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Akinyemi AJ, Thomé GR, Morsch VM, Bottari NB, Baldissarelli J, de Oliveira LS, Goularte JF, Belló-Klein A, Oboh G, Schetinger MRC. Dietary Supplementation of Ginger and Turmeric Rhizomes Modulates Platelets Ectonucleotidase and Adenosine Deaminase Activities in Normotensive and Hypertensive Rats. Phytother Res 2016; 30:1156-63. [PMID: 27151061 DOI: 10.1002/ptr.5621] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/13/2016] [Accepted: 03/15/2016] [Indexed: 01/15/2023]
Abstract
Hypertension is associated with platelet alterations that could contribute to the development of cardiovascular complications. Several studies have reported antiplatelet aggregation properties of ginger (Zingiber officinale) and turmeric (Curcuma longa) with limited scientific basis. Hence, this study assessed the effect of dietary supplementation of these rhizomes on platelet ectonucleotidase and adenosine deaminase (ADA) activities in Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME) induced hypertensive rats. Animals were divided into seven groups (n = 10): normotensive control rats; induced (l-NAME hypertensive) rats; hypertensive rats treated with atenolol (10 mg/kg/day); normotensive and hypertensive rats treated with 4% supplementation of turmeric or ginger, respectively. After 14 days of pre-treatment, the animals were induced with hypertension by oral administration of l-NAME (40 mg/kg/day). The results revealed a significant (p < 0.05) increase in platelet ADA activity and ATP hydrolysis with a concomitant decrease in ADP and AMP hydrolysis of l-NAME hypertensive rats when compared with the control. However, dietary supplementation with turmeric or ginger efficiently prevented these alterations by modulating the hydrolysis of ATP, ADP and AMP with a concomitant decrease in ADA activity. Thus, these activities could suggest some possible mechanism of the rhizomes against hypertension-derived complications associated to platelet hyperactivity. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Ayodele Jacob Akinyemi
- Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology Akure, Private Mail Bag 704, Akure, 340001, Nigeria
- Department of Biochemistry, Afe Babalola University, Private Mail Bag 5454, Ado-Ekiti, Nigeria
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
| | - Gustavo Roberto Thomé
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
| | - Vera Maria Morsch
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
| | - Nathieli B Bottari
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
| | - Jucimara Baldissarelli
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
| | - Lizielle Souza de Oliveira
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
| | - Jeferson Ferraz Goularte
- Health Basic Sciences Institute, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Adriane Belló-Klein
- Health Basic Sciences Institute, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ganiyu Oboh
- Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology Akure, Private Mail Bag 704, Akure, 340001, Nigeria
| | - Maria Rosa Chitolina Schetinger
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900, Santa Maria, RS, Brazil
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Akinyemi AJ, Thome GR, Morsch VM, Stefanello N, da Costa P, Cardoso A, Goularte JF, Belló-Klein A, Akindahunsi AA, Oboh G, Chitolina Schetinger MR. Effect of dietary supplementation of ginger and turmeric rhizomes on ectonucleotidases, adenosine deaminase and acetylcholinesterase activities in synaptosomes from the cerebral cortex of hypertensive rats. J Appl Biomed 2016. [DOI: 10.1016/j.jab.2015.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Akinyemi AJ, Adedara IA, Thome GR, Morsch VM, Rovani MT, Mujica LKS, Duarte T, Duarte M, Oboh G, Schetinger MRC. Dietary supplementation of ginger and turmeric improves reproductive function in hypertensive male rats. Toxicol Rep 2015; 2:1357-1366. [PMID: 28962478 PMCID: PMC5598100 DOI: 10.1016/j.toxrep.2015.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/27/2015] [Accepted: 10/03/2015] [Indexed: 02/07/2023] Open
Abstract
Ginger [Zingiber officinale Roscoe (Zingiberaceae)] and turmeric [Curcuma longa Linn (Zingiberaceae)] rhizomes have been reportedly used in folk medicine for the treatment of hypertension. However, the prevention of its complication such as male infertility remains unexplored. Hence, the aim of the present study was to investigate the preventive effects of ginger and turmeric rhizomes on some biomarkers of male reproductive function in L-NAME-induced hypertensive rats. Male Wistar rats were divided into seven groups (n = 10): normotensive control rats; induced (L-NAME hypertensive) rats; hypertensive rats treated with atenolol (10 mg/kg/day); normotensive and hypertensive rats treated with 4% supplementation of turmeric or ginger, respectively. After 14 days of pre-treatment, the animals were induced with hypertension by oral administration of L-NAME (40 mg/kg/day). The results revealed significant decrease in serum total testosterone and epididymal sperm progressive motility without affecting sperm viability in hypertensive rats. Moreover, increased oxidative stress in the testes and epididymides of hypertensive rats was evidenced by significant decrease in total and non-protein thiol levels, glutathione S-transferase (GST) activity with concomitant increase in 2′,7′-dichlorofluorescein (DFCH) oxidation and thiobarbituric acid reactive substances (TBARS) production. Similarly, decreased testicular and epididymal NO level with concomitant elevation in arginase activity was observed in hypertensive rats. However, dietary supplementation with turmeric or ginger efficiently prevented these alterations in biomarkers of reproductive function in hypertensive rats. The inhibition of arginase activity and increase in NO and testosterone levels by both rhizomes could suggest possible mechanism of action for the prevention of male infertility in hypertension. Therefore, both rhizomes could be harnessed as functional foods to prevent hypertension-mediated male reproductive dysfunction.
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Affiliation(s)
- Ayodele Jacob Akinyemi
- Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology Akure, Private Mail Bag 704, Akure 340001, Nigeria.,Department of Biochemistry, Afe Babalola University Ado-Ekiti, Private Mail Bag 5454, Nigeria.,Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas (CCNE), Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900 Santa Maria, RS, Brazil
| | - Isaac A Adedara
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97105-900 Santa Maria, RS, Brazil.,Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Gustavo Roberto Thome
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas (CCNE), Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900 Santa Maria, RS, Brazil
| | - Vera Maria Morsch
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas (CCNE), Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900 Santa Maria, RS, Brazil
| | - Monique Tomazele Rovani
- Laboratório de Biotecnologia e Reprodução Animal-BioRep, Universidade Federal de Santa Maria, CEP 97105-900, Santa Maria, RS, Brazil
| | - Lady Katerine Serrano Mujica
- Laboratório de Biotecnologia e Reprodução Animal-BioRep, Universidade Federal de Santa Maria, CEP 97105-900, Santa Maria, RS, Brazil
| | - Thiago Duarte
- Centro de Ciências da Saude, Universidade Luterana do Brazil (ULBRA), Campus Santa Maria, Santa Maria, RS, Brazil
| | - Marta Duarte
- Centro de Ciências da Saude, Universidade Luterana do Brazil (ULBRA), Campus Santa Maria, Santa Maria, RS, Brazil
| | - Ganiyu Oboh
- Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology Akure, Private Mail Bag 704, Akure 340001, Nigeria
| | - Maria Rosa Chitolina Schetinger
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas (CCNE), Universidade Federal de Santa Maria, Campus Universitário, Camobi, CEP 97105-900 Santa Maria, RS, Brazil
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Chaswal M, Das S, Prasad J, Katyal A, Mishra AK, Fahim M. Effect of losartan, an angiotensin II type 1 receptor antagonist on cardiac autonomic functions of rats during acute and chronic inhibition of nitric oxide synthesis. Physiol Res 2012; 61:135-44. [PMID: 22292721 DOI: 10.33549/physiolres.932243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We studied the effect of losartan on baroreflex sensitivity (BRS) and heart rate variability (HRV) of adult Wistar rats during acute and chronic inhibition of nitric oxide synthesis by N(G)-nitro-L-arginine methyl ester (L-NAME). Chronic L-NAME administration (50 mg/kg per day for 7 days, orally through gavage) increased mean arterial pressure (MAP), heart rate but significantly decreased BRS. In addition, a significant fall of standard deviation of normal RR intervals, total spectral power, high frequency spectral power and a rise of low frequency to high frequency (LF: HF) ratio was seen. Acute L-NAME administration (30 mg/kg, i.v. bolus dose) also raised MAP and impaired HRV but it was associated with augmented BRS for bradycardia reflex. Losartan treatment (10 mg/kg, i.v.) in both acute and chronic L-NAME treated rats, decreased MAP but the difference was not significant. On the other hand, losartan administration normalized depressed BRS for bradycardia reflex and significantly reduced LF to HF ratio in chronic L-NAME treated rats. But this improvement was not observed in acute L-NAME group. These results indicate importance of mechanisms other than renin-angiotensin system in the pressor response of both acute as well as chronic L-NAME. However, autonomic dysregulation especially following chronic L-NAME appears to be partly angiotensin dependent.
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Affiliation(s)
- M Chaswal
- Department of Physiology, Vardhaman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
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Chaswal M, Das S, Prasad J, Katyal A, Fahim M. Cardiac autonomic function in acutely nitric oxide deficient hypertensive rats: role of the sympathetic nervous system and oxidative stress. Can J Physiol Pharmacol 2011; 89:865-74. [PMID: 22115075 DOI: 10.1139/y11-084] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We evaluated the role of the sympathetic nervous system and oxidative stress in hemodynamic and autonomic control after acute inhibition of the synthesis of nitric oxide, using intravenous (i.v.) injection of 30 mg·kg(-1) N(G)-nitro-l-arginine methyl ester (L-NAME) in adult Wistar rats. Baroreflex sensitivity (BRS) and heart rate variability (HRV) were measured as indices of cardiac autonomic control, before and after L-NAME treatment in rats with intact autonomic innervation, and in rats with chemical sympathectomy by 6-hydroxydopamine. Serum malondialdehyde (MDA) was measured as a marker of oxidative stress. In control rats, L-NAME treatment resulted in a significant rise in blood pressure, augmentation of BRS, and enhanced serum MDA. HRV showed an attenuation of total spectral power and high frequency spectral power, along with a rise of the low to high frequency ratio (LF:HF). Administration of L-NAME produced a pressor response even in sympathectomised rats, but augmented BRS was not observed, and the high frequency spectral power showed an increase, in addition to a significant decline of LF:HF and serum MDA. We therefore conclude that even though pressor response was unaffected, reversal of cardiac autonomic responses and decline in oxidative stress following sympathectomy in L-NAME-treated rats reflects a significant role for sympathetic innervation in acute L-NAME-induced hypertension.
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Affiliation(s)
- Meenakshi Chaswal
- a Department of Physiology, Vardhaman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
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Dias LD, Casali KR, Leguisamo NM, Azambuja F, Souza MS, Okamoto M, Machado UF, Irigoyen MC, Schaan BD. Renal denervation in an animal model of diabetes and hypertension: impact on the autonomic nervous system and nephropathy. Cardiovasc Diabetol 2011; 10:33. [PMID: 21496329 PMCID: PMC3110548 DOI: 10.1186/1475-2840-10-33] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Accepted: 04/17/2011] [Indexed: 11/11/2022] Open
Abstract
Background The effects of renal denervation on cardiovascular reflexes and markers of nephropathy in diabetic-hypertensive rats have not yet been explored. Methods Aim: To evaluate the effects of renal denervation on nephropathy development mechanisms (blood pressure, cardiovascular autonomic changes, renal GLUT2) in diabetic-hypertensive rats. Forty-one male spontaneously hypertensive rats (SHR) ~250 g were injected with STZ or not; 30 days later, surgical renal denervation (RD) or sham procedure was performed; 15 days later, glycemia and albuminuria (ELISA) were evaluated. Catheters were implanted into the femoral artery to evaluate arterial pressure (AP) and heart rate variability (spectral analysis) one day later in conscious animals. Animals were killed, kidneys removed, and cortical renal GLUT2 quantified (Western blotting). Results Higher glycemia (p < 0.05) and lower mean AP were observed in diabetics vs. nondiabetics (p < 0.05). Heart rate was higher in renal-denervated hypertensive and lower in diabetic-hypertensive rats (384.8 ± 37, 431.3 ± 36, 316.2 ± 5, 363.8 ± 12 bpm in SHR, RD-SHR, STZ-SHR and RD-STZ-SHR, respectively). Heart rate variability was higher in renal-denervated diabetic-hypertensive rats (55.75 ± 25.21, 73.40 ± 53.30, 148.4 ± 93 in RD-SHR, STZ-SHR- and RD-STZ-SHR, respectively, p < 0.05), as well as the LF component of AP variability (1.62 ± 0.9, 2.12 ± 0.9, 7.38 ± 6.5 in RD-SHR, STZ-SHR and RD-STZ-SHR, respectively, p < 0.05). GLUT2 renal content was higher in all groups vs. SHR. Conclusions Renal denervation in diabetic-hypertensive rats improved previously reduced heart rate variability. The GLUT2 equally overexpressed by diabetes and renal denervation may represent a maximal derangement effect of each condition.
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Affiliation(s)
- Lucinara D Dias
- Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia (IC/FUC), Porto Alegre, Brazil
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L-NAME-treatment alters ectonucleotidase activities in kidney membranes of rats. Life Sci 2010; 87:325-32. [PMID: 20655932 DOI: 10.1016/j.lfs.2010.07.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 07/02/2010] [Accepted: 07/06/2010] [Indexed: 11/21/2022]
Abstract
AIMS To investigate the effect of N(omega)-Nitro-L-arginine methyl ester (l-NAME) treatment, known to induce a sustained elevation of blood pressure, on ectonucleotidase activities in kidney membranes of rats. MAIN METHODS L-NAME (30 mg/kg/day) was administered to Wistar rats for 14 days in the drinking water. Enzyme activities were determined colorimetrically and their gene expression patterns were analyzed by semi-quantitative RT-PCR. The metabolism of ATP and the accumulation of adenosine were evaluated by HPLC in kidney membranes from control and hypertensive rats. PKC phosphorylation state was investigated by Western blot. KEY FINDINGS We observed an increase in systolic blood pressure from 115+/-12 mmHg (control group) to 152+/-18 mmHg (l-NAME-treated group). Furthermore, the hydrolysis of ATP, ADP, AMP, and p-Nph-5'TMP was also increased (17%, 35%, 27%, 20%, respectively) as was the gene expression of NTPDase2, NTPDase3 and NPP3 in kidneys of hypertensive animals. Phospho-PKC was increased in hypertensive rats. SIGNIFICANCE The general increase in ATP hydrolysis and in ecto-5'-nucleotidase activity suggests a rise in renal adenosine levels and in renal autoregulatory responses in order to protect the kidney against the threat presented by hypertension.
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Senador D, Kanakamedala K, Irigoyen MC, Morris M, Elased KM. Cardiovascular and autonomic phenotype of db/db diabetic mice. Exp Physiol 2009; 94:648-58. [PMID: 19218356 DOI: 10.1113/expphysiol.2008.046474] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The db/db mice serve as a good model for type 2 diabetes characterized by hyperinsulinaemia and progressive hyperglycaemia. There are limited and conflicting data on the cardiovascular changes in this model. The aim of the present study was to characterize the cardiovascular and autonomic phenotype of male db/db mice and evaluate the role of angiotensin II AT(1) receptors. Radiotelemetry was used to monitor 24 h blood pressure (BP) in mice for 8 weeks. Parameters measured were mean arterial pressure (MAP), heart rate (HR) and their variabilities. In 8-week-old db/db mice, the MAP and BP circadian rhythms were not different from age-matched control mice, while HR and locomotor activity were decreased. With ageing, MAP gradually increased in db/db mice, and the 12 h light values did not dip significantly from the 12 h dark periods. In 14-week-old mice, MAP was increased during light (101 +/- 1 versus 117 +/- 2 mmHg, P < 0.01; control versus db/db mice) and dark phases (110 +/- 1.7 versus 121 +/- 3.1 mmHg, P < 0.01; control versus db/db mice). This increase in MAP was associated with a significant increase in plasma angiotensin-converting enzyme activity and angiotensin II levels. Chronic treatment with losartan (10 mg kg(-1) day(-1)) blocked the increase in MAP in db/db mice, with no effect in control animals. Spectral analysis was used to monitor autonomic cardiovascular function. The circadian rhythm observed in systolic arterial pressure variance and its low-frequency component in control mice was absent in db/db mice. There were no changes in HR variability and spontaneous baroreflex sensitivity between control and db/db mice. The results document an age-related increase in MAP in db/db mice, which can be reduced by antagonism of angiotensin II AT(1) receptors, and alterations in autonomic balance and components of the renin-angiotensin system.
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Affiliation(s)
- Danielle Senador
- Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
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Souza M, Machado U, Okamoto M, Bertoluci M, Ponpermeyer C, Leguisamo N, Azambuja F, Irigoyen M, Schaan B. Reduced cortical renal GLUT1 expression induced by angiotensin-converting enzyme inhibition in diabetic spontaneously hypertensive rats. Braz J Med Biol Res 2008; 41:960-8. [DOI: 10.1590/s0100-879x2008001100004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 11/04/2008] [Indexed: 11/21/2022] Open
Affiliation(s)
- M.S. Souza
- Fundação Universitária de Cardiologia, Brasil
| | | | | | | | | | | | - F. Azambuja
- Fundação Universitária de Cardiologia, Brasil
| | - M.C. Irigoyen
- Fundação Universitária de Cardiologia, Brasil; Universidade de São Paulo, Brasil
| | - B.D. Schaan
- Fundação Universitária de Cardiologia, Brasil; Universidade Federal do Rio Grande do Sul, Brasil
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Fürstenau CR, Trentin DDS, Gossenheimer AN, Ramos DB, Casali EA, Barreto-Chaves MLM, Sarkis JJF. Ectonucleotidase activities are altered in serum and platelets of L-NAME-treated rats. Blood Cells Mol Dis 2008; 41:223-9. [PMID: 18559295 DOI: 10.1016/j.bcmd.2008.04.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 02/15/2008] [Accepted: 04/30/2008] [Indexed: 12/31/2022]
Abstract
It is well known that hypertension is closely associated to the development of vascular diseases and that the inhibition of nitric oxide biosynthesis by administration of Nomega-Nitro-L-arginine methyl ester hydrochloride(L-NAME) leads to arterial hypertension. In the vascular system, extracellular purines mediate several effects;thus, ADP is the most important platelet agonist and recruiting ag ent, while adenosine, an end product of nucleotide metabolism, is a vasodilator and inhibitor of platelet activation and recruitment. Members of several families of enzymes, known as ectonucleotidases, including E-NTPDases (ecto-nucleoside triphosphate diphosphohydrolase), E-NPP (ecto-nucleotide pyrophosphatase/phosphodiesterase) and 5'-nucleotidase are able to hydrolyze extracellular nucleotides until their respective nucleosides. We investigated the ectonucleotidase activities of serum and platelets from rats made hypertensive by oral administration of L-NAME (30 mg/kg/day for 14 days or 30 mg/kg/day for 14 days plus 7 days of L-NAME washout, in the drinking water) in comparison to normotensive control rats. L-NAME promoted a significant rise in systolic blood pressure from 112 +/- 9.8 to 158 +/- 23 mmHg. The left ventricle weight index (LVWI) was increased in rats treated with L-NAME for 14 days when compared to control animals. In serum samples, ATP, ADP and AMP hydrolysis were reduced by about 27%, 36% and 27%, respectively. In platelets, the decrease in ATP, ADP and AMP hydrolysis was approximately 27%, 24% and 32%, respectively. All parameters recovered after 7 days of L-NAME washout. HPLC demonstrated a reduction in ADP, AMP and hypoxanthine levels by about 64%, 69% and 87%,respectively. In this study, we showed that ectonucleotidase activities are decreased in serum and platelets from L-NAME-treated rats, which should represent an additional risk for the development of hypertension. The modulation of ectonucleotidase activities may represent an approach to antihypertensive therapy via inhibition of spontaneous platelet activation and recruitment, as well as thrombus formation.
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Affiliation(s)
- Cristina Ribas Fürstenau
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Farah VDMA, De Angelis K, Joaquim LF, Candido GO, Bernardes N, Fazan R, Schaan BD, Irigoyen MC. Autonomic modulation of arterial pressure and heart rate variability in hypertensive diabetic rats. Clinics (Sao Paulo) 2007; 62:477-82. [PMID: 17823711 DOI: 10.1590/s1807-59322007000400015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 03/20/2007] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The aim of the present study was to evaluate the autonomic modulation of the cardiovascular system in streptozotocin (STZ)-induced diabetic spontaneously hypertensive rats (SHR), evaluating baroreflex sensitivity and arterial pressure and heart rate variability. METHODS Male SHR were divided in control (SHR) and diabetic (SHR+DM, 5 days after STZ) groups. Arterial pressure (AP) and baroreflex sensitivity (evaluated by tachycardic and bradycardic responses to changes in AP) were monitored. Autoregressive spectral estimation was performed for systolic AP (SAP) and pulse interval (PI) with oscillatory components quantified as low (LF:0.2-0.6Hz) and high (HF:0.6-3.0Hz) frequency ranges. RESULTS Mean AP and heart rate in SHR+DM (131+/-3 mmHg and 276+/-6 bpm) were lower than in SHR (160+/-7 mmHg and 330+/-8 bpm). Baroreflex bradycardia was lower in SHR+DM as compared to SHR (0.55+/-0.1 vs. 0.97+/-0.1 bpm/mmHg). Overall SAP variability in the time domain (standard deviation of beat-by-beat time series of SAP) was lower in SHR+DM (3.1+/-0.2 mmHg) than in SHR (5.7+/-0.6 mmHg). The standard deviation of the PI was similar between groups. Diabetes reduced the LF of SAP (3.3+/-0.8 vs. 28.7+/-7.6 mmHg2 in SHR), while HF of SAP were unchanged. The power of oscillatory components of PI did not differ between groups. CONCLUSIONS These results show that the association of hypertension and diabetes causes an impairment of the peripheral cardiovascular sympathetic modulation that could be, at least in part, responsible for the reduction in AP levels. Moreover, this study demonstrates that diabetes might actually impair the reduced buffer function of the baroreceptors while reducing blood pressure.
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Maeda CY, Schaan BD, Oliveira EM, Oliveira VL, De Angelis K, Irigoyen MC. CHRONIC SALT LOADING AND CARDIOVASCULAR-ASSOCIATED CHANGES IN EXPERIMENTAL DIABETES IN RATS. Clin Exp Pharmacol Physiol 2007; 34:574-80. [PMID: 17581211 DOI: 10.1111/j.1440-1681.2007.04625.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1. High-sodium intake may increase blood pressure and diabetes is a salt-sensitive condition. In the present study, we evaluated cardiovascular changes and their neurohumoral mechanisms in streptozotocin (STZ)-diabetic rats that underwent chronic salt loading. 2. We studied male Wistar rats (150-280 g) 14 days after the injection of either STZ (50 mg/kg, i.v.; D; n = 18) or citrate buffer (C; n = 16). After the induction of diabetes, animals were maintained for 14 days with free access to standard rat chow and tap water (C and D groups) or 1% NaCl solution (C-S and D-S groups). We conducted two experiments. Experiment 1 consisted of basal arterial pressure (AP) measurement (30 min) followed by the evaluation of AP responsiveness to phenylephrine and sodium nitroprusside. One day later, with the rats anaesthetized, a blood sample was collected to test for glycaemia, plasma angiotensin-converting enzyme (ACE) activity and renin. Kidneys were removed for the determination of tissue ACE activity. Experiment 2 comprised 24 h urine collection followed by 3 days of cardiovascular records, which consisted of a 30 min basal AP measurement, followed by injection of blockers of the vasopressin system, the renin-angiotensin system (RAS) and the sympathetic system. Basal haemodynamic data, baroreflex evaluation and AP responses to blockade of the vasopressin system with vasopressin V(1) receptor antagonist (aAVP; 10 mg/kg, i.v.), the RAS by losartan (10 mg/kg, i.v.) and the sympathetic system by hexamethonium (20 mg/kg, i.v.) were determined. 3. Glycaemia was similar between C and C-S (P = 0.612) and between D and D-S (P = 0.552), but higher in diabetic compared with non-diabetic rats (P < 0.0001). The D-S rats had an increment of 24% in mean AP compared with D (120 +/- 4 vs 97 +/- 2 mmHg, respectively; P = 0.0001), which was not seen in C-S compared with C rats. A positive association was noted between urinary sodium and mean AP (r = 0.37; P = 0.04). Plasma renin was undetectable in D-S rats. The response to acute drug blockade of vasopressin and the RAS was similar among groups, but hexamethonium elicited a more pronounced decrease in AP in D-S compared with D rats (P = 0.001). 4. The main neurohumoral mechanisms of salt-induced cardiovascular changes in STZ-diabetes are increased sodium and vascular sensitivity to adrenergic stimuli, which act in combination to produce a final result of higher AP levels, a finding not observed in control rats. Baroreflex derangements induced by diabetes were not affected by salt overload.
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Affiliation(s)
- C Y Maeda
- Hypertension Unit, Heart Institute, University of São Paulo, São Paulo, and Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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De Angelis K, D'Agord Schaan B, Rodrigues B, Malfitano C, Irigoyen MC. Disfunção autonômica cardiovascular no diabetes mellitus experimental. ACTA ACUST UNITED AC 2007; 51:185-94. [PMID: 17505625 DOI: 10.1590/s0004-27302007000200007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2006] [Accepted: 01/03/2007] [Indexed: 01/17/2023]
Abstract
Muitas informações novas têm sido publicadas nos últimos anos a respeito da fisiopatologia da disfunção autonômica cardiovascular em ratos e camundongos diabéticos. Nosso grupo tem estudado o curso temporal das alterações cardiovasculares associadas ao diabetes experimental há alguns anos, obtendo evidências consistentes de grave disautonomia em modelos animais de diabetes. O objetivo deste trabalho foi revisar a contribuição que estudos envolvendo diferentes modelos de deficiência e resistência à insulina têm fornecido para o entendimento, tratamento e prevenção da disfunção autonômica cardiovascular do diabetes.
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