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Meshram S, Verma VK, Mutneja E, Sahu AK, Malik S, Mishra P, Bhatia J, Arya DS. Evidence-based mechanistic role of chrysin towards protection of cardiac hypertrophy and fibrosis in rats. Br J Nutr 2022; 129:1-14. [PMID: 35177130 DOI: 10.1017/s0007114522000472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cardiac hypertrophy is the enlargement of cardiomyocytes in response to persistent release of catecholamine which further leads to cardiac fibrosis. Chrysin, flavonoid from honey, is well known for its multifarious properties like antioxidant, anti-inflammatory, anti-fibrotic and anti-apoptotic. To investigate the cardioprotective potential of chrysin against isoproterenol (ISO), cardiac hypertrophy and fibrosis are induced in rats. Acclimatised male albino Wistar rats were divided into seven groups (n 6): normal (carboxymethyl cellulose at 0·5 % p.o.; as vehicle), hypertrophy control (ISO 3 mg/kg, s.c.), CHY15 + H, CHY30 + H & CHY60 + H (chrysin; p.o.15, 30 and 60 mg/kg respectively + ISO at 3 mg/kg, s.c.), CHY60 (chrysin 60 mg/kg in per se) and LST + H (losartan 10 mg/kg p.o. + ISO 3 mg/kg, s.c.) were treated for 28 d. After the dosing schedule on day 29, haemodynamic parameters were recorded, after that blood and heart were excised for biochemical, histological, ultra-structural and molecular evaluations. ISO administration significantly increases heart weight:body weight ratio, pro-oxidants, inflammatory and cardiac injury markers. Further, histopathological, ultra-structural and molecular studies confirmed deteriorative changes due to ISO administration. Pre-treatment with chrysin of 60 mg/kg reversed the ISO-induced damage to myocardium and prevent cardiac hypertrophy and fibrosis through various anti-inflammatory, anti-apoptotic, antioxidant and anti-fibrotic pathways. Data demonstrated that chrysin attenuated myocardial hypertrophy and prevented fibrosis via activation of transforming growth factor-beta (TGF-β)/Smad signalling pathway.
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Affiliation(s)
- Sonali Meshram
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Vipin Kumar Verma
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Ekta Mutneja
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Anil Kumar Sahu
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Salma Malik
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Prashant Mishra
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Jagriti Bhatia
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
| | - Dharamvir S Arya
- Cardiovascular Research Laboratory, Department of Pharmacology, All India Institute of Medical Sciences, New Delhi110029, India
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Patten GS, Abeywardena MY. Effects of Antihypertensive Agents on Intestinal Contractility in the Spontaneously Hypertensive Rat: Angiotensin Receptor System Downregulation by Losartan. J Pharmacol Exp Ther 2016; 360:260-266. [PMID: 27903643 PMCID: PMC5267511 DOI: 10.1124/jpet.116.237586] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/21/2016] [Indexed: 12/23/2022] Open
Abstract
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.
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Bertagnolli M, Dios A, Béland-Bonenfant S, Gascon G, Sutherland M, Lukaszewski MA, Cloutier A, Paradis P, Schiffrin EL, Nuyt AM. Activation of the Cardiac Renin-Angiotensin System in High Oxygen-Exposed Newborn Rats: Angiotensin Receptor Blockade Prevents the Developmental Programming of Cardiac Dysfunction. Hypertension 2016; 67:774-82. [PMID: 26857347 DOI: 10.1161/hypertensionaha.115.06745] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/07/2016] [Indexed: 11/16/2022]
Abstract
Newborn rats exposed to high oxygen (O2), mimicking preterm birth-related neonatal stress, develop later in life cardiac hypertrophy, dysfunction, fibrosis, and activation of the renin-angiotensin system. Cardiac renin-angiotensin system activation in O2-exposed adult rats is characterized by an imbalance in angiotensin (Ang) receptors type 1/2 (AT1/2), with prevailing AT1 expression. To study the role of renin-angiotensin system in the developmental programming of cardiac dysfunction, we assessed Ang receptor expression during neonatal high O2 exposure and whether AT1 receptor blockade prevents cardiac alterations in early adulthood. Sprague-Dawley newborn rats were kept with their mother in 80% O2 or room air (control) from days 3 to 10 (P3-P10) of life. Losartan or water was administered by gavage from P8 to P10 (n=9/group). Rats were studied at P3 (before O2 exposure), P5, P10 (end of O2), and P28. Losartan treatment had no impact on growth or kidney development. AT1 and Ang type 2 receptors were upregulated in the left ventricle by high O2 exposure (P5 and P10), which was prevented by Losartan treatment at P10. Losartan prevented the cardiac AT1/2 imbalance at P28. Losartan decreased cardiac hypertrophy and fibrosis and improved left ventricle fraction of shortening in P28 O2-exposed rats, which was associated with decreased oxidation of calcium/calmodulin-dependent protein kinase II, inhibition of the transforming growth factor-β/SMAD3 pathway, and upregulation of cardiac angiotensin-converting enzyme 2. In conclusion, short-term Ang II blockade during neonatal high O2 prevents the development of cardiac alterations later in life in rats. These findings highlight the key role of neonatal renin-angiotensin system activation in the developmental programming of cardiac dysfunction induced by deleterious neonatal conditions.
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Affiliation(s)
- Mariane Bertagnolli
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Anne Dios
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Sarah Béland-Bonenfant
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Gabrielle Gascon
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Megan Sutherland
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Marie-Amélie Lukaszewski
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Anik Cloutier
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Pierre Paradis
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Ernesto L Schiffrin
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.)
| | - Anne Monique Nuyt
- From the Department of Pediatrics, Sainte-Justine University Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (M.B., A.D., S.B.-B., G.G., M.S., M.-A.L., A.C., A.M.N.); and Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Medicine, McGill University, Montreal, Quebec, Canada (P.P., E.L.S.).
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Samuel P, Ali Q, Sabuhi R, Wu Y, Hussain T. High Na intake increases renal angiotensin II levels and reduces expression of the ACE2-AT(2)R-MasR axis in obese Zucker rats. Am J Physiol Renal Physiol 2012; 303:F412-9. [PMID: 22592638 DOI: 10.1152/ajprenal.00097.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
High sodium intake is known to regulate the renal renin-angiotensin system (RAS) and is a risk factor for the pathogenesis of obesity-related hypertension. The complex nature of the RAS reveals that its various components may have opposing effects on natriuresis and blood pressure regulation. We hypothesized that high sodium intake differentially regulates and shifts a balance between opposing components of the renal RAS, namely, angiotensin-converting enzyme (ACE)-ANG II-type 1 ANG II receptor (AT(1)R) vs. AT(2)-ACE2-angiotensinogen (Ang) (1-7)-Mas receptor (MasR), in obesity. In the present study, we evaluated protein and/or mRNA expression of angiotensinogen, renin, AT(1A/B)R, ACE, AT(2)R, ACE2, and MasR in the kidney cortex following 2 wk of a 8% high-sodium (HS) diet in lean and obese Zucker rats. The expression data showed that the relative expression pattern of ACE and AT(1B)R increased, renin decreased, and ACE2, AT(2)R, and MasR remained unaltered in HS-fed lean rats. On the other hand, HS intake in obese rats caused an increase in the cortical expression of ACE, a decrease in ACE2, AT(2)R, and MasR, and no changes in renin and AT(1)R. The cortical levels of ANG II increased by threefold in obese rats on HS compared with obese rats on normal salt (NS), which was not different than in lean rats. The HS intake elevated mean arterial pressure in obese rats (27 mmHg) more than in lean rats (16 mmHg). This study suggests that HS intake causes a pronounced increase in ANG II levels and a reduction in the expression of the ACE2-AT(2)R-MasR axis in the kidney cortex of obese rats. We conclude that such changes may lead to the potentially unopposed function of AT(1)R, with its various cellular and physiological roles, including the contribution to the pathogenesis of obesity-related hypertension.
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Affiliation(s)
- Preethi Samuel
- Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA
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Yang R, Yang B, Wen Y, Fang F, Cui S, Lin G, Sun Z, Wang R, Dai Y. Losartan, an Angiotensin type I receptor, restores erectile function by downregulation of cavernous renin-angiotensin system in streptozocin-induced diabetic rats. J Sex Med 2008; 6:696-707. [PMID: 19175863 DOI: 10.1111/j.1743-6109.2008.01054.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION The high incidence of erectile dysfunction (ED) in diabetes highlights the need for good treatment strategies. Recent evidence indicates that blockade of the angiotensin type I receptor (AT1) may reverse ED from various diseases. AIM To explore the role of cavernous renin-angiotensin system (RAS) in the pathogenesis of diabetic ED and the role of losartan in the treatment of diabetic ED. METHODS The AT1 blocker (ARB) losartan (30 mg/kg/d) was administered to rats with streptozocin (65 mg/kg)-induced diabetes. Erectile function, cavernous structure, and tissue gene and protein expression of RAS in the corpora cavernosa were studied. MAIN OUTCOME MEASURE We sought to determine the changes of cavernous RAS in the condition of diabetes and after treatment with losartan. RESULTS RAS components (angiotensinogen, [pro]renin receptor, angiotensin-converting enzyme [ACE], and AT1) were expressed in cavernosal tissue. In diabetic rats, RAS components were upregulated, resulting in the increased concentration of angiotensin II (Ang II) in the corpora. A positive feedback loop for Ang II formation in cavernosum was also identified, which could contribute to overactivity of cavernous RAS in diabetic rats. Administration of losartan blocked the effect of Ang II, downregulated the expression of AT1 and Ang II generated locally, and partially restored erectile function (losartan-treated group revealed an improved intracavernous pressure/mean systemic arterial pressure ratio as compared with the diabetic group (0.480 +/- 0.031 vs. 0.329 +/- 0.020, P < 0.01). However, losartan could not elevate the reduced smooth muscle/collagen ratio in diabetic rats. CONCLUSIONS The cavernous RAS plays a role in modulating erectile function in corpora cavernosa and is involved in the pathogenesis of diabetic ED. ARB can restore diabetic ED through downregulating cavernous RAS.
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Affiliation(s)
- Rong Yang
- Affiliated Drum Tower Hospital of Nanjing University, School of Medicine-Urology, Nanjing, China
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Liu D, Gao L, Roy SK, Cornish KG, Zucker IH. Role of oxidant stress on AT1 receptor expression in neurons of rabbits with heart failure and in cultured neurons. Circ Res 2008; 103:186-93. [PMID: 18566341 DOI: 10.1161/circresaha.108.179408] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have previously reported that the expression of Angiotensin II (Ang II) type 1 receptors (AT1R) was increased in the rostral ventrolateral medulla (RVLM) of rabbits with chronic heart failure (CHF) and in the RVLM of normal rabbits infused with intracerebroventricular (ICV) Ang II. The present study investigated whether oxidant stress plays a role in Ang II-induced AT1R upregulation and its relationship to the transcription factor activator protein 1 (AP1) in CHF rabbits and in the CATHa neuronal cell line. In CATHa cells, Ang II significantly increased AT1R mRNA by 123+/-11%, P<0.01; c-Jun mRNA by 90+/-20%, P<0.01; c-fos mRNA by 148+/-49%, P<0.01; NADPH oxidase activity by 126+/-43%, P<0.01 versus untreated cells. Tempol and Apocynin reversed the increased expression of AT1R mRNA, c-Jun mRNA, c-fos mRNA, and superoxide production induced by Ang II. We also examined the effect of ICV Tempol on the RVLM of CHF rabbits. Compared to vehicle treated CHF rabbits, Tempol significantly decreased AT1R protein expression (1.6+/-0.29 versus 0.88+/-0.16, P<0.05), phosphorylated Jnk protein (0.4+/-0.05 versus 0.2+/-0.04, P<0.05), cytosolic phosphorylated c-Jun (0.56+/-0.1 versus 0.36+/-0.05, P<0.05), and nuclear phosphorylated c-Jun (0.67+/-0.1 versus 0.3+/-0.08, P<0.01). Tempol also significantly decreased the AP-1-DNA binding activity in the RVLM of CHF rabbits compared to the vehicle group (9.14 x 10(3) versus 41.95 x 10(3) gray level P<0.01). These data suggest that Ang II induces AT1R upregulation at the transcriptional level by induction of oxidant stress and activation of AP1 in both cultured neuronal cells and in intact brain of rabbits. Antioxidant agents may be beneficial in CHF and other states where brain Ang II is elevated by decreasing AT1R expression through the Jnk and AP1 pathway.
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Affiliation(s)
- Dongmei Liu
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
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