling are crucial to understanding the mechanisms of smooth muscle contraction leading to hypertension. This study aimed to investigate the Ang II–induced expression of RhoGEFs in vascular smooth muscle cells (VSMCs of spontaneously hypertensive rats (SHRs and to identify the possible regulator associated with hypertension.Methods: Cultured VSMCs of the aorta from SHRs and Wistar-Kyoto (WKY rats were treated with or without Ang II or Ang II plus Ang II type 2 receptor antagonists. The expression levels of RhoGEF messenger RNA (mRNA and protein were determined. To evaluate the changes of aortic ring contractile force in response to Ang II, a nonviral carrier system was adopted to deliver the leukemia-associated RhoGEF (LARG small interfering RNA via nanoparticles into aortic rings.Results: The baseline mRNA levels of three RhoGEFs in cultured VSMCs of WKY rats did not increase with age, but they were significantly higher in 12-week-old SHRs than in 5-week-old SHRs. Expression levels of LARG mRNA were higher in SHRs than in age-matched WKY rats. The baseline LAGR protein of 12-week-old SHRs was about four times higher than that of WKY rats of the same age. After Ang II stimulation, LAGR protein expression was significantly

  11. [Hypertension].

    Science.gov (United States)

    Ohishi, Mitsuru

    2014-04-01

    Hypertension is well known to one of the risk factors to reduce cognitive function, however, it is still unclear whether anti-hypertensive therapy is effective to prevent development of dementia or Alzheimer's disease. Epidemiological studies suggested antihypertensive therapy from the middle-age could reduce risk of dementia. The meta-analysis including HYVET also suggested blood pressure lowering from the elderly might be also effective to prevent development of dementia. The network meta-analysis and the cohort study using mega-data bank suggested ARB might be effective to prevent development of dementia or Alzheimer's disease compared to administration with other anti-hypertensive drugs. Although the further major clinical investigation is required, anti-hypertensive treatment might be useful to manage hypertensive patients with dementia.

  12. Adding thiazide to a rennin-angiotensin blocker regimen to improve left ventricular relaxation in diabetes and nondiabetes patients with hypertension

    Directory of Open Access Journals (Sweden)

    Takami T

    2012-09-01

    Full Text Available Takeshi Takami,1 Hiroshi Ito,2 Katsuhisa Ishii,3 Kenei Shimada,4 Katsuomi Iwakura,5 Hiroyuki Watanabe,6 Shota Fukuda,7 Junichi Yoshikawa81Department of Internal Medicine, Clinic Jingumae, Kashihara, Japan; 2Department of Cardiovascular Medicine, Okayama University, Graduate School of Medicine, Okayama, Japan; 3Department of Cardiology, Kansai Electric Power Hospital, Osaka, Japan; 4Department of Internal Medicine and Cardiology, Osaka City University of Medicine, Osaka, Japan; 5Cardiovascular Center, Sakurabashi Watanabe Hospital, Osaka, Japan; 6Department of Cardiology, Sakakibara Heart Institute, Tokyo, Japan; 7Department of Medicine, Osaka Ekisaikai Hospital, Osaka, Japan; 8Nishinomiya Watanabe Cardiovascular Center, Nishinomiya, JapanAbstract: The urinary albumin to creatinine ratio (UACR is an independent predictor of outcomes in patients with diastolic dysfunction. Thus, we investigated the relationship between diastolic dysfunction, UACR, and diabetes mellitus (DM in the EDEN study. We investigated the effect of switching from an angiotensin-converting enzyme inhibitor (ACEi or angiotensin receptor blocker (ARB to a combination of losartan and hydrochlorothiazide on left ventricular (LV relaxation in patients with hypertension and diastolic dysfunction. We enrolled 106 patients with and 265 patients without DM. All patients had diastolic dysfunction and had not achieved their treatment goals with an ACEi or ARB. The measurements of e′ velocity and E/e′ ratio was performed with echocardiography as markers of LV diastolic function. We switched the ACEi or ARB to losartan/hydrochlorothiazide and followed these patients for 24 weeks. UACR was decreased in patients with DM (123.4 ± 288.4 to 66.5 ± 169.2 mg/g creatinine; P = 0.0024, but not in patients without DM (51.2 ± 181.8 to 39.2 ± 247.9 mg/g creatinine; P = 0.1051. Among DM patients, there was a significant relationship between changes in UACR and changes in e′ velocity (r =

  13. Expression and localization of the AT1 and AT2 angiotensin II receptors and α1A and α1D adrenergic receptors in aorta of hypertensive and diabetic rats.

    Science.gov (United States)

    Rodríguez, Jessica Edith; Romero-Nava, Rodrigo; Reséndiz-Albor, Aldo Arturo; Rosales-Cruz, Erika; Hong, Enrique; Huang, Fengyang; Villafaña, Santiago

    2017-01-01

    Hypertension and diabetes are multifactorial diseases that frequently coexist and exacerbate each another. During the development of diabetes, the impairment of noradrenergic and renin-angiotensin systems has been reported in the response mediated by α1-AR and AT1 receptors. Although their participation in the development of cardiovascular complications is still controversial, some studies have found increased or diminished response to the vasoconstrictive effect of noradrenaline or angiotensin II in a time-dependent manner of diabetes. Thus, the aim of this work was to investigate the possible changes in the expression or localization of α1-AR (α1A and α1D) and angiotensin II receptors (AT1 and AT2) in aorta of rats after 4 weeks of the onset of diabetes. In order to be able to examine the expression of these receptors, immunofluorescence procedure was performed in tunica intima and tunica media of histological sections of aorta. Fluorescence was detected by a confocal microscopy. Our results showed that the receptors are expressed in both tunics, where adrenergic receptors have a higher density in tunica intima and tunica media of SHR compared with WKY; meanwhile, the expression of angiotensin II receptors is not modified in both groups of rats. On the other hand, the results showed that diabetes produced an increase or a decrease in the expression of receptors that is not associated to a specific type of receptor, vascular region, or strain of rat. In conclusion, diabetes and hypertension modify the expression of the receptors in tunica intima and tunica media of aorta in a different way.

  14. Angiotensin-(1-7): an active member of the renin-angiotensin system.

    Science.gov (United States)

    Kucharewicz, I; Pawlak, R; Matys, T; Chabielska, E; Buczko, W

    2002-12-01

    Angiotensin-(1-7) [Ang-(1-7)] is an active member of renin-angiotensin system (RAS). It counterbalances vasoconstriction, mitogenic, arrhythmogenic and prothrombotic actions of Ang II. Inducing natiuresis and diuresis opposes also the water and sodium retention produced by Ang II. Till now the specific receptor side for Ang-(1-7) has been not cloned, but the current data strongly suggest that an interaction (cross-talk) between angiotensin receptors may play a role in the effects of Ang-(1-7).

  15. Hypertension

    OpenAIRE

    2012-01-01

    Hypertension is responsible for roughly one-in-six adult deaths annually in the United States and is associated with five of the top nine causes of death. 1 Ten trillion dollars is the estimated annual cost worldwide of the direct and indirect effects of hypertension. 2,3 In the U.S. alone, costs estimated at almost $74 billion in 2009 placed a huge economic burden on the health care system. 4 The prevalence of hypertension increases with advancing age to the point where more than half of peo...

  16. TMEM16A Contributes to Endothelial Dysfunction by Facilitating Nox2 NADPH Oxidase-Derived Reactive Oxygen Species Generation in Hypertension.

    Science.gov (United States)

    Ma, Ming-Ming; Gao, Min; Guo, Kai-Min; Wang, Mi; Li, Xiang-Yu; Zeng, Xue-Lin; Sun, Lu; Lv, Xiao-Fei; Du, Yan-Hua; Wang, Guan-Lei; Zhou, Jia-Guo; Guan, Yong-Yuan

    2017-03-20

    Ca2(+)-activated Cl(-) channels play a crucial role in various physiological processes. However, the role of TMEM16A in vascular endothelial dysfunction during hypertension is unclear. In this study, we investigated the specific involvement of TMEM16A in regulating endothelial function and blood pressure and the underlying mechanism. Reverse transcription-polymerase chain reaction, Western blotting, coimmunoprecipitation, confocal imaging, patch-clamp recordings, and TMEM16A endothelial-specific transgenic and knockout mice were used. We found that TMEM16A was expressed abundantly and functioned as a Ca2(+)-activated Cl(-) channel in endothelial cells. Angiotensin II induced endothelial dysfunction with an increase in TMEM16A expression. The knockout of endothelial-specific TMEM16A significantly lowered the blood pressure and ameliorated endothelial dysfunction in angiotensin II-induced hypertension, whereas the overexpression of endothelial-specific TMEM16A resulted in the opposite effects. These results were related to the increased reactive oxygen species production, Nox2-containing NADPH oxidase activation, and Nox2 and p22phox protein expression that were facilitated by TMEM16A on angiotensin II-induced hypertensive challenge. Moreover, TMEM16A directly bound with Nox2 and reduced the degradation of Nox2 through the proteasome-dependent degradation pathway. Therefore, TMEM16A is a positive regulator of endothelial reactive oxygen species generation via Nox2-containing NADPH oxidase, which induces endothelial dysfunction and hypertension. Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated diseases.

  17. Dietary nitrate improves age-related hypertension and metabolic abnormalities in rats via modulation of angiotensin II receptor signaling and inhibition of superoxide generation.

    Science.gov (United States)

    Hezel, Michael; Peleli, Maria; Liu, Ming; Zollbrecht, Christa; Jensen, Boye L; Checa, Antonio; Giulietti, Alessia; Wheelock, Craig E; Lundberg, Jon O; Weitzberg, Eddie; Carlström, Mattias

    2016-10-01

    Advanced age is associated with increased risk for cardiovascular disease and type 2 diabetes. A proposed central event is diminished amounts of nitric oxide (NO) due to reduced generation by endothelial NO synthase (eNOS) and increased oxidative stress. In addition, it is widely accepted that increased angiotensin II (ANG II) signaling is also implicated in the pathogenesis of endothelial dysfunction and hypertension by accelerating formation of reactive oxygen species. This study was designed to test the hypothesis that dietary nitrate supplementation could reduce blood pressure and improve glucose tolerance in aged rats, via attenuation of NADPH oxidase activity and ANG II receptor signaling. Dietary nitrate supplementation for two weeks reduced blood pressure (10-15mmHg) and improved glucose clearance in old, but not in young rats. These favorable effects were associated with increased insulin responses, reduced plasma creatinine as well as improved endothelial relaxation to acetylcholine and attenuated contractility to ANG II in resistance arteries. Mechanistically, nitrate reduced NADPH oxidase-mediated oxidative stress in the cardiovascular system and increased cGMP signaling. Finally, nitrate treatment in aged rats normalized the gene expression profile of ANG II receptors (AT1A, AT2, AT1A/AT2 ratio) in the renal and cardiovascular systems without altering plasma levels of renin or ANG II. Our results show that boosting the nitrate-nitrite-NO pathway can partly compensate for age-related disturbances in endogenous NO generation via inhibition of NADPH oxidase and modulation of ANG II receptor expression. These novel findings may have implications for nutrition-based preventive and therapeutic strategies against cardiovascular and metabolic diseases.

  18. Angiotensin II type 1 receptor blockade partially attenuates hypoxia-induced pulmonary hypertension in newborn piglets: relationship with the nitrergic system

    Energy Technology Data Exchange (ETDEWEB)

    Camelo, J.S. Jr. [Departamento de Puericultura e Pediatria, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Martins, A.R. [Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Instituto de Ciências Biológicas, Universidade Federal do Triângulo Mineiro, Uberaba, MG (Brazil); Rosa, E. [Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Ramos, S.G. [Departamento de Patologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SPBrasil (Brazil); Hehre, D.; Bancalari, E.; Suguihara, C. [Department of Pediatrics, Division of Neonatology, Neonatal Developmental Biology Laboratory, University of Miami Miller School of Medicine, Miami, FL (United States)

    2012-02-10

    The objective of this study was to observe possible interactions between the renin-angiotensin and nitrergic systems in chronic hypoxia-induced pulmonary hypertension in newborn piglets. Thirteen chronically instrumented newborn piglets (6.3 ± 0.9 days; 2369 ± 491 g) were randomly assigned to receive saline (placebo, P) or the AT{sub 1} receptor (AT{sub 1}-R) blocker L-158,809 (L) during 6 days of hypoxia (FiO{sub 2} = 0.12). During hypoxia, pulmonary arterial pressure (Ppa; P < 0.0001), pulmonary vascular resistance (PVR; P < 0.02) and the pulmonary to systemic vascular resistance ratio (PVR/SVR; P < 0.05) were significantly attenuated in the L (N = 7) group compared to the P group (N = 6). Western blot analysis of lung proteins showed a significant decrease of endothelial NOS (eNOS) in both P and L animals, and of AT{sub 1}-R in P animals during hypoxia compared to normoxic animals (C group, N = 5; P < 0.01 for all groups). AT{sub 1}-R tended to decrease in L animals. Inducible NOS (iNOS) did not differ among P, L, and C animals and iNOS immunohistochemical staining in macrophages was significantly more intense in L than in P animals (P < 0.01). The vascular endothelium showed moderate or strong eNOS and AT{sub 1}-R staining. Macrophages and pneumocytes showed moderate or strong iNOS and AT{sub 1}-R staining, but C animals showed weak iNOS and AT{sub 1}-R staining. Macrophages of L and P animals showed moderate and weak AT{sub 2}-R staining, respectively, but the endothelium of all groups only showed weak staining. In conclusion, pulmonary hypertension induced by chronic hypoxia in newborn piglets is partially attenuated by AT{sub 1}-R blockade. We suggest that AT{sub 1}-R blockade might act through AT{sub 2}-R and/or Mas receptors and the nitrergic system in the lungs of hypoxemic newborn piglets.

  19. EFFECT OF ANGIOTENSIN-II RECEPTOR ANTAGONIST LOSARTAN AND ITS COMBINATION WITH DIURETICS ON MYOCARDIAL MORPHO-FUNCTIONAL CONDITIONS IN HYPERTENSIVE PATIENTS WITH LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    S. N. Tolpygina

    2008-01-01

    Full Text Available Aim. To compare the effects of long-term therapy with angiotensin-II receptor antagonist losartan, alone or in combination with hydrochlorothiazide, and amlodipine treatment on left ventricular morpho-functional variables and blood pressure (BP in hypertensive patients.Material and methods. 25 women and 27 men (average age 52,7±1,2 y.o. with essential hypertension (1-2 grade and left ventricular hypertrophy (LVH were included into the study. After 3 week washout period the patients were randomized in 2:1 fashion to receive either losartan (n=34 or amlodipine (n=17. In 17 patients with insufficient response to losartan monotherapy (50-100mg/day hydrochlorothiazide (12,5mg was added to losartan (50mg 4 weeks later. The daily dose of amlodipine was increased from 5 to 10 mg in 10 patients. At baseline and after 24 weeks of treatment 24-h BP monitoring and echocardiography (with evaluation of cardiac chamber dimensions, inter-ventricular septal and posterior wall thickness, left ventricular mass index -LVMI were performed.Results. 4-week losartan treatment significantly decreased clinic BP (-14,1±2,2/8,2±1,4 mm Hg, p<0,01, mean daily systolic and diastolic BP (-15,1±2,4 mm Hg and -8,9±1,7 mm Hg , p<0,001, mean day-time and night-time BP and systolic and diastolic BP load in 34 patients. Addition of hydrochlorothiazide induced a further decrease of mean night-time BP, pulse BP, improved circadian rhythm and normalized BP in 75% of patients compared with 50% in losartan alone. Significant decrease of clinic BP (-24,1±3,6/15,2±2,3, p<0,01, mean daily systolic and diastolic BP and BP load were noticed at 24 week of amlodipine treatment. Circadian BP rhythm didn’t change; night-time decrease of BP was insufficient. Antihypertensive efficacy was similar in both groups. Losartan, alone or combined with hydrochlorothiazide, caused regression of LVH in all patients, normalized geometry of left ventricle in 33% of patients and improved left

  20. Antihypertensive, insulin-sensitising and renoprotective effects of a novel, potent and long-acting angiotensin II type 1 receptor blocker, azilsartan medoxomil, in rat and dog models.

    Science.gov (United States)

    Kusumoto, Keiji; Igata, Hideki; Ojima, Mami; Tsuboi, Ayako; Imanishi, Mitsuaki; Yamaguchi, Fuminari; Sakamoto, Hiroki; Kuroita, Takanobu; Kawaguchi, Naohiro; Nishigaki, Nobuhiro; Nagaya, Hideaki

    2011-11-01

    The pharmacological profile of a novel angiotensin II type 1 receptor blocker, azilsartan medoxomil, was compared with that of the potent angiotensin II receptor blocker olmesartan medoxomil. Azilsartan, the active metabolite of azilsartan medoxomil, inhibited the binding of [(125)I]-Sar(1)-I1e(8)-angiotensin II to angiotensin II type 1 receptors. Azilsartan medoxomil inhibited angiotensin II-induced pressor responses in rats, and its inhibitory effects lasted 24h after oral administration. The inhibitory effects of olmesartan medoxomil disappeared within 24h. ID(50) values were 0.12 and 0.55 mg/kg for azilsartan medoxomil and olmesartan medoxomil, respectively. In conscious spontaneously hypertensive rats (SHRs), oral administration of 0.1-1mg/kg azilsartan medoxomil significantly reduced blood pressure at all doses even 24h after dosing. Oral administration of 0.1-3mg/kg olmesartan medoxomil also reduced blood pressure; however, only the two highest doses significantly reduced blood pressure 24h after dosing. ED(25) values were 0.41 and 1.3mg/kg for azilsartan medoxomil and olmesartan medoxomil, respectively. In renal hypertensive dogs, oral administration of 0.1-1mg/kg azilsartan medoxomil reduced blood pressure more potently and persistently than that of 0.3-3mg/kg olmesartan medoxomil. In a 2-week study in SHRs, azilsartan medoxomil showed more stable antihypertensive effects than olmesartan medoxomil and improved the glucose infusion rate, an indicator of insulin sensitivity, more potently (≥ 10 times) than olmesartan medoxomil. Azilsartan medoxomil also exerted more potent antiproteinuric effects than olmesartan medoxomil in Wistar fatty rats. These results suggest that azilsartan medoxomil is a potent angiotensin II receptor blocker that has an attractive pharmacological profile as an antihypertensive agent.

  1. RAAS激活与老年高血压合并抑郁的关系%Relationship between Activation of Rennin-angiotensin-aldosterone System and Hypertension in the Elderly Patients with Depression

    Institute of Scientific and Technical Information of China (English)

    田歌; 陶贵周; 屈宝泽; 李科研; 孙丽敏; 张雅卓

    2012-01-01

    探讨老年高血压合并抑郁患者肾素-血管紧张素-醛固酮系统( RAAS)的变化及二者之间的关系.入选原发性高血压病患者210例,其中高血压合并抑郁组(80倒)、高血压不合并抑郁组(130例),两组检测血糖、血肌酐、血脂等指标,用放射免疫分析法测定血浆肾素、血管紧张素Ⅱ、醛固酮水平.结果两组在性别、年龄、血糖、血脂等方面无统计学差异,高血压合并抑郁组肾素、血管紧张素及醛固酮水平均显著高于高血压不合并抑郁组.高血压合并抑郁组血浆肾素(r=0.283,P<0.01)、血管紧张素Ⅱ(r=0.312,P<0.01)、醛固酮水平(r=0.276,P<0.01)与HAMD量表总分呈正相关.RAAS系统激活与老年高血压合并抑郁关系密切,这对老年高血压合并抑郁患者的治疗提供了一定的临床价值.%To investigate the role of renin— angiotensin — aldosterone system(RAAS) in the elderly hypertensive patients with depression, 206 patients with hypertension were divided into simple hypertension group (n=127) and depression hypertension group (n=79) according to whether or not there was symptoms of depression. Age,sex,blood glucose,blood lipids and other related factors were compared between the two groups. The plasma rennin— angiotensin—aldosterone levels were measured by radioimmunoassay. The result is the plasma rennin — angiotensin — aldosterone level was higher in elderly hypertensive patients with depression than that in elderly hypertensive patients. The plasma rennin— angiotensin— aldosterone levels had positive correlation with the duration of depression. RAAS was closely related to the elderly hypertensive patients with depression. This might be useful for the treatment of the elderly depression hypertension.

  2. An open-label, randomized, controlled, 4-week comparative clinical trial of barnidipine hydrochloride, a calcium-channel blocker, and benazepril, an angiotensin-converting enzyme inhibitor, in Chinese patients with renal parenchymal hypertension.

    Science.gov (United States)

    Chen, X; Zheng, F; Chen, P; Tang, L; Wei, R; Yu, Y; Su, Y; Kikkawa, T; Yamamoto, M

    2006-01-01

    This study compared barnidipine, a calcium-channel blocker, and benazepril, an angiotensin-converting enzyme inhibitor, in 85 Chinese patients with renal parenchymal hypertension (diastolic blood pressure range 95 - 110 mmHg). Patients were randomly assigned to receive either 10 mg barnidipine or 10 mg benazepril orally daily for 4 weeks. In patients with diastolic blood pressure > 90 mmHg after 2 weeks of treatment, the dose of barnidipine or benazepril was increased by 5 or 10 mg, respectively. Both the barnidipine-treated group (n = 43) and the benazepril-treated group (n = 42) showed significant mean reductions from baseline in sitting systolic and diastolic blood pressures. The decrease in diastolic blood pressure with benazepril was significantly greater than with barnidipine treatment. Sitting heart rate was not changed by either drug. There was no significant difference in adverse events between the two groups. Barnidipine is similar to benazepril for the treatment of renal parenchymal hypertension.

  3. Angiotensin System Blockade Combined With Calcium Channel Blockers Is Superior to Other Combinations in Cardiovascular Protection With Similar Blood Pressure Reduction: A Meta-Analysis in 20,451 Hypertensive Patients.

    Science.gov (United States)

    Chi, Chen; Tai, Chenhui; Bai, Bin; Yu, Shikai; Karamanou, Marianna; Wang, Jiguang; Protogerou, Athanase; Blacher, Jacques; Safar, Michel E; Zhang, Yi; Xu, Yawei

    2016-08-01

    The authors aimed to investigate the superiority of angiotensin system blockade (angiotensin-converting enzyme [ACE] inhibitor/angiotensin receptor blocker [ARB]) plus a calcium channel blocker (CCB) (A+C) over other combination therapies in antihypertensive treatment. A meta-analysis in 20,451 hypertensive patients from eight randomized controlled trials was conducted to compare the A+C treatment with other combination therapies in terms of blood pressure (BP) reduction, clinical outcomes, and adverse events. The results showed that BP reduction did not differ significantly among the A+C therapy and other combination therapies in systolic and diastolic BP (P=.87 and P=.56, respectively). However, A+C therapy, compared with other combination therapies, achieved a significantly lower incidence of cardiovascular composite endpoints, including cardiovascular mortality, nonfatal myocardial infarction, and nonfatal stroke (risk ratio [RR], 0.80; 95% confidence interval [CI], 0.70-0.91; Pother combinations (Pother combination therapies (P=.34) but presented a significantly lower incidence of serious adverse events (RR, 0.85; 95% CI, 0.73-0.98; P=.03). In conclusion, A+C therapy is superior to other combinations of antihypertensive treatment as it shows a lower incidence of cardiovascular events and adverse events, while it has similar effects in lowering BP and preserving renal function.

  4. The therapeutic advantage of combination antihypertensive drug therapy using amlodipine and irbesartan in hypertensive patients: Analysis of the post-marketing survey data from PARTNER (Practical combination therapy of Amlodin and angiotensin II Receptor blocker; safety and efficacy in patients with hypertension) study.

    Science.gov (United States)

    Ishimitsu, Toshihiko; Fukuda, Hirofumi; Uchida, Masako; Ishibashi, Kazushi; Sato, Fusako; Nukui, Kazuhiko; Nagao, Munehiko

    2015-01-01

    Two-thirds of hypertensive patients need a combination antihypertensive therapy to achieve the target blood pressure (BP). The PARTNER (Practical combination therapy of Amlodin and angiotensin II Receptor blocker; Safety and efficacy in paTieNts with hypERtension) study is a prospective specific clinical use survey examining the efficacy and safety of 12-week treatment with amlodipine (AML) and Angiotensin II Receptor Blocker (ARB) in 5900 hypertensive patients. The current analysis was performed as to the BP control, adverse reactions, and the effects on laboratory data in patients treated with the combination of AML and irbesartan (IRB), namely the patients added AML to already taking IRB (AML add-on group, n = 1202) and the patients added IRB to AML (IRB add-on group, n = 1050). Both study groups showed distinct decreases in office BP at 4 week (p p 40/90 mmHg was ∼70% in either group. Proteinuria and estimated glomerular filtration rate (eGFR) were significantly improved in hypertensive patients with baseline eGFR 7 mg/dl. The incidence of adverse reactions was as few as 1.11% and there were no severe adverse reactions which hampered the continuation of combination therapy. In conclusion, combination antihypertensive therapy with AML and IRB effectively lowers BP without particular safety problems, reduces serum uric acid especially in patients with hyperuricemia and exhibits renoprotective effects in patients with chronic kidney disease.

  5. The efficacy and safety of dual blockage of the renin-angiotensin-aldosterone system in patients with type 2 diabetes, hypertension and obesity without renal dysfunction

    Directory of Open Access Journals (Sweden)

    S A Savelyeva

    2012-09-01

    Full Text Available The purpose of the study was to evaluate the clinical efficacy and safety of dual RAAS blockage during treatment with angiotensin-converting enzyme (ACE inhibitors in combination with a direct renin inhibitor (PIR aliskiren versus combination therapy with ACE inhibitors and angiotensin receptor blocker II (ARB valsartan in patients with type 2 diabetes mellitus (T2DM, arterial hypertension (AH and obesity, without renal dysfunction. Materials and methods. The study included 26 patients with T2DM (10 men and 16 women, mean age 59,0±6,2 years with inadequate control of blood pressure (over 130 and/or 80 mm Hg on prior antihypertensive therapy and without renal dysfunctions (glomerular filtration rate (GFR> 60 ml/min/1, 73 m2 and the of albumin/creatinine (A/C ratio in the morning urine sample <10 mg/mol. After screening with the continuation of the initial therapy, including ACE inhibitors, 14 patients were added aliskiren 150–300 mg/day, 12 patients – valsartan 80–160 mg/day. Evaluation of the treatment effectiveness in terms of blood pressure (mean of three consecutive measurements in the sitting position and the parameters of renal function (serum creatinine and potassium, GFR, A/C ratio in the urine was performed at 4, 12 and 24 weeks of therapy. Results. In the group of patients treated with aliskiren, after 4 weeks of treatment a significant decrease in systolic and diastolic blood pressure (SBP and DBP, respectively was noted as compared to baseline: 146,1 and 138,9 mm Hg, p<0,05, 87,1 and 81,1 mm Hg, p <0,05, respectively; with systolic BP after 24 weeks of treatment decreased to 127,8 (-18,2 mm Hg, p<0,05, diastolic BP to 75,0 (-12, 1 mm Hg, p<0,05, the target blood pressure (≤130/80 mm Hg was achieved in 83% of patients. The group of patients treated with valsartan, after 4 weeks of therapy showed a significant reduction in systolic BP 148 and 141,6 mm Hg, p <0,05, diastolic BP - to 85,8 and 81,7 mm Hg, p=0,059; after 24 weeks

  6. 血管紧张素转换酶基因多态性与高血压病早期腔隙性脑梗死的关系%Relationships between angiotensin-converting enzyme gene polymorphism and lacunar infarction in early stage of essential hypertension

    Institute of Scientific and Technical Information of China (English)

    徐岩; 毛建华

    2003-01-01

    AIM:To investigate the relationships between angiotensin converting enzyme gene polymorphism and lacunar infarction in patients with essential hypertension.METHODS:Polymerase chain reaction(PCR) was used to determine the genotypes for an insertion/deletion polymorphism of 287 pb fragment of ACE gene in 50 healthy persons,50 patients with simple essential hypertension and 30 patients with essential hypertension and lacunar infarction.RESULTS:There was no significant difference of genotype and allele between healthy persons and patients with simple essential hypertension;but there was significant difference of D allele and DD genotype of ACE gene between esential hypertensive patients with lacunar infarction and patients with simple essential hypertension and healthy persons.CONCLUSION:There is a significant relation between ACE gene polymorphism and essential hypertensive patients with lacunar infarction.

  7. The effect of esmolol on corrected-QT interval, corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients taking an angiotensin-converting enzyme inhibitor

    Directory of Open Access Journals (Sweden)

    Zahit Çeker

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: The importance of minimizing the exaggerated sympatho-adrenergic responses and QT interval and QT interval dispersion changes that may develop due to laryngoscopy and tracheal intubation during anesthesia induction in the hypertensive patients is clear. Esmolol decreases the hemodynamic response to laryngoscopy and intubation. However, the effect of esmolol in decreasing the prolonged QT interval and QT interval dispersion as induced by laryngoscopy and intubation is controversial. We investigated the effect of esmolol on the hemodynamic, and corrected-QT interval and corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients using angiotensin converting enzyme inhibitors. METHODS: 60 ASA I-II patients, with essential hypertension using angiotensin converting enzyme inhibitors were included in the study. The esmolol group received esmolol at a bolus dose of 500 mcg/kg followed by a 100 mcg/kg/min infusion which continued until the 4th min after intubation. The control group received 0.9% saline similar to the esmolol group. The mean blood pressure, heart rate values and the electrocardiogram records were obtained as baseline values before the anesthesia, 5 min after esmolol and saline administration, 3 min after the induction and 30 s, 2 min and 4 min after intubation. RESULTS: The corrected-QT interval was shorter in the esmolol group (p = 0.012, the corrected-QT interval dispersion interval was longer in the control group (p = 0.034 and the mean heart rate was higher in the control group (p = 0.022 30 s after intubation. The risk of arrhythmia frequency was higher in the control group in the 4-min period following intubation (p = 0.038. CONCLUSION: Endotracheal intubation was found to prolong corrected-QT interval and corrected-QT interval dispersion, and increase the heart rate during anesthesia induction with propofol in hypertensive patients using angiotensin converting

  8. Hypertension

    OpenAIRE

    2016-01-01

    Defining hypertension in pregnancy is challenging because blood pressure levels in pregnancy are dynamic, having a circadian rhythm and also changing with advancing gestational age. The accepted definition is a sustained systolic (sBP) of ≥140 mmHg or a sustained diastolic blood pressure (dBP) ≥90 mmHg, by office (or in-hospital) measurement. Measurement of blood pressure in pregnancy should follow standardised methods, as outside pregnancy. Blood pressure measurement may occur in three types...

  9. The central mechanism underlying hypertension: a review of the roles of sodium ions, epithelial sodium channels, the renin-angiotensin-aldosterone system, oxidative stress and endogenous digitalis in the brain.

    Science.gov (United States)

    Takahashi, Hakuo; Yoshika, Masamichi; Komiyama, Yutaka; Nishimura, Masato

    2011-11-01

    The central nervous system has a key role in regulating the circulatory system by modulating the sympathetic and parasympathetic nervous systems, pituitary hormone release, and the baroreceptor reflex. Digoxin- and ouabain-like immunoreactive materials were found >20 years ago in the hypothalamic nuclei. These factors appeared to localize to the paraventricular and supraoptic nuclei and the nerve fibers at the circumventricular organs and supposed to affect electrolyte balance and blood pressure. The turnover rate of these materials increases with increasing sodium intake. As intracerebroventricular injection of ouabain increases blood pressure via sympathetic activation, an endogenous digitalis-like factor (EDLF) was thought to regulate cardiovascular system-related functions in the brain, particularly after sodium loading. Experiments conducted mainly in rats revealed that the mechanism of action of ouabain in the brain involves sodium ions, epithelial sodium channels (ENaCs) and the renin-angiotensin-aldosterone system (RAAS), all of which are affected by sodium loading. Rats fed a high-sodium diet develop elevated sodium levels in their cerebrospinal fluid, which activates ENaCs. Activated ENaCs and/or increased intracellular sodium in neurons activate the RAAS; this releases EDLF in the brain, activating the sympathetic nervous system. The RAAS promotes oxidative stress in the brain, further activating the RAAS and augmenting sympathetic outflow. Angiotensin II and aldosterone of peripheral origin act in the brain to activate this cascade, increasing sympathetic outflow and leading to hypertension. Thus, the brain Na(+)-ENaC-RAAS-EDLF axis activates sympathetic outflow and has a crucial role in essential and secondary hypertension. This report provides an overview of the central mechanism underlying hypertension and discusses the use of antihypertensive agents.

  10. A comparison between diuretics and angiotensin-receptor blocker agents in patients with stage I hypertension (PREVER-treatment trial): study protocol for a randomized double-blind controlled trial

    Science.gov (United States)

    2011-01-01

    Background Cardiovascular disease is the leading cause of death in Brazil, and hypertension is its major risk factor. The benefit of its drug treatment to prevent major cardiovascular events was consistently demonstrated. Angiotensin-receptor blockers (ARB) have been the preferential drugs in the management of hypertension worldwide, despite the absence of any consistent evidence of advantage over older agents, and the concern that they may be associated with lower renal protection and risk for cancer. Diuretics are as efficacious as other agents, are well tolerated, have longer duration of action and low cost, but have been scarcely compared with ARBs. A study comparing diuretic and ARB is therefore warranted. Methods/design This is a randomized, double-blind, clinical trial, comparing the association of chlorthalidone and amiloride with losartan as first drug option in patients aged 30 to 70 years, with stage I hypertension. The primary outcomes will be variation of blood pressure by time, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new subclinical atherosclerosis and sudden death. The study will last 18 months. The sample size will be of 1200 participants for group in order to confer enough power to test for all primary outcomes. The project was approved by the Ethics committee of each participating institution. Discussion The putative pleiotropic effects of ARB agents, particularly renal protection, have been disputed, and they have been scarcely compared with diuretics in large clinical trials, despite that they have been at least as efficacious as newer agents in managing hypertension. Even if the null hypothesis is not rejected, the information will be useful for health care policy to treat hypertension in Brazil. Clinical trials registration number Clinical

  11. A comparison between diuretics and angiotensin-receptor blocker agents in patients with stage I hypertension (PREVER-treatment trial: study protocol for a randomized double-blind controlled trial

    Directory of Open Access Journals (Sweden)

    Figueiredo Neto José A

    2011-02-01

    Full Text Available Abstract Background Cardiovascular disease is the leading cause of death in Brazil, and hypertension is its major risk factor. The benefit of its drug treatment to prevent major cardiovascular events was consistently demonstrated. Angiotensin-receptor blockers (ARB have been the preferential drugs in the management of hypertension worldwide, despite the absence of any consistent evidence of advantage over older agents, and the concern that they may be associated with lower renal protection and risk for cancer. Diuretics are as efficacious as other agents, are well tolerated, have longer duration of action and low cost, but have been scarcely compared with ARBs. A study comparing diuretic and ARB is therefore warranted. Methods/design This is a randomized, double-blind, clinical trial, comparing the association of chlorthalidone and amiloride with losartan as first drug option in patients aged 30 to 70 years, with stage I hypertension. The primary outcomes will be variation of blood pressure by time, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new subclinical atherosclerosis and sudden death. The study will last 18 months. The sample size will be of 1200 participants for group in order to confer enough power to test for all primary outcomes. The project was approved by the Ethics committee of each participating institution. Discussion The putative pleiotropic effects of ARB agents, particularly renal protection, have been disputed, and they have been scarcely compared with diuretics in large clinical trials, despite that they have been at least as efficacious as newer agents in managing hypertension. Even if the null hypothesis is not rejected, the information will be useful for health care policy to treat hypertension in Brazil. Clinical trials

  12. Mortality in patients with hypertension on angiotensin-I converting enzyme (ACE)-inhibitor treatment is influenced by the ACE insertion/deletion polymorphism

    NARCIS (Netherlands)

    Bleumink, GS; Schut, Anna F.C.; Sturkenboom, MCJM; van Duijn, CM; Deckers, JW; Hofman, A; Kingma, J. Herre; Witteman, JCM; Stricker, BHC

    2005-01-01

    Background The response to angiotensin-l converting enzyme (ACE)-inhibitor therapy is highly variable. Residual ACE activity during treatment, potentially modified by the ACE insertion/deletion (I/D) polymorphism, may explain part of this variability. We studied the possible interaction between ACE-

  13. Varying patterns of the antihypertensive and antialbuminuric response to higher doses of renin-angiotensin-aldosterone system blockade in albuminuric hypertensive type 2 diabetes mellitus patients

    DEFF Research Database (Denmark)

    Weir, Matthew R; Hollenberg, Norman K; Remuzzi, Giuseppe;

    2011-01-01

    In patients with type 2 diabetes mellitus (T2DM), blocking of the renin-angiotensin-aldosterone system (RAAS) has demonstrated efficacy in lowering blood pressure (BP) and urinary albumin excretion rate (UAER). Nonetheless, not all patients successfully respond to RAAS blockade with a reduction i...

  14. Snakes and Hypertension.

    Science.gov (United States)

    Miller, Edward D

    2017-02-01

    Inhibition of Angiotensin Conversion in Experimental Renovascular Hypertension. By Miller ED Jr, Samuels A, Haber E, and Barger AC. Science 1972; 177:1108-9. Reprinted with permission from AAAS.Constriction of the renal artery and controlled reduction of renal perfusion pressure is followed by a prompt increase in systemic renin activity and a concomitant rise in blood pressure in trained, unanesthetized dogs. The elevated blood pressure induced by the renal artery stenosis can be prevented by prior treatment with the nonapeptide Pyr-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro, which blocks conversion of angiotensin I to angiotensin II. Further, the nonapeptide can restore systemic pressure to normal in the early phase of renovascular hypertension. These results offer strong evidence that the renin- angiotensin system is responsible for the initiation of hypertension in the unilaterally nephrectomized dog with renal artery constriction.

  15. Reduced Expression of the Extracellular Calcium-Sensing Receptor (CaSR Is Associated with Activation of the Renin-Angiotensin System (RAS to Promote Vascular Remodeling in the Pathogenesis of Essential Hypertension.

    Directory of Open Access Journals (Sweden)

    Yuan-Yuan Qu

    Full Text Available The proliferation of vascular smooth muscle cells (VSMCs, remodeling of the vasculature, and the renin-angiotensin system (RAS play important roles in the development of essential hypertension (EH, which is defined as high blood pressure (BP in which secondary causes, such as renovascular disease, are absent. The calcium-sensing receptor (CaSR is involved in the regulation of BP. However, the underlying mechanisms by which the CaSR regulates BP are poorly understood. In the present study, the role of the CaSR in EH was investigated using male spontaneously hypertensive rats (SHRs and rat and human plasma samples. The percentages of medial wall thickness to external diameter (WT%, total vessel wall cross-sectional area to the total area (WA% of thoracic arteries, as well as the percentage of wall area occupied by collagen to total vessel wall area (CA% were determined. Tissue protein expression and plasma concentrations of the CaSR, cyclic adenosine monophosphate (cAMP, renin, and angiotensin II (Ang II were additionally assessed. WT%, WA%, and CA% were found to increase with increasing BP, whereas the plasma concentration of CaSR was found to decrease. With increasing BP, the levels of smooth muscle actin and calponin decreased, whereas those of osteopontin and proliferating cell nuclear antigen increased. The CaSR level negatively correlated with the levels of cAMP and Ang II, but positively correlated with those of renin. Our data suggest that reduced expression of the CaSR is correlated with activation of the RAS, which induces increased vascular remodeling and VSMC proliferation, and thereby associated with EH in the SHR model and in the Han Chinese population. Our findings provide new insights into the pathogenesis of EH.

  16. The rationale and design of the antihypertensives and vascular, endothelial, and cognitive function (AVEC trial in elderly hypertensives with early cognitive impairment: Role of the renin angiotensin system inhibition

    Directory of Open Access Journals (Sweden)

    Hart Meaghan

    2009-11-01

    Full Text Available Abstract Background Prior evidence suggests that the renin angiotensin system and antihypertensives that inhibit this system play a role in cognitive, central vascular, and endothelial function. Our objective is to conduct a double-blind randomized controlled clinical trial, the antihypertensives and vascular, endothelial, and cognitive function (AVEC, to compare 1 year treatment of 3 antihypertensives (lisinopril, candesartan, or hydrochlorothiazide in their effect on memory and executive function, cerebral blood flow, and central endothelial function of seniors with hypertension and early objective evidence of executive or memory impairments. Methods/Design The overall experimental design of the AVEC trial is a 3-arm double blind randomized controlled clinical trial. A total of 100 community eligible individuals (60 years or older with hypertension and early cognitive impairment are being recruited from the greater Boston area and randomized to lisinopril, candesartan, or hydrochlorothiazide ("active control" for 12 months. The goal of the intervention is to achieve blood pressure control defined as SBP 20 and without clinical diagnosis of dementia or Alzheimer's disease. Individuals who are currently receiving antihypertensives are eligible to participate if the participants and the primary care providers are willing to taper their antihypertensives. Participants undergo cognitive assessment, measurements of cerebral blood flow using Transcranial Doppler, and central endothelial function by measuring changes in cerebral blood flow in response to changes in end tidal carbon dioxide at baseline (off antihypertensives, 6, and 12 months. Our outcomes are change in cognitive function score (executive and memory, cerebral blood flow, and carbon dioxide cerebral vasoreactivity. Discussion The AVEC trial is the first study to explore impact of antihypertensives in those who are showing early evidence of cognitive difficulties that did not reach the

  17. Statins inhibit angiotensin II/Smad pathway and related vascular fibrosis, by a TGF-β-independent process.

    Directory of Open Access Journals (Sweden)

    Raúl Rodrigues Díez

    Full Text Available We have recently described that in an experimental model of atherosclerosis and in vascular smooth muscle cells (VSMCs statins increased the activation of the Smad pathway by transforming growth factor-β (TGF-β, leading to an increase in TGF-β-dependent matrix accumulation and plaque stabilization. Angiotensin II (AngII activates the Smad pathway and contributes to vascular fibrosis, although the in vivo contribution of TGF-β has not been completely elucidated. Our aim was to further investigate the mechanisms involved in AngII-induced Smad activation in the vasculature, and to clarify the beneficial effects of statins on AngII-induced vascular fibrosis. Infusion of AngII into rats for 3 days activates the Smad pathway and increases fibrotic-related factors, independently of TGF-β, in rat aorta. Treatment with atorvastatin or simvastatin inhibited AngII-induced Smad activation and related-fibrosis. In cultured rat VSMCs, direct AngII/Smad pathway activation was mediated by p38 MAPK and ROCK activation. Preincubation of VSMCs with statins inhibited AngII-induced Smad activation at all time points studied (from 20 minutes to 24 hours. All these data show that statins inhibited several AngII-activated intracellular signaling systems, including p38-MAPK and ROCK, which regulates the AngII/Smad pathway and related profibrotic factors and matrix proteins, independently of TGF-β responses. The inhibitory effect of statins on the AngII/Smad pathway could explain, at least in part, their beneficial effects on hypertension-induced vascular damage.

  18. Efficacy of angiotensin II type 1 receptor blockade on reperfusion-induced arrhythmias and mortality early after myocardial infarction is increased in transgenic rats with cardiac angiotensin II type 1 overexpression

    NARCIS (Netherlands)

    de Boer, RA; van Geel, PP; Pinto, YM; Suurmeijer, AJH; Crijns, HJGM; van Gilst, WH; van Veldhuisen, DJ

    2002-01-01

    Angiotensin II induces ischemia/reperfusion (I/R)-induced arrhythmias and blockade of the angiotensin II type I receptor (AT1R) may therefore be beneficial in preventing arrhythmias and decreasing mortality after myocardial infarction (MI). Because the AT1R is upregulated after myocardial ischemia,

  19. Age- and Hypertension-Associated Protein Aggregates in Mouse Heart Have Similar Proteomic Profiles.

    Science.gov (United States)

    Ayyadevara, Srinivas; Mercanti, Federico; Wang, Xianwei; Mackintosh, Samuel G; Tackett, Alan J; Prayaga, Sastry V S; Romeo, Francesco; Shmookler Reis, Robert J; Mehta, Jawahar L

    2016-05-01

    Neurodegenerative diseases are largely defined by protein aggregates in affected tissues. Aggregates contain some shared components as well as proteins thought to be specific for each disease. Aggregation has not previously been reported in the normal, aging heart or the hypertensive heart. Detergent-insoluble protein aggregates were isolated from mouse heart and characterized on 2-dimensional gels. Their levels increased markedly and significantly with aging and after sustained angiotensin II-induced hypertension. Of the aggregate components identified by high-resolution proteomics, half changed in abundance with age (392/787) or with sustained hypertension (459/824), whereas 30% (273/901) changed concordantly in both, each Phypertensive hearts, we posited that aging of fibroblasts may contribute to the aggregates observed in cardiac tissue. Indeed, as cardiac myofibroblasts "senesced" (approached their replicative limit) in vitro, they accrued aggregates with many of the same constituent proteins observed in vivo during natural aging or sustained hypertension. In summary, we have shown for the first time that compact (detergent-insoluble) protein aggregates accumulate during natural aging, chronic hypertension, and in vitro myofibroblast senescence, sharing many common proteins. Thus, aggregates that arise from disparate causes (aging, hypertension, and replicative senescence) may have common underlying mechanisms of accrual.

  20. An ongoing role of α-calcitonin gene-related peptide as part of a protective network against hypertension, vascular hypertrophy, and oxidative stress.

    Science.gov (United States)

    Smillie, Sarah-Jane; King, Ross; Kodji, Xenia; Outzen, Emilie; Pozsgai, Gabor; Fernandes, Elizabeth; Marshall, Nichola; de Winter, Patricia; Heads, Richard J; Dessapt-Baradez, Cecile; Gnudi, Luigi; Sams, Anette; Shah, Ajay M; Siow, Richard C; Brain, Susan D

    2014-05-01

    α-Calcitonin gene-related peptide (αCGRP) is a vasodilator, but there is limited knowledge of its long-term cardiovascular protective influence. We hypothesized that αCGRP protects against the onset and development of angiotensin II-induced hypertension and have identified protective mechanisms at the vascular level. Wild-type and αCGRP knockout mice that have similar baseline blood pressure were investigated in the angiotensin II hypertension model for 14 and 28 days. αCGRP knockout mice exhibited enhanced hypertension and aortic hypertrophy. αCGRP gene expression was increased in dorsal root ganglia and at the conduit and resistance vessel level of wild-type mice at both time points. βCGRP gene expression was also observed and shown to be linked to plasma levels of CGRP. Mesenteric artery contractile and relaxant responses in vitro and endothelial NO synthase expression were similar in all groups. The aorta exhibited vascular hypertrophy, increased collagen formation, and oxidant stress markers in response to angiotensin II, with highest effects observed in αCGRP knockout mice. Gene and protein expression of endothelial NO synthase was lacking in the aortae after angiotensin II treatment, especially in αCGRP knockout mice. These results demonstrate the ongoing upregulation of αCGRP at the levels of both conduit and resistance vessels in vascular tissue in a model of hypertension and the direct association of this with protection against aortic vascular hypertrophy and fibrosis. This upregulation is maintained at a time when expression of aortic endothelial NO synthase and antioxidant defense genes have subsided, in keeping with the concept that the protective influence of αCGRP in hypertension may have been previously underestimated.

  1. Effect of renin-angiotensin -aldosterone system blockers on myocardial remodeling processes and risk for atrial fibrillation in patients with arterial hypertension

    Directory of Open Access Journals (Sweden)

    O. M. Drapkina

    2014-07-01

    Full Text Available The given review considers the mechanisms underlying the development and maintenance of atrial fibrillations (AF. It is noted that the processes of atrial fibrosis, ion channel remodeling, inflammation, apoptosis, impaired intercellular interactions, and myocardiocyte hypertrophy may give rise to atrial structural and functional changes in AF. The efficacy of angiotensinonverting enzyme inhibitors and angiotensin receptor antagonists is justified in patients with left ventricular systolic dysfunction.

  2. Angiotensin II contributes to renal fibrosis independently of Notch pathway activation.

    Directory of Open Access Journals (Sweden)

    Carolina Lavoz

    Full Text Available Recent studies have described that the Notch signaling pathway is activated in a wide range of renal diseases. Angiotensin II (AngII plays a key role in the progression of kidney diseases. AngII contributes to renal fibrosis by upregulation of profibrotic factors, induction of epithelial mesenchymal transition and accumulation of extracellular matrix proteins. In cultured human tubular epithelial cells the Notch activation by transforming growth factor-β1 (TGF-β1 has been involved in epithelial mesenchymal transition. AngII mimics many profibrotic actions of TGF-β1. For these reasons, our aim was to investigate whether AngII could regulate the Notch/Jagged system in the kidney, and its potential role in AngII-induced responses. In cultured human tubular epithelial cells, TGF-β1, but not AngII, increased the Notch pathway-related gene expression, Jagged-1 synthesis, and caused nuclear translocation of the activated Notch. In podocytes and renal fibroblasts, AngII did not modulate the Notch pathway. In tubular epithelial cells, pharmacological Notch inhibition did not modify AngII-induced changes in epithelial mesenchymal markers, profibrotic factors and extracellular matrix proteins. Systemic infusion of AngII into rats for 2 weeks caused tubulointerstitial fibrosis, but did not upregulate renal expression of activated Notch-1 or Jagged-1, as observed in spontaneously hypertensive rats. Moreover, the Notch/Jagged system was not modulated by AngII type I receptor blockade in the model of unilateral ureteral obstruction in mice. These data clearly indicate that AngII does not regulate the Notch/Jagged signaling system in the kidney, in vivo and in vitro. Our findings showing that the Notch pathway is not involved in AngII-induced fibrosis could provide important information to understand the complex role of Notch system in the regulation of renal regeneration vs damage progression.

  3. Angiotensin II contributes to renal fibrosis independently of Notch pathway activation.

    Science.gov (United States)

    Lavoz, Carolina; Rodrigues-Diez, Raquel; Benito-Martin, Alberto; Rayego-Mateos, Sandra; Rodrigues-Diez, Raúl R; Alique, Matilde; Ortiz, Alberto; Mezzano, Sergio; Egido, Jesús; Ruiz-Ortega, Marta

    2012-01-01

    Recent studies have described that the Notch signaling pathway is activated in a wide range of renal diseases. Angiotensin II (AngII) plays a key role in the progression of kidney diseases. AngII contributes to renal fibrosis by upregulation of profibrotic factors, induction of epithelial mesenchymal transition and accumulation of extracellular matrix proteins. In cultured human tubular epithelial cells the Notch activation by transforming growth factor-β1 (TGF-β1) has been involved in epithelial mesenchymal transition. AngII mimics many profibrotic actions of TGF-β1. For these reasons, our aim was to investigate whether AngII could regulate the Notch/Jagged system in the kidney, and its potential role in AngII-induced responses. In cultured human tubular epithelial cells, TGF-β1, but not AngII, increased the Notch pathway-related gene expression, Jagged-1 synthesis, and caused nuclear translocation of the activated Notch. In podocytes and renal fibroblasts, AngII did not modulate the Notch pathway. In tubular epithelial cells, pharmacological Notch inhibition did not modify AngII-induced changes in epithelial mesenchymal markers, profibrotic factors and extracellular matrix proteins. Systemic infusion of AngII into rats for 2 weeks caused tubulointerstitial fibrosis, but did not upregulate renal expression of activated Notch-1 or Jagged-1, as observed in spontaneously hypertensive rats. Moreover, the Notch/Jagged system was not modulated by AngII type I receptor blockade in the model of unilateral ureteral obstruction in mice. These data clearly indicate that AngII does not regulate the Notch/Jagged signaling system in the kidney, in vivo and in vitro. Our findings showing that the Notch pathway is not involved in AngII-induced fibrosis could provide important information to understand the complex role of Notch system in the regulation of renal regeneration vs damage progression.

  4. Estrogen normalizes perinatal nicotine-induced hypertensive responses in adult female rat offspring.

    Science.gov (United States)

    Xiao, Daliao; Huang, Xiaohui; Yang, Shumei; Zhang, Lubo

    2013-06-01

    Perinatal nicotine exposure caused a sex-dependent heightened vascular response to angiotensin II (Ang II) and increased blood pressure in adult male but not in female rat offspring. The present study tested the hypothesis that estrogen normalizes perinatal nicotine-induced hypertensive response to Ang II in female offspring. Nicotine was administered to pregnant rats via subcutaneous osmotic minipumps from day 4 of gestation to day 10 after birth. Ovariectomy and 17β-estradiol replacement were performed on 8-week-old female offspring. At 5 months of age, Ang II-induced blood pressure responses were not changed by nicotine treatment in the sham groups. In contrast, nicotine significantly enhanced Ang II-induced blood pressure responses as compared with saline control in the ovariectomy groups, which was associated with increased Ang II-induced vascular contractions. These heightened responses were abrogated by 17β-estradiol replacement. In addition, nicotine enhanced Ang II receptor type I, NADPH (nicotinamide adenine dinucleotide phosphate) oxidase type 2 protein expressions, and reactive oxygen species production of aortas as compared with saline control in the ovariectomy groups. Antioxidative agents, both apocynin and tempol, inhibited Ang II-induced vascular contraction and eliminated the differences of contractions between nicotine-treated and control ovariectomy rats. These findings support a key role of estrogen in the sex difference of perinatal nicotine-induced programming of vascular dysfunction, and suggest that estrogen may counteract heightened reactive oxygen species production, leading to protection of females from development programming of hypertensive phenotype in adulthood.

  5. Single nucleotide polymorphisms of the angiotensin-converting enzyme (ACE gene are associated with essential hypertension and increased ACE enzyme levels in Mexican individuals.

    Directory of Open Access Journals (Sweden)

    Nancy Martínez-Rodríguez

    Full Text Available AIM: To explore the role of the ACE gene polymorphisms in the risk of essential hypertension in Mexican Mestizo individuals and evaluate the correlation between these polymorphisms and the serum ACE levels. METHODS: Nine ACE gene polymorphisms were genotyped by 5' exonuclease TaqMan genotyping assays and polymerase chain reaction (PCR in 239 hypertensive and 371 non- hypertensive Mexican individuals. Haplotypes were constructed after linkage disequilibrium analysis. ACE serum levels were determined in selected individuals according to different haplotypes. RESULTS: Under a dominant model, rs4291 rs4335, rs4344, rs4353, rs4362, and rs4363 polymorphisms were associated with an increased risk of hypertension after adjusting for age, gender, BMI, triglycerides, alcohol consumption, and smoking. Five polymorphisms (rs4335, rs4344, rs4353, rs4362 and rs4363 were in strong linkage disequilibrium and were included in four haplotypes: H1 (AAGCA, H2 (GGATG, H3 (AGATG, and H4 (AGACA. Haplotype H1 was associated with decreased risk of hypertension, while haplotype H2 was associated with an increased risk of hypertension (OR = 0.77, P = 0.023 and OR = 1.41, P = 0.004 respectively. According to the codominant model, the H2/H2 and H1/H2 haplotype combinations were significantly associated with risk of hypertension after adjusted by age, gender, BMI, triglycerides, alcohol consumption, and smoking (OR = 2.0; P = 0.002 and OR = 2.09; P = 0.011, respectively. Significant elevations in serum ACE concentrations were found in individuals with the H2 haplotype (H2/H2 and H2/H1 as compared to H1/H1 individuals (P = 0.0048. CONCLUSION: The results suggest that single nucleotide polymorphisms and the "GGATG" haplotype of the ACE gene are associated with the development of hypertension and with increased ACE enzyme levels.

  6. Obesity-Related Hypertension

    OpenAIRE

    Re, Richard N.

    2009-01-01

    Obesity-associated arterial hypertension is characterized by activation of the sympathetic nervous system, activation of the renin-angiotensin system, and sodium retention, among other abnormalities. In this review, the following 3 facets of the obesity/hypertension nexus will be discussed: the potential mechanisms by which obesity can lead to elevated arterial pressure, the interaction of obesity with the sequelae of hypertension, and the therapies that are believed to optimally treat obesit...

  7. Over-expressed copper/zinc superoxide dismutase localizes to mitochondria in neurons inhibiting the angiotensin II-mediated increase in mitochondrial superoxide

    Directory of Open Access Journals (Sweden)

    Shumin Li

    2014-01-01

    Full Text Available Angiotensin II (AngII is the main effector peptide of the renin–angiotensin system (RAS, and contributes to the pathogenesis of cardiovascular disease by exerting its effects on an array of different cell types, including central neurons. AngII intra-neuronal signaling is mediated, at least in part, by reactive oxygen species, particularly superoxide (O2·−. Recently, it has been discovered that mitochondria are a major subcellular source of AngII-induced O2·−. We have previously reported that over-expression of manganese superoxide dismutase (MnSOD, a mitochondrial matrix-localized O2·− scavenging enzyme, inhibits AngII intra-neuronal signaling. Interestingly, over-expression of copper/zinc superoxide dismutase (CuZnSOD, which is believed to be primarily localized to the cytoplasm, similarly inhibits AngII intra-neuronal signaling and provides protection against AngII-mediated neurogenic hypertension. Herein, we tested the hypothesis that CuZnSOD over-expression in central neurons localizes to mitochondria and inhibits AngII intra-neuronal signaling by scavenging mitochondrial O2·−. Using a neuronal cell culture model (CATH.a neurons, we demonstrate that both endogenous and adenovirus-mediated over-expressed CuZnSOD (AdCuZnSOD are present in mitochondria. Furthermore, we show that over-expression of CuZnSOD attenuates the AngII-mediated increase in mitochondrial O2·− levels and the AngII-induced inhibition of neuronal potassium current. Taken together, these data clearly show that over-expressed CuZnSOD in neurons localizes in mitochondria, scavenges AngII-induced mitochondrial O2·−, and inhibits AngII intra-neuronal signaling.

  8. Over-expressed copper/zinc superoxide dismutase localizes to mitochondria in neurons inhibiting the angiotensin II-mediated increase in mitochondrial superoxide.

    Science.gov (United States)

    Li, Shumin; Case, Adam J; Yang, Rui-Fang; Schultz, Harold D; Zimmerman, Matthew C

    2013-01-01

    Angiotensin II (AngII) is the main effector peptide of the renin-angiotensin system (RAS), and contributes to the pathogenesis of cardiovascular disease by exerting its effects on an array of different cell types, including central neurons. AngII intra-neuronal signaling is mediated, at least in part, by reactive oxygen species, particularly superoxide (O2 (•-)). Recently, it has been discovered that mitochondria are a major subcellular source of AngII-induced O2 (•-). We have previously reported that over-expression of manganese superoxide dismutase (MnSOD), a mitochondrial matrix-localized O2 (•-) scavenging enzyme, inhibits AngII intra-neuronal signaling. Interestingly, over-expression of copper/zinc superoxide dismutase (CuZnSOD), which is believed to be primarily localized to the cytoplasm, similarly inhibits AngII intra-neuronal signaling and provides protection against AngII-mediated neurogenic hypertension. Herein, we tested the hypothesis that CuZnSOD over-expression in central neurons localizes to mitochondria and inhibits AngII intra-neuronal signaling by scavenging mitochondrial O2 (•-). Using a neuronal cell culture model (CATH.a neurons), we demonstrate that both endogenous and adenovirus-mediated over-expressed CuZnSOD (AdCuZnSOD) are present in mitochondria. Furthermore, we show that over-expression of CuZnSOD attenuates the AngII-mediated increase in mitochondrial O2 (•-) levels and the AngII-induced inhibition of neuronal potassium current. Taken together, these data clearly show that over-expressed CuZnSOD in neurons localizes in mitochondria, scavenges AngII-induced mitochondrial O2 (•-), and inhibits AngII intra-neuronal signaling.

  9. Changes in the renin-angiotensin-aldosterone system in response to dietary salt intake in normal and hypertensive pregnancy. A randomized trial

    DEFF Research Database (Denmark)

    Nielsen, Lise Hald; Ovesen, Per; Hansen, Mie R

    2016-01-01

    during low-salt diet in PE patients (n = 7), healthy pregnant women (n = 15), and nonpregnant women (n = 13). High-salt intake decreased renin and angiotensin II concentrations significantly in healthy pregnant women (P ... in aldosterone and increases in brain natriuretic peptid (BNP) were similar in the groups. In PE patients, uterine and umbilical artery indices were not adversely changed during low-salt diet. Creatinine clearance was significantly lower in PE with no change by salt intake. PE patients displayed alterations...

  10. The Renin-Angiotensin System Modulates Inflammatory Processes in Atherosclerosis: Evidence from Basic Research and Clinical Studies

    Directory of Open Access Journals (Sweden)

    Fabrizio Montecucco

    2009-01-01

    Full Text Available Recent evidence shows that the renin-angiotensin system is a crucial player in atherosclerotic processes. The regulation of arterial blood pressure was considered from its first description of the main mechanism involved. Vasoconstriction (mediated by angiotensin II and salt and water retention (mainly due to aldosterone were classically considered as pivotal proatherosclerotic activities. However, basic research and animal studies strongly support angiotensin II as a proinflammatory mediator, which directly induces atherosclerotic plaque development and heart remodeling. Furthermore, angiotensin II induces proatherosclerotic cytokine and chemokine secretion and increases endothelial dysfunction. Accordingly, the pharmacological inhibition of the renin-angiotensin system improves prognosis of patients with cardiovascular disease even in settings of normal baseline blood pressure. In the present review, we focused on angiotensin-convertingenzyme (ACE inhibitors, angiotensin II receptor blockers (ARBs, and renin inhibitors to update the direct activities of the renin-angiotensin system in inflammatory processes governing atherosclerosis.

  11. Renin-angiotensin system in ventilator-induced diaphragmatic dysfunction: Potential protective role of Angiotensin (1-7).

    Science.gov (United States)

    Sigurta', Anna; Zambelli, Vanessa; Bellani, Giacomo

    2016-09-01

    Ventilator-induced diaphragmatic dysfunction is a feared complication of mechanical ventilation that adversely affects the outcome of intensive care patients. Human and animal studies demonstrate atrophy and ultrastructural alteration of diaphragmatic muscular fibers attributable to increased oxidative stress, depression of the anabolic pathway regulated by Insulin-like growing factor 1 and increased proteolysis. The renin-angiotensin system, through its main peptide Angiotensin II, plays a major role in skeletal muscle diseases, mainly increasing oxidative stress and inducing insulin resistance, atrophy and fibrosis. Conversely, its counter-regulatory peptide Angiotensin (1-7) has a protective role in these processes. Recent data on rodent models show that renin-angiotensin system is activated after mechanical ventilation and that infusion of Angiotensin II induces diaphragmatic skeletal muscle atrophy. Given: (A) common pathways shared by ventilator-induced diaphragmatic dysfunction and skeletal muscle pathology induced by renin-angiotensin system, (B) evidences of an involvement of renin-angiotensin system in diaphragm atrophy and dysfunction, we hypothesize that renin-angiotensin system plays an important role in ventilator-induced diaphragmatic dysfunction, while Angiotensin (1-7) can have a protective effect on this pathological process. The activation of renin-angiotensin system in ventilator-induced diaphragmatic dysfunction can be demonstrated by quantification of its main components in the diaphragm of ventilated humans or animals. The infusion of Angiotensin (1-7) in an established rodent model of ventilator-induced diaphragmatic dysfunction can be used to test its potential protective role, that can be further confirmed with the infusion of Angiotensin (1-7) antagonists like A-779. Verifying this hypothesis can help in understanding the processes involved in ventilator-induced diaphragmatic dysfunction pathophysiology and open new possibilities for its

  12. Atrial fibrillation and arterial hypertension: A common duet with dangerous consequences where the renin angiotensin-aldosterone system plays an important role.

    Science.gov (United States)

    Seccia, Teresa Maria; Caroccia, Brasilina; Muiesan, Maria Lorenza; Rossi, Gian Paolo

    2016-03-01

    Atrial fibrillation (AF) represents the most common sustained cardiac arrhythmia, as it affects 1%-2% of the general population and up to 15% of people over 80 years. High blood pressure, due to its high prevalence in the general population, is by far the most common condition associated with AF, although a variety of diseases, including valvular, coronary heart and metabolic diseases, are held to create the substrate favouring AF. Due to the concomitance of these conditions, it is quite challenging to dissect the precise role of high blood pressure in triggering/causing AF. Hence, even though the intimate association between high blood pressure and AF has been known for decades, the underlying mechanisms remain partially unknown. Accumulating evidences point to a major role of the renin-angiotensin-aldosterone system in inducing cardiac inflammation and fibrosis, and therefore electric and structural atrial and ventricular remodelling, with changes in ions and cell junctions leading to AF development. These evidences are herein reviewed with a particular emphasis to the role of the renin-angiotensin-system aldosterone system.

  13. Examination of nanoformulated crosslinked polymers complexed with copper/zinc superoxide dismutase as a therapeutic strategy for angiotensin II-mediated hypertension

    Science.gov (United States)

    Savalia, Krupa

    Excessive generation of superoxide (O2·-) has been extensively implicated as a signaling molecule in cardiovascular pathologies, including hypertension. As a major risk factor for myocardial infarction, stroke, and heart failure, the morbidity and mortality associated with hypertension is a worldwide epidemic. Although there are several standard therapies that effectively lower blood pressure, many hypertensive patients have uncontrolled blood pressure despite taking available medications. Thus, there is a necessity to develop new pharmacotherapies that target novel molecular effectors (e.g. O2·-) that have been implicated to be integral in the pathogenesis of hypertension. To overcome the failed therapeutic impact of currently available antioxidants in cardiovascular disease, we developed a nanomedicine-based delivery system for the O2 ·- scavenging enzyme, copper/zinc superoxide dismutase (CuZnSOD), in which CuZnSOD protein is electrostatically bound to poly-L-lysine (PLL 50)-polyethylene glycol (PEG) block co-polymer to form CuZnSOD nanozyme. Different formulations of CuZnSOD nanozyme are covalently stabilized by either reducible or non-reducible crosslinked bonds between the PLL50-PEG polymers. Herein, we tested the overall hypothesis that PLL50-PEG CuZnSOD nanozyme delivers active CuZnSOD protein to neurons and decreases blood pressure in a model of Angll-dependent hypertension. As determined by electron paramagnetic resonance (EPR) spectroscopy, nanozymes retain full SOD enzymatic activity. Furthermore, non-reducible crosslinked nanozyme delivers active CuZnSOD protein to central neurons in culture (CATH.a neurons) without inducing significant neuronal toxicity. In vivo studies conducted in Angll-mediated hypertensive adult male C57BL/6 mice demonstrate that the non-reducible crosslinked nanozyme significantly attenuates blood pressure when given directly into the brain and prevents the further increase in hypertension when intravenously (IV) administered

  14. Angiotensin-II mediates ACE2 Internalization and Degradation through an Angiotensin-II type I receptor-dependent mechanism

    OpenAIRE

    Deshotels, Matthew R.; Xia, Huijing; Lazartigues, Eric; Filipeanu, Catalin M.

    2014-01-01

    Angiotensin Converting Enzyme type 2 (ACE2) is a pivotal component of the renin-angiotensin system, promoting the conversion of Angiotensin (Ang)-II to Ang-(1-7). We previously reported that decreased ACE2 expression and activity contribute to the development of Ang-II-mediated hypertension in mice. The present study aimed to investigate the mechanisms involved in ACE2 down-regulation during neurogenic hypertension. In ACE2-transfected Neuro-2A cells, Ang-II treatment resulted in a significan...

  15. [Hypertension and arteriosclerosis].

    Science.gov (United States)

    Sasamura, Hiroyuki; Itoh, Hiroshi

    2011-01-01

    Hypertension is a known risk factor for arteriosclerosis, and causes both atherosclero= sis of medium-large arteries and arteriolosclerosis of the arterioles. Elevated blood pressure causes damage to the endothelium and vascular wall through both mechanical and humoral factors. We and others have shown that inhibition of the renin-angiotensin system at a 'critical period' during the development of hypertension results in a permanent suppression of hypertension in animal models. We have also reported that high-dose renin-angiotensin inhibition results in regression of hypertension, possibly by regression of renal arteriolar hypertrophy. These results suggest that understanding the process of arterial remodeling may play a key role in the development of new strategies for prevention and regression of hypertension and arteriosclerosis.

  16. Cushing's disease and hypertension: In vivo and in vitro study of the role of the renin-Angiotensin-Aldosterone system and effects of medical therapy

    NARCIS (Netherlands)

    R. van der Pas (Rob); J.H.M. Esch, van (Joep); C. de Bruin (Christiaan); A.H.J. Danser (Jan); A.M. Pereira (Alberto); P.M. Zelissen (Pierre M.); R.T. Netea-Maier (Romana ); D. Sprij-Mooij (Diana); I.M. van den Berg-Garrelds (I.); R.H.N. van Schaik (Ron); S.W.J. Lamberts (Steven); A.H. van den Meiracker (Anton); L.J. Hofland (Leo); R.A. Feelders (Richard)

    2014-01-01

    textabstractAbstract Objective/methods: Cushing's disease (CD) is often accompanied by hypertension. CD can be treated surgically and, given the expression of somatostatin subtype 5 and dopamine 2 receptors by corticotroph pituitary adenomas, pharmacologically. Indeed, we recently observed that step

  17. Cushing's disease and hypertension: in vivo and in vitro study of the role of the renin-angiotensin-aldosterone system and effects of medical therapy

    NARCIS (Netherlands)

    Pas, R. van der; Esch, J.H. van; Bruin, C. de; Danser, A.H.; Pereira, A.M.; Zelissen, P.M.; Netea-Maier, R.; Sprij-Mooij, D.M.; Berg-Garrelds, I.M. van den; Schaik, R.H. van; Lamberts, S.W.J.; Meiracker, A.H. van den; Hofland, L.J.; Feelders, R.A.

    2014-01-01

    OBJECTIVE/METHODS: Cushing's disease (CD) is often accompanied by hypertension. CD can be treated surgically and, given the expression of somatostatin subtype 5 and dopamine 2 receptors by corticotroph pituitary adenomas, pharmacologically. Indeed, we recently observed that stepwise medical combinat

  18. The use of ultralow doses of antibodies to C-terminal fragment of angiotensin II AT1 receptor (kardos) in the therapy of arterial hypertension.

    Science.gov (United States)

    Petrov, V I; Nedogoda, S V; Epshtein, O I; Chalyabi, T A; Brel', U A; Chepurina, N G; Mazina, G V; Kachanova, M V; Sabanov, L V; Tarasov, S A; Zabolotneva, Yu A; Kolosova, A E; Sergeeva, S A

    2009-08-01

    Kardos monotherapy allows attaining the target levels of systolic and diastolic blood pressure in patients with high-risk and very-high-risk hypertension. We demonstrated excellent tolerability of the preparation in combination with reliable blood pressure decrease over 24 h, during day and night hours.

  19. The angiotensin II receptor antagonist telmisartan reduces urinary albumin excretion in patients with isolated systolic hypertension : results of a randomized, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    Vogt, Liffert; Navis, Gerjan; Koester, Juergen; Manolis, Athanasios J.; Reid, John L.; de Zeeuw, Dick

    2005-01-01

    Objective To examine the effect of telmisartan or hydrochlorothiazide on the control of urinary albumin excretion (UAE) in patients with isolated systolic hypertension (ISH) unselected for albuminuria in a pre-planned substudy of a large, multicentre, double-blind, placebo-controlled, randomized stu

  20. The angiotensin II receptor antagonist telmisartan reduces urinary albumin excretion in patients with isolated systolic hypertension: results of a randomized, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    Vogt, Liffert; Navis, Gerjan; Koester, Juergen; Manolis, Athanasios J.; Reid, John L.; de Zeeuw, Dick

    2005-01-01

    Objective To examine the effect of telmisartan or hydrochlorothiazide on the control of urinary albumin excretion (UAE) in patients with isolated systolic hypertension (ISH) unselected for albuminuria in a pre-planned substudy of a large, multicentre, double-blind, placebo-controlled, randomized stu

  1. The Angiotensin-Melatonin Axis

    Directory of Open Access Journals (Sweden)

    Luciana A. Campos

    2013-01-01

    Full Text Available Accumulating evidence indicates that various biological and neuroendocrine circadian rhythms may be disrupted in cardiovascular and metabolic disorders. These circadian alterations may contribute to the progression of disease. Our studies direct to an important role of angiotensin II and melatonin in the modulation of circadian rhythms. The brain renin-angiotensin system (RAS may modulate melatonin synthesis, a hormone with well-established roles in regulating circadian rhythms. Angiotensin production in the central nervous system may not only influence hypertension but also appears to affect the circadian rhythm of blood pressure. Drugs acting on RAS have been proven effective in the treatment of cardiovascular and metabolic disorders including hypertension and diabetes mellitus (DM. On the other hand, since melatonin is capable of ameliorating metabolic abnormalities in DM and insulin resistance, the beneficial effects of RAS blockade could be improved through combined RAS blocker and melatonin therapy. Contemporary research is evidencing the existence of specific clock genes forming central and peripheral clocks governing circadian rhythms. Further research on the interaction between these two neurohormones and the clock genes governing circadian clocks may progress our understanding on the pathophysiology of disease with possible impact on chronotherapeutic strategies.

  2. The Angiotensin-melatonin axis.

    Science.gov (United States)

    Campos, Luciana A; Cipolla-Neto, Jose; Amaral, Fernanda G; Michelini, Lisete C; Bader, Michael; Baltatu, Ovidiu C

    2013-01-01

    Accumulating evidence indicates that various biological and neuroendocrine circadian rhythms may be disrupted in cardiovascular and metabolic disorders. These circadian alterations may contribute to the progression of disease. Our studies direct to an important role of angiotensin II and melatonin in the modulation of circadian rhythms. The brain renin-angiotensin system (RAS) may modulate melatonin synthesis, a hormone with well-established roles in regulating circadian rhythms. Angiotensin production in the central nervous system may not only influence hypertension but also appears to affect the circadian rhythm of blood pressure. Drugs acting on RAS have been proven effective in the treatment of cardiovascular and metabolic disorders including hypertension and diabetes mellitus (DM). On the other hand, since melatonin is capable of ameliorating metabolic abnormalities in DM and insulin resistance, the beneficial effects of RAS blockade could be improved through combined RAS blocker and melatonin therapy. Contemporary research is evidencing the existence of specific clock genes forming central and peripheral clocks governing circadian rhythms. Further research on the interaction between these two neurohormones and the clock genes governing circadian clocks may progress our understanding on the pathophysiology of disease with possible impact on chronotherapeutic strategies.

  3. Antenatal Antioxidant Prevents Nicotine-Mediated Hypertensive Response in Rat Adult Offspring.

    Science.gov (United States)

    Xiao, DaLiao; Huang, Xiaohui; Li, Yong; Dasgupta, Chiranjib; Wang, Lei; Zhang, Lubo

    2015-09-01

    Previous studies have demonstrated that perinatal nicotine exposure increased blood pressure (BP) in adult offspring. However, the underlying mechanisms were unclear. The present study tested the hypothesis that perinatal nicotine-induced programming of hypertensive response is mediated by enhanced reactive oxygen species (ROS) in the vasculature. Nicotine was administered to pregnant rats via subcutaneous osmotic mini-pumps from Day 4 of gestation to Day 10 after birth, in the absence or presence of the ROS inhibitor N-acetyl-cysteine (NAC) in the drinking water. Experiments were conducted in 8-mo-old male offspring. Perinatal nicotine treatment resulted in a significant increase in arterial ROS production in offspring, which was abrogated by NAC. Angiotensin II (Ang II)-induced BP responses were significantly higher in nicotine-treated group than in saline-treated control group, and NAC treatment blocked the nicotine-induced increase in BP response. Consistent with that, the nicotine treatment significantly increased both Ang II-induced and phorbol [12, 13]-dibutyrate (PDBu, a Prkc activator)-induced arterial contractions in adult offspring, which were blocked by NAC treatment. In addition, perinatal nicotine treatment significantly attenuated acetylcholine-induced arterial relaxation in offspring, which was also inhibited by NAC treatment. Results demonstrate that inhibition of ROS blocks the nicotine-induced increase in arterial reactivity and BP response to vasoconstrictors in adult offspring, suggesting a key role for increased oxidative stress in nicotine-induced developmental programming of hypertensive phenotype in male offspring.

  4. Aspirin suppresses cardiac fibroblast proliferation and collagen formation through downregulation of angiotensin type 1 receptor transcription

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianwei, E-mail: XWang2@UAMS.edu; Lu, Jingjun; Khaidakov, Magomed; Mitra, Sona; Ding, Zufeng; Raina, Sameer; Goyal, Tanu; Mehta, Jawahar L., E-mail: MehtaJL@UAMS.edu

    2012-03-15

    Aspirin (acetyl salicylic acid, ASA) is a common drug used for its analgesic and antipyretic effects. Recent studies show that ASA not only blocks cyclooxygenase, but also inhibits NADPH oxidase and resultant reactive oxygen species (ROS) generation, a pathway that underlies pathogenesis of several ailments, including hypertension and tissue remodeling after injury. In these disease states, angiotensin II (Ang II) activates NADPH oxidase via its type 1 receptor (AT1R) and leads to fibroblast growth and collagen synthesis. In this study, we examined if ASA would inhibit NADPH oxidase activation, upregulation of AT1R transcription, and subsequent collagen generation in mouse cardiac fibroblasts challenged with Ang II. Mouse heart fibroblasts were isolated and treated with Ang II with or without ASA. As expected, Ang II induced AT1R expression, and stimulated cardiac fibroblast growth and collagen synthesis. The AT1R blocker losartan attenuated these effects of Ang II. Similarly to losartan, ASA, and its SA moiety suppressed Ang II-mediated AT1R transcription and fibroblast proliferation as well as expression of collagens and MMPs. ASA also suppressed the expression of NADPH oxidase subunits (p22{sup phox}, p47{sup phox}, p67{sup phox}, NOX2 and NOX4) and ROS generation. ASA did not affect total NF-κB p65, but inhibited its phosphorylation and activation. These observations suggest that ASA inhibits Ang II-induced NADPH oxidase expression, NF-κB activation and AT1R transcription in cardiac fibroblasts, and fibroblast proliferation and collagen expression. The critical role of NADPH oxidase activity in stimulation of AT1R transcription became apparent in experiments where ASA also inhibited AT1R transcription in cardiac fibroblasts challenged with H{sub 2}O{sub 2}. Since SA had similar effect as ASA on AT1R expression, we suggest that ASA's effect is mediated by its SA moiety. -- Highlights: ► Aspirin in therapeutic concentrations decreases mouse cardiac

  5. Prevalence of angiotensin converting enzyme (ACE gene insertion/deletion polymorphism in South Indian population with hypertension and chronic kidney disease

    Directory of Open Access Journals (Sweden)

    R Shanmuganathan

    2015-01-01

    Full Text Available Context: Chronic Kidney Disease (CKD is associated with a high risk of developing further severe complications such as, cardiovascular disease and eventually End Stage Renal Disease (ESRD leading to death. Hypertension plays a key role in the progression of renal failure and is also a chief risk factor for the occurrence of End Stage Renal Disease (ESRD. Aim: This study investigates the possible association of insertion (I and deletion (D polymorphism of ACE gene in patients of Chronic Kidney Disease (CKD with and without hypertension (HT. Settings and Design: Total 120 participants with 30 members in each group (Control, HT, CKD and CKD-HT were chosen followed by informed consent. Materials and Methods: Blood samples were collected and subjected to biochemical analyses and nested PCR amplification was performed to genotype the DNA, for ACE I/D using specific primers. Statistical Analysis: Statistical analyses were performed using SPSS version 13. Allele and genotypic frequency was calculated by direct gene counting method. Comparison of the different genotypes was done by using Chi square test. Odd′s ratios were calculated with a 95% confidence interval limit. Results: The ACE genotype were distributed as II, 27 (90%; DD, 2 (6.67% and ID, 1 (3.33% in control, II, 1 (3.33%; DD, 5 (16.67% and ID, 24 (80% in HT, II, 4 (13.33%; DD, 24 (80% and ID, 2 (6.67% in CKD and II, 0 (0%; DD, 2 (6.67% and ID, 28 (93.33% in CKD-HT group. Conclusions: D allele of ACE gene confers a greater role in genetic variations underlying CKD and hypertension. This result suggest that CKD patients should be offered analysis for defects in ACE I/D polymorphisms, especially if they are hypertensive.

  6. Beneficial effect of combination therapy using an angiotensin-converting enzyme inhibitor plus verapamil on circulating resistin levels in hypertensive patients with type 2 diabetes

    Science.gov (United States)

    Rubio-Guerra, Alberto F; Vargas-Robles, Hilda; Lozano Nuevo, Jose J; Elizalde-Barrera, Cesar I; Huerta-Ramirez, Saul; Escalante-Acosta, Bruno A

    2012-01-01

    BACKGROUND: Resistin levels are strongly correlated with insulin resistance and vascular inflammation. Type 2 diabetic and hypertensive patients have higher circulating levels of resistin, which is associated with endothelial dysfunction. OBJECTIVE: To compare the effect of trandolapril (T) and its fixed-dose combination with verapamil (FDTV) on resistin levels in hypertensive, type-2 diabetic patients. METHODS: Forty type-2 diabetic patients with never-treated hypertension were randomly assigned to two groups. One group received FDTV 2 mg/180 mg once per day; the other group received T 2 mg once per day. Study drugs were administered for three months in both groups. Resistin levels were measured using ELISA at the beginning of the study and at study end. Patients were evaluated monthly for blood pressure, fasting serum glucose levels and adverse events. Statistical analysis was performed using ANOVA. RESULTS: All patients experienced a significant reduction in blood pressure. Both therapeutic regimens reduced resistin levels; however, FDTV treatment resulted in a greater decrease in resistin levels (mean [± SD] 25.5±13 ng/mL to 17.2±10 ng/mL) when compared with T treatment (22.4±12 ng/mL to 18.5±8 ng/mL) (P<0.05). None of the patients experienced an adverse event. CONCLUSION: Results showed that FDTV resulted in a greater reduction in resistin levels than T treatment alone. PMID:23592936

  7. Dopamine receptor and hypertension.

    Science.gov (United States)

    Zeng, Chunyu; Eisner, Gilbert M; Felder, Robin A; Jose, Pedro A

    2005-01-01

    Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and reactive oxygen and by interacting with vasopressin, renin-angiotensin, and the sympathetic nervous system. Decreased renal dopamine production and/or impaired dopamine receptor function have been reported in hypertension. Disruption of any of the dopamine receptors (D(1), D(2), D(3), D(4), and D(5)) results in hypertension. In this paper, we review the mechanisms by which hypertension develops when dopamine receptor function is perturbed.

  8. Combination therapy of renin-angiotensin system inhibitors plus calcium channel blockers versus other two-drug combinations for hypertension: a systematic review and meta-analysis.

    Science.gov (United States)

    Lu, Z; Chen, Y; Li, L; Wang, G; Xue, H; Tang, W

    2017-01-01

    Many randomized clinical trials (RCTs) have investigated the efficacy and safety of renin-angiotensin system inhibitors (RASIs) plus calcium channel blockers (CCBs), compared with other two-drug combinations, but systematic assessment in this aspect is still lacking. We carried out the present meta-analysis of randomized controlled trials to evaluate the long-term effect and safety of RASIs plus CCBs. Literatures were searched in MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials in September 2014. A fixed-effect model was used to estimate the pooled effect of trials identified. Thirty-four trials with 41 694 patients were included. Compared with RASIs plus diuretics, RASIs plus CCBs decreased total cardiovascular (CV) events (relative risk (RR) 0.82, 95% confidence interval (CI): 0.75, 0.91, adjusted RR (ARR) 1.7%) and withdrawals due to adverse effect (WDAE) (RR 0.87, 95% CI: 0.80, 0.94, ARR 1.3%). Compared with CCBs plus diuretics, RASIs plus CCBs decreased WDAE (RR 0.63, 95% CI: 0.45, 0.90, ARR 1.1%). Our meta-analysis indicates that RASIs plus CCBs provide a superior safety and prevention of CV events to RASIs plus diuretics, whereas this combination is also safer than CCBs plus diuretics. We also raise a new hypothesis. More high-quality RCTs focused on hard end points with CV, cerebrovascular and renal events are needed to confirm the hypothesis we have brought out.

  9. Arterial hypertension treated with angiotensin converting enzyme inhibitors and glucocorticoids are independent risk factors associated with decreased glomerular filtration rate in systemic sclerosis.

    Science.gov (United States)

    Ostojic, Predrag; Stojanovski, Natasa

    2017-03-01

    The aim of this study was to estimate prevalence and severity of renal insufficiency in systemic sclerosis (SSc) and to assess risk factors associated with reduced glomerular filtration rate (GFR) in SSc patients. Seventy-three consecutive patients with SSc (67 women and 6 men), mean age 56.2 years, mean disease duration 6.7 years, were included in this cross-sectional study. GFR was measured by creatinine clearance (CCr) in all patients, as well as 24-h proteinuria. We assessed frequency and severity of renal insufficiency in our patients with SSc and estimated the association of renal insufficiency with age, disease duration, subtype of the disease, earlier diagnosed arterial hypertension, and medications for which we assumed to affect renal function-cytostatics, nonsteroidal anti-inflammatory drugs, glucocorticoids, ACE inhibitors, diuretics, and calcium channel blockers (CCB). Fifty-six out of 73 patients with SSc (76.7%) had reduced GFR (CCr lower than 90 ml/min), compared to 17/73 (23.3%) of patients with normal renal function. Mild renal insufficiency was noticed in 28/73 (38.4%), moderate in 21/73 (28.8%) and severe renal insufficiency in 5/73 (6.8%). End-stage renal disease (CCr arterial hypertension and treatment with glucocorticoids are independent risk factors for reduced GFR. On the other hand, age, disease duration, disease form, as well as antibodies (anticentromere antibodies-ACA and anti-topoisomerase I antibodies-ATA) were excluded as independent risk factors. Patients with SSc and arterial hypertension treated with CCB had significantly higher mean CCr than patients treated with diuretics (90.4 vs 53.5 ml/min, p = 0.03), or patients treated with ACE inhibitors (90.4 vs 41.7 ml/min, p = 0.001). Decreased GFR is common in SSc. Most of patients have mild or moderate renal insufficiency. Previously diagnosed arterial hypertension, especially when treated with ACE inhibitors or diuretics, and glucocorticoids are independent risk factors

  10. [Hypertension in women].

    Science.gov (United States)

    Tagle, Rodrigo; Tagle V, Rodrigo; Acevedo, Mónica; Valdés, Gloria

    2013-02-01

    The present review examines the types of hypertension that women may suffer throughout life, their physiopathological characteristics and management. In early life, the currently used low-dose oral contraceptives seldom cause hypertension. Pregnancy provokes preeclampsia, its main medical complication, secondary to inadequate transformation of the spiral arteries and the subsequent multisystem endothelial damage caused by deportation of placental factors and microparticles. Hypertension in preeclampsia is an epiphenomenon which needs to be controlled at levels that reduce maternal risk without impairing placental perfusion. The hemodynamic changes of pregnancy may unmask a hypertensive phenotype, may exacerbate a chronic hypertension, or may complicate hypertension secondary to lupus, renovascular lesions, and pheochromocytoma. On the other hand a primary aldosteronism may benefit from the effect of progesterone and present as a postpartum hypertension. A hypertensive pregnancy, especially preeclampsia, represents a risk for cardiac, vascular and renal disease in later life. Menopause may mimic a pheochromocytoma, and is associated to endothelial dysfunction and salt-sensitivity. Among women, non-pharmacological treatment should be forcefully advocated, except for sodium restriction during pregnancy. The blockade of the renin-angiotensin system should be avoided in women at risk of pregnancy; betablockers could be used with precautions during pregnancy; diuretics, ACE inhibitors and angiotensin receptor antagonists should not be used during breast feeding. Collateral effects of antihypertensives, such as hyponatremia, cough and edema are more common in women. Thus, hypertension in women should be managed according to the different life stages.

  11. Angiotensin II receptor mRNA expression and vasoconstriction in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Pantev, Emil; Emilson, Malin;

    2004-01-01

    Angiotensin II is a potent vasoconstrictor that is implicated in the pathogenesis of hypertension, heart failure and atherosclerosis. In the present study, angiotensin II receptor mRNA expression levels were quantified by real-time polymerase chain reaction and the vasocontractile responses...... to angiotensin II were characterised by in vitro pharmacology in endothelium-denuded human coronary arteries. Angiotensin II type 1 (AT(1)) and type 2 (AT(2)) receptor mRNA expression levels were significantly down-regulated in arteries from patients with heart failure as compared to controls. The angiotensin II...

  12. Sirtuin3 Dysfunction Is the Key Determinant of Skeletal Muscle Insulin Resistance by Angiotensin II.

    Directory of Open Access Journals (Sweden)

    Daniela Macconi

    Full Text Available Angiotensin II promotes insulin resistance. The mechanism underlying this abnormality, however, is still poorly defined. In a different setting, skeletal muscle metabolism and insulin signaling are regulated by Sirtuin3.Here, we investigate whether angiotensin II-induced insulin resistance in skeletal muscle is associated with Sirtuin3 dysregulation and whether pharmacological manipulation of Sirtuin3 confers protection.Parental and GLUT4-myc L6 rat skeletal muscle cells exposed to angiotensin II are used as in vitro models of insulin resistance. GLUT4 translocation, glucose uptake, intracellular molecular signals such as mitochondrial reactive oxygen species, Sirtuin3 protein expression and activity, along with its downstream targets and upstream regulators, are analyzed both in the absence and presence of acetyl-L-carnitine. The role of Sirtuin3 in GLUT4 translocation and intracellular molecular signaling is also studied in Sirtuin3-silenced as well as over-expressing cells.Angiotensin II promotes insulin resistance in skeletal muscle cells via mitochondrial oxidative stress, resulting in a two-fold increase in superoxide generation. In this context, reactive oxygen species open the mitochondrial permeability transition pore and significantly lower Sirtuin3 levels and activity impairing the cell antioxidant defense. Angiotensin II-induced Sirtuin3 dysfunction leads to the impairment of AMP-activated protein kinase/nicotinamide phosphoribosyltransferase signaling. Acetyl-L-carnitine, by lowering angiotensin II-induced mitochondrial superoxide formation, prevents Sirtuin3 dysfunction. This phenomenon implies the restoration of manganese superoxide dismutase antioxidant activity and AMP-activated protein kinase activation. Acetyl-L-carnitine protection is abrogated by specific Sirtuin3 siRNA.Our data demonstrate that angiotensin II-induced insulin resistance fosters mitochondrial superoxide generation, in turn leading to Sirtuin3 dysfunction. The

  13. Association of Polymorphisms of β3-Adrenergic Receptor,Angiotensinogen and Angiotensin-Converting Enzyme Gene with Hypertension in type 2 DM

    Institute of Scientific and Technical Information of China (English)

    丁国宪; 沈捷; 陈家伟

    2002-01-01

    ObjectiveTo explore the relationship between the mutant genes of ACE,ATN,β3-AR and hypertension in patients with type 2 DM.Methods281 recruited Chinese subjects were divided into two groups according to the mellitus (DM):112 cases.The subjects were genotyped for the ACE gene,the ATN gene and the codon 64 of β3-AR gene polymorphisms by applying polymerase chain reaction (PCR),PCR restriction fragment-length polymorphisms screening with the use of endonuclease.ResultsOur study found that the frequency of D/D genotype and D allele of ACE gene,a/a genotype and an allele of ATN gene in HT patients without DM were increased (P all <0.05);that the frequency of codon 64 mutation of β3-AR gene also increased in HT patients with NGT (P <0.05).In the model of multiple factors non-condition-al Logistic regression analyses,HT had relationship with history of hypertension,age and glucose tolerance (OR=10.745 7,1.780 4,2.034 6;P=0.000 4,0.000 0,0.024 6;respectively),with polymorphism of ATN gene,β3AR gene,ACE gene (OR=2.273 6,1.935 3,1.830 9;P=0.054 3,0.028 7,0.043 2;resceptively).ConclusionThese results suggest that variants of ACE gene,β3AR gene,ATN gene were associated with HT in type 2 DM.``

  14. 血管紧张素转化酶基因多态性与高血压病的关联研究%Correlation between gene polymorphism of angiotensin converting enzyme and hypertension

    Institute of Scientific and Technical Information of China (English)

    陈宏毅; 陈慧; 骆杰伟; 沈晓丽

    2012-01-01

    Objectives To investigate correlation between gene polymorphism of angiotensin converting enzyme (ACE) (insertion, I/deletion, D) and essential hypertension (EH). Methods-. A total of 176 EH patients with normal cardiac function were enrolled as EH group, and another 176 subjects with corresponding gender, age, residence, normal blood pressure and cardiac function were regard as normal control group. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect ACE (I/D) polymorphism genotype. Chi-square test was used to compare different genotypes and distribution frequency of genotype combinations between two groups and chi-square test with goodness of fit was used to analyze Hardy-Weinberg balance. Results; 1. Hardy-Weinberg genetic equilibrium test indicated that different genotype distribution of ACE gene was consistent with Hardy-Weinberg genetic equilibrium (P>0.05 all), and the sample possessed group representation; 2. Compared with normal control group, there were significant increase in genotype frequencies of II (42.61% vs. 43.18%) and DD (10.80% vs. 12.50%), and significant decrease in genotype frequency of ID (46.59% vs. 44.31%) in EH group, P<0.05 all. Conclusion: I/D polymorphism of angiotensin converting enzyme gene is significantly correlated with essential hypertension.%目的:探讨血管紧张素转换酶(ACE)基因多态性(insertion,I/deletion,D)与高血压病的相关性.方法:收集176例心功能正常的高血压病患者(EH组)及与之性别、年龄、居住地相匹配的血压、心功能正常对照组176例.应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)检测ACE (I/D)多态性基因型.采用x2检验比较两组不同基因型及基因型组合分布频率,Hardy-Weinberg平衡用拟合良好x2检验.结果:1、Hardy-Weinberg 遗传平衡检验示:ACE基因不同基因型分布符合Hardy-Weinberg遗传平衡(P均>0.05),样本具有群体代表性;2、与正常

  15. Comparison of efficacy and side effects of combination therapy of angiotensin-converting enzyme inhibitor (benazepril) with calcium antagonist (either nifedipine or amlodipine) versus high-dose calcium antagonist monotherapy for systemic hypertension.

    Science.gov (United States)

    Messerli, F H; Oparil, S; Feng, Z

    2000-12-01

    The present 2 multicenter studies were designed to evaluate whether patients with essential hypertension derived equal benefits from use of combination therapy with a calcium antagonist and angiotensin-converting enzyme (ACE) inhibitor as from doubling the dose of the calcium antagonist. After a 2-week washout and a 2-week single-blind placebo run-in period, a total of 1,390 patients were treated with either nifedipine 30 mg (study 1) or amlodipine 5 mg (study 2) once daily for 4 weeks. The 1,079 patients whose diastolic blood pressure remained between 95 and 115 mm Hg were randomized to 8 weeks of double-blind therapy with amlodipine 5 mg/benazepril 10 mg, amlodipine 5 mg/ benazepril 20 mg, nifedipine 30 mg or nifedipine 60 mg (study 1), and amlodipine 5 mg/benazepril 10 mg, amlodipine 5 mg/benazepril 20 mg, amlodipine 5 mg or amlodipine 10 mg (study 2). Both doses of the calcium antagonist/ACE inhibitor combination therapy lowered diastolic pressure as much as the high dose and significantly better than the lower dose of calcium antagonist monotherapy (with either nifedipine or amlodipine). However, 15% of patients in the nifedipine high-dose monotherapy group and 24% in the amlodipine high-dose monotherapy group presented with some form of edema. In contrast, the incidence of edema was similar for patients treated with both combination therapy and low-dose calcium antagonists. Thus, combination therapy with a calcium antagonist and an ACE inhibitor provides blood pressure control equal to that of high-dose calcium antagonist monotherapy but with significantly fewer dose-dependent adverse experiences such as vasodilatory edema. Inc.

  16. Clinical events in high-risk hypertensive patients randomly assigned to calcium channel blocker versus angiotensin-converting enzyme inhibitor in the antihypertensive and lipid-lowering treatment to prevent heart attack trial.

    Science.gov (United States)

    Leenen, Frans H H; Nwachuku, Chuke E; Black, Henry R; Cushman, William C; Davis, Barry R; Simpson, Lara M; Alderman, Michael H; Atlas, Steven A; Basile, Jan N; Cuyjet, Aloysius B; Dart, Richard; Felicetta, James V; Grimm, Richard H; Haywood, L Julian; Jafri, Syed Z A; Proschan, Michael A; Thadani, Udho; Whelton, Paul K; Wright, Jackson T

    2006-09-01

    The Antihypertensive and Lipid-Lowering treatment to prevent Heart Attack Trial (ALLHAT) provides a unique opportunity to compare the long-term relative safety and efficacy of angiotensin-converting enzyme inhibitor and calcium channel blocker-initiated therapy in older hypertensive individuals. Patients were randomized to amlodipine (n=9048) or lisinopril (n=9054). The primary outcome was combined fatal coronary heart disease or nonfatal myocardial infarction, analyzed by intention-to-treat. Secondary outcomes included all-cause mortality, stroke, combined cardiovascular disease (CVD), end-stage renal disease (ESRD), cancer, and gastrointestinal bleeding. Mean follow-up was 4.9 years. Blood pressure control was similar in nonblacks, but not in blacks. No significant differences were found between treatment groups for the primary outcome, all-cause mortality, ESRD, or cancer. Stroke rates were higher on lisinopril in blacks (RR=1.51, 95% CI 1.22 to 1.86) but not in nonblacks (RR=1.07, 95% CI 0.89 to 1.28), and in women (RR=1.45, 95% CI 1.17 to 1.79), but not in men (RR=1.10, 95% CI 0.92 to 1.31). Rates of combined CVD were higher (RR=1.06, 95% CI 1.00 to 1.12) because of higher rates for strokes, peripheral arterial disease, and angina, which were partly offset by lower rates for heart failure (RR=0.87, 95% CI 0.78 to 0.96) on lisinopril compared with amlodipine. Gastrointestinal bleeds and angioedema were higher on lisinopril. Patients with and without baseline coronary heart disease showed similar outcome patterns. We conclude that in hypertensive patients, the risks for coronary events are similar, but for stroke, combined CVD, gastrointestinal bleeding, and angioedema are higher and for heart failure are lower for lisinopril-based compared with amlodipine-based therapy. Some, but not all, of these differences may be explained by less effective blood pressure control in the lisinopril arm.

  17. Quercetin and isorhamnetin prevent endothelial dysfunction, superoxide production, and overexpression of p47phox induced by angiotensin II in rat aorta.

    Science.gov (United States)

    Sanchez, Manuel; Lodi, Federica; Vera, Rocio; Villar, Inmaculada C; Cogolludo, Angel; Jimenez, Rosario; Moreno, Laura; Romero, Miguel; Tamargo, Juan; Perez-Vizcaino, Francisco; Duarte, Juan

    2007-04-01

    The dietary flavonoid quercetin reduces blood pressure and improves endothelial function in several rat models of hypertension. We analyzed the effects of quercetin and its methylated metabolite isorhamnetin on the aortic endothelial dysfunction induced by incubation with angiotensin II (AngII) in vitro for 6 h. AngII diminished the relaxant responses to acetylcholine in phenylephrine-contracted aorta. Coincubation with quercetin or isorhamnetin, or addition of superoxide (O(2)(-)) dismutase or apocynin to the assay medium, prevented these inhibitory effects. At 6 h, AngII induced a marked increase in O(2)(-) production as measured by dihydroethidium fluorescence, which was prevented by quercetin and isorhamnetin. AngII also increased the expression of p47(phox), a regulatory subunit of the membrane NADPH oxidase. Immunohistochemical analysis revealed that overexpression of p47(phox) occurred mainly in the medial layer. p47(phox) overexpression was also prevented by quercetin and isorhamnetin. Taken together, these results show for the first time, to our knowledge, that quercetin and isorhamnetin prevent AngII-induced endothelial dysfunction by inhibiting the overexpression of p47(phox) and the subsequent increased O(2)(-) production, resulting in increased nitric oxide bioavailability.

  18. Hypertensive crisis in children.

    Science.gov (United States)

    Chandar, Jayanthi; Zilleruelo, Gastón

    2012-05-01

    Hypertensive crisis is rare in children and is usually secondary to an underlying disease. There is strong evidence that the renin-angiotensin system plays an important role in the genesis of hypertensive crisis. An important principle in the management of children with hypertensive crisis is to determine if severe hypertension is chronic, acute, or acute-on-chronic. When it is associated with signs of end-organ damage such as encephalopathy, congestive cardiac failure or renal failure, there is an emergent need to lower blood pressures to 25-30% of the original value and then accomplish a gradual reduction in blood pressure. Precipitous drops in blood pressure can result in impairment of perfusion of vital organs. Medications commonly used to treat hypertensive crisis in children are nicardipine, labetalol and sodium nitroprusside. In this review, we discuss the pathophysiology, differential diagnosis and recent developments in management of hypertensive crisis in children.

  19. A peptide vaccine targeting angiotensin II attenuates the cardiac dysfunction induced by myocardial infarction

    Science.gov (United States)

    Watanabe, Ryo; Suzuki, Jun-ichi; Wakayama, Kouji; Maejima, Yasuhiro; Shimamura, Munehisa; Koriyama, Hiroshi; Nakagami, Hironori; Kumagai, Hidetoshi; Ikeda, Yuichi; Akazawa, Hiroshi; Morishita, Ryuichi; Komuro, Issei; Isobe, Mitsuaki

    2017-01-01

    A peptide vaccine targeting angiotensin II (Ang II) was recently developed as a novel treatment for hypertension to resolve the problem of noncompliance with pharmacotherapy. Ang II plays a crucial role in the pathogenesis of cardiac remodeling after myocardial infarction (MI), which causes heart failure. In the present study, we examined whether the Ang II vaccine is effective in preventing heart failure. The injection of the Ang II vaccine in a rat model of MI attenuated cardiac dysfunction in association with an elevation in the serum anti-Ang II antibody titer. Furthermore, any detrimental effects of the Ang II vaccine were not observed in the rats that underwent sham operations. Treatment with immunized serum from Ang II vaccine-injected rats significantly suppressed post-MI cardiac dysfunction in MI rats and Ang II-induced remodeling-associated signaling in cardiac fibroblasts. Thus, our present study demonstrates that the Ang II vaccine may provide a promising novel therapeutic strategy for preventing heart failure. PMID:28266578

  20. Reactive oxygen species and angiotensin II signaling in vascular cells: implications in cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Touyz R.M.

    2004-01-01

    Full Text Available Diseases such as hypertension, atherosclerosis, hyperlipidemia, and diabetes are associated with vascular functional and structural changes including endothelial dysfunction, altered contractility and vascular remodeling. Cellular events underlying these processes involve changes in vascular smooth muscle cell (VSMC growth, apoptosis/anoikis, cell migration, inflammation, and fibrosis. Many factors influence cellular changes, of which angiotensin II (Ang II appears to be amongst the most important. The physiological and pathophysiological actions of Ang II are mediated primarily via the Ang II type 1 receptor. Growing evidence indicates that Ang II induces its pleiotropic vascular effects through NADPH-driven generation of reactive oxygen species (ROS. ROS function as important intracellular and intercellular second messengers to modulate many downstream signaling molecules, such as protein tyrosine phosphatases, protein tyrosine kinases, transcription factors, mitogen-activated protein kinases, and ion channels. Induction of these signaling cascades leads to VSMC growth and migration, regulation of endothelial function, expression of pro-inflammatory mediators, and modification of extracellular matrix. In addition, ROS increase intracellular free Ca2+ concentration ([Ca2+]i, a major determinant of vascular reactivity. ROS influence signaling molecules by altering the intracellular redox state and by oxidative modification of proteins. In physiological conditions, these events play an important role in maintaining vascular function and integrity. Under pathological conditions ROS contribute to vascular dysfunction and remodeling through oxidative damage. The present review focuses on the biology of ROS in Ang II signaling in vascular cells and discusses how oxidative stress contributes to vascular damage in cardiovascular disease.

  1. Angiotensin peptides and central autonomic regulation.

    Science.gov (United States)

    Diz, Debra I; Arnold, Amy C; Nautiyal, Manisha; Isa, Katsunori; Shaltout, Hossam A; Tallant, E Ann

    2011-04-01

    Aging, hypertension, and fetal-programmed cardiovascular disease are associated with a functional deficiency of angiotensin (Ang)-(1-7) in the brain dorsomedial medulla. The resulting unrestrained activity of Ang II in brainstem regions negatively impacts resting mean arterial pressure, sympathovagal balance, and baroreflex sensitivity for control of heart rate. The differential effects of Ang II and Ang-(1-7) may be related to the cellular sources of these peptides as well as different precursor pathways. Long-term alterations of the brain renin-angiotensin system may influence signaling pathways including phosphoinositol-3-kinase and mitogen-activated protein kinase and their downstream mediators, and as a consequence may influence metabolic function. Differential regulation of signaling pathways in aging and hypertension by Ang II versus Ang-(1-7) may contribute to the autonomic dysfunction accompanying these states.

  2. Angiotensin Signaling in Cardio-Renal Disease

    Science.gov (United States)

    Diz, Debra I.; Arnold, Amy C.; Nautiyal, Manisha; Isa, Katsunori; Shaltout, Hossam A.; Tallant, E. Ann

    2011-01-01

    Aging, hypertension and fetal programmed cardiovascular disease are associated with a functional deficiency of angiotensin (Ang)-(1–7) in the brain dorsomedial medulla. The resulting unrestrained activity of Ang II in brainstem regions negatively impacts resting mean arterial pressure, sympathovagal balance and baroreflex sensitivity for control of heart rate. The differential effects of Ang II and Ang-(1–7) may be related to the cellular sources of these peptides as well as different precursor pathways. Long-term alterations of the brain renin-angiotensin system may influence signaling pathways including phosphoinositol-3-kinase and mitogen-activated protein kinase and their downstream mediators, and as a consequence may influence metabolic function. Differential regulation of signaling pathways in aging and hypertension by Ang II versus Ang-(1–7) may contribute to the autonomic dysfunction accompanying these states. PMID:21367658

  3. Comparison of the Antialbuminuric Effects of Benidipine and Hydrochlorothiazide in Renin-Angiotensin System (RAS) Inhibitor-Treated Hypertensive Patients with Albuminuria: the COSMO-CKD (COmbination Strategy on Renal Function of Benidipine or Diuretics TreatMent with RAS inhibitOrs in a Chronic Kidney Disease Hypertensive Population) Study

    Science.gov (United States)

    Ando, Katsuyuki; Nitta, Kosaku; Rakugi, Hiromi; Nishizawa, Yoshiki; Yokoyama, Hitoshi; Nakanishi, Takeshi; Kashihara, Naoki; Tomita, Kimio; Nangaku, Masaomi; Takahashi, Katsutoshi; Isshiki, Masashi; Shimosawa, Tatsuo; Fujita, Toshiro

    2014-01-01

    Objective: This study evaluated the non-inferiority of renoprotection afforded by benidipine versus hydrochlorothiazide in hypertensive patients with chronic kidney disease (CKD). Methods: In this prospective, multicenter, open-labeled, randomized trial, the antialbuminuric effects of benidipine and hydrochlorothiazide were examined in renin-angiotensin system (RAS) inhibitor-treated patients with blood pressure (BP) readings of ≥ 130/80 mmHg and ≤ 180/110 mmHg, a urinary albumin to creatinine ratio (UACR) of ≥ 300 mg/g, and an estimated glomerular filtration rate (eGFR) of ≥ 30 ml/min/1.73m2. Patients received benidipine (n = 176, final dose: 4.8 mg/day) or hydrochlorothiazide (n = 170, 8.2 mg/day) for 12 months. Results: Benidipine and hydrochlorothiazide exerted similar BP- and eGFR-decreasing actions. The UACR values for benidipine and hydrochlorothiazide were 930.8 (95% confidence interval: 826.1, 1048.7) and 883.1 (781.7, 997.7) mg/g at baseline, respectively. These values were reduced to 790.0 (668.1, 934.2) and 448.5 (372.9, 539.4) mg/g at last observation carried forward (LOCF) visits. The non-inferiority of benidipine versus hydrochlorothiazide was not demonstrated (benidipine/hydrochlorothiazide ratio of LOCF value adjusted for baseline: 1.67 (1.40, 1.99)). Conclusions: The present study failed to demonstrate the non-inferiority of the antialbuminuric effect of benidipine relative to that of hydrochlorothiazide in RAS inhibitor-treated hypertensive patients with macroalbuminuria. PMID:25013370

  4. 血管紧张素Ⅱ1型受体基因多态性与原发性高血压的关系%Association of angiotensin Ⅱ type 1 receptor gene polymorphism with essential hypertension

    Institute of Scientific and Technical Information of China (English)

    龚洪涛; 杜凤和

    2010-01-01

    Objective To investigate whether angiotensin Ⅱ type 1 receptor(AT1R)gene polymorphism is associated with essential hypertension(EH). Methods A total of 200 hypertension patients and 192 normotensive controls were enrolled. The AT1R gene 1166A/C and -810A/T polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP), and the association between the SNPs and the EH were analyzed statistically. Some biochemical index such as serum glucose (GLU) and total cholesterol (TC),triglyceride (TG), high density lipoprotein (HDL-C) and low density lipoprotein (LDL-C) were also measured. Results There was no significant difference between two groups of 1166A/C polymorphisms of AT1R gene(P > 0.05 ). However, for the -810A/T polymorphism of AT1R gene, -810 AT and TT genotypes frequencies were significantly higher in EH patients than control (P = 0. 004). The -810T allele frequencies were higher in case than in control (22.5% vs. 11.5% ;P =0.000). We also found an association between EH and -810AT and TT genotypes by logistic regression analysis ( P = 0. 003 ), adjusted for other risk factors. The odds ratio was 2.57 (95% CI:1. 37 ~4. 84). Conclusions AT1R -810A/T polymorphism is associated with EH and -810T allele may be a risk factor of hypertension%目的 探讨血管紧张素Ⅱ1型受体(AT1R)基因多态性与原发性高血压(EH)之间的关系.方法 应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)对200例汉族EH患者(EH组)和192例正常血压者(对照组)的AT1R基因1166A/C及-810A/T多态性进行检测,测定空腹血糖、甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)等生物化学指标,分析各基因型和等位基因频率与EH的关系.结果 1166A/C等位基因和基因型频率在EH组和对照组的分布无统计学差异(P均>0.05),-810A/T各基因型在EH组和对照组间差异有统计学意义(x2=10.862,P=0

  5. Perioperative hypertension

    Directory of Open Access Journals (Sweden)

    G. Pinna

    2013-05-01

    transdermic way. ACE-ihinibitors and angiotensin- II-antagonists are allowed, but with caution, like as dihydropiridinic calcium-antagonists. Sublingual nifedipin is not recommended, owing to the evidence of an increased morbidity and mortality. Diuretics can lead to dangerous liquids depletions and would not be used in absence of specific indications (such as congestive heart failure, etc.. In hypertensive crisis the most used drugs remain NPS, nitrates, i.v. β-blockers (labetalol, esmolol, fenoldopam. CONCLUSIONS Postoperative BP should always be reviewed with reference to the preoperative and intraoperative assessments.

  6. Exendin-4 Prevents Vascular Smooth Muscle Cell Proliferation and Migration by Angiotensin II via the Inhibition of ERK1/2 and JNK Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Kosuke Nagayama

    Full Text Available Angiotensin II (Ang II is a main pathophysiological culprit peptide for hypertension and atherosclerosis by causing vascular smooth muscle cell (VSMC proliferation and migration. Exendin-4, a glucagon-like peptide-1 (GLP-1 receptor agonist, is currently used for the treatment of type-2 diabetes, and is believed to have beneficial effects for cardiovascular diseases. However, the vascular protective mechanisms of GLP-1 receptor agonists remain largely unexplained. In the present study, we examined the effect of exendin-4 on Ang II-induced proliferation and migration of cultured rat aortic smooth muscle cells (RASMC. The major findings of the present study are as follows: (1 Ang II caused a phenotypic switch of RASMC from contractile type to synthetic proliferative type cells; (2 Ang II caused concentration-dependent RASMC proliferation, which was significantly inhibited by the pretreatment with exendin-4; (3 Ang II caused concentration-dependent RASMC migration, which was effectively inhibited by the pretreatment with exendin-4; (4 exendin-4 inhibited Ang II-induced phosphorylation of ERK1/2 and JNK in a pre-incubation time-dependent manner; and (5 U0126 (an ERK1/2 kinase inhibitor and SP600125 (a JNK inhibitor also inhibited both RASMC proliferation and migration induced by Ang II stimulation. These results suggest that exendin-4 prevented Ang II-induced VSMC proliferation and migration through the inhibition of ERK1/2 and JNK phosphorylation caused by Ang II stimulation. This indicates that GLP-1 receptor agonists should be considered for use in the treatment of cardiovascular diseases in addition to their current use in the treatment of diabetes mellitus.

  7. The Renin-Angiotensin System in the Endocrine Pancreas

    Directory of Open Access Journals (Sweden)

    Carlsson PO

    2001-01-01

    Full Text Available Experimental data suggest that a tissue renin-angiotensin system is present in the pancreatic islets of several species, including man. However, the physiological role for this local renin-angiotensin system remains largely unknown. In vitro findings argue against a direct effect of angiotensin II on alpha- and beta-cells. In contrast, when the influence of angiotensin II on the pancreatic islets has been evaluated in the presence of an intact vascular system either in vivo or in the perfused pancreas, a suppression of insulin release has been observed, also in man. These discrepancies may be explained by the profound effects of the renin-angiotensin system on pancreatic islet blood perfusion. Alterations in the systemic renin-angiotensin system and an increased vascular sensitivity for its components have been observed in diabetes mellitus and hypertension. Whether changes occur also in the pancreatic islet renin-angiotensin system during these conditions remains unknown. Future research may help to provide an answer to this question, and to elucidate to what extent the renin-angiotensin system may contribute to beta-cell dysfunction in these diseases.

  8. EL SISTEMA RENINA−ANGIOTENSINA DESDE LA CIRCULACIÓN HASTA LA CÉLULA: IMPLICACIONES MÁS ALLÁ DE LA HIPERTENSIÓN / The renin−angiotensin system from circulation to the cell: implications beyond hypertension

    Directory of Open Access Journals (Sweden)

    Arik Ponce Gutiérrez

    2012-10-01

    Full Text Available ResumenEl sistema renina-angiotensina es más complejo de lo que se conocía hasta hace poco tiempo, ya que su acción no solo se circunscribe al plasma sanguíneo, sino que igualmente se ha demostrado su existencia en tejidos como: corazón, cerebro, riñón, páncreas, aparato reproductor, sistema linfático y el tejido adiposo; con acciones activas específicas en todos ellos, y al mismo tiempo está presente en el interior de diferentes tipos de células, como cardiomiocitos y fibroblastos. Constituye un sistema endocrino, paracrino y autocrino que es capaz de actuar a sus diferentes niveles de manera independiente o relacionada, y participa no solo en el control de la presión arterial y homeostasis del agua y sodio como se le atribuía inicialmente, sino que también interviene en el correcto funcionamiento de numerosos órganos, así como en el mecanismo fisiopatológico de alteraciones estructurales y funcionales, fundamentalmente cardiovasculares y renales que van mucho más allá de la hipertensión arterial. / AbstractThe renin-angiotensin system is more complex than was known until recently, since its action is not only limited to the plasma. Its presence has been shown in tissues such as the heart, brain, kidney, pancreas, reproductive system, lymphatic system and adipose tissue, with specific active actions in all of them, and at the same time it is present at the intracellular level of different cell types such as cardiomyocytes and fibroblasts. It is an endocrine, paracrine and autocrine system which is capable of acting at different levels in an independent or related form, taking part not only in the control of blood pressure and homeostasis of water and sodium as initially attributed, but it is also involved in the proper functioning of numerous organs and in the pathophysiological mechanism of structural and functional alterations, mainly cardiovascular and renal, which go far beyond hypertension.

  9. 老年原发性高血压AT1一R基因多态性的研究%The Polymorphism of Angiotensin Ⅱ Type 1 Receptor Gene in Essential Hypertensive Elders

    Institute of Scientific and Technical Information of China (English)

    方宁远; 张怡; 陆惠华; 邬亦贤; 郑迪辉; 郑道声

    2000-01-01

    目的 研究老年原发性高血压(EH)血管紧张素Ⅱ型受体(AT1一R)基因A/C1166多态性的特征。方法 应用聚合酶链反应一限制性片段长度多态性(PCR—RFLP)技术检测87例汉族老年EH患者和55例正常老年人的AT1-R基因A/C1166多态性分布。结果87例老年EH患者的C1166等位基因频率为0.115,55例正常老年人为0.036,经统计学分析两组间有显著差异(P<0.05)。结论老年EH的患者C1166等位基因频率明显升高,可能为EH发病的危险因素。%Objective This study was to detect the A/C1166 polymorphism of angiotensin Ⅱtype 1 receptor (AT1 - R) gene in the essential hypertensive elder. Methods The A/C1166 polymor-phism of AT1 - R gene was assessed by polymerase chain reaction- restriction fragment length polymor-phism (PCR- RFLP) in a case- control study of 87 EH elders and 55 normotensive elders (NT).Results The genotype frequencies of AA, AC, CC were 0. 805, 0. 161, 0. 034 in EH group and0. 927, 0. 073, 0. 000 in NT group. The frequency of A/C1166 allele was higher in EH group (0. 115)than in NT group (0. 036) (P < 0.05). Conclusion The frequency of C1166 allele was significantlyhigher in EH group than in NT group, which indicated that A/C1166 polymorphism of AT1 - R gene maybe associated with EH in the elderly.

  10. The Relevance of the Renin-Angiotensin System in the Development of Drugs to Combat Preeclampsia

    Directory of Open Access Journals (Sweden)

    Norikazu Ueki

    2015-01-01

    Full Text Available Preeclampsia is a hypertensive disorder that occurs during pregnancy. It has an unknown etiology and affects approximately 5–8% of pregnancies worldwide. The pathophysiology of preeclampsia is not yet known, and preeclampsia has been called “a disease of theories.” The central symptom of preeclampsia is hypertension. However, the etiology of the hypertension is unknown. In this review, we analyze the molecular mechanisms of preeclampsia with a particular focus on the pathogenesis of the hypertension in preeclampsia and its association with the renin-angiotensin system. In addition, we propose potential alternative strategies to target the renin-angiotensin system, which is enhanced during pregnancy.

  11. Regulatory T cells in human and angiotensin II-induced mouse abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Zhou, Yi; Wu, Wenxue; Lindholt, Jes S

    2015-01-01

    concentration in blood cell lysates from 485 AAA patients and 204 age- and sex-matched controls. AAA patients exhibited lower blood cell Foxp3 expression than controls (P Pearson's correlation test demonstrated a significant but negative correlation between Foxp3 and AAA annual expansion rate before...... (r = -0.147, P = 0.007) and after (r = -0.153, P = 0.006) adjustment for AAA risk factors. AAA in apolipoprotein E-deficient (Apoe(-/-)) mice that received different doses of Ang-II exhibited a negative correlation of lesion Foxp3(+) Treg numbers with AAA size (r = -0.883, P

  12. Mechanism of Hepatocyte Growth Factor Inhibition of Angiotensin II-induced Apoptosis in Primary Lung Cells

    Science.gov (United States)

    2010-02-19

    joints. In addition, they may experience enlargement and bulb-like development of the fingertips and nails , a condition called clubbing [41]. Clinical...2 family, which act to regulate the permeability of the mitochondrial membrane and its release of cytochrome . Initiator caspase 9 is activated in...either a Bax channel blocker (BCB) or a Bax inhibiting peptide (V-5), while a control peptide had no effect (Fig 3B). We found that cell permeable

  13. Combined Angiotensin Receptor Antagonism and Neprilysin Inhibition.

    Science.gov (United States)

    Hubers, Scott A; Brown, Nancy J

    2016-03-15

    Heart failure affects ≈5.7 million people in the United States alone. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, and aldosterone antagonists have improved mortality in patients with heart failure and reduced ejection fraction, but mortality remains high. In July 2015, the US Food and Drug Administration approved the first of a new class of drugs for the treatment of heart failure: Valsartan/sacubitril (formerly known as LCZ696 and currently marketed by Novartis as Entresto) combines the angiotensin receptor blocker valsartan and the neprilysin inhibitor prodrug sacubitril in a 1:1 ratio in a sodium supramolecular complex. Sacubitril is converted by esterases to LBQ657, which inhibits neprilysin, the enzyme responsible for the degradation of the natriuretic peptides and many other vasoactive peptides. Thus, this combined angiotensin receptor antagonist and neprilysin inhibitor addresses 2 of the pathophysiological mechanisms of heart failure: activation of the renin-angiotensin-aldosterone system and decreased sensitivity to natriuretic peptides. In the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial, valsartan/sacubitril significantly reduced mortality and hospitalization for heart failure, as well as blood pressure, compared with enalapril in patients with heart failure, reduced ejection fraction, and an elevated circulating level of brain natriuretic peptide or N-terminal pro-brain natriuretic peptide. Ongoing clinical trials are evaluating the role of valsartan/sacubitril in the treatment of heart failure with preserved ejection fraction and hypertension. We review here the mechanisms of action of valsartan/sacubitril, the pharmacological properties of the drug, and its efficacy and safety in the treatment of heart failure and hypertension.

  14. Hypertension og hjertet

    DEFF Research Database (Denmark)

    Wachtell, Kristian; Svendsen, Tage Lysbo; Andersen, Niels Holmark

    2009-01-01

    Within the latest ten years research in left ventricular hypertrophy as cardiac target organ damage has uncovered its prognostic importance, and studies indicate that treatment with angiotensin II receptor blockade is most effective in reducing left ventricular hypertrophy. In addition, reduction...... of left ventricular mass is associated with substantial and significant reduction of cardiovascular morbidity and mortality. Hypertension is strongly associated with increased risk of subsequent heart failure. Meta analysis data suggests that reduction in blood pressure is also associated with very...... reduction of traditional cardiovascular risk factors as well as blood pressure reduction for blood pressures exceeding 130/185 mmHg. Reductions which should be achieved using angiotensin converting enzyme inhibitor or angiotensin receptor blockers in order to improve the hemodynamic status of the patient...

  15. The renin-angiotensin system and its blockers

    Directory of Open Access Journals (Sweden)

    Igić Rajko

    2014-01-01

    Full Text Available Research on the renin-angiotensin system (RAS has contributed significantly to advances in understanding cardiovascular and renal homeostasis and to the treatment of cardiovascular diseases. This review offers a brief history of the RAS with an overview of its major components and their functions, as well as blockers of the RAS, their clinical usage and current research that targets various components of the RAS. Because angiotensin-converting enzyme (ACE metabolizes two biologically active peptides, one in the kallikrein-kinin system (KKS and one in the RAS, it is the essential connection between the two systems. ACE releases very powerful hypertensive agent, angiotensin II and also inactivates strong hypotensive peptide, bradykinin. Inhibition of ACE thus has a dual effect, resulting in decreased angiotensin II and increased bradykinin. We described the KKS as well.

  16. Dopamine, the kidney, and hypertension.

    Science.gov (United States)

    Harris, Raymond C; Zhang, Ming-Zhi

    2012-04-01

    There is increasing evidence that the intrarenal dopaminergic system plays an important role in the regulation of blood pressure, and defects in dopamine signaling appear to be involved in the development of hypertension. Recent experimental models have definitively demonstrated that abnormalities in intrarenal dopamine production or receptor signaling can predispose to salt-sensitive hypertension and a dysregulated renin-angiotensin system. In addition, studies in both experimental animal models and in humans with salt-sensitive hypertension implicate abnormalities in dopamine receptor regulation due to receptor desensitization resulting from increased G-protein receptor kinase 4 (GRK4) activity. Functional polymorphisms that predispose to increased basal GRK4 activity both decrease dopamine receptor activity and increase angiotensin II type 1 (AT1) receptor activity and are associated with essential hypertension in a number of different human cohorts.

  17. Preeclampsia, the Renin-Angiotensin-Aldosterone System and beyond

    NARCIS (Netherlands)

    K. Verdonk (Koen)

    2015-01-01

    markdownabstract__Abstract__ The renin-angiotensin-aldosterone system (RAAS) plays an essential role in the regulation of blood pressure and body fluid homeostasis, but also contributes importantly to the pathophysiology of hypertension, renal disease and heart failure. Clinically, the RAAS is of g

  18. Vascular inflammatory cells in hypertension

    Directory of Open Access Journals (Sweden)

    David G. Harrison

    2012-05-01

    Full Text Available Hypertension is a common disorder with uncertain etiology. In the last several years, it has become evident that components of both the innate and adaptive immune system play an essential role in hypertension. Macrophages and T cells accumulate in the perivascular fat, the heart and the kidney of hypertensive patients and in animals with experimental hypertension. Various immunosuppressive agents lower blood pressure and prevent end-organ damage. Mice lacking lymphocytes are protected against hypertension, and adoptive transfer of T cells, but not B cells in the animals restores their blood pressure response to stimuli such as angiotensin II or high salt. Recent studies have shown that mice lacking macrophages have blunted hypertension in response to angiotensin II and that genetic deletion of macrophages markedly reduces experimental hypertension. Dendritic cells have also been implicated in this disease. Many hypertensive stimuli have triggering effects on the central nervous system and signals arising from the circumventricular organ seem to promote inflammation. Studies have suggested that central signals activate macrophages and T cells, which home to the kidney and vasculature and release cytokines, including IL-6 and IL-17, which in turn cause renal and vascular dysfunction and lead to blood pressure elevation. These recent discoveries provide a new understanding of hypertension and provide novel therapeutic opportunities for treatment of this serious disease.

  19. Dopamine, the Kidney, and Hypertension

    OpenAIRE

    Raymond C. Harris; Zhang, Ming-Zhi

    2012-01-01

    There is increasing evidence that the intrarenal dopaminergic system plays an important role in the regulation of blood pressure, and defects in dopamine signaling appear to be involved in the development of hypertension. Recent experimental models have definitively demonstrated that abnormalities in intrarenal dopamine production or receptor signaling can predispose to salt-sensitive hypertension and a dysregulated renin-angiotensin system. In addition, studies in both experimental animal mo...

  20. 血管紧张素转换酶基因插入或缺失多态性与飞行员原发性高血压的相关性%Relationship between insertion/deletion polymorphism of the angiotensin-convetting enzyme gene and essential hypertension in pilots

    Institute of Scientific and Technical Information of China (English)

    蔡庆; 刘红巾; 陈涛; 朱美财

    2011-01-01

    目的 探讨血管紧张素转换酶(ACE)基因插入或缺失(L/D)多态性和飞行员原发性高血压的相关性,为飞行员原发性高血压的预防提供依据.方法 用聚合酶链反应(PCR)扩增检测48例飞行员原发性高血压患者和50例飞行员健康对照者的ACE基因I/D多态性.结果 飞行员高血压组ACE DD基因型(25%)和D等位基因频率(0.47)显著高于健康对照组(分别为8%和0.30).结论 ACE DD基因型和D等位基因与飞行员原发性高血压病相关.%Objective To investigate the relationship between insertion/delation (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene and essential hypertension of pilots and provide an important reference for essential hypertension of pilots. Methods 48 pilots with essential hypertension and SO healthy control pilots were genotyped for the I/D polymorphism of the ACE gene by the polymerase chain reaction (PCR). Results It was showed that the genotype DD and D allele frequency of ACE were significantly higher in pilots with essential hypertension (25% and 0.47) than that in healthy control subjects (8% and 0.30). Conclusion The genotype DD and D allele of ACE were correlated with essential hypertension in pilots.

  1. Oxidative stress and hypertension.

    Science.gov (United States)

    Harrison, David G; Gongora, Maria Carolina

    2009-05-01

    This review has summarized some of the data supporting a role of ROS and oxidant stress in the genesis of hypertension. There is evidence that hypertensive stimuli, such as high salt and angiotensin II, promote the production of ROS in the brain, the kidney, and the vasculature and that each of these sites contributes either to hypertension or to the untoward sequelae of this disease. Although the NADPH oxidase in these various organs is a predominant source, other enzymes likely contribute to ROS production and signaling in these tissues. A major clinical challenge is that the routinely used antioxidants are ineffective in preventing or treating cardiovascular disease and hypertension. This is likely because these drugs are either ineffective or act in a non-targeted fashion, such that they remove not only injurious ROS Fig. 5. Proposed role of T cells in the genesis of hypertension and the role of the NADPH oxidase in multiple cells/organs in modulating this effect. In this scenario, angiotensin II stimulates an NADPH oxidase in the CVOs of the brain, increasing sympathetic outflow. Sympathetic nerve terminals in lymph nodes activate T cells, and angiotensin II also directly activates T cells. These stimuli also activate expression of homing signals in the vessel and likely the kidney, which attract T cells to these organs. T cells release cytokines that stimulate the vessel and kidney NADPH oxidases, promoting vasoconstriction and sodium retention. SFO, subfornical organ. 630 Harrison & Gongora but also those involved in normal cell signaling. A potentially important and relatively new direction is the concept that inflammatory cells such as T cells contribute to hypertension. Future studies are needed to understand the interaction of T cells with the CNS, the kidney, and the vasculature and how this might be interrupted to provide therapeutic benefit.

  2. Hypertension and liver disease

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Møller, Søren

    2004-01-01

    to increased arterial blood pressure. Subjects with established arterial hypertension (essential, secondary) may become normotensive during the development of cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin......Arterial hypertension is a common disorder with a frequency of 10% to 15% in subjects in the 40- to 60-year age group. Yet most reports find the prevalence of arterial hypertension in patients with chronic liver disease (cirrhosis) much lower. In this review, we consider the alterations in systemic...... hemodynamics in cirrhosis. The most characteristic findings in cirrhotic patients are vasodilatation with low systemic vascular resistance, increased cardiac output, high arterial compliance, secondary activation of counterregulatory systems (sympathetic nervous system, renin-angiotensin-aldosterone system...

  3. Elevated N-terminal pro-brain natriuretic peptide levels predict an enhanced anti-hypertensive and anti-proteinuric benefit of dietary sodium restriction and diuretics, but not angiotensin receptor blockade, in proteinuric renal patients

    NARCIS (Netherlands)

    Slagman, Maartje C. J.; Waanders, Femke; Vogt, Liffert; Damman, Kevin; Hemmelder, Marc; Navis, Gerjan; Laverman, Gozewijn D.

    2012-01-01

    Background. Renin angiotensin aldosterone system (RAAS) blockade only partly reduces blood pressure, proteinuria and renal and cardiovascular risk in chronic kidney disease (CKD) but often requires sodium targeting [i.e. low sodium diet (LS) and/or diuretics] for optimal efficacy. However, both unde

  4. Ideas for Hypertensive Experimental Study Prevented and Treated by TCM

    Institute of Scientific and Technical Information of China (English)

    王振涛

    2004-01-01

    Hypertensive experimental studies prevented and treated by TCM are matured relevant studies of western medicine for reference, such as the hypotensive effect and elucidating its therapeutic mechanism. Comprehension in all literatures, most simple herbs and compound recipes show functions such as: Adjustment of renin-angiotensin-aldosterone system (RAAS), like angiotensin converting enzyme inhibitor (ACEI);

  5. Ideas for Hypertensive Experimental Study Prevented and Treated by TCM

    Institute of Scientific and Technical Information of China (English)

    王振涛

    2004-01-01

    @@ Hypertensive experimental studies prevented and treated by TCM are matured relevant studies of western medicine for reference,such as the hypotensive effect and elucidating its therapeutic mechanism.Comprehension in all literatures, most simple herbs and compound recipes show functions such as: Adjustment of renin-angiotensin-aldosterone system (RAAS), like angiotensin converting enzyme inhibitor (ACEI);

  6. Effect of the inhibitors of renin-angiotensin system on the lipid metabolism of patients with hypertension%肾素-血管紧张素系统抑制剂对高血压患者脂代谢的改善作用

    Institute of Scientific and Technical Information of China (English)

    程军

    2016-01-01

    Current data show that over half of hypertensive patients have lipid metabolic abnormalities. Coexistence of hypertension and lipid metabolic abnormality may significantly increase the morbidity and mortality of coronary heart disease. Effects of different kinds of antihypertensive agents on lipid metabolism vary. Renin-angiotensin system (RAS), widely distributed in human body, plays an important role in regulation of blood pressure, water-electrolyte balance as well as glucose and lipid metabolism. RAS inhibitors (RASI) can also improve lipid metabolism in hypertensive patients besides the effective reduction of blood pressure. This article reviews the interaction of RAS system and lipid metabolism and the improvement of lipid metabolism by RASI in hypertensive patients.%据统计,超过半数的高血压患者合并脂代谢异常,两者并存时,冠心病的发病和死亡风险显著增加。不同降压药物对脂代谢的影响不尽相同。肾素-血管紧张素系统(RAS)在体内广泛分布,在血压调节、水电解质平衡及糖脂代谢等诸多方面发挥重要作用。RAS抑制剂(RASI)在有效降压的同时,在一定程度上对高血压患者的脂代谢具有改善作用。本文拟从RAS系统与脂代谢的相互作用以及RASI对高血压患者脂代谢的改善作用两个方面进行综述。

  7. A critical role of cardiac fibroblast-derived exosomes in activating renin angiotensin system in cardiomyocytes.

    Science.gov (United States)

    Lyu, Linmao; Wang, Hui; Li, Bin; Qin, Qingyun; Qi, Lei; Nagarkatti, Mitzi; Nagarkatti, Prakash; Janicki, Joseph S; Wang, Xing Li; Cui, Taixing

    2015-12-01

    Chronic activation of the myocardial renin angiotensin system (RAS) elevates the local level of angiotensin II (Ang II) thereby inducing pathological cardiac hypertrophy, which contributes to heart failure. However, the precise underlying mechanisms have not been fully delineated. Herein we report a novel paracrine mechanism between cardiac fibroblasts (CF)s and cardiomyocytes whereby Ang II induces pathological cardiac hypertrophy. In cultured CFs, Ang II treatment enhanced exosome release via the activation of Ang II receptor types 1 (AT1R) and 2 (AT2R), whereas lipopolysaccharide, insulin, endothelin (ET)-1, transforming growth factor beta (TGFβ)1 or hydrogen peroxide did not. The CF-derived exosomes upregulated the expression of renin, angiotensinogen, AT1R, and AT2R, downregulated angiotensin-converting enzyme 2, and enhanced Ang II production in cultured cardiomyocytes. In addition, the CF exosome-induced cardiomyocyte hypertrophy was blocked by both AT1R and AT2R antagonists. Exosome inhibitors, GW4869 and dimethyl amiloride (DMA), inhibited CF-induced cardiomyocyte hypertrophy with little effect on Ang II-induced cardiomyocyte hypertrophy. Mechanistically, CF exosomes upregulated RAS in cardiomyocytes via the activation of mitogen-activated protein kinases (MAPKs) and Akt. Finally, Ang II-induced exosome release from cardiac fibroblasts and pathological cardiac hypertrophy were dramatically inhibited by GW4869 and DMA in mice. These findings demonstrate that Ang II stimulates CFs to release exosomes, which in turn increase Ang II production and its receptor expression in cardiomyocytes, thereby intensifying Ang II-induced pathological cardiac hypertrophy. Accordingly, specific targeting of Ang II-induced exosome release from CFs may serve as a novel therapeutic approach to treat cardiac pathological hypertrophy and heart failure.

  8. Hypertension is a conditional factor for the development of cardiac hypertrophy in type 2 diabetic mice.

    Directory of Open Access Journals (Sweden)

    Marc van Bilsen

    Full Text Available BACKGROUND: Type 2 diabetes is frequently associated with co-morbidities, including hypertension. Here we investigated if hypertension is a critical factor in myocardial remodeling and the development of cardiac dysfunction in type 2 diabetic db/db mice. METHODS: Thereto, 14-wks-old male db/db mice and non-diabetic db/+ mice received vehicle or angiotensin II (AngII for 4 wks to induce mild hypertension (n = 9-10 per group. Left ventricular (LV function was assessed by serial echocardiography and during a dobutamine stress test. LV tissue was subjected to molecular and (immunohistochemical analysis to assess effects on hypertrophy, fibrosis and inflammation. RESULTS: Vehicle-treated diabetic mice neither displayed marked myocardial structural remodeling nor cardiac dysfunction. AngII-treatment did not affect body weight and fasting glucose levels, and induced a comparable increase in blood pressure in diabetic and control mice. Nonetheless, AngII-induced LV hypertrophy was significantly more pronounced in diabetic than in control mice as assessed by LV mass (increase +51% and +34%, respectively, p<0.01 and cardiomyocyte size (+53% and +31%, p<0.001. This was associated with enhanced LV mRNA expression of markers of hypertrophy and fibrosis and reduced activation of AMP-activated protein kinase (AMPK, while accumulation of Advanced Glycation End products (AGEs and the expression levels of markers of inflammation were not altered. Moreover, AngII-treatment reduced LV fractional shortening and contractility in diabetic mice, but not in control mice. CONCLUSIONS: Collectively, the present findings indicate that type 2 diabetes in its early stage is not yet associated with adverse cardiac structural changes, but already renders the heart more susceptible to hypertension-induced hypertrophic remodeling.

  9. Influential factors of renin-angiotensin-aldosterone system in patients with essential hypertension%原发性高血压病患者肾素-血管紧张素-醛固酮系统活性的影响因素

    Institute of Scientific and Technical Information of China (English)

    符春晖; 严华; 陆永光; 陈湘桂; 黄军章

    2011-01-01

    Objective To study the influential factors of renin-angiotensin-aldosterone system in essential hypertension. Methods One hundred patients with essential hypertension were divided into groups according to blood pressure grades, ages and body mass indexes. The levels of plasma renin activity, angiotensin Ⅱ and aldosterone were measured with radioimmunoassay at erect and decubitus position. Multiple linear regression analysis was performed to evaluate the relationships of age,height, body mass, systolic blood pressure and diastolic blood pressure with plasma renin activity,angiotensin Ⅱ and aldosterone. Results With the severity of the blood pressure, the levels of plasma renin activity decreased, but angiotensin Ⅱ and aldosterone increased, which showed significant differences in three hypertension groups(P<0.05). The levels of plasma renin activity, angiotensin Ⅱ and aldosterone decreased with the aging in three different ages groups(P<0.01), and showed no significant differences in three different body mass index groups(P>0.05). Multiple linear regression analysis showed systolic blood pressure and diastolic blood pressure were the positive independent predictors, and the age was the negative independent predictor for angiotensin Ⅱ and aldosterone.The age, systolic blood pressure and diastolic blood pressure were the negative independent predictors for plasma renin activity. The height, body mass and body mass index were not correlated with plasma renin activity, angiotensin Ⅱ and aldosterone. Conclusion The over-reactivity of reninangiotensin-aldosterone system could be observed in patients with essential hypertension, which is closely correlated with the age and blood pressure.%目的:探讨原发性高血压病患者血浆肾素-血管紧张素Ⅱ-醛固酮水平的影响因素.方法:原发性高血压病男性患者100例分别按高血压级别、年龄及体质量指数(body mass index,BMI)进行分组,采用放射免疫方法测定立位

  10. Angiotensin II inhibitor facilitates epidermal wound regeneration in diabetic mice

    Directory of Open Access Journals (Sweden)

    Maria eKamber

    2015-06-01

    Full Text Available Tissue regeneration and wound healing are severely impaired in diabetes and are associated with poor circulation and dysfunctional blood vessels. Angiotensin II inhibitors are anti-hypertensive drugs used in clinical practice to regulate blood pressure and could affect tissue remodeling. We hypothesize that blocking angiotensin II, using Losartan, could facilitate tissue regeneration in diabetic mice. To this end, we established an experimental model of wound healing in streptozotocin-induced diabetic mice. Our data demonstrated that Losartan accelerates wound repair and normalizes wound stromal responses, having a beneficial role in diabetic wounds. Our findings highlight a potential therapeutic use of Losartan in improving wound repair in diabetic conditions.

  11. Pharmacologic Management of Pediatric Hypertension.

    Science.gov (United States)

    Misurac, Jason; Nichols, Kristen R; Wilson, Amy C

    2016-02-01

    Hypertension in children is common, and the prevalence of primary hypertension is increasing with the obesity epidemic and changing dietary choices. Careful measurement of blood pressure is important to correctly diagnose hypertension, as many factors can lead to inaccurate blood pressure measurement. Hypertension is diagnosed based on comparison of age-, sex-, and height-based norms with the average systolic and diastolic blood pressures on three separate occasions. In the absence of hypertensive target organ damage (TOD), stage I hypertension is managed first by diet and exercise, with the addition of drug therapy if this fails. First-line treatment of stage I hypertension with TOD and stage II hypertension includes both lifestyle changes and medications. First-line agents include angiotensin-converting enzyme (ACE) inhibitors, thiazide diuretics, and calcium-channel blockers. Hypertensive emergency with end-organ effects requires immediate modest blood pressure reduction to alleviate symptoms. This is usually accomplished with IV medications. Long-term reduction in blood pressure to normal levels is accomplished gradually. Specific medication choice for outpatient hypertension management is determined by the underlying cause of hypertension and the comparative adverse effect profiles, along with practical considerations such as cost and frequency of administration. Antihypertensive medication is initiated at a starting dose and can be gradually increased to effect. If ineffective at the recommended maximum dose, an additional medication with a complementary mechanism of action can be added.

  12. 高血压病合并心房颤动患者ACE多态性与TGFβ1/CTGF的关系%Correlation between angiotensin converting enzyme gene polymorphisms and TGFβ1/CTGF in hypertensive patients with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    林宪如; 任永强; 史悦; 吴娜; 马颖; 王正忠; 王海洋

    2014-01-01

    目的:探讨高血压病(EH)合并心房颤动(AF)患者血管紧张素转换酶(ACE)基因插入/缺失(I/D)多态性与转化生长因子β1(TGFβ1)、结缔组织生长因子(CTGF)的关系。方法选择75例EH合并AF患者分为阵发性AF组(EH+pAF,44例)和慢性AF组(EH+cAF,31例),记录一般临床资料及行超声心动图检查,用ELISA法测定血清TGFβ1、CTGF,用PCR方法检测ACE基因插入/缺失(I/D)多态性,并与EH且为窦性心律(SR)组(EH+SR,37例)及健康对照者(NC,36例)进行比较;比较EH+AF组不同基因型间TGFβ1与CTGF的血清浓度。结果 EH+cAF组和EH+pAF组血清TGFβ1及CTGF水平均显著高于EH+SR组和NC组(P0.05),但D等位基因分布频率在EH+AF组中较EH+SR组和NC组明显增加(P<0.05);EH+AF组不同基因型之间TGFβ1及CTGF浓度比较发现,DD基因型TGFβ1浓度显著高于DI型(P<0.01)和II型(P<0.01),DD基因型CTGF浓度明显高于II型(P<0.05)。结论 D等位基因可能是高血压病合并心房颤动的易患基因;房颤患者ACE DD基因型TGFβ1和CTGF水平明显升高,藉此可引起心房肌纤维化及心房重构,导致房颤的发生和发展。%Objective To explore the relationship between the polymorphisms of angiotensin converting en-zyme (ACE) insertion/deletion (I/D) gene and transforming growth factorβ1 (TGFβ1)/connective tissue growth factor (CTGF) in patients with essential hypertension (EH) and atrial fibrillation (AF). Methods Seventy-five EH patients with documented AF were divided into the paroxysmal AF group (EH+pAF group, n=44) or the chronic AF group (EH+cAF group, n=31), and 37 EH patients with sinus rhythm (SR) were selected into the EH+SR group. All clinical data including blood pressure, lipids, glucose and atrial diameter measured from ultrasonic cardiogram were recorded. Thirty-six healthy subjects from the medical examination center were assigned to normal controls (NC group). The se-rum TGFβ1, CTGF were measured by

  13. Hypercortisolism in obesity-associated hypertension.

    Science.gov (United States)

    Varughese, Amy G; Nimkevych, Oksana; Uwaifo, Gabriel I

    2014-07-01

    Obesity is prevalent worldwide and associated with co-morbidities that result in increased cardiovascular risk. Hypertension is the most prevalent obesity comorbidity associated with increased cardiovascular risk. Obesity hypertension is a distinct subtype of essential hypertension. While endogenous Cushing's syndrome is an uncommon cause of both obesity and hypertension, the recent recognition of other hypercortisolemic states has raised the profile of hypercortisolism as an important contributor in obesity hypertension. The high prevalence of exogenous, iatrogenic, pseudo, and subclinical Cushing's syndromes makes hypercortisolism an important diagnostic consideration in the evaluation and management of patients with obesity hypertension who are resistant to conventional management. Available data suggest that the renin-angiotensin-aldosterone system modulating antihypertensives have the best efficacy in hypercortisolism-mediated obesity hypertension. Strategies aimed at reducing cortisol production and action also have utility. This review provides a comprehensive overview of the epidemiology, etiopathogenesis and management options available for glucocorticoid-mediated obesity hypertension.

  14. Hypertension and Atrial Fibrillation

    DEFF Research Database (Denmark)

    Dzeshka, Mikhail S.; Shahid, Farhan; Shantsila, Alena

    2017-01-01

    Atrial fibrillation (AF) is the most prevalent sustained arrhythmia found in clinical practice. AF rarely exists as a single entity but rather as part of a diverse clinical spectrum of cardiovascular diseases, related to structural and electrical remodeling within the left atrium, leading to AF o...... of complications as the first clinical manifestation of the disease. Antithrombotic prevention in AF combined with strict blood pressure control is of primary importance, since stroke risk and bleeding risk are both greater with underlying hypertension....... onset, perpetuation, and progression. Due to the high overall prevalence within the AF population arterial hypertension plays a significant role in the pathogenesis of AF and its complications. Fibroblast proliferation, apoptosis of cardiomyocytes, gap junction remodeling, accumulation of collagen both...... in atrial and ventricular myocardium all accompany ageing-related structural remodeling with impact on electrical activity. The presence of hypertension also stimulates oxidative stress, systemic inflammation, rennin-angiotensin-aldosterone and sympathetic activation, which further drives the remodeling...

  15. [Obesity and hypertension].

    Science.gov (United States)

    Simonyi, Gábor; Kollár, Réka

    2013-11-01

    The frequency of hypertension and obesity is gradually growing in Hungary. At present 68.5% of men and 78% of women are obese. Hypertension and obesity are the most important risk factors of morbidity and mortality from cardiovascular disease. The relationship between increased sympathetic activity and hypertension is well known. Waist circumference and body fat mass correlate significantly with sympathetic activity, in which hyperlipidemia plays also a role. The increased activity of renin-angiotensin-aldosterone system via its vascular and renal effects also contributes to an increase of blood pressure. Increased sympathetic activity with decreasing vagal tone accompanying the imbalance of the autonomous nervous system is independent and significant risk factor of cardiovascular events including sudden cardiac death.

  16. Liver cirrhosis and arterial hypertension

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Møller, Søren

    2006-01-01

    blood pressure. This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development...... of cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most......Characteristic findings in patients with cirrhosis are vasodilatation with low overall systemic vascular resistance, high arterial compliance, increased cardiac output, secondary activation of counter-regulatory systems (renin-angiotensin-aldosterone system, sympathetic nervous system, release...

  17. The Ang II-induced growth of vascular smooth muscle cells involves a phospholipase D-mediated signaling mechanism.

    Science.gov (United States)

    Freeman, E J

    2000-02-15

    Angiotensin (Ang) II acts as a mitogen in vascular smooth muscle cells (VSMC) via the activation of multiple signaling cascades, including phospholipase C, tyrosine kinase, and mitogen-activated protein kinase pathways. However, increasing evidence supports signal-activated phospholipases A(2) and D (PLD) as additional mechanisms. Stimulation of PLD results in phosphatidic acid (PA) formation, and PA has been linked to cell growth. However, the direct involvement of PA or its metabolite diacylglycerol (DAG) in Ang II-induced growth is unclear. PLD activity was measured in cultured rat VSMC prelabeled with [(3)H]oleic acid, while the incorporation of [(3)H]thymidine was used to monitor growth. We have previously reported the Ang II-dependent, AT(1)-coupled stimulation of PLD and growth in VSMC. Here, we show that Ang II (100 nM) and exogenous PLD (0.1-100 units/mL; Streptomyces chromofuscus) stimulated thymidine incorporation (43-208% above control). PA (100 nM-1 microM) also increased thymidine incorporation to 135% of control. Propranolol (100 nM-10 microM), which inhibits PA phosphohydrolase, blocked the growth stimulated by Ang II, PLD, or PA by as much as 95%, an effect not shared by other beta-adrenergic antagonists. Propranolol also increased the production of PA in the presence of Ang II by 320% and reduced DAG and arachidonic acid (AA) accumulation. The DAG lipase inhibitor RHC-80267 (1-10 microM) increased Ang II-induced DAG production, while attenuating thymidine incorporation and release of AA. Thus, it appears that activation of PLD, formation of PA, conversion of PA to DAG, and metabolism of DAG comprise an important signaling cascade in Ang II-induced growth of VSMC.

  18. Engagement of renin-angiotensin system in prostate cancer.

    Science.gov (United States)

    Uemura, Hiroji; Hoshino, Koji; Kubota, Yoshinobu

    2011-05-01

    Angiotensin II (Ang-II) plays a role not only as a vasoconstrictor in controlling blood pressure and electrolyte and fluid homeostasis, but also as a mitogenic factor through the Ang-II type-1 (AT1) receptor in cardiovascular cells. Since a low prevalence of cancer in hypertensive patients receiving angiotensin converting enzyme inhibitors has been reported, the molecular mechanisms of the renin-angiotensin system (RAS) in cancer cells have been elucidated. Interestingly, there is increasing evidence that the RAS is implicated in the development of prostate cancer. As previously reported, AT1 receptor blockers (ARBs), a class of antihypertensive agent, have the potential to inhibit the growth of prostate cancer cells and tumors through the AT1 receptor. This review highlights that the RAS plays a potential role in various aspects of prostate cancer, and ARBs could be useful for treatment of prostate cancer or its chemoprevention.

  19. Association of angiotensin Ⅱ type 1 receptor gene polymorphism with essential hypertension%血管紧张素Ⅱ受体1基因多态性与原发性高血压的相关性研究

    Institute of Scientific and Technical Information of China (English)

    蒋珍妮; 俞锋; 徐耕; 赵文胜

    2001-01-01

    Objective To determine whether the polymorphism A1166C in the angiotensin Ⅱ type 1 receptor (AT1R) gene is associated with essential hypertension Methods A casecontrol study was carried out using 125 hypertensive and 103 normotensive subjects The AC variant at position 1166 (A1166C) of the AT 1R gene was identified by polymerase chain reaction (PCR) and PCR/restriction fragment length polymorphism (PCR/RFLP) analysis The digestion products were separated on 2% agarose gels and visualized with ethidium bromide under ultraviolet ray Results The differences in C1166 allele frequency and in the AC genotype distribution of the AT 1R gene between the hypertensive and normotensive groups were statistically significant (C allele: 0.092 vs 0.034, χ2=6.1.86,P<0.05; AC genotype: 0.184 vs 0.068, χ2=6.654,P<0.05) Conclusion The AC genotype is associated with essential hypertension, and the C allele may be a marker for predisposition to hypertension in Chinese Han population%目的本研究旨在观察中国汉族人血管紧张素Ⅱ受体1基因多态性与原发性高血压的关系。方法应用聚合酶链反应-限制性内切酶片段长度多态(PCR-RFLP)与电泳分型的方法检测125例原发性高血压患者和103例正常者AT1R基因1166位(A1166C)的多态性分布。结果原发性高血压患者AT1R基因AC型频率比正常对照组高(0.184 vs 0.068, χ2=6.654,P<0.05),C1166等位基因频率原发性高血压组高于正常对照组(0.092 vs 0.034,χ2=6.186,P<0.05)。结论在中国汉族人群中,AC基因型与原发性高血压有关,C等位基因可能是高血压的易感基因。

  20. Involvement of the Intrarenal Renin-Angiotensin System in Experimental Models of Glomerulonephritis

    Directory of Open Access Journals (Sweden)

    Maki Urushihara

    2012-01-01

    Full Text Available The intrarenal renin-angiotensin system (RAS has several pathophysiologic functions not only in blood pressure regulation but also in the development of glomerulonephritis (GN. Angiotensin II (Ang II is the biologically active product of the RAS. Locally produced Ang II induces inflammation, renal cell growth, mitogenesis, apoptosis, migration, and differentiation, regulates the gene expression of bioactive substances, and activates multiple intracellular signaling pathways, leading to tissue damage. Activation of the Ang II type 1 (AT1 receptor pathway results in the production of proinflammatory mediators, cell proliferation, and extracellular matrix synthesis, which facilitates glomerular injury. Previous studies have shown that angiotensin-converting enzyme inhibitors and/or AT1 receptor blockers have beneficial effects in experimental GN models and humans with various types of GN, and that these effects are more significant than their suppressive effects on blood pressure. In this paper, we focus on intrarenal RAS activation in the pathophysiology of experimental models of GN.

  1. Angiotensin-converting enzyme

    DEFF Research Database (Denmark)

    Sørensen, P G; Rømer, F K; Cortes, D

    1984-01-01

    In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical or radiolog......In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical...

  2. Renin and aldosterone measurements in the management of arterial hypertension.

    Science.gov (United States)

    Viola, A; Monticone, S; Burrello, J; Buffolo, F; Lucchiari, M; Rabbia, F; Williams, T A; Veglio, F; Mengozzi, G; Mulatero, P

    2015-06-01

    Renin-angiotensin-aldosterone system (RAAS) is recognized as the main regulatory system of hemodynamics in man, and its derangements have a key role in the development and maintenance of arterial hypertension. Classification of the hypertensive states according to different patterns of renin and aldosterone levels ("RAAS profiling") allows the diagnosis of specific forms of secondary hypertension and may identify distinct hemodynamic subsets in essential hypertension. In this review, we summarize the application of RAAS profiling for the diagnostic assessment of hypertensive patients and discuss how the pathophysiological framework provided by RAAS profiling may guide therapeutic decision-making, especially in the context of uncontrolled hypertension not responding to multi-therapy.

  3. [Role of matrix metalloproteinases and tissue inhibitors of metalloproteinases in hypertension. Pathogenesis of hypertension and obesity].

    Science.gov (United States)

    Trojanek, Joanna B

    2015-01-01

    Hypertension (HT), obesity and related metabolic disorders are increasing cause diseases with risk of premature death in western societies. Both hypertension and obesity are characterized by similar disorders such as chronic low systemic inflammation, changes in the vessel wall, abdominal obesity, insulin-resistance or dyslipidemia. Chronic, untreated HT leads to adverse changes in internal organs like kidney damage, arterial remodeling and hypertrophy of the left ventricle. The important role metalloproteinases and their inhibitors (TIMPs) in the pathophysiology of hypertension is associated with the degradation of vascular wall components, especially collagen and elastin. The activated RAAS system (renin-angiotensin-aldosterone) is displaying direct impact in the pathogenesis and progress of hypertension. Angiotensin II affects the expression and activation of many growth factors, cytokines and MMPs. The fat tissue of obese people is in the state of low intensity chronic inflammation and undergoes continual process of remodeling. Obesity is one of the direct cause of hypertension.

  4. Meta Analysis of the Effects of Calcium Channel Blockers or Renin-Angiotensin System Blockers on Arterial Stiffness in Hypertension%钙离子拮抗剂和肾素-血管紧张素系统阻断剂对高血压动脉僵硬度作用差异的荟萃分析

    Institute of Scientific and Technical Information of China (English)

    张艺军; 裴静娴; 王月刚; 吴平生

    2012-01-01

    目的 系统评价钙离子拮抗剂和肾素-血管紧张素系统阻断剂在高血压治疗中,动脉僵硬度变化的差异.方法 按循证医学的要求,制定相应的纳入、排除标准及其检索策略.通过PubMed、EMBASE、Ovid EMBReviews、中周期刊全文数据库、中文科技期刊全文数据库、万方数据库检索相关的随机对照临床研究,计算机检索时间从各数据库建库至2012年1月;同时辅助其他检索,纳入经过钙离子拮抗剂和肾素-血管紧张素系统阻断剂治疗原发性高血压患者的随机对照试验,治疗时间至少12周.采用RevMan5.0软件进行统计分析.结果 纳入7篇随机对照研究,共计524例高血压患者.荟萃分析结果显示:肾素-血管紧张素系统阻断剂在改善动脉僵硬度方面优于钙离子拮抗剂(均数差=160.15,95%可信区间57.10~263.21),差异有统计学意义.但是在降低收缩压(均数差=-2.94,95%可信区间-4.59~-1.29)和舒张压(均数差=-6.63,95%可信区间-9.56~-3.70)方面,较钙离子拮抗剂弱,在降低脉压差(均数差=-6.12,95%可信区间-2.3~14.55)方面与钙离子拮抗剂相比无显著性差异.结论 肾素-血管紧张素系统阻断剂在改善高血压患者动脉僵硬度方面优于钙离子拮抗剂,该作用与其降压作用无关.%Objective To evaluate the differences of the changes of pulse wave velocity(PWV) of hypertension patients with the treatment of calcium channel blockers or Renin-angiotensin system blockers. Methods Based on the principles of evidence-based medicine, corresponding inclusion and exclusion criteria, along with search strategies were developed. We searched the Ovid EMB Reviews, PubMed, EMBASE, Chinese Biomedical Literature Database, Chinese Scientific Journal Full-text Database, and Chinese Journal Full-text Database up to January 2012 to identify randomized controlled trials comparing the effects of calcium channel hlockers with that of Renin-angiotensin

  5. Low-Dose Dextromethorphan, a NADPH Oxidase Inhibitor, Reduces Blood Pressure and Enhances Vascular Protection in Experimental Hypertension

    Science.gov (United States)

    Wu, Tao-Cheng; Chao, Chih-Yu; Lin, Shing-Jong; Chen, Jaw-Wen

    2012-01-01

    Background Vascular oxidative stress may be increased with age and aggravate endothelial dysfunction and vascular injury in hypertension. This study aimed to investigate the effects of dextromethorphan (DM), a NADPH oxidase inhibitor, either alone or in combination treatment, on blood pressure (BP) and vascular protection in aged spontaneous hypertensive rats (SHRs). Methodology/Principal Findings Eighteen-week-old WKY rats and SHRs were housed for 2 weeks. SHRs were randomly assigned to one of the 12 groups: untreated; DM monotherapy with 1, 5 or 25 mg/kg/day; amlodipine (AM, a calcium channel blocker) monotherapy with 1 or 5 mg/kg/day; and combination therapy of DM 1, 5 or 25 mg/kg/day with AM 1 or 5 mg/kg/day individually for 4 weeks. The in vitro effects of DM were also examined. In SHRs, AM monotherapy dose-dependently reduced arterial systolic BP. DM in various doses significantly and similarly reduced arterial systolic BP. Combination of DM with AM gave additive effects on BP reduction. DM, either alone or in combination with AM, improved aortic endothelial function indicated by ex vivo acetylcholine-induced relaxation. The combination of low-dose DM with AM gave most significant inhibition on aortic wall thickness in SHRs. Plasma total antioxidant status was significantly increased by all the therapies except for the combination of high-dose DM with high-dose AM. Serum nitrite and nitrate level was significantly reduced by AM but not by DM or the combination of DM with AM. Furthermore, in vitro treatment with DM reduced angiotensin II-induced reactive oxygen species and NADPH oxidase activation in human aortic endothelial cells. Conclusions/Significance Treatment of DM reduced BP and enhanced vascular protection probably by inhibiting vascular NADPH oxidase in aged hypertensive animals with or without AM treatment. It provides the potential rationale to a novel combination treatment with low-dose DM and AM in clinical hypertension. PMID:23049937

  6. Low-dose dextromethorphan, a NADPH oxidase inhibitor, reduces blood pressure and enhances vascular protection in experimental hypertension.

    Directory of Open Access Journals (Sweden)

    Tao-Cheng Wu

    Full Text Available BACKGROUND: Vascular oxidative stress may be increased with age and aggravate endothelial dysfunction and vascular injury in hypertension. This study aimed to investigate the effects of dextromethorphan (DM, a NADPH oxidase inhibitor, either alone or in combination treatment, on blood pressure (BP and vascular protection in aged spontaneous hypertensive rats (SHRs. METHODOLOGY/PRINCIPAL FINDINGS: Eighteen-week-old WKY rats and SHRs were housed for 2 weeks. SHRs were randomly assigned to one of the 12 groups: untreated; DM monotherapy with 1, 5 or 25 mg/kg/day; amlodipine (AM, a calcium channel blocker monotherapy with 1 or 5 mg/kg/day; and combination therapy of DM 1, 5 or 25 mg/kg/day with AM 1 or 5 mg/kg/day individually for 4 weeks. The in vitro effects of DM were also examined. In SHRs, AM monotherapy dose-dependently reduced arterial systolic BP. DM in various doses significantly and similarly reduced arterial systolic BP. Combination of DM with AM gave additive effects on BP reduction. DM, either alone or in combination with AM, improved aortic endothelial function indicated by ex vivo acetylcholine-induced relaxation. The combination of low-dose DM with AM gave most significant inhibition on aortic wall thickness in SHRs. Plasma total antioxidant status was significantly increased by all the therapies except for the combination of high-dose DM with high-dose AM. Serum nitrite and nitrate level was significantly reduced by AM but not by DM or the combination of DM with AM. Furthermore, in vitro treatment with DM reduced angiotensin II-induced reactive oxygen species and NADPH oxidase activation in human aortic endothelial cells. CONCLUSIONS/SIGNIFICANCE: Treatment of DM reduced BP and enhanced vascular protection probably by inhibiting vascular NADPH oxidase in aged hypertensive animals with or without AM treatment. It provides the potential rationale to a novel combination treatment with low-dose DM and AM in clinical hypertension.

  7. Atrial natriuretic peptide (ANP) as a neuropeptide: Interaction with angiotensin II on volume control and renal sodium handling

    OpenAIRE

    Unger, Th.; Badoer, E.; Gareis, C.; Girchev, R.; Kotrba, M.; Qadri, F; Rettig, R.; Rohmeiss, P

    1990-01-01

    1 Angiotensin II (ANG II) and atrial natriuretic peptide (ANP) are functionally antagonistic circulating hormones involved in blood pressure and body fluid regulation. An inappropriate atrial secretion of ANP has been implicated in the pathogenesis of hypertension, but clinical and experimental results on the role of ANP in hypertension are still conflicting.

  8. Animal models in obesity and hypertension.

    Science.gov (United States)

    Segal-Lieberman, Gabriella; Rosenthal, Talma

    2013-06-01

    Although obesity is a well-known risk factor for hypertension, the mechanisms by which hypertension develops in obese patients are not entirely clear. Animal models of obesity and their different susceptibilities to develop hypertension have revealed some of the mechanisms linking obesity and hypertension. Adipose tissue is an endocrine organ secreting hormones that impact blood pressure, such as elements of the renin-angiotensin system whose role in hypertension have been established. In addition, the appetite-suppressing adipokine leptin activates the sympathetic nervous system via the melanocortin system, and this activation, especially in the kidney, increases blood pressure. Leptin secretion from adipocytes is increased in most models of obesity due to leptin resistance, although the resistance is often selective to the anorexigenic effect, while the susceptibility to the hypertensive effect remains intact. Understanding the pathways by which obesity contributes to increased blood pressure will hopefully pave the way to and better define the appropriate treatment for obesity-induced hypertension.

  9. [Rehabilitation medicine, laboratory medicine, and hypertension--my 38-year academic career in Tohoku University and Hirosaki University].

    Science.gov (United States)

    Yasujima, Minoru

    2012-02-01

    Hypertension is a major contributor to the risks for cardiovascular diseases. The cause of approximately 90% of hypertension cases is unknown, despite decades of research and debate. Many factors including renal mechanisms and the renin-angiotensin system are involved in the regulatory mechanisms of blood pressure. Genetic and environmental factors interact to affect multiple factors related to hypertensive mechanisms. Recent data suggested that genetic risk factors have been useful in clinical practice. The evidence that treatment of hypertension reduces cardiovascular diseases come from the results of large-scale therapeutic trials. Significant progress has been made during the last several decades in the treatment of hypertension through the use of inhibitors of the renin-angiotensin system, with either angiotensin converting enzyme inhibitors or angiotensin receptor type 1 blockers. In this review, I summarize my personal career related to hypertension research.

  10. Hypotensive effect of angiotensin II after AT1-receptor blockade with losartan.

    Science.gov (United States)

    Matys, T; Pawlak, R; Kucharewicz, I; Chabielska, E; Buczko, W

    2000-03-01

    Recent data suggest that hypotensive effect of losartan may not be attributed solely to AT1-receptor blockade, but also to excessive AT2 or other receptors stimulation by elevated angiotensin II and its derivative peptides. Therefore in the present study we examined the effect of angiotensin II on mean blood pressure after AT -receptor blockade with losartan. Male Wistar rats were anaesthetised and received injection of either losartan (30 mg/kg, 1 ml/kg, i.v.) or saline (the same volume and route) followed by bolus injection of angiotensin II (100, 300 or 1,000 ng/kg; 1 ml/kg, i.v.) or 1-hour infusion of angiotensin II (200 ng/kg/min; 2.5 ml/kg/h, i.v.). Control animals received saline instead. Angiotensin II, given either as the injection or the infusion, caused an evident increase in mean blood pressure (p ranged from 0.05 to 0.001 depending on the experimental group). Losartan caused a rapid drop in mean blood pressure and blunted the hypertensive effect of angiotensin II (p < 0.01). Moreover, in the losartan-pretreated animals the hypotensive phase was enhanced by the infusion, but not single injection of angiotensin II, which was most evident from the 30 th minute of observation (p < 0.05 vs control). In conclusion, hypotensive effect of losartan may be amplified by simultaneous increase in angiotensin II level, the situation observed during chronic AT1-receptor blockade.

  11. Pharmacotherapy and analysis of gaseous mediators in hypertensive patients

    Directory of Open Access Journals (Sweden)

    Letícia Palota Eid

    2015-02-01

    Full Text Available OBJECTIVE To evaluate the effect of using antihypertensive classes of drugs of the calcium channel antagonists and inhibitors of angiotensin-converting enzyme in plasma concentrations of hydrogen sulfide and nitric oxide in patients with hypertension. METHODS Cross-sectional study with quantitative approach conducted with hypertensive patients in use of antihypertensive classes of drugs: angiotensin-converting enzyme inhibitors or calcium channel antagonists. RESULTS It was found that the concentration of plasma nitric oxide was significantly higher in hypertensive patients that were in use of angiotensin-converting enzyme inhibitors (p<0.03 and the hydrogen sulphide concentration was significantly higher in hypertensive plasma in use of calcium channel antagonists (p<0.002. CONCLUSION The findings suggest that these medications have as additional action mechanism the improvement of endothelial dysfunction by elevate plasma levels of vasodilatory substances.

  12. Angiotensin type 2 receptors

    DEFF Research Database (Denmark)

    Sumners, Colin; de Kloet, Annette D; Krause, Eric G;

    2015-01-01

    R blockade. Despite a lack of effect on blood pressure, AT2R stimulation still protects from hypertensive end-organ damage. Current data and evidence therefore suggest that AT2R agonists will not be suitable as future anti-hypertensive drugs, but that they may well be useful for end-organ protection...

  13. Alteration of RhoA Prenylation Ameliorates Cardiac and Vascular Remodeling in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2016-06-01

    Full Text Available Background: In our previous study, farnesyl pyrophosphate synthase (FPPS was shown to be increased in spontaneously hypertensive rats (SHR and in mice with angiotensin-II induced cardiac hypertrophy. Overexpression of FPPS induced cardiac hypertrophy and fibrosis in mice, accompanied by an increase in the synthesis of farnesyl pyrophosphate (FPP and geranylgeranyl pyrophosphate (GGPP. In the present study, we investigated the mechanisms of reversing cardiovascular remodeling in SHR by inhibiting FPPS. Methods and Results: Six-week-old rats were given vehicle or an FPPS inhibitor (alendronate, 100 ug/kg/d daily for twelve weeks by osmotic mini-pump. The results demonstrated that FPPS inhibition attenuated cardiac hypertrophy and fibrosis in SHR as shown by the heart weight to body weight ratio, echocardiographic parameters, and histological examination. In addition, FPPS inhibition attenuated aortic remodeling as shown by reduced media thickness, media cross-sectional area and collagen of the aorta as well as SBP, DBP, MBP. Furthermore, 12 weeks of alendronate treatment significantly decreased FPP and GGPP levels, RhoA activation and geranylgeranylation in the heart and aorta, all of which were significantly upregulated in SHR compared with normotensive Wistar-Kyoto rats. Conclusion: Taken together, these results indicate that chronic treatment with alendronate decreases the development of cardiac and aortic remodeling, by a pathway which involves inhibition of the geranylgeranylation and activation of RhoA.

  14. The Angiotensin-Melatonin Axis

    OpenAIRE

    Campos, Luciana A.; Jose Cipolla-Neto; Amaral, Fernanda G.; Michelini, Lisete C.; Michael Bader; Baltatu, Ovidiu C.

    2013-01-01

    Accumulating evidence indicates that various biological and neuroendocrine circadian rhythms may be disrupted in cardiovascular and metabolic disorders. These circadian alterations may contribute to the progression of disease. Our studies direct to an important role of angiotensin II and melatonin in the modulation of circadian rhythms. The brain renin-angiotensin system (RAS) may modulate melatonin synthesis, a hormone with well-established roles in regulating circadian rhythms. Angiotensin ...

  15. [Hyperuricemia, diabetes and hypertension].

    Science.gov (United States)

    Viazzi, Francesca; Bonino, Barbara; Ratto, Elena; Desideri, Giovambattista; Pontremoli, Roberto

    2015-01-01

    Hyperuricemia is frequently found in association with several condition predisposing to cardiovascular events such as arterial hypertension and diabetes mellitus. This has led researchers to investigate possible pathogenetic mechanisms underlying this association. Several experimental studies and some indirect clinical evidence support a causal link between mild hyperuricemia and the developement of hypertension as well as new onset diabetes. At the tissue level, chronic exposure to increased uric acid has been shown to promote vascular changes leading to renal ischemia as well as stimulation of the renin angiotensin system. Furthermore, uric acid has been shown to promote the development of insulin resistance, hypertrglyceridemia and haepatic steatosis through pro-oxidative mechanisms. These experimental pathophysiological changes may be partly preventable by hypouricemic treatments. Whether clinical implications of these findings are confirmed by solid clinical intervention trials, mild hyperuricemia may soon change its status from risk predictor to treatment target for patients at high cardiovascular and renal risk.

  16. Angiotensin Converting Enzyme Regulates Cell Proliferation and Migration

    Science.gov (United States)

    Carvalho, Clarissa Coelho; Florentino, Rodrigo Machado; França, Andressa; Matias, Eveline; Guimarães, Paola Bianchi; Batista, Carolina; Freire, Valder; Carmona, Adriana Karaoglanovic; Pesquero, João Bosco; de Paula, Ana Maria; Foureaux, Giselle; Leite, Maria de Fatima

    2016-01-01

    Background The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. Aim Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. Results We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the β3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. Conclusion ACE activation regulates melanoma cell proliferation and migration. PMID:27992423

  17. Suppression of TGF-β1/Smad signaling pathway by sesamin contributes to the attenuation of myocardial fibrosis in spontaneously hypertensive rats.

    Science.gov (United States)

    Zhao, Mengqiu; Zheng, Shuguo; Yang, Jieren; Wu, Yuanjie; Ren, Younan; Kong, Xiang; Li, Wei; Xuan, Jiali

    2015-01-01

    This study investigated the effect of sesamin on myocardial fibrosis in spontaneously hypertensive rats (SHRs) and the possible mechanisms involved. Twenty-eight male SHRs were randomly allocated to SHR group, Ses160 group (sesamin 160 mg/kg), Ses80 group (sesamin 80 mg/kg) and Cap30 group (captopril 30 mg/kg). Seven male WKY rats were used as control. Sesamin and captopril were administered intragastrically for 12 weeks. Captopril significantly reduced systolic blood pressure and angiotensin II (Ang II) levels in SHRs, accompanied by a marked attenuation of left ventricular hypertrophy (LVH) and collagen deposition (P sesamin had no significant influence on Ang II levels, and the hypotensive effect was also significantly inferior to that of captopril (P Sesamin markedly reduced transforming growth factor-β1 (TGF-β1) content in cardiac tissues, with Smad3 phosphorylation decreased and Smad7 protein expression increased notably (P sesamin (P sesamin significantly increased total antioxidant capacity and superoxide dismutase protein in cardiac tissues (P sesamin was able to suppress Ang II induced phosphorylation of Smad3 and secretion of TGF-β1 and type I and type III collagen in cultured rat cardiac fibroblasts. These data suggest that sesamin is capable of attenuating hypertensive myocardial fibrosis through, at least partly, suppression of TGF-β1/Smad signaling pathway.

  18. Milk protein-derived peptide inhibitors of angiotensin-I-converting enzyme

    OpenAIRE

    Fitzgerald, Richard J; Meisel, Hans

    2000-01-01

    peer-reviewed Numerous casein and whey protein-derived angiotensin-I-converting enzyme (ACE) inhibitory peptides/hydrolysates have been identified. Clinical trials in hypertensive animals and humans show that these peptides/hydrolysates can bring about a significant reduction in hypertension. These peptides/hydrolysates may be classified as functional food ingredients and nutraceuticals due to their ability to provide health benefits i.e. as functional food ingredients in reduc...

  19. Angiotensinogen gene polymorphism predicts hypertension, and iridological constitutional classification enhances the risk for hypertension in Koreans.

    Science.gov (United States)

    Cho, Joo-Jang; Hwang, Woo-Jun; Hong, Seung-Heon; Jeong, Hyun-Ja; Lee, Hye-Jung; Kim, Hyung-Min; Um, Jae-Young

    2008-05-01

    This study investigated the relationship between iridological constitution and angiotensinogen (AGN) gene polymorphism in hypertensives. In addition to angiotensin converting enzyme gene, AGN genotype is also one of the most well studied genetic markers of hypertension. Furthermore, iridology, one of complementary and alternative medicine, is the diagnosis of the medical conditions through noting irregularities of the pigmentation in the iris. Iridological constitution has a strong familial aggregation and is implicated in heredity. Therefore, the study classified 87 hypertensive patients with familial history of cerebral infarction and controls (n = 88) according to Iris constitution, and determined AGN genotype. As a result, the AGN/TT genotype was associated with hypertension (chi2 = 13.413, p iridological constitutional classification increased the relative risk for hypertension in the subjects with AGN/T allele. These results suggest that AGN polymorphism predicts hypertension, and iridological constitutional classification enhances the risk for hypertension associated with AGN/T in a Korean population.

  20. 血管紧张素转换酶基因导向治疗原发性高血压及左心室射血分数保留的心力衰竭研究进展%Progress of angiotensin-converting enzyme gene directed therapy for essentiaI hypertension and heart faiIure with preserved ejection fraction

    Institute of Scientific and Technical Information of China (English)

    王慧; 陈伟达; 王薇; 王俏; 隋小芳; 张磊艺

    2016-01-01

    Angiotensin converting enzyme (ACE), a drug that has a genetic polymorphisms is a key enzyme in the renin angiotensin aldosterone system (RAAS), are closely related to hypertension, cardiovascular disease and the damage of target organs caused by hypertension. The individual differences in drug reactions can be caused by it in human beings. In recent years, the heart failure of the left ventricular ejection fraction (HFPEF) is gradually attached importance and has become a hot research. At present, the correlation between ACE (I/D) gene polymorphisms and essential hypertension (EH), EH and HFPEF are not consistent with the results of the study. But the overall conclusion tends to the relationship between DD gene ACE genotype or D-allele and EH and HFPEF, and obviously it is higher. The genotype of ACE gene DD is more sensitive to ACEI drugs in patients with EH. The effect of ACE gene DD genotype on the effect of ACEI is better for patients with HFPEF. To investigate the relationship between ACE gene targeting treatment for EH and HFPEF, and to guide the clinical rational and scientific medication have the unprecedented inspiration.%血管紧张素转换酶(ACE)是肾素-血管紧张素-醛固酮系统(RAAS)的一种关键酶,与高血压病、心血管疾病及高血压病所致的靶器官损害密切相关,是一种具有基因多态性的药物代谢酶,可以造成人类对药物反应的显著个体差异。最近几年,左心室射血分数保留的心力衰竭(HFPEF)日渐受到重视,并成为研究的热点。目前,国内外有关ACE(I/D)基因多态性与原发性高血压(EH)及HFPEF的相关性的研究结果各家报道不一致,但总的结论倾向于ACE基因DD基因型或D等位基因与EH及HFPEF有关系,且明显升高;EH患者ACE基因DD基因型对ACEI类降压药物更敏感;HFPEF患者ACE基因DD基因型对ACEI类药物效果更好。故探讨ACE基因导向治疗原发性高血压及HFPEF的关系

  1. Role of EGFR transactivation in angiotensin II signaling to extracellular regulated kinase in preglomerular smooth muscle cells.

    Science.gov (United States)

    Andresen, Bradley T; Linnoila, Jenny J; Jackson, Edwin K; Romero, Guillermo G

    2003-03-01

    Angiotensin (Ang) II promotes the phosphorylation of extracellular regulated kinase (ERK); however, the mechanisms leading to Ang II-induced ERK phosphorylation are debated. The currently accepted theory involves transactivation of epidermal growth factor receptor (EGFR). We have shown that generation of phosphatidic acid (PA) is required for the recruitment of Raf to membranes and the activation of ERK by multiple agonists, including Ang II. In the present report, we confirm that phospholipase D-dependent generation of PA is required for Ang II-mediated phosphorylation of ERK in Wistar-Kyoto and spontaneously hypertensive rat preglomerular smooth muscle cells (PGSMCs). However, EGF stimulation does not activate phospholipase D or generate PA. These observations indicate that EGF recruits Raf to membranes via a mechanism that does not involve PA, and thus, Ang II-mediated phosphorylation of ERK is partially independent of EGFR-mediated signaling cascades. We hypothesized that phosphoinositide-3-kinase (PI3K) can also act to recruit Raf to membranes; therefore, inhibition of PI3K should inhibit EGF signaling to ERK. Wortmannin, a PI3K inhibitor, inhibited EGF-mediated phosphorylation of ERK (IC50, approximately 14 nmol/L). To examine the role of the EGFR in Ang II-mediated phosphorylation of ERK we utilized 100 nmol/L wortmannin to inhibit EGFR signaling to ERK and T19N RhoA to block Ang II-mediated ERK phosphorylation. Wortmannin treatment inhibited EGF-mediated but not Ang II-mediated phosphorylation of ERK. Furthermore, T19N RhoA inhibited Ang II-mediated ERK phosphorylation, whereas T19N RhoA had significantly less effect on EGF-mediated ERK phosphorylation. We conclude that transactivation of the EGFR is not primarily responsible for Ang II-mediated activation of ERK in PGSMCs.

  2. Heme oxygenase attenuates angiotensin II-mediated superoxide production in cultured mouse thick ascending loop of Henle cells.

    Science.gov (United States)

    Kelsen, Silvia; Patel, Bijal J; Parker, Lawson B; Vera, Trinity; Rimoldi, John M; Gadepalli, Rama S V; Drummond, Heather A; Stec, David E

    2008-10-01

    Heme oxygenase (HO)-1 induction can attenuate the development of angiotensin II (ANG II)-dependent hypertension. However, the mechanism by which HO-1 lowers blood pressure is not clear. The goal of this study was to test the hypothesis that induction of HO-1 can reduce the ANG II-mediated increase in superoxide production in cultured thick ascending loop of Henle (TALH) cells. Studies were performed on an immortalized cell line of mouse TALH (mTALH) cells. HO-1 was induced in cultured mTALH cells by treatment with cobalt protoporphyrin (CoPP, 10 microM) or hemin (50 microM) or by transfection with a plasmid containing the human HO-1 isoform. Treatment of mTALH cells with 10(-9) M ANG II increased dihydroethidium (DHE) fluorescence (an index of superoxide levels) from 35.5+/-5 to 136+/-18 relative fluorescence units (RFU)/microm2. Induction of HO-1 via CoPP, hemin, or overexpression of the human HO-1 isoform significantly reduced ANG II-induced DHE fluorescence to 64+/-5, 64+/-8, and 41+/-4 RFU/microm2, respectively. To determine which metabolite of HO-1 is responsible for reducing ANG II-mediated increases in superoxide production in mTALH cells, cells were preincubated with bilirubin or carbon monoxide (CO)-releasing molecule (CORM)-A1 (each at 100 microM) before exposure to ANG II. DHE fluorescence averaged 80+/-7 RFU/microm2 after incubation with ANG II and was significantly decreased to 55+/-7 and 53+/-4 RFU/microm2 after pretreatment with bilirubin and CORM-A1. These results demonstrate that induction of HO-1 in mTALH cells reduces the levels of ANG II-mediated superoxide production through the production of both bilirubin and CO.

  3. Inhibition of the renin-angiotensin system for prevention of atrial fibrillation.

    Science.gov (United States)

    Zografos, Theodoros; Katritsis, Demosthenes G

    2010-10-01

    Atrial fibrillation (AF) is a source of considerable morbidity and mortality. There has been compelling evidence supporting the role of renin-angiotensin system (RAS) in the genesis and perpetuation of AF through atrial remodeling, and experimental studies have validated the utilization of RAS inhibition for AF prevention. This article reviews clinical trials on the use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) for the prevention of AF. Results have been variable, depending on the clinical background of treated patients. ACEIs and ARBs appear beneficial for primary prevention of AF in patients with heart failure, whereas they are not equally effective in hypertensive patients with normal left ventricular function. Furthermore, the use of ACEIs or ARBs for secondary prevention of AF has been found beneficial only after electrical cardioversion. Additional data are needed to establish the potential clinical role of renin-angiotensin inhibition for prevention of AF.

  4. Radioimmunoassay of renin-angiotensin-aldosterone in patients with adrenal tumors

    Energy Technology Data Exchange (ETDEWEB)

    Slavnov, V.N.; Yakovlev, A.A.; Yugrinov, O.G.; Gandzha, T.I. (Kievskij Nauchno-Issledovatel' skij Inst. Ehndokrinologii i Obmena Veshchestv (Ukrainian SSR))

    1983-02-01

    The results are presented of a study of the renin-angiotensin-aldosterone system in 89 patients with aldosteronoma, corticosteroma, pheochromocytoma and hypertension. Radioimmunoassay was used to measure aldosterone concentration and renin activity in the peripheral blood and blood from vena cava inferior, the renal and adrenal veins, the circadian cycle of their content and the responsiveness of the glomerular zone of the adrenal cortex and the juxtaglomerular renal system under the influence of lasix intake and the change over from a horizontal into vertical position. Patients with adrenal tumors have shown disorders of renin-angiotensin-aldosterone function. Radioimmunoassay of the renin-angiotensin-aldosterone system promotes early detection of adrenal tumors in the general population of patients with hypertension and can be used for control over therapeutic efficacy.

  5. Improvement of Sodium Status to Optimize the Efficacy of Renin-Angiotensin System Blockade

    NARCIS (Netherlands)

    Laverman, Gozewijn D.; Navis, Gerjan

    2011-01-01

    Blockade of the renin-angiotensin-aldosterone system (RAAS) offers superior renoprotection in the treatment of patients with hypertension, but the efficacy of RAAS inhibition strongly depends on sodium status, presumably in relation to extracellular volume status. Because assessing volume status by

  6. INHIBITION OF KIDNEY DISORDERS IN CARDIOVASCULAR DISEASES: THE ROLE OF ANGIOTENSIN II RECEPTOR BLOCKERS

    Directory of Open Access Journals (Sweden)

    V. V. Fomin

    2008-01-01

    Full Text Available Mechanisms of renal disorders in cardiovascular diseases are presented. The main of these mechanisms is an endothelium dysfunction. It is related with some factors: arterial hypertension, insulin resistance syndrome, diabetes type 2, dyslipidemia, obesity. Approaches to prevention of kidney disorder and cardiovascular complications are discussed with focus on usage of angiotensin II receptor blockers.

  7. Comparison of the antagonistic effects of different angiotensin II receptor blockers in human coronary arteries

    DEFF Research Database (Denmark)

    Pantev, Emil; Stenman, Emelie; Wackenfors, Angelica;

    2002-01-01

    BACKGROUND: Angiotensin II (Ang II) is a potent vasoconstrictor and a deleterious factor in cardiovascular pathophysiology. Ang II receptor blockers (ARBs) have recently been introduced into clinical practice for treatment of hypertension and congestive heart failure. AIMS: This study was underta...

  8. Effect of angiotensin II on proliferation and differentiation of mouse induced pluripotent stem cells into mesodermal progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Ishizuka, Toshiaki, E-mail: tishizu@ndmc.ac.jp [Department of Pharmacology, National Defense Medical College, Tokorozawa, Saitama 359-8513 (Japan); Goshima, Hazuki; Ozawa, Ayako; Watanabe, Yasuhiro [Department of Pharmacology, National Defense Medical College, Tokorozawa, Saitama 359-8513 (Japan)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Treatment with angiotensin II enhanced LIF-induced DNA synthesis of mouse iPS cells. Black-Right-Pointing-Pointer Angiotensin II may enhance the DNA synthesis via induction of superoxide. Black-Right-Pointing-Pointer Treatment with angiotensin II significantly increased JAK/STAT3 phosphorylation. Black-Right-Pointing-Pointer Angiotensin II enhanced differentiation into mesodermal progenitor cells. Black-Right-Pointing-Pointer Angiotensin II may enhance the differentiation via activation of p38 MAPK. -- Abstract: Previous studies suggest that angiotensin receptor stimulation may enhance not only proliferation but also differentiation of undifferentiated stem/progenitor cells. Therefore, in the present study, we determined the involvement of the angiotensin receptor in the proliferation and differentiation of mouse induced pluripotent stem (iPS) cells. Stimulation with angiotensin II (Ang II) significantly increased DNA synthesis in mouse iPS cells cultured in a medium with leukemia inhibitory factor (LIF). Pretreatment of the cells with either candesartan (a selective Ang II type 1 receptor [AT{sub 1}R] antagonist) or Tempol (a cell-permeable superoxide scavenger) significantly inhibited Ang II-induced DNA synthesis. Treatment with Ang II significantly increased JAK/STAT3 phosphorylation. Pretreatment with candesartan significantly inhibited Ang II- induced JAK/STAT3 phosphorylation. In contrast, induction of mouse iPS cell differentiation into Flk-1-positive mesodermal progenitor cells was performed in type IV collagen (Col IV)- coated dishes in a differentiation medium without LIF. When Col IV-exposed iPS cells were treated with Ang II for 5 days, the expression of Flk-1 was significantly increased compared with that in the cells treated with the vehicle alone. Pretreatment of the cells with both candesartan and SB203580 (a p38 MAPK inhibitor) significantly inhibited the Ang II- induced increase in Flk-1 expression

  9. New therapies for arterial hypertension.

    Science.gov (United States)

    Pagliaro, Beniamino; Santolamazza, Caterina; Rubattu, Speranza; Volpe, Massimo

    2016-03-01

    Arterial hypertension is the most common chronic disease in developed countries and it is the leading risk factor for stroke, ischemic heart disease, congestive heart failure, chronic renal failure and peripheral artery disease. Its prevalence appears to be about 30-45% of the general population. Recent European guidelines estimate that up to 15-20% of the hypertensive patients are not controlled on a dual antihypertensive combination and they require three or more different antihypertensive drug classes to achieve adequate blood pressure control. The guidelines confirmed that diuretics, beta-blockers, calcium-channel blockers, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are suitable for the initiation and maintenance of antihypertensive treatment, either as monotherapy or in combination therapy. Very few antihypertensive agents have reached the market over the last few years, but no new therapeutic class has really emerged. The long-term adherence to cardiovascular drugs is still low in both primary and secondary prevention of cardiovascular diseases. In particular, the issue of compliance is persistently high in hypertension, despite the fixed-dose combination therapy. As a consequence, a cohort of high-risk hypertensive population, represented by patients affected by refractory and resistant hypertension, can be identified. Therefore, the need of controlling BP in high-risk patients may be addressed, in part, by the development of new drugs, devices and procedures that are designed to treat hypertension and comorbidities. In this review we will comprehensively discuss the current literature on recent therapeutic advances in hypertension, including both medical therapy and interventional procedures.

  10. Organisation and functional role of the brain angiotensin system

    Directory of Open Access Journals (Sweden)

    Catherine Llorens-Cortes

    2002-03-01

    Full Text Available The discovery that all components of the renin-angiotensin system (RAS are present in the brain led investigators to postulate the existence of a local brain RAS. Supporting this, angiotensin immunoreactive neurones have been visualised in the brain. Two major pathways were described: a forebrain pathway which connects circumventricular organs to the median preoptic nucleus, paraventricular and supraoptic nuclei, and a second pathway connecting the hypothalamus to the medulla oblongata. Blood-brain-barrier deficient circumventricular organs are rich in angiotensin II (Ang II receptors. By activating these receptors, circulating Ang II may act on central cardiovascular centres via angiotensinergic neurones, providing a link between peripheral and central Ang II systems. Among the effector peptides of the brain RAS, Ang II and angiotensin III (Ang III have the same affinity for type 1 and type 2 Ang II receptors. When injected into the brain, both peptides increase blood pressure (BP, water intake and pituitary hormone release and may modify learning and memory. Since Ang II is converted in vivo to Ang III, the nature of the true effector is unknown. This review summarises new insights into the predominant role of brain Ang III in the control of BP and underlines the fact that brain aminopeptidase A, the enzyme forming central Ang III, could constitute a putative central therapeutic target for the treatment of hypertension.

  11. Reappraisal of role of angiotensin receptor blockers in cardiovascular protection

    Directory of Open Access Journals (Sweden)

    Ram CV

    2011-05-01

    Full Text Available C Venkata S RamTexas Blood Pressure Institute, Clinical Research Institute of Dallas Nephrology Associates; and Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USAAbstract: Angiotensin-converting enzyme inhibitors (ACEIs and angiotensin receptor blockers (ARBs have shown cardioprotective and renoprotective properties. These agents are recommended as first-line therapy for the treatment of hypertension and the reduction of cardiovascular risk. Early studies pointed to the cardioprotective and renoprotective effects of ARBs in high-risk patients. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET established the clinical equivalence of the cardioprotective and renoprotective effects of telmisartan and ramipril, but did not find an added benefit of the combination over ramipril alone. Similar findings were observed in the Telmisartan Randomized AssessmeNt Study in aCE INtolerant subjects with cardiovascular Disease (TRANSCEND trial conducted in ACEI-intolerant patients. In ONTARGET, telmisartan had a better tolerability profile with similar renoprotective properties compared with ramipril, suggesting a potential clinical benefit over ramipril. The recently completed Olmesartan Reducing Incidence of Endstage Renal Disease in Diabetic Nephropathy Trial (ORIENT and Olmesartan and Calcium Antagonists Randomized (OSCAR studies will further define the role of ARBs in cardioprotection and renoprotection for high-risk patients.Keywords: angiotensin receptor blockers, hypertension, outcomes, clinical trials

  12. Selective endothelial overexpression of arginase II induces endothelial dysfunction and hypertension and enhances atherosclerosis in mice.

    Directory of Open Access Journals (Sweden)

    Boris L Vaisman

    Full Text Available Cardiovascular disorders associated with endothelial dysfunction, such as atherosclerosis, have decreased nitric oxide (NO bioavailability. Arginase in the vasculature can compete with eNOS for L-arginine and has been implicated in atherosclerosis. The aim of this study was to evaluate the effect of endothelial-specific elevation of arginase II expression on endothelial function and the development of atherosclerosis.Transgenic mice on a C57BL/6 background with endothelial-specific overexpression of human arginase II (hArgII gene under the control of the Tie2 promoter were produced. The hArgII mice had elevated tissue arginase activity except in liver and in resident peritoneal macrophages, confirming endothelial specificity of the transgene. Using small-vessel myography, aorta from these mice exhibited endothelial dysfunction when compared to their non-transgenic littermate controls. The blood pressure of the hArgII mice was 17% higher than their littermate controls and, when crossed with apoE -/- mice, hArgII mice had increased aortic atherosclerotic lesions.We conclude that overexpression of arginase II in the endothelium is detrimental to the cardiovascular system.

  13. Severe hepatic encephalopathy in a patient with liver cirrhosis after administration of angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker combination therapy: a case report

    Directory of Open Access Journals (Sweden)

    Podda Mauro

    2010-05-01

    Full Text Available Abstract Introduction A combination therapy of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers has been used to control proteinuria, following initial demonstration of its efficacy. However, recently concerns about the safety of this therapy have emerged, prompting several authors to urge for caution in its use. In the following case report, we describe the occurrence of a serious and unexpected adverse drug reaction after administration of a combination of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers to a patient with nephrotic syndrome and liver cirrhosis with severe portal hypertension. Case presentation We administered this combination therapy to a 40-year-old Caucasian man with liver cirrhosis in our Hepatology Clinic, given the concomitant presence of glomerulopathy associated with severe proteinuria. While the administration of one single drug appeared to be well-tolerated, our patient developed severe acute encephalopathy after the addition of the second one. Discontinuation of the therapy led to the disappearance of the side-effect. A tentative rechallenge with the same drug combination led to a second episode of acute severe encephalopathy. Conclusion We speculate that this adverse reaction may be directly related to the effect of angiotensin II on the excretion of blood ammonia. Therefore, we suggest that patients with liver cirrhosis and portal hypertension are at risk of developing clinically relevant encephalopathy when angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker combination therapy is administered, thus indicating the need for a careful clinical follow-up. In addition, the incidence of this serious side-effect should be rigorously evaluated in all patients with liver cirrhosis administered with this common treatment combination.

  14. Association of α-adducin and angiotensin converting enzyme gene polymorphisms with salt-sensitive hypertension and early renal injury%α-内收蛋白基因、血管紧张素转换酶基因多态性与盐敏感性高血压及其早期肾损害的相关性

    Institute of Scientific and Technical Information of China (English)

    卢荔红; 陈慧; 俞玲; 骆杰伟; 吴小盈; 杨柳青

    2008-01-01

    目的 探讨α-内收蛋白(α-adducin)基因G460T和血管紧张素转换酶(angiotensin converting enzyme,AcE)基因插入或缺失(insertion/detetion,I/D)多态性与汉族盐敏感性高血压(salt-sensitive hypertension,SSHT)及早期肾损害的关系.方法 用改良的Sullivan's法(急性口服盐水负荷试验)将200例原发性高血压(essential hypertension,EH)患者分为盐敏感109例和非盐敏感91例,用PCR检测ACE基因I/D多态性基因型,聚合酶链反应-限制性片段长度多态性方法检测α-adducin基因型,用放射免疫法检测晨尿微量白蛋白.结果 (1)EH组的α-adducin基因TT型频率显著高于健康对照组(200名)(P<0.05),而EH组和对照组ACE I/D基因型分布差异无统计学意义(P>0.05);盐敏感组的α-adducin基因TT型、α-adducin基因TT+ACE Ⅱ型频率显著高于非盐敏感组(P<0.05).(2)盐敏感组尿微量白蛋白/尿肌酐显著高于非盐敏感组(P<0.05);盐敏感组的ACE Ⅱ型尿微量白蛋白/尿肌酐显著高于ID、DD型(P<0.05),α-adducin基因TT型尿微量白蛋白/尿肌酐显著高于GT、GG型(P<0.05),α-adduein基因TT+ACE基因Ⅱ型尿微量自蛋白/尿肌酐显著高于其它基因组合型(P<0.05).结论 α-adducin基因TT基因型或与ACE基因Ⅱ型协同可能是SSHT的遗传标志之一,可能是SSHT早期肾损害的遗传易感因素.%Objective To investigate the association between the α-adducin gene G460T,angiotensin converting enzyme(ACE)insertion/deletion(I/D)polymorphisms and salt-sensitive hypertension and early renal injury in Chinese people.Methods The case-control study was performed in 200 essential hypertension(EH)and 200 normal control subjects in China.The 200 EH patients were divided into salt-sensitive(SS=109)and non-salt-sensitive(NSS=91)groups according to modified Sullivan's method.The genotypes of α-adducin gene were determined by polymerase chain reaction-restriction fragment length pelymorphism(PCR-RFLP).The ACE genotypes

  15. Ets-1 upregulation mediates angiotensin II-related cardiac fibrosis.

    Science.gov (United States)

    Hao, Guanghua; Han, Zhenhua; Meng, Zhe; Wei, Jin; Gao, Dengfeng; Zhang, Hong; Wang, Nanping

    2015-01-01

    Ets-1, the prototypical member of the family of Ets transcription factors, has been shown to participate in tissue fibrotic remodeling. However, its role in cardiac fibrosis has not been established. The aim of this study was to investigate the role of Ets-1 in profibrotic actions of angiotensin II (Ang II) in cardiac fibroblasts (CFs) and in the in vivo heart. In growth-arrested CFs, Ang II induced Ets-1 expression in a time- and concentration-dependent manner. Pretreatment with Ang II type 1 receptor blocker losartan, protein kinase C inhibitor bisindolylmaleimide I, extracellular signal-regulated kinase (ERK) inhibitor PD98059, or c-Jun NH(2)-terminal kinase (JNK) inhibitor SP600125 partly inhibited this induction accompanied with impaired cell proliferation and production of plasminogen activator inhibitor-1 (PAI-1) and connective tissue growth factor (CTGF) protein, the two downstream targets of Ets-1. Knockdown of Ets-1 by siRNA significantly inhibited the inductive effects of Ang II on cell proliferation and expression of CTGF and PAI-1. Moreover, the levels of Ets-1, PAI-1 and CTGF protein were simultaneously upregulated in left ventricle of Ang II-infused rats in parallel with an increase in the activation of ERK and JNK. Our data suggest that Ets-1 may mediate Ang II-induced cardiac fibrotic effects.

  16. The Soluble Epoxide Hydrolase Inhibitor AR9281 Decreases Blood Pressure, Ameliorates Renal Injury and Improves Vascular Function in Hypertension

    Directory of Open Access Journals (Sweden)

    Sean Shaw

    2009-12-01

    Full Text Available Soluble epoxide hydrolase inhibitors (sEHIs are demonstrating promise as potential pharmaceutical agents for the treatment of cardiovascular disease, diabetes, inflammation, and kidney disease. The present study determined the ability of a first-inclass sEHI, AR9281, to decrease blood pressure, improve vascular function, and decrease renal inflammation and injury in angiotensin hypertension. Rats were infused with angiotensin and AR9281 was given orally during the 14-day infusion period. Systolic blood pressure averaged 180 ± 5 mmHg in vehicle treated and AR9281 treatment significantly lowered blood pressure to 142 ± 7 mmHg in angiotensin hypertension. Histological analysis demonstrated decreased injury to the juxtamedullary glomeruli. Renal expression of inflammatory genes was increased in angiotensin hypertension and two weeks of AR9281 treatment decreased this index of renal inflammation. Vascular function in angiotensin hypertension was also improved by AR9281 treatment. Decreased afferent arteriolar and mesenteric resistance endothelial dependent dilator responses were ameliorated by AR9281 treatment of angiotensin hypertensive rats. These data demonstrate that the first-in-class sEHI, AR9281, lowers blood pressure, improves vascular function and reduces renal damage in angiotensin hypertension.

  17. Case–control association study of polymorphisms in the angiotensinogen and angiotensin-converting enzyme genes and coronary artery disease and systemic artery hypertension in African-Brazilians and Caucasian-Brazilians

    Indian Academy of Sciences (India)

    Ricardo Bonfim-Silva; Larissa Oliveira Guimarães; Jandson Souza Santos; Jaqueline Fagundes Pereira; Ana Angélica Leal Barbosa; Domingos Lazaro Souza Rios

    2016-03-01

    The rennin–angiotensin–aldosterone system (RAAS) is a critical pathway in regulating blood pressure and salt/water homeostasis, possessing an intimate relationship with the development of systemic artery hypertension (SAH). Once hypertension is considered a risk factor for coronary artery disease (CAD), the RAAS is also related to this pathology. This investigation aimed to analyse if the frequencies of AGT M235T (rs699) and ACE I/D (rs4646994) polymorphisms are associated with CAD and SAH in African-Brazilians and Caucasian-Brazilians. In this study we analysed 714 subjects who underwent coronary angiography to detect obstructive lesions and CAD, as well as blood pressure measurement and SAH, grouped according to ethnicity: 266 African-Brazilians and 448 Caucasian-Brazilians. Among CAD and SAH cases and controls, the genotype and allele frequencies of ACE I/D polymorphism were similar in both ethnic groups. The AGT 235TT genotype and 235T allele frequencies were higher in SAH cases (32%, 54.7%) versus controls in Caucasian-Brazilians (19.8%, 46.4%; = 0.038, = 0.031, respectively). The AGT 235TT (OR = 1.8; = 0.028) demonstrated to be an independent factor risk in a multivariate logistic regression increasing SAH risk in Caucasians but not in African-Brazilians. In summary, AGT M235T polymorphism was associated with SAH risk in Caucasian-Brazilians, and no association was detected with CAD. No association was also observed in ACE I/D polymorphism either in CAD or SAH in African-Brazilians and Caucasian-Brazilians.

  18. [Arteriosclerosis obliterans. Treatment with angiotensin-converting enzyme inhibitors].

    Science.gov (United States)

    Orea, A; Valdés, R; Niebla, L; Rivas, R; Camacho, B

    1990-01-01

    We compare the effects of two of the main angiotensin convertase enzyme inhibitors, captopril and enalapril, aiming to evaluate their effects in the arterial circulation performance, micro-circulation, and changes in regional blood flow, assuming their property of lowering the angiotensin II blood levels, a very strong peripheral vasoconstrictor. We studied 22 patients: all of them with hypertension and/or skin ulcerations, dropping out those who had venous. They were evaluated periodically, clinically and with photoelectric plethysmography of lower extremities. To interpret the traces we designed an ideogram which gathered the plethysmographic behavior before and after the treatment. Nearly 80% showed considerable improvement in pain, functional capacity and plethysmographic traces patterns. healing of the ulcerations was achieved in all case. We propose some hypothesis to explain the good effect that we have observed.

  19. Association between the angiotensin Ⅱ type Ⅰ receptor gene A1166C polymorphism with the essential hypertension in chongqing%AT1R基因A1166C多态性与重庆地区高札压病的相关性研究

    Institute of Scientific and Technical Information of China (English)

    向林; 柳青; 雷寒

    2009-01-01

    目的:研究重庆地区人口血管紧张素Ⅱ的T型受体(Angiotensin Ⅱ type Ⅰ,AT1R)A1166C基因多态性与原发性高血压的关系方法:用多聚酶联反应(Polymerase chain reaction,PCR)结合限制性片段长度多态性(Restriction fragment length poly mor-phism,RFLP)方法对104例原发性高血压(Essentiac hypertension,EH)患者和100例健康体检者进行AT1R(A1166C)的基因多态性分析.结果:EH组AC基因型频率明显高于正常对照组(0.240 vs 0.005,P<0.05),EH组C1166等位基凶频率明显高于正常对照组(0.130 vs0.025,P<0.05);而EH组中的AA基因型频率明显低丁正常对照组(0.750 vs0.950,P<0.05);EH组中还发现了较罕见的CC纯合子基因型.结论:高血压组和正常对照组AT1R基因的AC、AA基因型频率有显著性差异,而其它指标无显著性差异.重庆地区原发性高血压与AT1R基因的A1166C多念性有密切的关系.

  20. The rationale and design of the perindopril genetic association study (PERGENE): A pharmacogenetic analysis of angiotensin-converting enzyme inhibitor therapy in patients with stable coronary artery disease

    NARCIS (Netherlands)

    J.J. Brugts (Jasper); M.P.M. de Maat (Moniek); H. Boersma (Eric); J.C.M. Witteman (Jacqueline); C.M. van Duijn (Cock); A.G. Uitterlinden (André); M.E. Bertrand (Michel); W.J. Remme (Willem); K.M. Fox (Kim); R. Ferrari (Roberto); A.H.J. Danser (Jan); M.L. Simoons (Maarten)

    2009-01-01

    textabstractBackground: Angiotensin-converting enzyme (ACE) inhibitors reduce clinical symptoms and improve outcome in patients with hypertension, heart failure, and stable coronary artery disease (CAD) and are among the most frequently used drugs in these patient groups. For hypertension, treatment

  1. Análise da variabilidade da freqüência cardíaca em pacientes hipertensos, antes e depois do tratamento com inibidores da enzima conversora da angiotensina II Analysis of heart rate variability in hypertensive patients before and after treatment with angiotensin II-converting enzyme inhibitors

    Directory of Open Access Journals (Sweden)

    Antônio da Silva Menezes Júnior

    2004-08-01

    Full Text Available OBJETIVO: Comparar a variabilidade de freqüência cardíaca em indivíduos normotensos e hipertensos e observar o comportamento do sistema nervoso autônomo após terapia com inibidores da enzima conversora de angiotensina II. MÉTODO: Estudados 286 pacientes com diagnóstico de hipertensão arterial, pela 1ª vez, e divididos em 4 grupos, conforme a pressão arterial diastólica (PAD: grupo A - PAD110 mmHg. Os pacientes do grupo A (normais e do grupo C (HA moderada, somando 110 e 79 pacientes, respectivamente, submeteram-se ao Holter-ECG 24h com análise de variabilidade de freqüência cardíaca no domínio do tempo (DT e no domínio da freqüência (DF. O grupo C foi tratado com inibidores da ECA durante 3 meses, e após esse período novamente avaliado com Holter-ECG 24h e variabilidade da freqüência cardíaca, e os valores comparados com os normotensos. RESULTADOS: Os parâmetros SDNN, PNN50 (DT e o espectro LF (DF foram significativamente diferentes para os dois grupos, com valores notadamente diminuídos em hipertensos (pOBJECTIVE: To compare heart rate variability in normotensive and hypertensive individuals and to observe the behavior of the autonomic nervous system after treatment with angiotensin II-converting enzyme inhibitors. METHOD: The study comprised 286 patients diagnosed with arterial hypertension (AH for the first time and divided into 4 groups according to diastolic blood pressure (DBP levels: group A - DBP110 mmHg. Group A (110 healthy individuals and group C (79 patients with moderate AH underwent 24-hour Holter-ECG with analysis of heart rate variability in time domain (TD and frequency domain (FD. The group C patients were treated with ACE inhibitors for 3 months, and, after this period, they underwent a new 24-hour Holter-ECG study for assessing heart rate variability, the values being compared with those of normotensive individuals. RESULTS: The SDNN and PNN50 parameters (TD, and the LF spectrum (FD were

  2. Azilsartan alone and in combination for the treatment of hypertension – clinical utility and patient considerations

    Directory of Open Access Journals (Sweden)

    Jones JD

    2013-08-01

    Full Text Available Jocelyn D Jones,1 Sylvia H Jackson,1 Charlie Colquitt21College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Jacksonville, FL, USA; 2College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tampa, FL, USAAbstract: Hypertension is a common disease that leads to significant cardiovascular morbidity and mortality. Adequate blood pressure control is essential in preventing end organ complications. One of the most popular antihypertensive strategies for the treatment of elevated blood pressure is to attenuate the actions of the renin-angiotensin-aldosterone system. The agents include the angiotensin converting enzyme inhibitors, angiotensin II receptor blockers (ARBs, direct renin inhibitors, and aldosterone antagonists. The ARBs inhibit the action of angiotensin II by binding to the angiotensin II type 1 receptor. The inhibition of angiotensin II results in a dose dependent decrease in peripheral resistance, reduction in vascular smooth muscle contraction, and reduced synthesis of aldosterone in the kidneys. Azilsartan medoxomil is a highly selective ARB. It was approved by the US Food and Drug Administration in February 2011 for the treatment of hypertension in adults. It is the eighth ARB to be added to the market. This article will discuss the pharmacologic and clinical characteristics of azilsartan medoxomil to help differentiate it from other ARBs that are used for the management of hypertension.Keywords: hypertension, azilsartan medoxomil, angiotensin II receptor blocker, ARB

  3. Hyponatremic hypertensive syndrome - a retrospective cohort study

    Science.gov (United States)

    Mukherjee, Devdeep; Sinha, Rajiv; Akhtar, Md Shakil; Saha, Agni Sekhar

    2017-01-01

    AIM To ascertain the frequency of hyponatremic hypertensive syndrome (HHS) in a cohort of children with hypertensive emergency in a tertiary pediatric hospital. METHODS A retrospective review was undertaken among children with hypertensive emergency admitted in our tertiary children hospital between June 2014 and December 2015 with an aim to identify any children with HHS. Three children with HHS were identified during this period. RESULTS The 3 patients with HHS presented with hypertensive emergency. They were initially managed with Labetalol infusion and thereafter switched to oral anti-hypertensives (combination of Nifedipine sustained release, Hydralazine and Beta Blocker). All 3 were diagnosed to have unilateral renal artery stenosis. One child was lost to follow up, whereas the other 2 underwent renal angioplasty which was followed with normalization of blood pressure. CONCLUSION Despite activation of renin angiotensin axis secondary to renal artery stenosis, these groups of children have significant hyponatremia. Renal re-vascularisation produces excellent results in most of them. PMID:28101450

  4. The Prorenin and (Prorenin Receptor: New Players in the Brain Renin-Angiotensin System?

    Directory of Open Access Journals (Sweden)

    Wencheng Li

    2012-01-01

    Full Text Available It is well known that the brain renin-angiotensin (RAS system plays an essential role in the development of hypertension, mainly through the modulation of autonomic activities and vasopressin release. However, how the brain synthesizes angiotensin (Ang II has been a debate for decades, largely due to the low renin activity. This paper first describes the expression of the vasoconstrictive arm of RAS components in the brain as well as their physiological and pathophysiological significance. It then focus on the (prorenin receptor (PRR, a newly discovered component of the RAS which has a high level in the brain. We review the role of prorenin and PRR in peripheral organs and emphasize the involvement of brain PRR in the pathogenesis of hypertension. Some future perspectives in PRR research are heighted with respect to novel therapeutic target for the treatment of hypertension and other cardiovascular diseases.

  5. Angiotensin II, Aldosterone, and Anti-Inflammatory Lymphocytes: Interplay and Therapeutic Opportunities

    Directory of Open Access Journals (Sweden)

    Daniel Arthur B. Kasal

    2012-01-01

    Full Text Available Inflammation is recognized as an important factor in the pathophysiology of hypertension, with the renin-angiotensin-aldosterone system (RAAS playing a key role in the disease. Initially described because of its contribution to extracellular fluid and electrolyte homeostasis, the RAAS has been implicated in endothelial dysfunction, vascular remodeling, oxidative stress, proinflammatory cytokine production, and adhesion molecule synthesis by the vascular wall. Both angiotensin II and aldosterone are involved in these systemic effects, activating innate and adaptive immune responses. This paper highlights some aspects connecting RAAS to the hypertensive phenotype, based on experimental and clinical studies, with emphasis on new findings regarding the contribution of an increasingly studied population of T lymphocytes: the T-regulatory lymphocytes. These cells can suppress inflammation and may exert beneficial vascular effects in animal models of hypertension.

  6. Angiotensin II increases CTGF expression via MAPKs/TGF-{beta}1/TRAF6 pathway in atrial fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Jun [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Liu, Xu, E-mail: xkliuxu@yahoo.cn [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Wang, Quan-xing, E-mail: shmywqx@126.com [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Tan, Hong-wei [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China); Guo, Meng [National Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai (China); Jiang, Wei-feng; Zhou, Li [Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University School of medicine, Shanghai (China)

    2012-10-01

    The activation of transforming growth factor-{beta}1(TGF-{beta}1)/Smad signaling pathway and increased expression of connective tissue growth factor (CTGF) induced by angiotensin II (AngII) have been proposed as a mechanism for atrial fibrosis. However, whether TGF{beta}1/non-Smad signaling pathways involved in AngII-induced fibrogenetic factor expression remained unknown. Recently tumor necrosis factor receptor associated factor 6 (TRAF6)/TGF{beta}-associated kinase 1 (TAK1) has been shown to be crucial for the activation of TGF-{beta}1/non-Smad signaling pathways. In the present study, we explored the role of TGF-{beta}1/TRAF6 pathway in AngII-induced CTGF expression in cultured adult atrial fibroblasts. AngII (1 {mu}M) provoked the activation of P38 mitogen activated protein kinase (P38 MAPK), extracellular signal-regulated kinase 1/2(ERK1/2) and c-Jun NH(2)-terminal kinase (JNK). AngII (1 {mu}M) also promoted TGF{beta}1, TRAF6, CTGF expression and TAK1 phosphorylation, which were suppressed by angiotensin type I receptor antagonist (Losartan) as well as p38 MAPK inhibitor (SB202190), ERK1/2 inhibitor (PD98059) and JNK inhibitor (SP600125). Meanwhile, both TGF{beta}1 antibody and TRAF6 siRNA decreased the stimulatory effect of AngII on TRAF6, CTGF expression and TAK1 phosphorylation, which also attenuated AngII-induced atrial fibroblasts proliferation. In summary, the MAPKs/TGF{beta}1/TRAF6 pathway is an important signaling pathway in AngII-induced CTGF expression, and inhibition of TRAF6 may therefore represent a new target for reversing Ang II-induced atrial fibrosis. -- Highlights: Black-Right-Pointing-Pointer MAPKs/TGF{beta}1/TRAF6 participates in AngII-induced CTGF expression in atrial fibroblasts. Black-Right-Pointing-Pointer TGF{beta}1/TRAF6 participates in AngII-induced atrial fibroblasts proliferation. Black-Right-Pointing-Pointer TRAF6 may represent a new target for reversing Ang II-induced atrial fibrosis.

  7. Angiotensin II reactivation and aldosterone escape phenomena in renin-angiotensin-aldosterone system blockade: is oral renin inhibition the solution?

    Science.gov (United States)

    Athyros, Vasilios G; Mikhailidis, Dimitri P; Kakafika, Anna I; Tziomalos, Konstantinos; Karagiannis, Asterios

    2007-04-01

    This editorial considers the use of the first selective oral renin inhibitor, aliskiren, in reducing angiotensin (Ang) II reactivation or aldosterone (ALDO) escape during renin-angiotensin-aldosterone system (RAAS) inhibition. RAAS blockade with angiotensin converting enzyme inhibitors (ACEIs) and/or angiotensin receptor AT(1) blockers (ARBs) is very useful for the treatment of arterial hypertension, chronic heart failure (CHF), atherosclerosis and diabetes. 'Ang II reactivation' and 'ALDO escape' or 'breakthrough' have been observed during either ACEI or ARB treatment, and may attenuate the clinical benefit of RAAS blockade. Renin and Ang I accumulate during ACE inhibition, and might overcome the ability of an ACEI to effectively suppress ACE activity. There is also data suggesting that 30 - 40% of Ang II formation in the healthy human during RAAS activation is formed via renin-dependent, but ACE-independent, pathways. Moreover, ACE gene polymorphisms contribute to the modulation and adequacy of the neurohormonal response to long-term ACE inhibition, at least in patients with CHF (up to 45% of CHF patients have elevated Ang II levels despite the long-term use of an ACEI) or diabetes. The reactivated Ang II promotes ALDO secretion and sodium reabsorption. ALDO breakthrough also occurs during long-term ARB therapy, mainly by an AT(2)-dependent mechanism. This was related to target-organ damage in animal models. Oral renin inhibition with aliskiren has showed excellent efficacy and safety in the treatment of hypertension. Aliskiren can be co-administered with ACEIs, ARBs or hydrochlorothiazide. Furthermore, there is evidence suggesting that aliskiren reduces Ang II reactivation in ACE inhibition and ALDO escape during treatment with an ACEI or an ARB, at least to the degree that this is associated with the RAAS. For RAAS-independent ALDO production, the combination of aliskiren with eplerenone might prove useful.

  8. Association of angiotensin converting enzyme 2 gene polymorphisms with essential hypertension%ACE2基因多态性与原发性高血压的关系

    Institute of Scientific and Technical Information of China (English)

    张曹进; 单志新; 陈富荣; 符永恒; 衣文君

    2007-01-01

    目的 研究血管紧张素转化酶2(angiotensin converting enzyme 2,ACE2)基因多态性与广东地区原发性高血压的相关性.方法 高血压组选择门诊与住院的汉族无血缘关系的原发性高血压369例,男194例,女175例;对照组为同期体检的广东地区健康汉族居民199例,男101例,女98例.排除冠心病、高血压、糖尿病、脑血管病及肝功能不良、肾功能不良.按照性别分为两组,采用病例对照的原则,应用聚合酶链反应和限制性内切酶片段长度多态性(polymerase chain reaction and restriction fragment length polymorphism,PCR-RFLP)的方法检测ACE2基因G9570A多态性,并随机抽取20份标本进行基因测序以核实基因分型.在分析各亚组的年龄、体重指数、血压及生化指标的基础上综合分析ACE2基因多态性与原发性高血压的关系.结果 高血压组G等位基因频率:男75.3%,对照组男60.4%,差异有统计学意义(χ2=7.0086,P=0.0081),高血压组,女57.4%,对照组45.4%,差异有统计学意义(χ2=6.9443,P=0.0084);女高血压组GG基因型的频率明显高于对照组(χ2=12.9499,P=0.0015);G等位基因人群发生高血压的风险高于A等位基因人群,男OR:1.9945,95% CI:1.1916~3.3385,P=0.0082;女OR:1.603,95% CI:1.1274~2.2792,P=0.0085.结论 ACE2-G9570A多态性与原发性高血压相关;携带G等位基因的男性和仅仅携带G基因的女性人群发生高血压的危险性相对较大,提示ACE2基因可作为原发性高血压的候选易感基因.

  9. Prevention of diabetes in hypertensive patients: Results and implications from the VALUE trial

    Directory of Open Access Journals (Sweden)

    Ming-Sheng Zhou

    2009-04-01

    Full Text Available Ming-Sheng Zhou, Ivonne Hernandez SchulmanNephrology-Hypertension Section, Veterans Affairs Medical Center and Division of Nephrology and Hypertension and Vascular Biology institute, University of Miami Miller School of Medicine, Miami, FL, USAAbstract: A growing number of experimental and clinical studies have provided evidence indicating that pharmacological blockade of the renin–angiotensin system (RAS by either angiotensin-converting enzyme inhibitors or angiotensin type 1 receptor blockers reduces the incidence of new onset type 2 diabetes in subjects with hypertension and/or cardiovascular disease, independently of antihypertensive and cardiovascular protective effects. The beneficial effects of RAS inhibition on the development of diabetes have been largely attributed to improvements in peripheral insulin sensitivity and glucose metabolism. This review focuses on recent experimental and clinical evidence supporting the role of RAS inhibition in the reduction of new onset type 2 diabetes and the mechanisms that may be involved.Keywords: renin–angiotensin system, antihypertensive, diabetes

  10. Effect of angiotensin Ⅱ and angiotensin Ⅱ type 1 receptor antagonist on the proliferation,contraction and collagen synthesis in rat hepatic stellate cells

    Institute of Scientific and Technical Information of China (English)

    LIU Jun; GONG Hao; ZHANG Zhong-tao; WANG Yu

    2008-01-01

    Background Angiotensin Ⅱ(Ang Ⅱ)is a very important vasoactive peptide that acts upon hepatic stellate cells(HSCs),which are major effector cells in hepatic cirrhosis and portal hypertension.The present study was aimed to investigate the effects of Ang Ⅱ and angiotensin Ⅱ type 1 receptor antagonist(AT1RA)on the proliferation,contraction and collagen synthesis in HSCs.Methods HSC-T6 rat hepatic stellate cell Iine was studied.The proliferation of the HSC cells was evaluated by MTT colorimetric assay while HSC DNA synthesis was measured by3 H-thymidine incorporation.The effects of angiotensin Ⅱ and AT1 RA on HSCs contraction were studied by analVSIs of the contraction of the collagen Iattice.CelI culture media were analyzed by RT-PCR to detect secretion of collagen Ⅰ(Col Ⅰ),collagen Ⅲ(Col Ⅲ)and transforming growth factor β1 (TGF-β1)by enzyme Iinked Immunosorbent assay.HSC was harvested to measure collagen Ⅰ,collagen Ⅲ and tissue inhibitor of metalloproteinase-1(TIMP-1)mRNA expression.Results Ang Ⅱ((1 x10-10-1×10-4)mol/L)stimulated DNA synthesis and proliferation in HSCs compared with untreated control cells.AT1 RA inhibited angiotensin Ⅱ induced proliferation of HSCs.A Iinear increase in the contractive area of collagen lattice correlated with the concentration of angiotensin Ⅱ(1×10-9-1×10-5mol/L)and with time over 48 hours.ATlRA blocks angiotensin Ⅱ induced contraction of collagen Iattice.Coll,Col Ⅲ and TGF-β1 levels of the Ang Ⅱ group were higher than those of control group and this increase was downregulated by AT1RA.The mRNA expressions of ColⅠ,CoI Ⅲ and TIMP-1 were higher in HSCs from the Ang Ⅱ group than the control group and downregulated by AT1RA.Conclusions Angiotensin Ⅱ increased DNA synthesis and proliferation of HSCs in a dose-dependent manner,stimulated the contraction of HSCs dose-and time-dependently.Angiotensin also promoted excretion of Col Ⅰ,ColⅢand TGF-β1 Ievels and stimulated Col Ⅰ,Col Ⅲ and

  11. The renin angiotensin system in the development of cardiovascular disease: role of aliskiren in risk reduction

    Directory of Open Access Journals (Sweden)

    Paolo Verdecchia

    2008-10-01

    Full Text Available Paolo Verdecchia1, Fabio Angeli1, Giovanni Mazzotta1, Giorgio Gentile2, Gianpaolo Reboldi21Department of Cardiology, Clinical Research Unit ‘Preventive Cardiology’, Hospital ‘Santa Maria della Misericordia’, and Fondazione Umbra Cuore e Ipertensione – AUCI Onlus, Perugia, Italy; 2Department of Internal Medicine University of Perugia, ItalyAbstract: An association has been shown between plasma renin activity (PRA and the risk of cardiovascular disease. There is also evidence that angiotensin II exerts detrimental effects on progression and instabilization of atherosclerotic plaque. The renin-angiotensin system (RAS can be inhibited through inhibition of angiotensin I (Ang I generation from angiotensinogen by direct renin inhibitors, inhibition of angiotensin II (Ang II generation from angiotensin I by angiotensin-converting enzyme inhibitors and finally by direct inhibition of the action of Ang II receptor level. Aliskiren, the first direct renin inhibitor to reach the market, is a lowmolecular-weight, orally active, hydrophilic nonpeptide. Aliskiren blocks Ang I generation, while plasma renin concentration increases because the drugs blocks the negative feed-back exerted by Ang II on renin synthesis. Because of its long pharmacological half-life, aliskiren is suitable for once-daily administration. Its through-to-peak ratio approximates 98% for the 300 mg/day dose. Because of its mechanism of action, aliskiren might offer the additional opportunity to inhibit progression of atherosclerosis at tissue level. Hypertension is an approved indication for this drug, which is also promising for the treatment of heart failure. The efficacy of this drug in reducing major clinical events is being tested in large ongoing clinical trials.Keywords: plasma renin activity, renin angiotensin system, aliskiren, angiotensinogen, renin, hypertension, heart failure, diabetes

  12. Hepatocyte Growth Factor Inhibits Apoptosis by the Profibrotic Factor Angiotensin II via Extracellular Signal-regulated Kinase 1/2 in Endothelial Cells and Tissue Explants

    Science.gov (United States)

    2010-12-01

    II via Extracellular Signal-regulated Kinase 1/2 in Endothelial Cells and Tissue Explants Young H. Lee, Ana P. Marquez , Ognoon Mungunsukh, and Regina...L., Gonzalez- Garcia , M., Page, C., Herrera, R., and Nunez, G. (1997). Interleukin-3-induced phosphorylation of BAD through the protein kinase Akt... Marquez , A. P., and Day, R. M. (2010). Angiotensin-II-induced apoptosis requires regulation of nucleolin and Bcl-xL by SHP-2 in primary lung endothelial

  13. The Fetal Safety of Angiotensin Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers

    Directory of Open Access Journals (Sweden)

    Myla E. Moretti

    2012-01-01

    Full Text Available Angiotensin converting enzyme (ACE inhibitors and angiotensin II receptor blockers (ARBs are known to cause fetal renal damage in pregnancy. Due to conflicting reports in the literature, their safety after first trimester exposure has been debated. Our aim was to determine whether the use of ACE inhibitors or ARBs in the first trimester of pregnancy is associated with an increased risk for major malformations or other adverse outcomes. All subjects were prospectively enrolled from among women contacting a teratogen information service. At initial contact, details of maternal medical history and exposures were collected and follow-up interviews were conducted to ascertain pregnancy outcomes. Two comparator groups, women with hypertension treated with other antihypertensives, and healthy controls were also recruited. Baseline maternal characteristics were not different among the three groups. There were no differences in rates of major malformations. Both the ACE-ARBs and disease-matched groups exhibited significantly lower birth weight and gestational ages than the healthy controls (P<0.001 for both variables. There was a significantly higher rate of miscarriage noted in the ACE/ARB group (P<0.001. These results suggest that ACE inhibitors/ARBs are not major human teratogens; however, they may be associated with an increased risk for miscarriage.

  14. Increased intracellular free calcium and sensitivity to angiotensin II in platelets of preeclamptic women.

    Science.gov (United States)

    Haller, H; Oeney, T; Hauck, U; Distler, A; Philipp, T

    1989-04-01

    Preeclampsia is characterized by a generalized vasoconstriction and increased vascular sensitivity to angiotensin II. Intracellular free calcium, implicated in vascular smooth muscle contraction, has been found to be elevated in platelets of other hypertensive disorders. We therefore measured intracellular free calcium concentrations by using the fluorescent probe quin-2 in platelets of six patients with preeclampsia and compared them to measurements in ten normotensive pregnant women and ten age-matched nonpregnant women. Intracellular free calcium was also determined in the preeclamptic women after delivery. We found that intracellular free calcium was slightly elevated in normal pregnancy (102 +/- 13 nmol/L v 87 +/- 17 nmol/L) but was markedly increased in preeclampsia (138 +/- 13 nmol/L, P less than .05). This increase disappeared six weeks after delivery (84 + 10 nmol/L, P less than .01). To investigate whether the increased intracellular free calcium was related to angiotensin II, the platelets were exposed to thrombin and angiotensin II in vitro. Exposure to thrombin and angiotensin II caused a dose-dependent increase in intracellular free calcium. The intracellular response to thrombin was not significantly different in the three groups. However, stimulation with angiotensin II revealed an increased response in intracellular free calcium in preeclampsia (P less than .05) that disappeared after delivery. Our findings show a sustained increase in platelet intracellular free calcium in preeclampsia and suggest a functional alteration of the angiotensin II receptor in this disease.

  15. Effect of angiotensin converting enzyme genetic polymorphism on cardiovascular response to endotracheal intubation in patients with hypertension%血管紧张素转换酶基因多态性对高血压患者气管插管心血管反应的影响

    Institute of Scientific and Technical Information of China (English)

    项玲; 王军; 曾因明; 王晓峰; 金月华; 邓波

    2012-01-01

    Objective To investigate the effect of angiotensin converting enzyme (ACE) genetic polymorphism on the cardiovascular response to endotracheal intubation in patients with hypertension.Methods The patients with primary hypertension,ASA Ⅱ or Ⅲ,aged 54-64 yr,weighing 50-70 kg,scheduled for elective operation under general anesthesia,were enrolled in this study.Polymerase chain reaction-restriction fragment length polymorphism was used to detect the polymorphism of ACE gene.The patients were assigned into 3 groups according to their genotypes:homozygote DD group (group DD),heterozygote ID group (group ID),and homozygote Ⅱ group (group Ⅱ).Systolic blood pressure (SBP),diastolic blood pressure (DBP) and heart rate (HR) were recorded before and after induction of anesthesia,and at 0,1.5 and 5.0 min after intubation (T0-4).The rate-pressure product (RPP) was calculated.The cardiovascular events were recorded.Results In groups DD,ID and Ⅱ,40,39 and 40 cases were included in the analysis respectively.Compared with group ID,there was no significant difference in SBP,DBP,HR and RPP at T0-4 in group DD (P > 0.05).Compared with groups DD and ID,SBP,DBP,HR and RPP were significantly deceased at T2,3,and SBP,HR and RPP were significantly deceased at T4 in group Ⅱ (P < 0.05).The incidences of the myocardial ischemia during intubation and cardiovascular response to intubation were significantly lower in group C than in groups DD and ID (P < 0.05).Conclusion ACE genetic polymorphism exerts an effect on the cardiovascular response to endotracheal intubation in patients with hypertension,and homozygote DD and heterozygote ID have the most influence.%目的 评价血管紧张素转换酶多态性对高血压患者气管插管心血管反应的影响.方法 择期全麻手术的原发性高血压患者,体重50~ 70 kg,ASA分级Ⅱ或Ⅲ级.根据血管紧张素转换酶(ACE)基因型进行分组:DD基因型组(DD组)、ID基因型组(ID组)和Ⅱ基

  16. Low K⁺ current in arterial myocytes with impaired K⁺-vasodilation and its recovery by exercise in hypertensive rats.

    Science.gov (United States)

    Seo, Eun Yeong; Kim, Hae Jin; Zhao, Zai Hao; Jang, Ji Hyun; Jin, Chun Zi; Yoo, Hae Young; Zhang, Yin-Hua; Kim, Sung Joon

    2014-11-01

    K(+) channels determine the plasma membrane potential of vascular myocytes, influencing arterial tone. In many types of arteries, a moderate increase in [K(+)]e induces vasorelaxation by augmenting the inwardly rectifying K(+) channel current (I Kir). K(+)-vasodilation matches regional tissue activity and O2 supply. In chronic hypertension (HT), small arteries and arterioles undergo various changes; however, ion channel remodeling is poorly understood. Here, we investigated whether K(+) channels and K(+)-induced vasodilation are affected in deep femoral (DFA) and cerebral artery (CA) myocytes of angiotensin II-induced hypertensive rats (Ang-HT). Additionally, we tested whether regular exercise training (ET) restores HT-associated changes in K(+) channel activity. In Ang-HT, both the voltage-gated K(+) channel current (I Kv) and I Kir were decreased in DFA and CA myocytes, and were effectively restored and further increased by combined ET for 2 weeks (HT-ET). Consistently, K(+)-vasodilation of the DFA was impaired in Ang-HT, and recovered in HT-ET. Interestingly, ET did not reverse the decreased K(+)-vasodilation of CA. CA myocytes from the Ang-HT and HT-ET groups demonstrated, apart from K(+) channel changes, an increase in nonselective cationic current (I NSC). In contrast, DFA myocytes exhibited decreased I NSC in both the Ang-HT and HT-ET groups. Taken together, the decreased K(+) conductance in Ang-HT rats and its recovery by ET suggest increased peripheral arterial resistance in HT and the anti-hypertensive effects of ET, respectively. In addition, the common upregulation of I NSC in the CA in the Ang-HT and HT-ET groups might imply a protective adaptation preventing excessive cerebral blood flow under HT and strenuous exercise.

  17. Pretreatment renal vascular tone predicts the effect of specific renin inhibition on natriuresis in essential hypertension

    NARCIS (Netherlands)

    van Paassen, P; Navis, GJ; de Jong, PE; de Zeeuw, D

    1999-01-01

    Background In essential hypertension an elevated renal vascular resistance (RVR) may be a marker of renin-angiotensin-aldosterone system-mediated impairment of renal sodium excretion. This hypothesis was tested by investigating whether, in subjects with essential hypertension, the natriuretic respon

  18. Therapeutic embolization of renal artery to control severe hypertension due to renal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Cotroneo, A.R.; Patane, D.; De Cinque, M.; Falappa, P.; Doglietto, G.

    1987-05-01

    In a young patient with a post-traumatic renal hematoma, severe systemic hypertension, secondary to the activation of the renin-angiotensin axis, developed. Because of persistent hypertension, after 3 months of drug therapy, selective percutaneous embolization of the damaged vessels was performed. One year after procedure, the patient is normotensive without drugs.

  19. Portal Hypertension

    Science.gov (United States)

    ... Obesity to Liver Cancer Additional Content Medical News Portal Hypertension By Steven K. Herrine, MD, Thomas Jefferson ... Liver Hepatic Encephalopathy Jaundice in Adults Liver Failure Portal Hypertension (See also Overview of Liver Disease .) Portal ...

  20. Hypertensive Crisis

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Hypertensive Crisis: When You Should Call 9-1-1 for ... 18,2017 Know the two types of HBP crisis to watch for A hypertensive ( high blood pressure ) ...

  1. New approaches in the treatment of hypertension.

    Science.gov (United States)

    Oparil, Suzanne; Schmieder, Roland E

    2015-03-13

    Hypertension is the most common modifiable risk factor for cardiovascular disease and death, and lowering blood pressure with antihypertensive drugs reduces target organ damage and prevents cardiovascular disease outcomes. Despite a plethora of available treatment options, a substantial portion of the hypertensive population has uncontrolled blood pressure. The unmet need of controlling blood pressure in this population may be addressed, in part, by developing new drugs and devices/procedures to treat hypertension and its comorbidities. In this Compendium Review, we discuss new drugs and interventional treatments that are undergoing preclinical or clinical testing for hypertension treatment. New drug classes, eg, inhibitors of vasopeptidases, aldosterone synthase and soluble epoxide hydrolase, agonists of natriuretic peptide A and vasoactive intestinal peptide receptor 2, and a novel mineralocorticoid receptor antagonist are in phase II/III of development, while inhibitors of aminopeptidase A, dopamine β-hydroxylase, and the intestinal Na(+)/H(+) exchanger 3, agonists of components of the angiotensin-converting enzyme 2/angiotensin(1-7)/Mas receptor axis and vaccines directed toward angiotensin II and its type 1 receptor are in phase I or preclinical development. The two main interventional approaches, transcatheter renal denervation and baroreflex activation therapy, are used in clinical practice for severe treatment resistant hypertension in some countries. Renal denervation is also being evaluated for treatment of various comorbidities, eg, chronic heart failure, cardiac arrhythmias and chronic renal failure. Novel interventional approaches in early development include carotid body ablation and arteriovenous fistula placement. Importantly, none of these novel drug or device treatments has been shown to prevent cardiovascular disease outcomes or death in hypertensive patients.

  2. Treatment Resistant Hypertension.

    Science.gov (United States)

    Egan, Brent M

    2015-11-05

    Treatment resistant hypertension (TRH) is defined by office blood pressure (BP) uncontrolled on ≥ 3 or controlled on ≥ 4 antihypertensive medications, preferably at optimal doses and including a diuretic. Apparent (a)TRH is used when optimal therapy, adherence, and measurement artifacts are unknown. Among treated hypertensives, ~30% of uncontrolled and 10% of controlled individuals have aTRH, with a higher prevalence in Blacks than other race-ethnicity groups. In ≥ 50% of aTRH patients, BP measurement artifacts ('office' TRH), suboptimal regimens, or suboptimal adherence are present, ie, pseudo-resistance. While patients with 'office' TRH have fewer cardiovascular events than those with 'true' TRH, no evidence confirms that patients with suboptimal regimens or adherence are spared. Averaging several office BPs obtained with an automated monitor can reduce 'office' TRH. Home or ambulatory BP monitoring can identify office resistance. Prescribing ≥ 3 different antihypertensive medication classes, eg, thiazide-type diuretic, renin-angiotensin blocker and calcium antagonist at ≥ 50% of maximum recommended doses reasonably defines optimal therapy. Intensifying diuretic therapy, eg, adding an aldosterone antagonist, is effective for many TRH patients who are volume expanded. Clinical information, hemodynamic and renin-guided therapeutics can inform other treatment options. Attention to adverse effects, medication costs, and pill burden can improve adherence and control. Patients with aTRH and suspected secondary hypertension should be evaluated. Interfering substances or medications should be discontinued. These approaches will identify or correct the problem in ~80% of aTRH patients. Referral to a hypertension specialist and newer therapeutic approaches are options for TRH patients who cannot take or do not respond to optimal therapy.

  3. Liver cirrhosis and arterial hypertension

    Institute of Scientific and Technical Information of China (English)

    Jens H Henriksen; Soren Moller

    2006-01-01

    Characteristic findings in patients with cirrhosis are vasodilatation with low overall systemic vascular resistance, high arterial compliance, increased cardiac output, secondary activation of counter-regulatory systems (renin-angiotensin-aldosterone system,sympathetic nervous system, release of vasopressin),and resistance to vasopressors. The vasodilatory state is mediated through adrenomedullin, calcitonin generelated peptide, nitric oxide, and other vasodilators,and is most pronounced in the splanchnic area.This constitutes an effective (although relative)counterbalance to increased arterial blood pressure.This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development of cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most likely includes the combination of vasodilatation and vasoconstriction in parallel.

  4. Angiotensin converting enzyme 2 and atherosclerosis.

    Science.gov (United States)

    Wang, Yutang; Tikellis, Chris; Thomas, Merlin C; Golledge, Jonathan

    2013-01-01

    Angiotensin converting enzyme 2 (ACE2) is a homolog of angiotensin converting enzyme (ACE) which generates angiotensin II from angiotensin I. ACE, its product angiotensin II and the downstream angiotensin type I receptor are important components of the renin-angiotensin system (RAS). Angiotensin II, the most important component of the RAS, promotes the development of atherosclerosis. The identification of ACE2 in 2000 opened a new chapter of research on the regulation of the RAS. ACE2 degrades pro-atherosclerotic angiotensin II and generates anti-atherosclerotic angiotensin 1-7. In this review, we explored the importance of ACE2 in protecting experimental animals from developing atherosclerosis and its involvement in human atherosclerosis. We also examined the published evidence assessing the importance of ACE2 in different cell types relevant to atherosclerosis and putative underlying cellular and molecular mechanisms linking ACE2 with protection from atherosclerosis. ACE2 shifts the balance from angiotensin II to angiotensin 1-7 inhibiting the progression of atherosclerosis in animal models.

  5. 血管紧张素Ⅱ-1型受体基因多态性与老年原发性高血压水平的关系%Relationship between angiotensin II type 1 receptor gene polymorphism and blood pressure levels in essential hypertensive elders

    Institute of Scientific and Technical Information of China (English)

    张怡; 陆惠华; 方宁远; 邬亦贤; 郑迪辉; 易雅萍

    2001-01-01

    Objective To investigate the relationship of angiotensin II type 1 receptor (AT1-R) gene A/C1166 polymorphism and blood pressure levels in essential hypertensive elders.Methods The A/C1166 polymorphism of AT1R gene was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a casecontrol study of 87 EH elders and 55 normotensive elders. In EH elders blood pressure was measured by 24 hours noninvasive ambulatory blood pressure monitoring. Results (1) The frequency of C1166 allele in EH elders was higher than that in normotensive elders (0.115 vs 0. 036,P<0.05). (2) The mean levels of 24 hours and nighttime SBP and MA, daytime SBP,and nighttime DBP were higher in the group with C allele (AC + CC) than that in AA group (P <0.05). Conclusion The results indicate that A/C1166 polymorphism of AT1-R gene is associated with EH elders.The frequency of C1166 allele is higher in EH elders than that in norrnotensive elders. The C1166 allele may contribute to the higher level of blood pressure in EH elders.%目的研究血管紧张素Ⅱ-1型受体(ATl-R)基因A/C1166多态性与老年原发性高血压(EH)血压水平的关系。方法应用PCR-RFLP技术检测87例老年EH患者和55例正常老年人的AT1-R基因A/C1166多态性,同时对老年EH患者作24小时动态血压监测。结果 (1)老年EH的C1166等位基因频率为0.115,明显高于正常人(0.036)(P<0.05)。(2)AC、CC基因型EH患者24小时及夜间SBP、MAP和白天SBP、夜间DBP水平明显高于基因型AA组(P<0.05)。结论研究提示AT1-R基因的A/C1166多态性与老年EH相关,C1166等位基因频率在EH患者明显升高,并与血压水平升高有关。

  6. Neuron-specific (pro)renin receptor knockout prevents the development of salt-sensitive hypertension.

    Science.gov (United States)

    Li, Wencheng; Peng, Hua; Mehaffey, Eamonn P; Kimball, Christie D; Grobe, Justin L; van Gool, Jeanette M G; Sullivan, Michelle N; Earley, Scott; Danser, A H Jan; Ichihara, Atsuhiro; Feng, Yumei

    2014-02-01

    The (pro)renin receptor (PRR), which binds both renin and prorenin, is a newly discovered component of the renin-angiotensin system that is highly expressed in the central nervous system. The significance of brain PRRs in mediating local angiotensin II formation and regulating blood pressure remains unclear. The current study was performed to test the hypothesis that PRR-mediated, nonproteolytic activation of prorenin is the main source of angiotensin II in the brain. Thus, PRR knockout in the brain is expected to prevent angiotensin II formation and development of deoxycorticosterone acetate-salt-induced hypertension. A neuron-specific PRR (ATP6AP2) knockout mouse model was generated using the Cre-LoxP system. Physiological parameters were recorded by telemetry. PRR expression, detected by immunostaining and reverse transcription-polymerase chain reaction, was significantly decreased in the brains of knockout mice compared with wild-type mice. Intracerebroventricular infusion of mouse prorenin increased blood pressure and angiotensin II formation in wild-type mice. This hypertensive response was abolished in PRR-knockout mice in association with a reduction in angiotensin II levels. Deoxycorticosterone acetate-salt increased PRR expression and angiotensin II formation in the brains of wild-type mice, an effect that was attenuated in PRR-knockout mice. PRR knockout in neurons prevented the development of deoxycorticosterone acetate-salt-induced hypertension as well as activation of cardiac and vasomotor sympathetic tone. In conclusion, nonproteolytic activation of prorenin through binding to the PRR mediates angiotensin II formation in the brain. Neuron-specific PRR knockout prevents the development of deoxycorticosterone acetate-salt-induced hypertension, possibly through diminished angiotensin II formation.

  7. Obesity-induced hypertension: interaction of neurohumoral and renal mechanisms.

    Science.gov (United States)

    Hall, John E; do Carmo, Jussara M; da Silva, Alexandre A; Wang, Zhen; Hall, Michael E

    2015-03-13

    Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65% to 75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include (1) physical compression of the kidneys by fat in and around the kidneys, (2) activation of the renin-angiotensin-aldosterone system, and (3) increased sympathetic nervous system activity. Activation of the renin-angiotensin-aldosterone system is likely due, in part, to renal compression, as well as sympathetic nervous system activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for sympathetic nervous system activation in obesity have not been fully elucidated but may require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes mellitus, and inflammation. Unless effective antiobesity drugs are developed, the effect of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase.

  8. AT1R基因、ACE基因和CYP基因多态性与妊娠期高血压疾病的相关性研究%Polymorphism of angiotension Ⅱ type 1 receptor gene, angiotensin converting enzyme gene and aldosterone synthase gene and hypertensive disorder complicating pregnancy

    Institute of Scientific and Technical Information of China (English)

    牛建清; 李宏芬; 沈志霞; 范淑英; 代琪; 张蕴霞

    2009-01-01

    目的 探讨血管紧张素Ⅱ-1型受体(AT1R)基因A1166-C、血管紧张素转换酶(ACE)基因插入/缺失(I/D)和醛固酮合成酶(CYP11B2)基因-344T/C位点多态性与妊娠期高血压疾病(HDCP)的相关关系.方法 采用聚合酶链反应-限制性内切酶片段长度多态性技术(PCR-RFLP),分别检测HDCP组86例和正常对照组175例AT1R基因A1166-C、ACE基因I/D和CYP11B2基因-344T/C突变位点的基因型.结果 HDCP组和正常对照组AT1R基因A1166-C、ACE基因I/D和CYPllB2基因-344T/C多态性18种组合的分布不同,构成比不同;这18种组合中,相对于AT1R-AA+ACE-Ⅱ+CYP 1182-TT基因型,携带AT1R-AA+ACE-DD+CYP11B2-TC基因型人群的OR值为7.289;携带AT1R-AC+ACE-ID+CYP11B2-TC基因型人群的OR值为5.315;携带AT1R.AC+ACE-DD+CYP11B2-TC基因型人群的OR值为5.694.其余联合基因型,差异均无统计学意义(P均0.05);或者由于样本量小,不具有代表性.结论 HDCP组和正常对照组AT1R基因A1166-C、ACE基因I/D和CYPllB2基因-344T/C多态性18种组合中,AT1R-AA+ACE-DD+CYP11B2-TC联合基因型、AT1R-AC+ACE-ID+CYP11B2-TC联合基因型、AT1R-AC+ACE-DD+CYP11B2-TC联合基因型可能增加HDCP的遗传易感性;HDCP的发生,可能是多个基因共同作用的结果 .%Objective To explore the relationship among genetic polymorphism of angiotension Ⅱ type 1 re-ceptor(AT1 R) A1166-C, angiotensin converting enzyme (ACE) insertion/deletion (I/D), aldosterone synthase (CYP11B2)-344T/C and hypertensive disorder complicating pregnancy.Methods Polymerase chain reaction-re-striction fragment length polymorphism (PCR-RFLP) assay was used to detect the genotypes of AT1 R A1166-C ,ACE (I/O) ,CYP11B2 -344T/C in 86 cases of hypertensive disorder complicating pregnancy and 175 cases of normal control.Results There was 18 combined types in hypertensive disorder complicating pregnancy cases and normal control cases.Compared to AT1R-AA + ACE-Ⅱ + CYP11B2-TT, Odds ratios (OR) of AT1R-AA + ACE-DO +CYP11

  9. Experimental models of melatonin-deficient hypertension.

    Science.gov (United States)

    Simko, Fedor; Reiter, Russel J; Pechanova, Olga; Paulis, Ludovit

    2013-01-01

    Melatonin secreted by the pineal gland plays an important role in the regulation of blood pressure (BP) and its administration reduces hypertension both in animals and humans. There are two experimental models of melatonin-deficient hypertension: one induced by pinealectomy and another by continuous 24 hour exposure to light. Both models cause melatonin deficiency and prevent darkness-mediated nocturnal melatonin secretion and are associated with increased BP and myocardial, vascular and renal dysfunction. These models also lead to neurohumoral activation of the renin-angiotensin system, sympathetic nervous system, adrenocorticotrophin-glucocorticoid axis and cause insulin resistance. Together, these alterations contribute to rise in blood pressure by vasoconstrictive or circulatory fluid volume overload. The light induced hypertension model mimics the melatonin deficiency in patients with insufficient nocturnal BP decline, in those who have night shift or who are exposed to environmental light pollution. For this reason, this model is useful in development of anti-hypertensive drugs.

  10. Obesity-Related Hypertension: Focus on Leptin

    DEFF Research Database (Denmark)

    Asferg, Camilla Lundegaard

    suggested to play a role in obesity-related hypertension such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, inflammation, insulin resistance, physical inactivity, and abnormal production of adipocytokines. Of all adipocytokines, leptin and adiponectin have received most...... attention and both hormones are considered as candidate intermediaries between adipose tissue and overweight and obesity-related disorders. Objectives: To study obesity-related hypertension with special focus on the hormone leptin. As obesity-related hypertension is multifactorial, other biological systems...... proposed to play a major role were also studied. Primary hypotheses: 1. leptin is a significant mediator of overweight- and obesity-related hypertension. 2. by investigating several biological systems involved in blood pressure regulation, it would be possible to identify specific factors which would...

  11. The compensatory renin-angiotensin system in the central regulation of arterial pressure: new avenues and new challenges.

    Science.gov (United States)

    Mendoza, Alberto; Lazartigues, Eric

    2015-08-01

    Hypertension is a widespread condition that affects millions of people around the world and has a major impact in public health. The classic renin-angiotensin system is a complex system comprised of multiple peptides and pathways that have been the driver of drug development over the years to control hypertension. However, there are still patients whose hypertension is very difficult to control with current drugs and strategies, thus motivating further research in this field. In the past two decades, important discoveries have expanded our knowledge of this system and new pathways are emerging that are helping us understand the complex interaction taking place not only in the periphery, but also in the central nervous system where the renin-angiotensin system is also very active. A new arm, called the ACE2/Ang-(1-7)/Mas receptor axis, was shown to exert antihypertensive properties and serve as a counterbalance to the classic ACE/angiotensin II/AT1 receptor axis, in this way modulating or even counteracting the negative effects of angiotensin II in blood pressure regulation and water retention. Modulation of this new axis through ACE2 activation, ADAM17 regulation or AT1 receptor internalization are some of the novel avenues and challenges that have the potential to become a target for new drug research and development for the treatment of hypertension.

  12. Effects of aspirin on angiotensin-converting enzyme inhibition and left ventricular dilation one year after acute myocardial infarction

    NARCIS (Netherlands)

    Oosterga, M; Anthonio, RL; de Kam, PJ; Kingma, JH; Crijns, HJGM; van Gilst, WH

    1998-01-01

    There are conflicting reports on the interaction of aspirin with angiotensin-converting enzyme inhibitors in heart failure and systemic hypertension. A past hoc analysis of the Captopril and Thrombolysis Study (CATS) study was conducted. At randomization, 94 patients (31.5%) took aspirin. In patient

  13. Angiotensin II activates endothelial constitutive nitric oxide synthase via AT1 receptors.

    Science.gov (United States)

    Saito, S; Hirata, Y; Emori, T; Imai, T; Marumo, F

    1996-09-01

    To determine whether angiotensin (ANG) II, a vasoconstrictor hormone, activates constitutive nitric oxide synthase (cNOS) in endothelial cells (ECs), we investigated the cellular mechanism by which ANG II induces nitric oxide (NO) formation in cultured bovine ECs. ANG II rapidly (within 1 min) and dose-dependently (10(-9)-10(-6) M) increased nitrate/nitrite (NOx) production. This effect of ANG II was abolished by a NOS inhibitor, NG-monomethyl-L-arginine. An ANG II type 1 (AT1) receptor antagonist (DuP 753), but not an ANG II type 2 (AT2) receptor antagonist (PD 123177), dose-dependently inhibited ANG II-induced NOx production. A Ca(2+)-channel blocker (barnidipine) failed to affect ANG II-induced NOx production, whereas an intracellular Ca2+ chelator (BAPTA) and a calmodulin inhibitor (W-7) abolished NOx production induced by ANG II. A protein kinase C (PKC) inhibitor (H-7) and down-regulation of endogenous PKC after pretreatment with phorbol ester decreased NOx production stimulated by ANG II. ANG II transiently stimulated inositol 1,4,5-trisphosphate (IP3) formation, and increased cytosolic free Ca2+ concentrations; these effects were blocked by DuP 753. Our data demonstrate that ANG II stimulates NO release by activation of Ca2+/calmodulin-dependent cNOS via AT1 receptors in bovine ECs.

  14. The human angiotensin AT(1) receptor supports G protein-independent extracellular signal-regulated kinase 1/2 activation and cellular proliferation

    DEFF Research Database (Denmark)

    Hansen, Jakob Lerche; Aplin, Mark; Hansen, Jonas Tind;

    2008-01-01

    The angiotensin AT(1) receptor is a key regulator of blood pressure and body fluid homeostasis, and it plays a key role in the pathophysiology of several cardiovascular diseases such as hypertension, cardiac hypertrophy, congestive heart failure, and arrhythmia. The importance of human angiotensi...... by the human angiotensin AT(1) receptor has clear pharmacological implications for development of drugs with pathway-specific actions and defined biological outcomes....

  15. Functional interactions between 7TM receptors in the renin-angiotensin system--dimerization or crosstalk?

    DEFF Research Database (Denmark)

    Lyngsø, Christina; Erikstrup, Niels; Hansen, Jakob L

    2008-01-01

    . The importance of the RAS is clearly emphasised by the widespread use of drugs targeting this system in clinical practice. These include, renin inhibitors, angiotensin II receptor type I blockers, and inhibitors of the angiotensin converting enzyme. Some of the important effectors within the system are 7......The Renin-Angiotensin System (RAS) is important for the regulation of cardiovascular physiology, where it controls blood pressure, and salt- and water homeostasis. Dysregulation of RAS can lead to severe diseases including hypertension, diabetic nephropathy, and cardiac arrhythmia, and -failure...... be important for receptor function, and in the development of cardiovascular diseases. This is very significant, since "dimers" may provide pharmacologists with novel targets for improved drug therapy. However, we know that 7TM receptors can mediate signals as monomeric units, and so far it has been very...

  16. TELMISARTAN IN THE TREATMENT OF ARTERIAL HYPERTENSION. CASE STUDY

    Directory of Open Access Journals (Sweden)

    V. I. Podzolkov

    2012-01-01

    Full Text Available Data on angiotensin II receptor blockers, one of the main drug classes used in cardiology , are presented. The advantages of this drugs class are highlighted with the focus on telmisartan. Additionally clinical example of successful telmisartan application in patients with hypertension, high risk of cardiovascular complications, and obesity is presented.

  17. Combination therapy in hypertension: An update

    Directory of Open Access Journals (Sweden)

    Kalra Sanjay

    2010-06-01

    Full Text Available Abstract Meticulous control of blood pressure is required in patients with hypertension to produce the maximum reduction in clinical cardiovascular end points, especially in patients with comorbidities like diabetes mellitus where more aggressive blood pressure lowering might be beneficial. Recent clinical trials suggest that the approach of using monotherapy for the control of hypertension is not likely to be successful in most patients. Combination therapy may be theoretically favored by the fact that multiple factors contribute to hypertension, and achieving control of blood pressure with single agent acting through one particular mechanism may not be possible. Regimens can either be fixed dose combinations or drugs added sequentially one after other. Combining the drugs makes them available in a convenient dosing format, lower the dose of individual component, thus, reducing the side effects and improving compliance. Classes of antihypertensive agents which have been commonly used are angiotensin receptor blockers, thiazide diuretics, beta and alpha blockers, calcium antagonists and angiotensin-converting enzyme inhibitors. Thiazide diuretics and calcium channel blockers are effective, as well as combinations that include renin-angiotensin-aldosterone system blockers, in reducing BP. The majority of currently available fixed-dose combinations are diuretic-based. Combinations may be individualized according to the presence of comorbidities like diabetes mellitus, chronic renal failure, heart failure, thyroid disorders and for special population groups like elderly and pregnant females.

  18. Apoptosis, myocardial fibrosis and angiotensin Ⅱ in the left ventricle of hypertensive rats treated with fosinopril or losartan%氯沙坦、福辛普利对高血压大鼠心肌细胞凋亡及心肌纤维化影响的对比研究

    Institute of Scientific and Technical Information of China (English)

    余国龙; 梁晓秋; 谢秀梅; 杨天伦; 孙明; 赵水平

    2002-01-01

    目的评价氯沙坦、福辛普利对自发性高血压大鼠(SHR)心肌细胞凋亡、心肌纤维化及左室重构的效应.方法 16周龄SHR随机分为3组:氯沙坦治疗组(SHR-L组)、福辛普利治疗组(SHR-F组)、空白对照组(SHR-C组),每组各10只.分别采用末端脱氧核糖核苷酸转移酶介导dUTP缺口末端标记(TUNEL)、放射免疫及病理检查方法对治疗8周、16周心肌细胞凋亡指数(APOI)、心肌胶原容积分数(CVF)和心肌血管周围胶原面积(PVCA)、血浆和组织血管紧张素Ⅱ检测.结果 (1)与对照组比较,两SHR治疗组治疗8周、16周后收缩压均有明显下降,两组间比较无显著性差异;两治疗组SHR心脏肥厚指标心脏重量(HW)、心脏重量指数(HWI)、左室重量(LVW)、左室重量指数(LVMI)均有显著性改善,治疗16周后SHR-F组与较SHR-L组LVMI显著性减低.(2)与对照组比较,治疗8周后仅SHR-F组心肌细胞凋亡指数(APOI)显著性下降,治疗16周后两治疗组APOI均有显著性下降,尤以SHR-F组下降明显.(3)与对照组比较,治疗8周后SHR-L、SHR-F两组CVF和PVCA有统计学意义下降.治疗16周后与对照组比较,两治疗组CVF和PVCA均显著性下降,其中SHR-F组CVF较SHR-L组下降显著.(4)治疗8周及16周后,SHR-F组心肌组织AngⅡ显著下降,SHR-L组血浆及心肌组织AngⅡ显著增加.结论两药物均能有效逆转心脏肥厚及抗心肌细胞凋亡及心肌纤维化,其中以福辛普利作用显著.两药物上述作用与拮抗心肌组织肾素-血管紧张素-醛固酮系统(RAS)效应有关.%Objective To investigate the different effects of an angiotensin Ⅱ type 1 (AT1) receptor antagonist, losartan, and an angiotensin converting enzyme (ACE) inhibitor, fosinopril, on cardiomyocyte apoptosis, myocardial fibrosis, and angiotensin Ⅱ (AngⅡ) in the left ventricle of spontaneously hypertensive rats (SHRs).Methods SHRs of 16-week-old were randomly divided into 3 groups: SHR-L (treated with

  19. The dopaminergic system in hypertension.

    Science.gov (United States)

    Zeng, Chunyu; Zhang, Meng; Asico, Laureano D; Eisner, Gilbert M; Jose, Pedro A

    2007-06-01

    Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport, vascular smooth muscle contractility and production of reactive oxygen species and by interacting with the renin-angiotensin and sympathetic nervous systems. Dopamine receptors are classified into D(1)-like (D(1) and D(5)) and D(2)-like (D(2), D(3) and D(4)) subtypes based on their structure and pharmacology. Each of the dopamine receptor subtypes participates in the regulation of blood pressure by mechanisms specific for the subtype. Some receptors regulate blood pressure by influencing the central and/or peripheral nervous system; others influence epithelial transport and regulate the secretion and receptors of several humoral agents. This review summarizes the physiology of the different dopamine receptors in the regulation of blood pressure, and the relationship between dopamine receptor subtypes and hypertension.

  20. Losartan-antioxidant hybrids: novel molecules for the prevention of hypertension-induced cardiovascular damage.

    Science.gov (United States)

    García, Gonzalo; Rodríguez-Puyol, Manuel; Alajarín, Ramón; Serrano, Isabel; Sánchez-Alonso, Patricia; Griera, Mercedes; Vaquero, Juan J; Rodríguez-Puyol, Diego; Alvarez-Builla, Julio; Díez-Marqués, María L

    2009-11-26

    We report the first examples of a new series of antioxidant-sartan hybrids (AO-sartans), which were made by adding an antioxidant fragment to the hydroxymethyl side chain of losartan. Experiments performed in cultured cells demonstrate that these new hybrids retain the ability to block the angiotensin II effect with increased antioxidant ability. In hypertensive rats, these compounds show properties that suggest they may be more useful than losartan for controlling hypertension and preventing hypertension-induced cardiovascular damage.

  1. 加味温胆汤治疗自发性高血压大鼠Ⅰ、Ⅲ型胶原及AngⅡ的影响%Effects of Use of Jiawei Wendan Tang on Collagen- Ⅰ Ⅲ Contents and Angiotensin Ⅱ (Ang Ⅱ ) of Spontaneously Hypertensive Rats(SHRs)

    Institute of Scientific and Technical Information of China (English)

    韦品清; 吴君; 黄萍; 王静; 邵兵

    2012-01-01

    目的:本课题旨在探讨加味温胆汤与开博通(卡托普利)联用对自发性高血压大鼠( SHR)血压Ⅰ、Ⅲ型胶原及AngⅡ的影响.方法:将48只10周龄雄性SHR随机分为6组,分别为SHR对照组(SHR-K)、加味温胆汤高剂量和开博