Effects of aerobic exercise training on cardiac renin-angiotensin system in an obese Zucker rat strain

• Published in: PloS one Vol. 7; no. 10; p. e46114
• Main Authors: Barretti, Diego Lopes Mendes, Magalhães, Flávio de Castro, Fernandes, Tiago, do Carmo, Everton Crivoi, Rosa, Kaleizu Teodoro, Irigoyen, Maria Claudia, Negrão, Carlos Eduardo, Oliveira, Edilamar Menezes
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.10.2012; Public Library of Science (PLoS)
• Subjects: ACE2; Aerobic exercises; Aerobics; Angiotensin; Angiotensin I; Angiotensin II; Angiotensin II - metabolism; Angiotensin-converting enzyme 2; Animals; Apoptosis; Biochemistry; Biology; Blood Pressure; Blotting, Western; Cardiomyopathy; Cardiovascular diseases; Cholesterol; Complications and side effects; Echocardiography; Enzymes; Exercise; Fitness training programs; Health aspects; Heart - physiopathology; Heart diseases; Heart Rate; High density lipoprotein; Hyperactivity; Hypertension; Hypertrophy; Laboratories; Lipoproteins (high density); Lipoproteins (low density); Low density lipoprotein; Male; Medical schools; Medicine; Molecular biology; Myosin Heavy Chains - metabolism; Obesity; Obesity - physiopathology; Peptidyl-dipeptidase A; Peptidyl-Dipeptidase A - metabolism; Physical Conditioning, Animal; Physical education; Physical fitness; Physical training; Physiological aspects; Rats; Rats, Zucker; Real-Time Polymerase Chain Reaction; Renin; Renin-Angiotensin System; Reverse Transcriptase Polymerase Chain Reaction; Risk factors; Rodents; Studies; Swimming; Training; Triglycerides; Weight control; Workloads; Brazil
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0046114

Obesity and renin angiotensin system (RAS) hyperactivity are profoundly involved in cardiovascular diseases, however aerobic exercise training (EXT) can prevent obesity and cardiac RAS activation. The study hypothesis was to investigate whether obesity and its association with EXT alter the systemic and cardiac RAS components in an obese Zucker rat strain. THE RATS WERE DIVIDED INTO THE FOLLOWING GROUPS: Lean Zucker rats (LZR); lean Zucker rats plus EXT (LZR+EXT); obese Zucker rats (OZR) and obese Zucker rats plus EXT (OZR+EXT). EXT consisted of 10 weeks of 60-min swimming sessions, 5 days/week. At the end of the training protocol heart rate (HR), systolic blood pressure (SBP), cardiac hypertrophy (CH) and function, local and systemic components of RAS were evaluated. Also, systemic glucose, triglycerides, total cholesterol and its LDL and HDL fractions were measured. The resting HR decreased (∼12%) for both LZR+EXT and OZR+EXT. However, only the LZR+EXT reached significance (p<0.05), while a tendency was found for OZR versus OZR+EXT (p = 0.07). In addition, exercise reduced (57%) triglycerides and (61%) LDL in the OZR+EXT. The systemic angiotensin I-converting enzyme (ACE) activity did not differ regardless of obesity and EXT, however, the OZR and OZR+EXT showed (66%) and (42%), respectively, less angiotensin II (Ang II) plasma concentration when compared with LZR. Furthermore, the results showed that EXT in the OZR prevented increase in CH, cardiac ACE activity, Ang II and AT2 receptor caused by obesity. In addition, exercise augmented cardiac ACE2 in both training groups. Despite the unchanged ACE and lower systemic Ang II levels in obesity, the cardiac RAS was increased in OZR and EXT in obese Zucker rats reduced some of the cardiac RAS components and prevented obesity-related CH. These results show that EXT prevented the heart RAS hyperactivity and cardiac maladaptive morphological alterations in obese Zucker rats.