possible role for testosterone hormone on lipid peroxidation and some parameters of oxidant-antioxidant balance in rat myocardial tissue

ABSTRACT

The link between androgens and coronary artery disease remains elusive and the possible mechanisms that may relate testosterone to the development of cardiovascular diseases have not been well established yet. This study was designed to clarify the effect of testosterone hormone on lipid peroxidation and oxidants-antioxidant balance in rat myocardial tissue. Forty male albino rats included in this study were divided into 4 equal groups. Group [1] served as control rats and the other three groups were subjected to castration. One week after castration, group [2] rats were injected with solvent, group [3] rats received i.m. testosterone enanthate 10 mg/kg once weekly and group [4] received i.m.daily injections of vitamin E [alpha-tocopherol] in a dose of 20 mg/kg/day. All injections were continued for 4 weeks then all rats were sacrificed by decapitation and the hearts were obtained and prepared for the estimation of lipid peroxides as thiobarbituric acid reactive substance [TBARS], nitrite concentration, glutathione [GSH], glutathione peroxidase [GSH-PX] activity and vitamin E [alpha tocopherol]. TBARS and nitrites concentrations were significantly higher in the myocardial tissue extract of group [2] than group [1] rats while GSH and GSH-PX were sign lower, indicating that castration put the rat myocardial tissue under oxidative stress. However, in group [3] and group [4], TBARS and nitrites were sign lower and GSH and GSH-PX activity were sign higher than group [2], indicating that testosterone replacement therapy as well as vitamin E therapy protected the castrated rats from the oxidative stress and restored the oxidant- antioxidant balance in rat myocardial tissue. It could be concluded that testosterone may have a role in preserving oxidant- antioxidant balance in myocardial tissue of albino rats and this may be one of the mechanisms that could explain a suggested cardioprotective role of testosterone