CLINICS

Clinics (Sao Paulo). 2017 May; 72(5): 310-316.
doi:10.6061/clinics/2017(05)09

Copyright © 2017 CLINICS

Aerobic Swim Training Restores Aortic Endothelial Function by Decreasing Superoxide Levels in Spontaneously Hypertensive Rats

Camila P Jordão III , Tiago Fernandes I , Leonardo Yuji Tanaka II , Luiz R. Grassmann Bechara I , Luis Gustavo Oliveira de Sousa I , Edilamar M Oliveira I , Paulo Rizzo Ramires I *

Laboratorio de Bioquimica e Biologia Molecular do Exercicio, Escola de Educacao Fisica e Esporte, Universidade de Sao Paulo, Sao Paulo, SP, BR

Laboratorio de Biologia Vascular, Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR

Unidade de Reabilitação, Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR

*Corresponding author. E-mail: ramires@usp.br

received October 17, 2016; revised January 5, 2017; accepted February 17, 2017.

Abstract

OBJECTIVE:

We aimed to determine whether aerobic training decreases superoxide levels, increases nitric oxide levels, and improves endothelium-dependent vasodilation in the aortas of spontaneously hypertensive rats.

METHODS:

Spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were distributed into 2 groups: sedentary (SHRsd and WKYsd, n=10 each) and swimming-trained (SHRtr, n=10 and WKYtr, n=10, respectively). The trained group participated in training sessions 5 days/week for 1 h/day with an additional work load of 4% of the animal’s body weight. After a 10-week sedentary or aerobic training period, the rats were euthanized. The thoracic aortas were removed to evaluate the vasodilator response to acetylcholine (10-10 to 10-4 M) with or without preincubation with L-NG-nitro-L-arginine methyl ester hydrochloride (L-NAME; 10-4 M) in vitro. The aortic tissue was also used to assess the levels of the endothelial nitric oxide synthase and nicotinamide adenine dinucleotide oxidase subunit isoforms 1 and 4 proteins, as well as the superoxide and nitrite contents. Blood pressure was measured using a computerized tail-cuff system.

RESULTS:

Aerobic training significantly increased the acetylcholine-induced maximum vasodilation observed in the SHRtr group compared with the SHRsd group (85.9±4.3 vs. 71.6±5.2%). Additionally, in the SHRtr group, superoxide levels were significantly decreased, nitric oxide bioavailability was improved, and the levels of the nicotinamide adenine dinucleotide oxidase subunit isoform 4 protein were decreased compared to the SHRsd group. Moreover, after training, the blood pressure of the SHRtr group decreased compared to the SHRsd group. Exercise training had no effect on the blood pressure of the WKYtr group.

CONCLUSIONS:

In SHR, aerobic swim training decreased vascular superoxide generation by nicotinamide adenine dinucleotide oxidase subunit isoform 4 and increased nitric oxide bioavailability, thereby improving endothelial function.

Keywords: Aerobic Training, Vasodilation, Nitric Oxide, Superoxide, Hypertension


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