[Study of effects of copper deficiency on internal organ through a copper deficiency model in rat]

To establish copper deficiency model in rats, and observe the damnification on internal organ of copper deficiency rats.

27 male weanling SD rats with 5-week-old were randomized into 3 groups (n = 9), i.e., control group 1, control group2 and copper deficiency group (CuD). The rats of the control group 1 were fed commercial feed with copper level of 7.0 mg/kg, the rats of the control group 2 and the copper deficiency group were fed half-purified diet with copper level of 0.73 mg/kg. In afternoons, rats were orally perfused copper sulphate solution with copper concentration 0 (control group 1), 0.133 (control group 2) and 0 mg/ml (copper deficiency group), respectively, the volume was 1% of body weight, so theory copper level of the feed in the control group2 was 11.37 mg/kg. All of rats had free access to both food and de-ionized water. Rats were sacrificed at the end of test feeding on the 42nd day, blood was sampled for analyzing the plasma ceruloplasmin activity (PCP) and its content (PPD), and erythrocyte Cu-Zn SOD (EC Cu-Zn SOD); liver was sampled for analyzing the content of Metallothionein (MT), and liver copper (LC). The organic tissues of kidney, brain, heart, liver, spleen, lung and testes are sampled for histopathologic examination.

The PCP and EC Cu-Zn SOD, PPD, LC and LMT of rats in copper deficiency group was significantly lower than those of rats in control group1 and control group2 (except EC Cu-Zn SOD) (P < 0.01). The cardiac muscle fibers of a part of rats in copper deficiency group were broken and eosinophilic. The endothelial cell of a coronary artery branch was presented proliferation and swelling, subendothelial space was broadened. An arteriole in the lung was showed thickening of the wall, and presented obliteration of the lumen. No obvious pathological changes of other internal organ were found.

Copper deficiency model in rats is successfully established after rats ingesting diet of low copper for 42 days. Slightly pathologic changes in the cardiovascular tissues of part of rats in copper deficiency groups are observed.