Abstract: BACKGROUND AND AIM: To study the effect of trace element copper on lipid peroxidation by analyze relations among copper concentration, copper-zinc ratio (Cu/Zn) and the biomarkers of lipid peroxidation in copper deficiency in rats. MATERIALS AND METHODS: Determined the content of copper in blood, the activities of Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-pX) and Catalase (CAT) and the content of Malondialdehyde (MDA) in copper deficiency. RESULTS: Copper-defficient rats treated with copper gluconate (Cu-G) in different doses showed fluctuating copper concentrations in the blood, while copper-zinc ratio (Cu/Zn) showed an ascending trend following the increase of copper intake and statistical significant results (P<0.01). In copper deficiency state, the SOD activity was lower than the normal level, and then followed an upward trend with increased copper intake, equivalent to the copper-zinc (Cu/Zn) ratio. The content of MDA was higher than the normal level, and its content decreased with increasing copper intake and the Cu/Zn ratio, and remained at a relatively low level. The decreased Cu/Zn ratio could induce the increase of the CAT activity, but with no linear correlation between them. No significant effect on the GSH-pX activity in rat blood was found during inadequate copper intake. CONCLUSION: Cu-Zn ratio has more practical significance in the research of physiological and biochemical roles of the trace element copper. In copper deficiency, theSOD activity in the rat blood was lower than the normal level and the content of MDA higher. With the increase of Cu/Zn ratio, the SOD activity increased gradually, while the content of MDA was reduced. Insufficient copper intake could enhance the CAT activity in blood with no effect on GSH-pX.

Key words: copper, copper deficiency, lipid peroxidation, superoxide dismutase, glutathione peroxidase, catalase, malondialdehyde