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Stump M, Guo D, Rahmouni K. LB1023 Deletion of bardet biedl syndrome 1 (BBS1) gene in T cells impairs wound healing in mice. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.1052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Rahmouni K, Shahinian J, Qureshi S, Elmistekawy E, Glineur D, Ruel M, Mesana T, Chan V. LONG-TERM DURABILITY OF SURGICAL MITRAL VALVE REPAIR FOR DEGENERATIVE DISEASE ACCORDING TO AGE AT SURGERY: INSIGHTS FROM > 1000 SURGICAL PROCEDURES. Can J Cardiol 2021. [DOI: 10.1016/j.cjca.2021.07.205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Laurin C, Chauvette V, El-Hamamsy I, Dumont É, Demers P, Dagenais F, Rahmouni K. OUTCOMES AFTER THORACIC AORTIC REPLACEMENT FOR GIANT CELL AORTITIS ANEURYSM: A MULTICENTER RETROSPECTIVE STUDY. Can J Cardiol 2019. [DOI: 10.1016/j.cjca.2019.07.525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Benhaddad L, Bazin C, Makhloufi L, Messaoudi B, Pillier F, Rahmouni K, Takenouti H. Effect of synthesis duration on the morphological and structural modification of the sea urchin-nanostructured γ-MnO2 and study of its electrochemical reactivity in alkaline medium. J Solid State Electrochem 2014. [DOI: 10.1007/s10008-014-2459-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tanida M, Hayata A, Shintani N, Yamamoto N, Kurata Y, Shibamoto T, Morgan DA, Rahmouni K, Hashimoto H. Central PACAP mediates the sympathetic effects of leptin in a tissue-specific manner. Neuroscience 2013; 238:297-304. [PMID: 23454538 DOI: 10.1016/j.neuroscience.2013.02.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 02/01/2013] [Accepted: 02/09/2013] [Indexed: 12/20/2022]
Abstract
We previously demonstrated that the peptidergic neurotransmitter pituitary adenylate cyclase-activating polypeptide (PACAP) affects the autonomic system and contributes to the control of metabolic and cardiovascular functions. Previous studies have demonstrated the importance of centrally-mediated sympathetic effects of leptin for obesity-related hypertension. Here we tested whether PACAP signaling in the brain is implicated in leptin-induced sympathetic excitation and appetite suppression. In anesthetized mice, intracerebroventricular (ICV) pre-treatment with PACAP6-38, an antagonist of the PACAP receptors (PAC1-R and VPAC2), inhibited the increase in white adipose tissue sympathetic nerve activity (WAT-SNA) produced by ICV leptin (2μg). In contrast, leptin-induced stimulation of renal sympathetic nerve activity (RSNA) was not affected by ICV pre-treatment with PACAP6-38. Moreover, in PACAP-deficient (Adcyap1-/-) mice, ICV leptin-induced WAT-SNA increase was impaired, whereas RSNA response was preserved. The reductions in food intake and body weight evoked by ICV leptin were attenuated in Adcyap1-/- mice. Our data suggest that hypothalamic PACAP signaling plays a key role in the control by leptin of feeding behavior and lipocatabolic sympathetic outflow, but spares the renal sympathetic traffic.
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Affiliation(s)
- M Tanida
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
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Deslouis C, Keddam M, Rahmouni K, Takenouti H, Grasset F, Lacroix O, Sala B. Characterization of porous texture of cermet electrode for steam electrolysis at intermediate temperature. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2010.12.107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Benhaddad L, Makhloufi L, Messaoudi B, Rahmouni K, Takenouti H. Reactivity of nanostructured MnO(2) in alkaline medium studied with a micro-cavity electrode: effect of synthesizing temperature. ACS Appl Mater Interfaces 2009; 1:424-432. [PMID: 20353233 DOI: 10.1021/am800118y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The influence of synthesizing temperature of manganese dioxide (MnO(2)) powders on their electrochemical reactivity in 1 M KOH was investigated. These powders were prepared chemically by the hydrothermal method by oxidation of Mn(2+) by ammonium peroxodisulphate. The observations by scanning electronic microscopy, energy-dispersive X-ray analyses, and transmission electron microscopy techniques on MnO(2) obtained at different temperatures show the formation of many nanometre scale sticks lumped together to form a spherical particle of several micrometers. The results obtained by BET and BJH methods reveal mesoporous texture, and the MnO(2) synthesized at 90 degrees C presents the largest expanded surface area. The electrochemical reactivity of these powders in 1 M KOH was characterized with microcavity electrode by cyclic voltammetry and electrochemical impedance spectroscopy. The results illustrate that the nanostructured MnO(2) powder synthesized at 90 degrees C shows the highest electrochemical reactivity in agreement with BET data. The X-ray powder diffraction identified the gamma-MnO(2), known as the most reactive species.
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Affiliation(s)
- L Benhaddad
- Laboratoire de Technologie des Matériaux et Génie des Procédés (LTMGP), Département de Génie des Procédés, Université A. Mira, Route de Targa Ouzemmour, Béjaia, Algeria
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Rahmouni K, Hajjaji N, Keddam M, Srhiri A, Takenouti H. The inhibiting effect of 3-methyl 1,2,4-triazole 5-thione on corrosion of copper in 3% NaCl in presence of sulphide. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2006.12.079] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Muresan L, Varvara S, Stupnišek-Lisac E, Otmačić H, Marušić K, Horvat-Kurbegović S, Robbiola L, Rahmouni K, Takenouti H. Protection of bronze covered with patina by innoxious organic substances. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.02.024] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dermaj A, Hajjaji N, Joiret S, Rahmouni K, Srhiri A, Takenouti H, Vivier V. Electrochemical and spectroscopic evidences of corrosion inhibition of bronze by a triazole derivative. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.01.068] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Serghini-Idrissi M, Bernard M, Harrif F, Joiret S, Rahmouni K, Srhiri A, Takenouti H, Vivier V, Ziani M. Electrochemical and spectroscopic characterizations of patinas formed on an archaeological bronze coin. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2005.01.050] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Mark AL, Rahmouni K, Correia M, Haynes WG. A leptin-sympathetic-leptin feedback loop: potential implications for regulation of arterial pressure and body fat. Acta Physiol Scand 2003; 177:345-9. [PMID: 12609005 DOI: 10.1046/j.1365-201x.2003.01085.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM This manuscript briefly reviews evidence and potential implications of a leptin-sympathetic-leptin feedback loop. RESULTS Leptin increases sympathetic nerve activity to brown adipose tissue, kidney and other tissues. This action has implications for regulation of arterial pressure. In turn, there is evidence that sympathoadrenal stimulation inhibits leptin mRNA expression and secretion from white adipose tissue through beta adrenergic mechanisms. CONCLUSION This sympathetic modulation of leptin expression has potential implications for regulation of body fat.
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Affiliation(s)
- A L Mark
- Specialized Center of Research in Hypertension Genetics, the Department of Internal Medicine, Lucille A Carver College of Medicine, and the Veterans Administration Medical Center, Iowa City, IA 52242-1101, USA
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Abstract
No other hormone has drawn more attention than leptin in recent studies on the control of appetite, body weight and obesity. This hormone is produced by adipose tissue and enters the brain via a saturable specific transport mechanism. Leptin acts in the hypothalamus to modulate food intake and heat production as well as several other neuroendocrine pathways. The mechanisms through which leptin exerts its central nervous effects are now better understood. Proopiomelanocortin- and neuropeptide Y-containing neurons in the hypothalamus have emerged as potent candidate mediators of leptin action. These two neuropeptides have been shown to exert opposing effects using different pathways. Recently, Cowley et al. (2001) described a new circuit in the regulation of neuronal activity by leptin with an interaction between these two pathways. These data add complexity to the mechanisms by which leptin achieves its effects in the central nervous system, but they also offer potential mechanisms to explain the phenomenon of leptin resistance observed in obesity.
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Affiliation(s)
- K Rahmouni
- Department of Internal Medicine, University of Iowa, Iowa City 52242, USA
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Rahmouni K, Barthelmebs M, Grima M, Imbs JL, De Jong W. Involvement of brain mineralocorticoid receptor in salt-enhanced hypertension in spontaneously hypertensive rats. Hypertension 2001; 38:902-6. [PMID: 11641306 DOI: 10.1161/hy1001.091781] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We recently showed that brain mineralocorticoid receptors (MRs) are involved in blood pressure and kidney function control in normotensive Wistar rats. We now assessed the involvement of brain MRs in spontaneously hypertensive rats (SHR), in which the presence of adrenocorticoids has been shown to be required for the development of hypertension. The effect of a single intracerebroventricular (ICV) injection of an MR antagonist (RU28318) on systolic blood pressure (SBP) and renal function was examined in conscious adult SHR and Wistar-Kyoto rats (WKY) maintained on a standard-sodium diet (0.4% Na(+)). In WKY, a long-lasting decrease in SBP was caused by the ICV injection of 10 ng RU28318 as previously reported in Wistar rats, associated with increased urinary excretion of water and electrolytes. In SHR maintained on the standard diet, the ICV injection of RU28318 (10 or 100 ng) had no effect on cardiovascular and renal functions. However, the ICV injection of 10 ng RU28318 in SHR after 3 weeks of high sodium intake (8% Na(+)) caused a long-lasting decrease in SBP. The effect was present at 8 hours (DeltaSBP 34+/-2 mm Hg), persisted at 24 hours (DeltaSBP 29+/-1 mm Hg), and disappeared at 48 hours after the injection. The hypotension was not associated with changes in heart rate, urinary excretion of water and electrolytes, and plasma renin activity, whereas renal denervation did not affect the decrease in SBP. A more pronounced decrease in SBP (49+/-3 mm Hg at 8 hours) was observed with 100 ng RU28318. This dose of the antagonist was without effect after subcutaneous administration. Thus, brain MRs appear to participate in the maintenance of hypertension in conscious adult SHR sensitized by sodium loading.
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Affiliation(s)
- K Rahmouni
- Institut de Pharmacologie, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
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Abstract
Mineralocorticoid receptors (MRs) expressed in limbic neurons, notably of hippocampus, retain both aldosterone and corticosterone. Basal concentrations of corticosterone already substantially occupy the limbic MR type, suggesting that in hippocampal neurons, MR activity rather than ligand bioavailability is rate limiting. The periventricular region expresses MRs involved in the control of salt homeostasis, which are aldosterone selective because of the presence of 11beta-hydroxysteroid dehydrogenase. MR is in hippocampal CA1, CA2, and dentate gyrus colocalized with glucocorticoid receptors (GRs). Both receptor types mediate in a coordinate manner the corticosterone action on information processing critical for behavioral adaptation and associated neuroendocrine responses to stress. MRs operate in proactive mode determining the sensitivity of the stress response system, while GRs facilitate recovery from stress in reactive mode. On the neuronal level, MR-mediated action maintains a stable excitatory tone and attenuates the influence of modulatory signals. In contrast, GR-mediated effects suppress excitability transiently raised by excitatory stimuli. MR is also involved in control of autonomic outflow and volume regulation. This was demonstrated by the effect of an MR antagonist, which was administered centrally, because mdr P-glycoproteins hamper the access of synthetic steroids to the brain. The MR antagonist attenuates pressor responses to a stressor, such as experienced during tail sphygmography. Diuresis and urinary electrolyte excretion are increased after the MR antagonist, but this effect is abolished after bilateral denervation of the kidney. It is presently unknown in which brain cells the MR-mediated effects on these aspects of central cardiovascular regulation occur.
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Affiliation(s)
- E R de Kloet
- Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands.
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Rahmouni K, Barthelmebs M, Grima M, Imbs JL, De Jong W. Cardiovascular and renal effects of central administration of a mineralocorticoid receptor antagonist in conscious female rats. Eur J Pharmacol 1999; 385:199-202. [PMID: 10607876 DOI: 10.1016/s0014-2999(99)00705-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In a previous study we showed that in normotensive male rats brain mineralocorticoid receptor blockade induced a long lasting decrease in blood pressure associated with increased urinary excretion of water and electrolytes. Here, we report the effect of intracerebroventricular injection of a mineralocorticoid receptor antagonist (RU28318; 3,3-oxo-7 propyl-17-hydroxy-androstan-4-en-17yl-propionic acid lactone) on cardiovascular and renal function in female rats. Compared with male rats, females are less sensitive to brain mineralocorticoid receptor blockade. Administration of RU28318 (10 ng, 100 ng) caused a significant decrease in systolic blood pressure (10-12.5%) only at 8 h after injection. An increased urinary excretion of water (about 160%) and electrolytes (about 175%) during the first 8 h after the injection was observed in the 100 ng RU28318 treated group. Heart rate, food intake and water consumption were not affected at either dose. In conclusion, in conscious female rats, brain mineralocorticoid receptors participate in blood pressure and renal function control.
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Affiliation(s)
- K Rahmouni
- Institut de Pharmacologie, Laboratoire de Pharmacologie-Physiologie Rénovasculaire, Faculté de Médecine, Université Louis Pasteur, 11 rue Humann, 67085, Strasbourg, France
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Abstract
Brain mineralocorticoid receptors appear to contribute to mineralocorticoid hypertension and may be involved in blood pressure control in normotensive rats. We examined the effect of blockade of central mineralocorticoid receptors with the use of a selective antagonist (RU28318) on cardiovascular and renal function in conscious normotensive rats. The contribution of renal innervation was evaluated in rats with bilaterally denervated kidneys. Young adult, male Wistar rats were trained for systolic blood pressure measurement by a tail sphygmographic method and accustomed to metabolic cages for collection of urine. One week before experimentation, an intracerebroventricular cannula was implanted. Systolic blood pressure was diminished 30 minutes after an intracerebroventricular dose of 10 ng of RU28318. The effect was maximal at 8 hours and was still present after 24 hours. Blood pressure returned to the basal level by 48 hours. During the period 0 to 8 hours after intracerebroventricular injection, rats treated with the antagonist showed an increase in diuresis and urinary electrolyte excretion. No significant effect on plasma renin activity, measured 8 and 30 hours after administration of RU28318, was observed. In denervated rats, the decrease in systolic blood pressure after administration of RU28318 was reduced. The difference was statistically significant compared with controls at 2 hours but not at 8 hours, and blood pressure returned to the basal value by 24 hours. The increases in diuresis and urinary electrolyte excretion induced by RU28318 were abolished in denervated rats. These results show that brain mineralocorticoid receptors are involved in blood pressure regulation and kidney function homeostasis in conscious normotensive rats. The renal nerves appear to participate in the brain mineralocorticoid receptor control of blood pressure.
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Affiliation(s)
- K Rahmouni
- Institut de Pharmacologie Laboratoire de Pharmacologie-Physiologie Rénovasculaire, Faculté de Mèdecine, Strasbourg, France
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Rahmouni K, Barthelmebs M, Imbs JL, De Jong W. [Brain mineralocorticoid receptor and blood pressure control in the conscious normotensive rat]. Arch Mal Coeur Vaiss 1998; 91:1009-12. [PMID: 9749155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Brain control of arterial blood pressure in man and in animals has been studied increasingly over the last few decades. Despite our knowledge about short term regulation (chemoreceptor and baroreceptor reflexes) there is much more uncertainty about the degree of involvement of brain mechanisms in long term control of blood pressure, and in hypertension. The last decade, a role of brain mineralocorticoid receptors (MR) has been outlined in animal experiments. Stimulation of brain MR by aldosterone or related mineralocorticoids induces an increase in blood pressure and hypertension under chronic conditions. These effects of mineralocorticoid excess can be blocked by specific MR antagonists administered centrally. Stimulation of brain glucocorticoid receptors, as compared to stimulation of brain MR, has an opposite effect, i.e. decreases blood pressure. As in the typical peripheral target organs of aldosterone, in the brain, enzymatic protection of MR against glucocorticoids appears to play an important role. We showed that in conscious normotensive rats intracerebroventricular (i.c.v.) injection of a specific MR antagonist (RU28318) in a low dose (10 ng) decreases blood pressure by about 20% without affecting heart rate. A similar but smaller effect (not statistically significant) was observed in conscious female rats. Only in the male rats an increased diuresis occurred and this may have contributed to the observed hypotension. We conclude that hypertension caused by mineralocorticoid excess may depend on a concerted action of the steroid on the kidney and on the brain. The mechanism by which brain MR increases blood pressure is unknown. It is possible that increased sympathetic outflow and renal mechanisms are involved. Interference with brain MR not only affects blood pressure but it also has effect on renal function.
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Affiliation(s)
- K Rahmouni
- Institut de pharmacologie, Faculté de médecine, Université Louis-Pasteur, Strasbourg
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Rahmouni K, Barthelmebs M, Jong W. EFFECT OF SINGLE ADMINISTRATION OF A MINERALOCORTICOÏD RECEPTOR ANTAGONIST (RU28318) ON BLOOD PRESSURE AND KIDNEY FUNCTION. Fundam Clin Pharmacol 1997. [DOI: 10.1111/j.1472-8206.1997.tb00906.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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