Ca(+) mishandling due to impaired activity of cardiac sarco(endo)plasmic reticulum Ca(2+) ATPase (SERCA2a) has been associated with the development of left ventricular diastolic dysfunction in insulin-resistant cardiomyopathy. However, the molecular causes underlying SERCA2a alterations induced by insulin resistance and related metabolic disorders, such as metabolic syndrome (MetS), are not completely understood. In this study, we used a sucrose-fed rat model of MetS to test the hypothesis that decreased SERCA2a activity is mediated by elevated oxidative stress produced in the MetS heart. Production of ROS and cytosolic Ca(2+) concentration were recorded in left ventricular myocytes using confocal imaging. The level of SERCA2a oxidation was determined in left ventricular homogenates by biotinylated iodoacetamide labeling. Compared with control rats, sucrose-fed rats exhibited several characteristics of MetS, including central obesity, insulin resistance, hyperinsulinemia, and hypertriglyceridemia. Moreover, relative to myocytes from control rats, myocytes from MetS rats exhibited elevated basal production of ROS accompanied by slowed cytosolic Ca(2+) removal, reflected by prolonged Ca(2+) transients. The slowed cytosolic Ca(2+) removal was associated with a significant decrease in SERCA2a-mediated Ca(2+) reuptake and increased SERCA2a oxidation. Importantly, myocytes from MetS rats treated with the antioxidant N-acetylcysteine showed normal ROS levels and SERCA2a-mediated Ca(2+) reuptake as well as accelerated cytosolic Ca(2+) removal. These data suggest that elevated oxidative stress may induce oxidative modifications on SERCA2a leading to abnormal function of this protein in the MetS heart.

The prevalence of the metabolic syndrome (MetS) and its cardiac comorbidities as cardiac hypertrophy (CH) have increased considerably due to the high consumption of carbohydrates, such as sucrose and/or fructose. We compared the effects of sucrose (S), fructose (F) and their combination (S + F) on the development of MetS in weaned male Wistar rats and established the relationship between the consumption of these sugars and the degree of cardiac CH development, oxidative stress (OS) and Calcium/calmodulin-dependent protein kinase type II subunit delta oxidation (ox-CaMKII δ ). 12 weeks after the beginning of treatments with S, F or S + F, arterial pressure (AP) was measured and 8 weeks later (to complete 20 weeks) the animals were sacri ced and blood samples, visceral adipose tissue and hearts were obtained. Biochemical parameters were determined in serum and cardiac tissue to evaluate the development of MetS and OS. To evaluate CH, atrial natriuretic peptide (ANP), CaMKII δ and ox-CaMKII δ were determined by western blot and histological studies were performed in cardiac tissue. Our data showed that chronic consumption of S + F exacerbates MetS-induced CH which is related with a higher OS and ox-CaMKII δ .

Serenoa repens has been widely used to treat benign prostatic hyperplasia and lower urinary tract symptoms; however, most of the studies have been conducted in individuals with normal weight and not obese. In this study, the effects of a lipidic extract of S. repens, in markers of oxidative stress, inflammation, and growth factors, in obese rats with testosterone-induced prostatic hyperplasia, were investigated. Total nitrites, malondialdehyde, total glutathione, superoxide dismutase (SOD), and catalase activity were measured; in addition, assays for inflammatory cytokines TNF-α, IL-1β, IL-6 and the growth factors basic fibroblast growth factor (FGFb) and vascular endothelial growth factor (VEGF) were performed. The obese rats had a higher prostate weight compared with controls. S. repens significantly decreased prostate weight, total nitrites, and malondialdehyde; improved total glutathione, SOD, and catalase activity; and significantly reduced inflammatory (TNF-α, IL-1β and IL-6) and growth factors (VEGF and FGFb). S. repens showed high antioxidant and antiinflammatory activity in obese rats, suggesting that their use could be beneficial in the treatment of benign prostatic hyperplasia.

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Capsaicin per se or its combination with moderate exercise could be a useful therapy against complications linked to obesity-IR in HE females.