The cupruretic effect of two chelators following copper loading in sheep.

The cupruretic effect of 2 copper chelators, d-penicillamine and trientine, was assessed in 12 fistulated South African Mutton Merino rams of approximately 6 mo age following copper loading. Each animal received 20 mg CuSO4.5H(2)0/kg body mass as an 0.5% m/v aqueous solution, intraruminally, daily for 35 d. The animals were randomly assigned to either a d-penicillamine (n = 4) or trientine treatment group (n = 4) or an unmedicated control group (n = 4). A separate group of 3 rams were kept as non-copper-loaded controls. Urinary copper excretion was measured before and during treatment. All the sheep were housed individually or placed intermittently on steel metabolic crates to facilitate urine collection. At the end of the trial the animals were euthanatized and specimens of organs collected for determination of copper concentrations. d-Penicillamine significantly (p < 0.05) increased urinary copper excretion. Trientine failed to increase copper excretion in the urine when compared to the unmedicated and non-copper-loaded control groups.