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Afzal S, Sattar MA, Albokhadaim I, Attiq A, Kandeel M, Manap ASA, Alhojaily SM. Interaction between Nuclear Receptor and Alpha-Adrenergic Agonist Subtypes in Metabolism and Systemic Hemodynamics of Spontaneously Hypertensive Rats. PPAR Res 2024; 2024:5868010. [PMID: 38899161 PMCID: PMC11186691 DOI: 10.1155/2024/5868010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/22/2023] [Accepted: 05/03/2024] [Indexed: 06/21/2024] Open
Abstract
Partial and full PPAR-γ agonists have shown promising effects and antihypertensive and antidiabetic agents through increased plasma adiponectin concentration. This study is aimed at examining the role of PPAR-γ, alpha-adrenoceptors, and adiponectin receptors in the modulation of vasopressor responses to angiotensin II (Ang II) and adrenergic agonists, after a subset treatment of partial and full PPAR-γ agonists, each individually, and also when coupled with adiponectin in SHRs. The antioxidant potential and metabolic indices for these animals were also determined. Group I (WKY) and group II (SHR) were designated as normotensive control and hypertensive control, respectively. Groups III (SHR) and IV (SHR) received irbesartan (30 mg/kg) and pioglitazone (10 mg/kg) orally for 28 days, and groups V (SHR), VI (SHR), and VII (SHR) were treated with adiponectin (2.5 μg/kg) intraperitoneally alone, in combination with irbesartan, and in combination with pioglitazone, respectively, from days 21 to 28 only. On day 29, sodium pentobarbitone (60 mg/kg) was used to anesthetize all test animals, and systemic hemodynamic and plasma adiponectin concentrations and in vitro and in vivo antioxidant potential were measured. As compared to the WKY control, the SHR control group's noninvasive blood pressure and basal mean arterial pressure were significantly greater, along with increased arterial stiffness, lower plasma nitric oxide, adiponectin concentration, and antioxidant enzyme levels (all P < 0.05). However, they were gradually normalized by single drug treatments in all groups, and to a greater extent in the SHR + Irb + Adp group (P < 0.05). In the acute study, the dose dependant mean arterial pressure responses to intravenously administered adrenergic agonists and angiotensin-II were significantly larger in SHRs as compared to WKY by 20-25%. Adiponectin alone and in combination significantly blunted vasopressor responses to these alpha-adrenergic agonists in the SHR + Pio + Adp group by 63%, whereas attenuated responses to ANG-II administration to 70% in SHR + Irb + Adp. In conclusion, the combined treatment of adiponectin with PPAR-agonists reduced the systemic vascular responses to adrenergic agonists and improved arterial stiffness. This an evidence of the interaction of adiponectin receptors, PPAR-γ, alpha-adrenoceptors, and ANG-II in the systemic vasculature of SHRs. A significant level of synergism has also been proved among full PPAR-γ agonists and adiponectin receptors.
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Affiliation(s)
- Sheryar Afzal
- Department of Biomedical ScienceCollege of Veterinary MedicineKing Faisal University, Al Hofuf, Saudi Arabia
- Discipline of PharmacologySchool of Pharmaceutical SciencesUniversiti Sains Malaysia, Gelugor 11800, Penang, Malaysia
| | - Munavvar Abdul Sattar
- Discipline of PharmacologySchool of Pharmaceutical SciencesUniversiti Sains Malaysia, Gelugor 11800, Penang, Malaysia
| | - Ibrahim Albokhadaim
- Department of Biomedical ScienceCollege of Veterinary MedicineKing Faisal University, Al Hofuf, Saudi Arabia
| | - Ali Attiq
- Discipline of PharmacologySchool of Pharmaceutical SciencesUniversiti Sains Malaysia, Gelugor 11800, Penang, Malaysia
| | - Mahmoud Kandeel
- Department of Biomedical ScienceCollege of Veterinary MedicineKing Faisal University, Al Hofuf, Saudi Arabia
| | - Aimi Syamima Abdul Manap
- Department of Biomedical ScienceCollege of Veterinary MedicineKing Faisal University, Al Hofuf, Saudi Arabia
| | - Sameer M. Alhojaily
- Department of Biomedical ScienceCollege of Veterinary MedicineKing Faisal University, Al Hofuf, Saudi Arabia
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Hamilton JL, Vashi M, Kishen EB, Fogg LF, Wimmer MA, Balk RA. The Association of an Alpha-2 Adrenergic Receptor Agonist and Mortality in Patients With COVID-19. Front Med (Lausanne) 2022; 8:797647. [PMID: 35059419 PMCID: PMC8764306 DOI: 10.3389/fmed.2021.797647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022] Open
Abstract
There is a need for treatments to reduce coronavirus disease 2019 (COVID-19) mortality. Alpha-2 adrenergic receptor (α2 AR) agonists can dampen immune cell and inflammatory responses as well as improve oxygenation through physiologic respiratory parameters. Therefore, α2 AR agonists may be effective in reducing mortality related to hyperinflammation and acute respiratory failure in COVID-19. Dexmedetomidine (DEX) is an α2 AR agonist used for sedation. We performed a retrospective analysis of adults at Rush University System for Health hospitals between March 1, 2020 and July 30, 2020 with COVID-19 requiring invasive mechanical ventilation and sedation (n = 214). We evaluated the association of DEX use and 28-day mortality from time of intubation. Overall, 28-day mortality in the cohort receiving DEX was 27.0% as compared to 64.5% in the cohort that did not receive DEX (relative risk reduction 58.2%; 95% CI 42.4–69.6). Use of DEX was associated with reduced 28-day mortality on multivariable Cox regression analysis (aHR 0.19; 95% CI 0.10–0.33; p < 0.001). Adjusting for time-varying exposure to DEX also demonstrated that DEX was associated with reduced 28-day mortality (aHR 0.51; 95% CI 0.28–0.95; p = 0.03). Earlier DEX use, initiated <3.4 days from intubation, was associated with reduced 28-day mortality (aHR 0.25; 95% CI 0.13–0.50; p < 0.001) while later DEX use was not (aHR 0.64; 95% CI 0.27–1.50; p = 0.30). These results suggest an α2 AR agonist might reduce mortality in patients with COVID-19. Randomized controlled trials are needed to confirm this observation.
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Affiliation(s)
- John L Hamilton
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, United States
| | - Mona Vashi
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL, United States
| | - Ekta B Kishen
- Bioinformatics and Biostatistics Core, Rush University Medical Center, Chicago, IL, United States
| | - Louis F Fogg
- Department of Community, Systems and Mental Health Nursing, Rush University Medical Center, Chicago, IL, United States
| | - Markus A Wimmer
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, United States
| | - Robert A Balk
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL, United States
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Tsai SH, Tung CS, Liu YP, Lin YC, Lin CC. Spectral analysis of cardiovascular oscillations in the 7-day regimen of losartan administration with and without cold stress. CHINESE J PHYSIOL 2022; 65:171-178. [DOI: 10.4103/0304-4920.354802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Afzal S, Sattar MA, Eseyin OA, Attiq A, Johns EJ. Crosstalk relationship between adiponectin receptors, PPAR-γ and α-adrenoceptors in renal vasculature of diabetic WKYs. Eur J Pharmacol 2021; 917:174703. [PMID: 34973951 DOI: 10.1016/j.ejphar.2021.174703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 11/25/2022]
Abstract
Hypoadiponectinemia is associated with renal dysfunctions. Irbesartan and pioglitazone activate Peroxisome proliferator-activated gamma receptor (PPAR-γ) as partial and full agonists. We investigated a crosstalk interaction and synergistic action between adiponectin receptors, PPAR-γ agonists in attenuating renal hemodynamics to adrenergic agonists in diabetic Wistar Kyoto rats (WKY). Streptozotocin (40 mg/kg) was used to induce diabetes, whereas, pioglitazone (10 mg/kg/day), irbesartan (30 mg/kg/day) administered orally for 28 days and adiponectin intraperitoneally (2.5 μg/kg/day) for last 7 days. Metabolic and plasma samples were analyzed on days 0, 8, 21, and 28. During the acute study (day 29), renal vasoconstrictor actions to adrenergic agonists and angiotensin-II were determined. Diabetic WKYs had lower plasma adiponectin, higher creatinine clearance, urinary and fractional sodium excretion but were normalized to a greater extent in pioglitazone and adiponectin combined treatment. Responses to intra-renal administration of adrenergic agonists including noradrenaline (NA), phenylephrine (PE), methoxamine (ME), and angiotensin-II (ANG-II) were larger in diabetic WKY, but significantly blunted with adiponectin treatment in diabetic WKYs to 35-40%, and further reduced by 65-70% in combination with pioglitazone. Attenuation to ANG-II responses in adiponectin and combination with irbesartan was 30-35% and 75-80%, respectively (P < 0.05). Pharmacodynamically, a crosstalk interaction exists between PPAR-γ, adiponectin receptors (adipo R1 & R2), alpha adrenoceptors, and angiotensin-I (ATI) receptors in the renal vasculature of diabetic WKYs. Exogenously administered adiponectin with full PPAR-γ agonist substantially attenuated renal hemodynamics and improved excretory functions, signifying their renoprotective action. Additionally, a degree of synergism exists between adiponectin and pioglitazone to a large extent compared to combination therapy with irbesartan (partial PPAR-γ agonist) in attenuating the renal vascular receptiveness to adrenergic agonists.
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Affiliation(s)
- Sheryar Afzal
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, Malaysia; Department of Pharmacology and Toxicology, Faculty of Pharmacy, MAHSA University, Selangor, Malaysia.
| | | | | | - Ali Attiq
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, MAHSA University, Selangor, Malaysia.
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Lezama-Martinez D, Elena Hernandez-Campos M, Flores-Monroy J, Valencia-Hernandez I, Martinez-Aguilar L. Time-Dependent Effects of Individual and Combined Treatments With Nebivolol, Lisinopril, and Valsartan on Blood Pressure and Vascular Reactivity to Angiotensin II and Norepinephrine. J Cardiovasc Pharmacol Ther 2021; 26:490-499. [PMID: 33779339 DOI: 10.1177/10742484211001861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Clinical guidelines suggest the combination of 2 drugs as a strategy to treat hypertension. However, some antihypertensive combinations have been shown to be ineffective. Therefore, it is necessary to determine whether differences exist between the results of monotherapy and combination therapy by temporal monitoring of the responses to angiotensin II and norepinephrine, which are vasoconstrictors involved in the development of hypertension. Thus, the purpose of this work was to determine the vascular reactivity to angiotensin II and norepinephrine in spontaneously hypertensive rat (SHR) aortic rings after treatment with valsartan, lisinopril, nebivolol, nebivolol-lisinopril, and nebivolol-valsartan for different periods of time. In this study, male SHR and Wistar Kyoto normotensive (WKY) rats were divided into 7 groups treated for 1, 2, and 4 weeks: (1) WKY + vehicle, (2) SHR + vehicle; (3) SHR + nebivolol; (4) SHR + lisinopril; (5) SHR + valsartan; (6) SHR + nebivolol-lisinopril; and (7) SHR + nebivolol-valsartan. Blood pressure was measured by the tail-cuff method, and vascular reactivity was determined from the concentration-response curve to angiotensin II and norepinephrine in aortic rings. The results showed that the combined and individual treatments reduced mean blood pressure at all times evaluated. All treatments decreased vascular reactivity to angiotensin II; however, in the case of lisinopril and nebivolol-lisinopril, the effect observed was significant up to 2 weeks. All treatments decreased the reactivity to norepinephrine up to week 4. These results show a time-dependent difference in vascular reactivity between the pharmacological treatments, with nebivolol-valsartan and nebivolol-lisinopril being both effective combinations. Additionally, the results suggest crosstalk between the renin-angiotensin and sympathetic nervous systems to reduce blood pressure and to improve treatment efficacy.
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Affiliation(s)
- Diego Lezama-Martinez
- Laboratory of Pharmacology, F.E.S.-Cuautitlan, 7180Universidad Nacional Autonoma de Mexico, Cuautitlan Izcalli, Mexico, Mexico
- Laboratory of Pharmacodynamics, Escuela Superior de Medicina, 27740Instituto Politecnico Nacional, D.F., Mexico, Mexico
| | - Maria Elena Hernandez-Campos
- Laboratory of Pharmacodynamics, Escuela Superior de Medicina, 27740Instituto Politecnico Nacional, D.F., Mexico, Mexico
| | - Jazmin Flores-Monroy
- Laboratory of Pharmacology, F.E.S.-Cuautitlan, 7180Universidad Nacional Autonoma de Mexico, Cuautitlan Izcalli, Mexico, Mexico
| | - Ignacio Valencia-Hernandez
- Laboratory of Pharmacodynamics, Escuela Superior de Medicina, 27740Instituto Politecnico Nacional, D.F., Mexico, Mexico
| | - Luisa Martinez-Aguilar
- Laboratory of Pharmacology, F.E.S.-Cuautitlan, 7180Universidad Nacional Autonoma de Mexico, Cuautitlan Izcalli, Mexico, Mexico
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Development of obesity can be prevented in rats by chronic icv infusions of AngII but less by Ang(1-7). Pflugers Arch 2018; 470:867-881. [PMID: 29430615 DOI: 10.1007/s00424-018-2117-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 02/07/2023]
Abstract
Considering that obesity is one of the leading risks for death worldwide, it should be noted that a brain-related mechanism is involved in AngII-induced and AT1-receptor-dependent weight loss. It is moreover established that activation of the Ang(1-7)/ACE2/Mas axis reduces weight, but it remains unclear whether this Ang(1-7) effect is also mediated via a brain-related mechanism. Additionally to Sprague Dawley (SD) rats, we used TGR(ASrAOGEN) selectively lacking brain angiotensinogen, the precursor to AngII, as we speculated that effects are more pronounced in a model with low brain RAS activity. Rats were fed with high-calorie cafeteria diet. We investigated weight regulation, food behavior, and energy balance in response to chronic icv.-infusions of AngII (200 ng•h-1), or Ang(1-7) (200/600 ng•h-1) or artificial cerebrospinal fluid. High- but not low-dose Ang(1-7) slightly decreased weight gain and energy intake in SD rats. AngII showed an anti-obese efficacy in SD rats by decreasing energy intake and increasing energy expenditure and also improved glucose control. TGR(ASrAOGEN) were protected from developing obesity. However, Ang(1-7) did not reveal any effects in TGR(ASrAOGEN) and those of AngII were minor compared to SD rats. Our results emphasize that brain AngII is a key contributor for regulating energy homeostasis and weight in obesity by serving as a negative brain-related feedback signal to alleviate weight gain. Brain-related anti-obese potency of Ang(1-7) is lower than AngII but must be further investigated by using other transgenic models as TGR(ASrAOGEN) proved to be less valuable for answering this question.
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Sauvet F, Florence G, Van Beers P, Drogou C, Lagrume C, Chaumes C, Ciret S, Leftheriotis G, Chennaoui M. Total sleep deprivation alters endothelial function in rats: a nonsympathetic mechanism. Sleep 2014; 37:465-73. [PMID: 24587568 DOI: 10.5665/sleep.3476] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
STUDY OBJECTIVES Sleep loss is suspected to induce endothelial dysfunction, a key factor in cardiovascular risk. We examined whether sympathetic activity is involved in the endothelial dysfunction caused by total sleep deprivation (TSD). DESIGN TWO GROUPS: TSD (24-h wakefulness), using slowly rotating wheels, and wheel control (WC). PARTICIPANTS Seven-month-old male Wistar rats. INTERVENTIONS Pharmacological sympathectomy (reserpine, 5 mg/kg, intraperitoneal), nitric oxide synthase (NOS) inhibition (N (G)-nitro-L-arginine, 20 mg/kg, intraperitoneally 30 min before experiment) and cyclooxygenase (COX) inhibition (indomethacin, 5 mg/kg, intraperitoneally 30 min before experiment). MEASUREMENTS AND RESULTS In protocol 1, changes in heart rate (HR) and blood pressure were continuously recorded in the sympathectomized and non-sympathectomized rats. Blood pressure and HR increased during TSD in non-sympathectomized rats. In protocol 2, changes in skin blood flow (vasodilation) were assessed in the sympathectomized and non-sympathectomized rats using laser-Doppler flowmetry coupled with iontophoretic delivery of acetylcholine (ACh), sodium nitroprusside (SNP), and anodal and cathodal currents. ACh- and cathodal current-induced vasodilations were significantly attenuated after TSD in non-sympathectomized and sympathectomized rats (51% and 60%, respectively). In protocol 3, ACh-induced vasodilation was attenuated after NOS and COX inhibition (66% and 49%, respectively). Cathodal current-induced vasodilation decreased by 40% after COX inhibition. In TSD compared to WC a decrease in ACh-induced vasodilation was still observed after COX inhibition. No changes in SNP- and anodal current-induced vasodilation were detected. CONCLUSION These results demonstrate that total sleep deprivation induces a reduction in endothelial-dependent vasodilation. This endothelial dysfunction is independent of blood pressure and sympathetic activity but associated with nitric oxide synthase and cyclooxygenase pathway alterations.
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Affiliation(s)
- Fabien Sauvet
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Geneviève Florence
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Pascal Van Beers
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Catherine Drogou
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Christophe Lagrume
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Cyrielle Chaumes
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Sylvain Ciret
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Georges Leftheriotis
- University of Angers, Angers, France ; Unité mixte Centre National de la Recherche Scientifique (CNRS) 6214 - Institut National de la Santé et de la Recherche Médicale (INSERM) 771, Angers, France
| | - Mounir Chennaoui
- Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
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Ali MA, Kazzam E, Amir N, Nyberg F, Adem A. Effects of dehydration and blockade of angiotensin II AT1 receptor on stress hormones and anti-oxidants in the one-humped camel. BMC Vet Res 2013; 9:232. [PMID: 24252635 PMCID: PMC4225509 DOI: 10.1186/1746-6148-9-232] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 11/08/2013] [Indexed: 01/18/2023] Open
Abstract
Background The objective of this study was to provide for the first time data on plasma catecholamines, cortisol, glutathione and malondialdehyde after long term dehydration (20 days) in the presence and absence of angiotensin II (Ang II) AT1 receptor blocker (losartan) versus levels in time-matched, non-dehydrated control camels and to record the responses of glutathione and malondialdehyde activity in liver and kidney homogenates in control, dehydrated-losartan treated and dehydrated camels. Eighteen male camels were studied, six hydrated (control group), six dehydrated and treated with losartan (treated group) and six dehydrated not treated (dehydrated). Results Plasma levels of norepinephrine and dopamine were significantly increased (P < 0.01) in both treated and dehydrated groups compared to time matched control, whereas Plasma epinephrine level showed significant decrease (P < 0.05) in both treated and dehydrated groups compared to control. Plasma cortisol also showed significant increase (P < 0.01) in both treated and dehydrated groups compared to control. Glutathione levels in plasma, liver and kidney homogenates for both treated and dehydrated groups reveled significant increase (P < 0.05) Likewise, malondialdehyde levels in plasma, liver and kidney homogenates were substantially and significantly increased in both treated and dehydrated groups. Conclusion In conclusion, the results of this study demonstrated that dehydration substantially increased the circulating levels of norepinephrine, dopamine and cortisol but decreased plasma epinephrine. Similarly, losartan showed similar effects to that of dehydration. In addition, this investigation showed dehydration alone or in combination with losartan induced significant increments in glutathione and malondialdehyde activities in plasma, liver and kidney homogenates, presumably in order to counteract the potentially damaging effects of free radicals. Blockade of angiotensin II AT1 receptors did not alter significantly the response of dehydration in any of these indices.
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Affiliation(s)
- Mahmoud Alhaj Ali
- Department of Pharmacology and Therapeutics, Faculty of Medicine and Health Sciences, United Arab Emirates University, P,O, Box 17666, Al Ain, United Arab Emirates.
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Dab H, Kacem K, Hachani R, Dhaouadi N, Hodroj W, Sakly M, Randon J, Bricca G. Physiological regulation of extracellular matrix collagen and elastin in the arterial wall of rats by noradrenergic tone and angiotensin II. J Renin Angiotensin Aldosterone Syst 2011; 13:19-28. [DOI: 10.1177/1470320311414752] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The interactions between the effects of the sympathetic nervous system (SNS) and angiotensin II (ANG II) on vascular extracellular matrix (ECM) synthesis were determined in rats. The mRNA and protein content of collagen I, collagen III and elastin in the abdominal aorta (AA) and femoral artery (FA) was investigated in Wistar–Kyoto rats treated for 5 weeks with guanethidine, a sympathoplegic, losartan, an ANG II AT1 receptor (AT1R) blocker, or both. The effects of noradrenaline (NE) and ANG II on collagen III and elastin mRNA, and the receptor involved, were tested in cultured vascular smooth muscle cells (VSMCs) in vitro. Guanethidine increased collagen types I and III and decreased elastin, while losartan had an opposite effect, although without effect on collagen III. The combination of treatments abrogated changes induced by simple treatment with collagen I and elastin, but increased collagen III mRNA in AA and not in FA. NE stimulated collagen III mRNA via β receptors and elastin via α1 and α2 receptors. ANG II stimulated collagen III but inhibited elastin mRNA via AT1R. Overall, SNS and ANG II exert opposite and antagonistic effects on major components of ECM in the vascular wall. This may be of relevance for the choice of a therapeutic strategy in vascular diseases.
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Affiliation(s)
- Houcine Dab
- INSERM ERI-22, Agressions Vasculaires et Réponses Tissulaires, Université de Claude Bernard, Lyon I, France
- Université de Carthage. Unité de Physiologie Intégrée, Laboratoire de Pathologies Vasculaires, Faculté des Sciences de Bizerte, Tunisia
| | - Kamel Kacem
- Université de Carthage. Unité de Physiologie Intégrée, Laboratoire de Pathologies Vasculaires, Faculté des Sciences de Bizerte, Tunisia
| | - Rafik Hachani
- Université de Carthage. Unité de Physiologie Intégrée, Laboratoire de Pathologies Vasculaires, Faculté des Sciences de Bizerte, Tunisia
| | - Nadra Dhaouadi
- INSERM ERI-22, Agressions Vasculaires et Réponses Tissulaires, Université de Claude Bernard, Lyon I, France
- Université de Carthage. Unité de Physiologie Intégrée, Laboratoire de Pathologies Vasculaires, Faculté des Sciences de Bizerte, Tunisia
| | - Wassim Hodroj
- INSERM ERI-22, Agressions Vasculaires et Réponses Tissulaires, Université de Claude Bernard, Lyon I, France
| | - Mohsen Sakly
- INSERM ERI-22, Agressions Vasculaires et Réponses Tissulaires, Université de Claude Bernard, Lyon I, France
| | - Jacques Randon
- INSERM ERI-22, Agressions Vasculaires et Réponses Tissulaires, Université de Claude Bernard, Lyon I, France
| | - Giampiero Bricca
- INSERM ERI-22, Agressions Vasculaires et Réponses Tissulaires, Université de Claude Bernard, Lyon I, France
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Pintérová M, Kuneš J, Zicha J. Altered neural and vascular mechanisms in hypertension. Physiol Res 2011; 60:381-402. [PMID: 21615201 DOI: 10.33549/physiolres.932189] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Essential hypertension is a multifactorial disorder which belongs to the main risk factors responsible for renal and cardiovascular complications. This review is focused on the experimental research of neural and vascular mechanisms involved in the high blood pressure control. The attention is paid to the abnormalities in the regulation of sympathetic nervous system activity and adrenoceptor alterations as well as the changes of membrane and intracellular processes in the vascular smooth muscle cells of spontaneously hypertensive rats. These abnormalities lead to increased vascular tone arising from altered regulation of calcium influx through L-VDCC channels, which has a crucial role for excitation-contraction coupling, as well as for so-called "calcium sensitization" mediated by the RhoA/Rho-kinase pathway. Regulation of both pathways is dependent on the complex interplay of various vasodilator and vasoconstrictor stimuli. Two major antagonistic players in the regulation of blood pressure, i.e. sympathetic nervous system (by stimulation of adrenoceptors coupled to stimulatory and inhibitory G proteins) and nitric oxide (by cGMP signaling pathway), elicit their actions via the control of calcium influx through L-VDCC. However, L-type calcium current can also be regulated by the changes in membrane potential elicited by the activation of potassium channels, the impaired function of which was detected in hypertensive animals. The dominant role of enhanced calcium influx in the pathogenesis of high blood pressure of genetically hypertensive animals is confirmed not only by therapeutic efficacy of calcium antagonists but especially by the absence of hypertension in animals in which L-type calcium current was diminished by pertussis toxin-induced inactivation of inhibitory G proteins. Although there is considerable information on the complex neural and vascular alterations in rats with established hypertension, the detailed description of their appearance during the induction of hypertension is still missing.
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Affiliation(s)
- M Pintérová
- Cardiovascular Research Center and Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Abdulla MH, Sattar MA, Abdullah NA, Khan AH, Anand Swarup KRL, Rathore HA, Kazi RN, Basri F, Johns EJ. Effect of renal sympathetic nerve on adrenergically and angiotensin II-induced renal vasoconstriction in normal Wistar-Kyoto rats. Ups J Med Sci 2011; 116:18-25. [PMID: 21047287 PMCID: PMC3039756 DOI: 10.3109/03009734.2010.526723] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND This study examined the effect of renal sympathetic innervation on adrenergically and angiotensin II (Ang II)-induced renal vasoconstriction in Wistar-Kyoto (WKY) rats. METHODS Forty-eight WKY rats were treated with either losartan (10 mg/kg/day p.o.) or carvedilol (5 mg/kg/day p.o.) or a combination of them (10 mg/kg/day + 5 mg/kg/day p.o.) for 7 days. On day 8, the rats were anaesthetized, and renal vasoconstrictor experiments were carried out. A group of rats was subjected to acute unilateral renal denervation during the acute study. Changes in the renal vasoconstrictor responses were determined in terms of reductions in renal blood flow caused by Ang II, noradrenaline (NA), and methoxamine (ME). RESULTS In normal animals, losartan decreased (P < 0.05) the renal vasoconstrictor response to Ang II but not to NA or ME. Carvedilol treatment, however, blunted (P < 0.05) the renal vasoconstrictor responses to Ang II and adrenergic agonists. Combination of losartan and carvedilol blunted (P < 0.05) the renal vasoconstrictor response to Ang II but augmented the responses to NA and ME (all P < 0.05). Interestingly, when denervated rats were treated with the same combination, there was a reduction (P < 0.05) in the renal vasoconstrictor responses to Ang II and adrenergic agonists. CONCLUSIONS Data suggest that the renal sympathetic nerve contributes to adrenergic agonist-mediated renal vasoconstrictions in normal rats. The data further indicate an interactive relationship between renin-angiotensin and sympathetic nervous systems in modulating adrenergically and Ang II-induced renal vasoconstriction in WKY rats.
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Affiliation(s)
- Mohammed H Abdulla
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia.
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Abdulla MH, Sattar MA, Abdullah NA, Khan MAH, Anand Swarup KRL, Johns EJ. The effect of losartan and carvedilol on vasopressor responses to adrenergic agonists and angiotensin II in the systemic circulation of Sprague Dawley rats. ACTA ACUST UNITED AC 2010; 31:13-20. [PMID: 21166975 DOI: 10.1111/j.1474-8673.2010.00461.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1 Interaction between renin-angiotensin (RAS) and sympathetic nervous systems (SNS) was investigated by examining the effect of cumulative blockade of angiotensin II (Ang II) and adrenergic receptors in normal Sprague Dawley rats. 2 Rats were treated with losartan (10 mg/kg), carvedilol (5 mg/kg), or losartan plus carvedilol (10+5 mg/kg) orally for 7 days. On day 8, the animals were anaesthetized with pentobarbitone and prepared for systemic haemodynamic study. Dose-response relationships for the elevation of mean arterial pressure or change in heart rate (HR) in response to intravenous injections of noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and Ang II were determined. 3 Losartan or the combination of losartan with carvedilol blunted vasopressor responses to ME and Ang II. Dose-response relationships for agonist action on HR were significantly inhibited by all treatments except for the combination of losartan and carvedilol on the decrease in HR induced by PE. Carvedilol decreased vasopressor responses to NA, PE and Ang II, and HR responses to NA, ME and Ang II. Combination treatment produced similar effects to losartan on the vasopressor and HR responses but had a greater effect on vasopressor responses to ME and Ang II, and on HR responses to NA and Ang II than carvedilol alone. 4 It is concluded that peripheral vasoconstriction induced by Ang II is partly mediated by adrenergic action and that the vasopressor responses to adrenergic agonists depend on an intact RAS. These observations suggest an interactive relationship between RAS and SNS in determining systemic haemodynamic responses in 'normal' rats.
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Affiliation(s)
- M H Abdulla
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800 Penang, Malaysia
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Dab H, Hachani R, Hodroj W, Sakly M, Bricca G, Kacem K. Differential control of MMP and t-PA/PAI-1 expressions by sympathetic and renin–angiotensin systems in rat left ventricle. Auton Neurosci 2009; 150:27-32. [DOI: 10.1016/j.autneu.2009.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 03/04/2009] [Accepted: 04/01/2009] [Indexed: 12/31/2022]
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Dab H, Hachani R, Hodroj W, Sakly M, Bricca G, Kacem K. Differential control of collagen synthesis by the sympathetic and renin-angiotensin systems in the rat left ventricle. Auton Neurosci 2009; 151:106-10. [PMID: 19679517 DOI: 10.1016/j.autneu.2009.07.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 06/25/2009] [Accepted: 07/15/2009] [Indexed: 01/19/2023]
Abstract
In the present study, we tested the hypothesis of the indirect (via the sympathetic nervous system (SNS)) and direct (via AT1 receptors) contributions of Angiotensin II (Ang II) on the synthesis of collagen types I and III in the left ventricle (LV) in vivo. Sympathectomy and blockade of the Ang II receptor AT1 were performed alone or in combination in normotensive rats. The mRNA and protein synthesis of collagen types I and III were examined by Q-RT-PCR and immunoblotting in the LV. Collagen types I and III mRNA were decreased respectively by 53% and 22% after sympathectomy and only collagen type I mRNA was increased by 52% after AT1 receptor blockade. mRNA was not changed for collagen type I but was decreased by 25% for collagen type III after double treatment. Only collagen protein type III was decreased after sympathectomy by 12%, but collagen proteins were increased respectively for types I and III by 145% and 52% after AT1 receptor blockade and by 45% and 60% after double treatment. Deducted interpretations from our experimental approach suggest that Ang II stimulates indirectly (via SNS) and inhibits directly (via AT1 receptors) the collagen type I at transcriptional and protein levels. For collagen type III, it stimulates indirectly the transcription and inhibited directly the protein level. Therefore, the Ang II regulates collagen synthesis differently through indirect and direct pathways.
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Affiliation(s)
- Houcine Dab
- Unité de Physiologie Intégrée, Laboratoire de Pathologies Vasculaires, Faculté des Sciences de Bizerte, Tunisia.
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Brown NJ, Bradford J, Wang Z, Lea W, Ma L, Ma J, Vaughan DE, Fogo AB. Modulation of angiotensin II and norepinephrine-induced plasminogen activator inhibitor-1 expression by AT1a receptor deficiency. Kidney Int 2007; 72:72-81. [PMID: 17429342 DOI: 10.1038/sj.ki.5002268] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Angiotensin (Ang) II stimulates plasminogen activator inhibitor-1 (PAI-1) expression in many cell types by mechanisms that are cell-type specific. We measured effects of Ang II or norepinephrine on PAI-1 expression in wild type (WT) and Ang type-1a receptor knockout mice (AT(1a)-/-) in the presence or absence of the non-specific AT(1) antagonist losartan. Ang II and norepinephrine increased systolic blood pressure equally, whereas losartan decreased the pressor response of the former but not the latter in WT mice. In AT(1a)-/- mice, baseline systolic blood pressure was lower with no effect of Ang II, norepinephrine, or losartan. Ang II stimulated PAI-1 expression in the heart, aorta, and kidney and markedly in the liver of WT mice. In AT(1a)-/- mice, Ang II-stimulated PAI-1 was significantly attenuated compared with the WT in the heart and aorta but significantly enhanced in the kidney. Losartan decreased the induction in the aorta and liver of WT, and in the kidney and liver of AT(1a)-/- mice. Norepinephrine increased PAI-1 expression in WT heart and aorta, and in AT(1a)-/- heart, kidney, and liver with no effect of losartan. Renal PAI-1 expression correlated with AT(1b) receptor mRNA. We conclude that Ang II stimulates PAI-1 expression in part through the AT(1b) receptor in the kidney and liver. Further, norepinephrine induces PAI-1 expression in vivo with AT(1a) receptor deficiency modulating the effect.
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Affiliation(s)
- N J Brown
- Vanderbilt University Medical Center, Nashville, Tennessee 37232-6602, USA.
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Dendorfer A, Dominiak P, Tempel K, Raasch W. Peripheral sympatholytic actions of four AT1 antagonists: are they relevant for long-term antihypertensive efficacy? J Hypertens 2005; 23:1861-7. [PMID: 16148610 DOI: 10.1097/01.hjh.0000179510.86265.63] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Angiotensin II causes hypertension not only by direct constriction of vascular smooth muscle, but also by facilitating the release of noradrenaline from sympathetic terminals and by enhancing vascular noradrenaline sensitivity. AT1 receptor antagonists attenuate all these actions, but display some evidence of substance-related selectivities. OBJECTIVE The contribution of pre- or postsynaptic impairment of sympathetic transmission to long-term antihypertensive efficacy should be determined for four structurally different, clinically approved AT1 antagonists. DESIGN Spontaneously hypertensive rats were treated with candesartan, eprosartan, irbesartan, or losartan via osmotic minipumps for 4 weeks at doses yielding identical reductions of blood pressure. Maximum efficacy was obtained with a tripled dose of candesartan. METHODS In the pithed rat model, stimulus/response dependencies were determined for vasopressor effectivity of preganglionic electrical stimulation, and of intravenous bolus applications of noradrenaline and angiotensin II. RESULTS Losartan, irbesartan, eprosartan, and candesartan at doses of 5, 40, 20, and 0.05 mg/kg per day, were equally effective in reducing basal systolic blood pressure (-42 mmHg), and the vasopressor potency of angiotensin II (approximately 10-fold). The efficacies of preganglionic stimulation and exogenous noradrenaline were unaltered, with the exception of irbesartan, which reduced vascular noradrenaline sensitivity. The tripled dose of candesartan further reduced basal and angiotensin II-stimulated blood pressures, and significantly attenuated vascular noradrenaline sensitivity. CONCLUSION AT1 antagonists at doses that effectively reduce blood pressure in chronic therapy do not generally suppress peripheral sympathetic function. A potential interaction consists in a reduction of vascular noradrenaline sensitivity, which can be considered as a class effect of AT1 antagonists at high dosage.
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Affiliation(s)
- Andreas Dendorfer
- Institute of Experimental and Clinical Pharmacology and Toxicology, University Clinic Schleswig-Holstein, Campus Luebeck, Luebeck, Germany.
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