Biliary copper excretion in the rat is enhanced by spironolactone

Tissue distribution and excretion (urinary, fecal, and biliary) of an intravenous bolus of 64Cu(NO3)2 were measured in rats pretreated with spironolactone and in controls. Intact animals pretreated with spironolactone excreted 10% more of a standard intravenous injection of copper in the first 24 hr than did controls. At the end of that time, kidney, red blood cell, and serum copper levels all were similar for the two groups, but liver copper concentrations were higher in controls. During the 1st hr after copper injection, plasma copper levels tended to fall more rapidly in pretreated animals, whereas liver copper concentrations increased more rapidly; red blood cell copper concentrations were not higher in animals given spironolactone. Pretreated animals excreted significantly more copper in the bile during the first 2 hr after 64Cu(NO3)2 injection, and had higher hepatic copper levels at 3 hr.