The aim of our study was to investigate the contribution of exogenous adrenomedullin (ADM): an antioxidant, and N sup omega nitro-L-arginine methyl ester (L-NAME); the nitric oxide synthase (NOS) enzyme inhibitor, to balance the oxidant/antioxidant status in hypothalamus and adrenal medulla, which are both key components of the hypothalamic-pituitary-adrenal (HPA) axis and affects some lipid metabolic mediators. Thirty six male albino Spraque-Dawley rats were randomly divided into three groups: the control group, the ADM group (8 nmol/kg, i.p.), and the L-NAME group (2 ml/kg, i.p.). Measurements of tissue superoxide dismutase (SOD), catalase (CAT), glutathion S-transferase (GST) and glutathion reductase (GR) activities and glutathione (GSH) were performed in tissues using chemical protocols. The biochemical analyses for total lipid, cholesterol, triglycerides, HDL, VLDL, and LDL were conducted on an auto-analyser. Administering exogenous ADM and L-NAME caused synergic changes in the tissues, antioxidative enzyme activities, and altered serum lipoprotein profiles in rats.