Associations between copper concentrations in liver and serum and ceruloplasmin in serum from horses

Objective. The aim of this study is to determine the reference intervals and the associations between the concentrations of liver and blood serum copper (Cu) and serum ceruloplasmin (Cp) in horses. Materials and Methods. Thirty eight adults horses slaughtered in the Araucania Region, Chile, were used for this study. Blood samples were obtained by jugular venipuncture for determination of serum Cu and Cp concentrations and a sample of liver, 10 g, was obtained after the animal was slaughtered to determine Cu concentration. The reference intervals were calculated and the correlation between serum and liver Cu concentration and serum Cp were determined using Pearson correlation and lineal regression. Results. Reference interval values for liver Cu (32 -161 mmol/kg wet matter), serum Cu (10 - 24 mmol/L) and Cp (0.08 -0.43 ΔDO) concentrations were established. Horses had adequate Cu status according with the liver Cu values, when compared with literature, except one horse which was under the lower reference limit. Serum concentrations of Cu and Cp were associated (r=0.49, p<0.05); but no appreciable association between the other variables (p>0.05) was found. Conclusions. Liver Cu concentrations of adult horses slaughtered in the region of Araucania, Chile, are within the intervals described in the literature. Liver Cu concentration was not associated with serum concentration of Cu or ceruloplasmin, and a moderate association between these last two variables was found.