Inflammation hormonally elevates activity levels of the serum copper protein ceruloplasmin (Cp). Marginal copper status could limit this rise to the extent that potential antiinflammatory actions are limited, but not to the extent that Cp activity levels reliably assess copper status during inflammation. This study demonstrated such behavior using rats fed graded amounts of copper (0.3, 3, 6, or 15 ppm Cu). Inflammation produced Cp activity levels inversely proportional to copper intake. However, inflammation in rats fed 3 or 6 ppm copper raised initially low Cp activities to values equal or exceeding, respectively, those of rats fed 15 ppm copper without inflammation. Injection of CuSO4 (0.5 mg Cu/kg, ip) raised Cp activities after 20 h in inflamed and noninflamed rats from each dietary treatment except the 15 ppm copper. The percent increases tended to be inversely proportional to copper intake. Serum copper responses to copper injections resembled those of Cp activities, but actual percent increases for the serum copper were sometimes different from those for Cp. Possibly, copper status in people with inflammatory diseases could be assessed by Cp activity response to bolus copper administration. © 1990 Pergamon Press plc.
