Modulation of cardiac renin-angiotensin system, redox status and inflammatory profile by different volumes of aerobic exercise training in obese rats
FREE RADICAL BIOLOGY AND MEDICINE
Authors: Alexandre-Santos, Beatriz; Alves, Renata; Matsuura, Cristiane; Sepulveda-Fragoso, Vinicius; Velasco, Larissa Lirio; Machado, Marcus Vinicius; Vieira, Aline Bomfim; Fernandes, Tiago; Oliveira, Edilamar Menezes; Tibirica, Eduardo; Nobrega, Antonio Claudio Lucas da; Magliano, D'Angelo Carlo; Frantz, Eliete Dalla Corte
Abstract
Overactivation of the classical arm of the renin-angiotensin (Ang) system (RAS) occurs during inflammation, oxidative stress and obesity-induced cardiomyopathy. The activation of the protective arm of RAS may act to counterbalance the deleterious effects of the classical RAS. Although aerobic exercise training (AET) shifts the balance of the RAS towards the protective arm, little is known about the molecular adaptations to different volumes of AET. The aim of this study was to evaluate the impact of AET volume on the modulation of RAS, as well as on cardiac biomarkers of oxidative stress and inflammation, in a diet-induced obesity model. Male Wistar rats were fed either control (CON) or high fat (HF) diet for 32 weeks. At week 20, HF group was subdivided into sedentary, low (LEV, 150 min/week) or high (HEV, 300 min/week) exercise volume. After 12 weeks of exercise, body mass gain, systolic blood pressure and heart rate were evaluated, as well as RAS, oxidative stress and inflammation in the heart. Body mass gain, systolic blood pressure and heart rate were higher in HF group when compared with SC group. Both trained groups restored systolic blood pressure and heart rate, but only HEV reduced body mass gain. Regarding the cardiac RAS, the HF group exhibited favoring of the classical arm and both trained groups shifted the balance towards the counterregulatory protective arm. The HF group had higher B1R expression and lower B2R expression than the control group, and B2R expression was reverted in both trained groups. The HF group also presented oxidative stress. The LEV and HEV groups improved the cardiac redox status by reducing Nox 2 and nitrotyrosine expression, but only the LEV group was able to increase the antioxidant defense by increasing Nrf2 signaling. While the HF group presented higher TNF-alpha, IL-6 and NF kappa B expression, and lower IL-10 expression, than the SC group, both training protocols improved the inflammatory profile. Although both trained groups improved the deleterious changes related to obesity cardiomyopathy, it is clear that the molecular mechanisms differ between them. Our results suggest that different exercise volumes might reach different molecular targets, and this could be a relevant factor when using exercise to manage obesity.
Hepatitis E Epidemiology, Clinical Course, Prevention, and Treatment
GASTROENTEROLOGY CLINICS OF NORTH AMERICA
Authors: Goel, Amit; Aggarwal, Rakesh
Abstract
Hepatitis E virus is a common cause of acute hepatitis and acute liver failure in resource-constrained parts of the world. The disease is particularly severe when the infection occurs during pregnancy. In developed countries, human infections occur primarily through zoonotic transmission from animal reservoirs; however, clinical disease is less frequent than in the developing world. The virus strains prevalent in these areas also cause chronic infection in immunocompromised persons, which, if untreated, can progress to cirrhosis; such infection responds well to oral ribavirin. A safe and highly effective recombinant vaccine is available in China, but is not available elsewhere.