title: Decreased endothelial nitric oxide, systemic oxidative stress, and increased sympathetic modulation contribute to hypertension in obese rats.
abstract: We investigated the involvement of nitric oxide (NO) and reactive oxygen species (ROS) on autonomic cardiovascular parameters, vascular reactivity, and endothelial cells isolated from aorta of monosodium glutamate (MSG) obese rats. Obesity was induced by administration of 4 mg/g body wt of MSG or equimolar saline [control (CTR)] to newborn rats. At the 60th day, the treatment was started with N(G)-nitro-L-arginine methyl ester (L-NAME, 20 mg/kg) or 0.9% saline. At the 90th day, after artery catheterization, mean arterial pressure (MAP) and heart rate were recorded. Plasma was collected to assess lipid peroxidation. Endothelial cells isolated from aorta were evaluated by flow cytometry and fluorescence intensity (FI) emitted by NO-sensitive dye [4,5-diaminofluoresceindiacetate (DAF-2DA)] and by ROS-sensitive dye [dihydroethidium (DHE)]. Vascular reactivity was made by concentration-response curves of acetylcholine. MSG showed hypertension compared with CTR. Treatment with L-NAME increased MAP only in CTR. The MSG induced an increase in the low-frequency (LF) band and a decrease in the high-frequency band of pulse interval. L-NAME treatment increased the LF band of systolic arterial pressure only in CTR without changes in MSG. Lipid peroxidation levels were higher in MSG and were attenuated after L-NAME. In endothelial cells, basal FI to DAF was higher in CTR than in MSG. In both groups, acetylcholine increased FI for DAF from basal. The FI baseline to DHE was higher in MSG than in CTR. Acetylcholine increased FI to DHE in the CTR group, but decreased in MSG animals. We suggest that reduced NO production and increased production of ROS may contribute to hypertension in obese MSG animals.
authors.affiliation: Department of Physiological Sciences State University of Londrina, Londrina, PR;
authors.forename: Natalia Veronez
authors.initials: NV
authors.lastname: da Cunha
authors.affiliation: Department of Pathological Sciences State University of Londrina, Londrina, PR;
authors.forename: Phileno
authors.initials: P
authors.lastname: Pinge-Filho
authors.affiliation: Department of Pathological Sciences State University of Londrina, Londrina, PR;
authors.forename: Carolina
authors.initials: C
authors.lastname: Panis
authors.affiliation: Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; and.
authors.forename: Bruno Rodrigues
authors.initials: BR
authors.lastname: Silva
authors.affiliation: Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; and.
authors.forename: Laena
authors.initials: L
authors.lastname: Pernomian
authors.affiliation: Faculty of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Marcella Daruge
authors.initials: MD
authors.lastname: Grando
authors.affiliation: Department of Pathological Sciences State University of Londrina, Londrina, PR;
authors.forename: Rubens
authors.initials: R
authors.lastname: Cecchini
authors.affiliation: Faculty of Pharmaceutical Sciences of Ribeirão Preto, Department of Physics and Chemistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Lusiane Maria
authors.initials: LM
authors.lastname: Bendhack
authors.affiliation: Department of Physiological Sciences State University of Londrina, Londrina, PR; martinspinge@uel.br.
authors.forename: Marli Cardoso
authors.initials: MC
authors.lastname: Martins-Pinge
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000187:drug effects; D009765:Obesity / Q000139:chemically induced / Q000150:complications / Q000503:physiopathology*; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D012970:Sodium Glutamate / Q000009:adverse effects; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*
chemical_list: D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D019331:NG-Nitroarginine Methyl Ester; D012970:Sodium Glutamate
keywords: autonomic; endothelium; monosodium glutamate; nitric oxide synthase