Comparison of therapeutic effects of L-Thyroxin, apelin and a combination of both on antioxidant enzymes in the heart of PTU-induced hypothyroid rats

ABSTRACT

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.