Copper distribution and reactivity in serum following administration of cuprous oxide to rats and guinea pigs.

Total serum copper levels produced by the administration of a single dose of cuprous oxide (500 mg/kg) both s.c. and orally to rats and guinea pigs are reported 1, 5, 7 and 24 h after administration, together with caeruloplasmin oxidase activities and changes in the sulphydryl group concentrations. The highest serum copper levels were obtained one hour after oral administration to the guinea pig. Both animal species exhibited increased serum copper levels after s.c. administration and this increase persisted for a longer time than after oral administration. Caeruloplasmin oxidase activity varied in a complex manner and sulphydryl group activity was significantly depressed in all cases except after s.c. administration to the guinea pig. The latter results must be treated cautiously since they may indicate interactions between copper and the test procedures. Analysis of serum fractions separated by electrophoresis indicated that the absorbed copper is mainly transported on albumin. The dissolution of cuprous oxide by amino acids and hydrochloric acid and the absorption of cuprous oxidcations of the results are discussed in terms of their relevance to pharmacological and clinical studies.