ABSTRACT
Cyclosporine therapy is associated with a variety of adverse effects. Recent studies have suggested increased oxidative stress as a cause of these side effects. Since, melatonin is one of the most powerful known antioxidants, and regarding that isoproterenol is one of the drugs stimulating endogenous melatonin production, we tried to determine the effect of isoproterenol on LDL susceptibility to oxidation and serum total antioxidant capacity in cyclosporine-treated rats.32 male Wistar rats were divided into four groups: of group A were controls that received placebo; group B, received intraperitoneal isoproterenol [20 mg/kg/d] alone; group C, intravenous cyclosporine [15 mg/kg/d] alone; and group D, both drugs simultaneously at the same doses and durations namely cyclosporine one week after administration of isoproterenol. Blood samples were drawn four times for each group: before injections, during the treatment, end of the treatment, and one week after the last injections. There was an increase in LDL susceptibility to oxidation [P<0.05], and a decrease in serum total antioxidant capacity [P<0.05] in group C rats. But, there were no significant changes in group B and D rats by point of LDL susceptibility to oxidation and total antioxidant capacity. Isoproterenol may be capable of delaying adverse effects of cyclosporine by preventing the increase in LDL susceptibility to oxidation, and decrease in serum total antioxidant capacity