Low and marginal copper intake by postweanling rats: effects on copper status and resistance to carbon tetrachloride hepatotoxicity

Serum Copper and Zinc Levels in Primary Immune Thrombocytopenia

Although the pathogenesis of immune thrombocytopenia is not fully known, oxidative stress is one of the etiological causes. Copper and zinc are elements in the antioxidant system, and their deficiency causes oxidative stress. We aimed to determine the serum copper and zinc levels and their effects on the response to treatment in patients with immune thrombocytopenia. We analyzed 51 patients with primary immune thrombocytopenia and 33 control cases. Age, gender, and platelet values at the time of diagnosis, drugs used for the treatment of immune thrombocytopenia, remission status, and serum copper and zinc levels were recorded. The primary immune thrombocytopenia and control groups were compared in terms of serum copper and zinc levels. In addition, the relationship between the response status to the treatment of patients with immune thrombocytopenia and serum copper and zinc levels was investigated. The serum zinc level in the immune thrombocytopenia group and control group was 10.35 ± 3.28 µmol/L and 12.82 ± 2.41 µmol/L, respectively (p = 0.01). The serum copper level in patients with immune thrombocytopenia (77.3 ± 22.23 µg/dL) was significantly lower than the control group (99.4 ± 20.82 µg/dL) (p = 0.01). A significant correlation was found between the response to first-line treatment of primary immune thrombocytopenia and serum copper level (p = 0.005). The serum copper level was significantly lower in relapsed cases (p = 0.001). In conclusion, serum copper and zinc levels are lower in patients with primary immune thrombocytopenia than in healthy cases. Patients with relapsed or unresponsive to immune thrombocytopenia treatment have lower serum copper levels than other patients.

Effect of copper deficiency on oxidative DNA damage in Jurkat T-lymphocytes

The micronutrient copper is a catalytic cofactor for copper, zinc superoxide dismutase and ceruloplasmin, which are two important antioxidant enzymes. As such, a lack of copper may promote oxidative stress and damage. The purpose of this study was to determine the effect of copper deficiency on oxidative damage to DNA in Jurkat T-lymphocytes. To induce copper deficiency, cells were incubated for 48 h with 5-20 microM 2,3,2-tetraamine (2,3,2-tet), a high affinity copper chelator. Such treatment did not affect cell proliferation/viability, as assessed by measuring mitochondrial reduction of WST-1 reagent (4-[3-(4-Iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-ben zen e disulfonate). Furthermore, the induction of copper deficiency did not promote oxidative DNA damage as evaluated by the comet assay. Comet scores were 15 +/- 0 and 16 +/- 1 for control and copper-deficient cells, respectively. However, the copper-deficient cells sustained greater oxidative DNA damage than the control cells (comet scores of 175 +/- 15 and 50 +/- 10, respectively) when both were oxidatively challenged with 50 microM hydrogen peroxide (H(2)O(2)). Supplemental copper but not zinc or iron prevented the potentiation of the H(2)O(2)-induced oxidative DNA damage caused by 2,3,2-tet. These data suggest that copper deficiency compromises the antioxidant defense system of cells, thereby increasing their susceptibility to oxidative DNA damage.

Newer aspects of micronutrients in chronic disease: copper

Cu ions are pro-oxidants when added to biological material in vitro and excessive levels of Cu in the body, such as in Wilson's Disease (Yarze et al. 1992) promote oxidant-related pathologies. In contrast there is now substantial evidence that an optimum level of Cu is required to maintain antioxidant defence and that Cu deficiency in animals increases oxidant stress. There are abundant mechanistic relationships linking Cu deficiency and processes associated with IHD, some of which do not directly involve oxidant damage. These mechanistic relationships, however, have mostly been demonstrated in animal models and more information is urgently required concerning possible chronic mild Cu deficiencies in human populations. A major hurdle to advances in this area is the lack of indices of Cu status which are sensitive enough to detect marginal Cu deficiency in humans. The question, therefore, of whether or not there is a role for mild Cu deficiency in the onset of chronic disease processes, including IHD, remains unanswered.