Nutritional supplementation with copper in the rat. I. Effects on adjuvant arthritis development and on some in vivo- and ex vivo-markers of blood neutrophils.

OBJECTIVE AND
DESIGN: The aims of the work were: 1) to confirm the preliminarily observed anti-arthritic potential of a 200 ppm copper-supplemented diet in the rat: 2) to study the impact of the nutritional treatment and of the experimental pathology on neutrophil activity. ANIMALS AND CELLS: Two hundred female Sprague-Dawley rats were used. Polymorphonuclear leukocytes were isolated from these animals for the ex vivo studies. TREATMENT: Control-rats were maintained on a standard diet containing 5 ppm of copper. Supplemented-rats were kept on a diet containing 200 ppm of the metal.
METHODS: Mycobacterium butyricum-induced arthritis was studied. Flame atomic absorption spectroscopy was used to assess copper and zinc levels. The "microplate-assay" technique was used to determine serum lysozyme concentration (lysis of Micrococcus lysodeikticus cell walls), as well as neutrophil O2- generation (superoxide dismutase-inhibitable reduction of ferricytochrome-c), and adhesion (activity of the membrane enzyme acid phosphatase). The results were statistically evaluated by the Student's t test.
RESULTS: The nutritional copper-supplementation: 1) significantly inhibited the adjuvant-arthritis development (33% +/- 5, P<0.01); 2) did not modify lysozyme secretion or superoxide production; 3) significantly decreased the percentage of cell adhesion by an average of 41% +/- 19 (P<0.01).
CONCLUSIONS: The copper-supplemented diet has an anti-arthritic effect which may be also primed by the effect of copper on the expression of the neutrophil cell-adhesion molecules.