RESUMO
Atherosclerosis is one of the common disorders among hypothyroidism, which, increased the risk of cardiovascular diseases. Reactive oxygen species are associated with atherosclerosis development. Antioxidant defense systems are the scavenger for free radicals. Apelin is an endogenous ligand for the APJ receptor (apelin receptor) that exists in most tissues, acts as an adiponectin. It has been identified that apelin administration, improve the antioxidant capacity (TAC). Therefore, this study was conducted to assess, therapeutic effects of apelin, T4 (L-Thyroxin) or both on antioxidant capacity in 6-propyl-2-thiouracil (PTU)-induced hypothyroid rats. Forty male Wistar rats were randomly assigned into five groups: C: control group; P group (hypothyroid): PTU (0.05 %) administration for six weeks; P+A, P+T and P+A+T groups: after 4 weeks of PTU administration, animals treated with Apelin (200 μg/kg/day, ip) T4 (0.02 µg/g/day, gavage) and apelin+T4; for two weeks respectively accompanied by PTU administration. Aplein administration in P+A group and P+A+T group had beneficial effect to lowering of malondialdehyde (MDA) content as compared to hypothyroid group (8.52±0.64 and 8.53±1 vs. 13.67±1.64 nmol/g tissue, P<0.05) and also had increasing effect on Superoxide dismutase (SOD) and glutathion peroxidase (GPx) activity and the total antioxidant capacity (TAC) content compared to the hypothyroid group. This study showed that apelin was able to improve the oxidant-antioxidant balance in the heart tissue of the hypothyroid rats by elevating of antioxidant enzyme activity.
RESUMO
Vanillic acid is an oxidized form of vanillin produced during the conversion of vanillin to ferulic acid and has free radical scavenging, antioxidant and anti-inflammatory properties. In this study, we investigated the effects of vanillic acid on hemodynamic parameters and infarct size in ischemia-reperfusion of isolated rat heart. Adult male Sprague Dawley rats were randomly divided into control and treatment groups (n=10). The treatment groups were administered vanillic acid 5, 10 and 20 mg/kg orally for 10 days, then the hearts isolated and were exposed to 30 min ischemia and 1 h reperfusion, using langendorff apparatus. The effects of vanillic acid, on left ventricular developed pressure (LVDP), LV end diastolic pressure (LVEDP), LV pressure (LVP), peak rate of rise and fall of LVP (±dp/dt), coronary flow (CF), rate pressure product (RPP) and infarct size were examined. Rats administered with vanillic acid (10 and 20 mg/kg), displayed significantly improved recovery of LVEDP, RPP, LVDP, LVP and ± dp/dt as compared to control group. There was also significant beneficial effect of these two doses to reduce infarct size. Our results suggest that vanillic acid can effectively improve ventricular function and reduce infarct size in ischemia-reperfusion of isolated rat heart.