Copper salicylate complex: thermoregulatory and biochemical effects

The antipyretic properties of copper (II) salicylate and its effect on plasma copper, iron, zinc and ceruloplasmin concentrations was investigated in adult rabbits at an ambient temperature of 21.5 +/- 0.5 degrees C. The experiments indicated that copper salicylate (200 mg/kg/h i.v.) was a more potent antipyretic than sodium salicylate given in the same manner and doses. This pharmacological activity was found on a model of experimental fever induced by i.v. injection of lipopolysaccharide Escherichia coli at a dose of 1 microgram/kg. Furthermore, unlike sodium salicylate, this copper complex caused a decrease in core temperature in normothermic rabbits. At the same time copper salicylate activated heat dissipation much more efficiently than the parent drug, as manifested by decreases in vasomotor tone and reversal of postpyrogen inhibition of RF. As was expected, treatment with copper salicylate increased plasma copper and ceruloplasmin levels in both normothermic and febrile rabbits. These increases did not lead to any disturbances in iron and zinc concentrations. Neither salicylate affected postpyrogen falls in plasma iron concentrations. They both, however, delayed the appearance of zinc decreases in febrile rabbits. The results of this study suggest that copper modifies the thermoregulatory effects of salicylate. Moreover, the increased amounts of this metal do not seem to disturb seriously the ionic status of the blood.