R. Milanino

Copper and zinc body levels in inflammation: An overview of the data obtained from animal and human studies

The development of acute and chronic inflammatory processes induces, in the laboratory animal, a net accumulation of both copper and zinc in many body compartments, the inflammed area included. In rheumatoid arthritis, as well as in animal models, only plasma zinc concentration seems to be significantly correlated with disease severity, while the increase in total plasma copper could be described as an “all or nothing” phenomenon. Moreover, in rheumatoid arthritis, it appears that the disease develops and progresses without being linked to either copper or zinc deficiency conditions.Thus, it seems reasonable to suggest that a rationale for the use of copper and/or zinc in the treatment of inflammatory disorders can only be drawn from the intrinsic pharmacological properties of such trace elements, rather than from the need for their repletion.

Review: Copper and inflammation — a possible rationale for the pharmalogical manipulation of inflammatory discorders

Acute and chronic inflammations are characterized, among other features, by changes in the metabolism of copper and by a widespread responsiveness to the therapy with copper-containing molecules.The exact map of inflammation-induced copper movements as well as the role played by the metal in the pathogenesis of inflammatory disorders are, however, far from being clear, and this is especially true in the case of chronic processes.Nevertheless the present knowledge suggests that the ‘copper approach’ may provide a new way for coping with the problem of anti-inflammatory/anti-arthritic therapies. The administration of exogenous copper, and thein vivo manipulation of the endogenous metal levels are proposed as two possible therapeutic strategies, not necessarily mutually exclusive.For a better understanding of the value of such an approach, further research work is needed, especially to attain a more detailed know-how on the involved chemical forms, distribution and functions of copper in both normal as well as inflamed organisms.

Copper metabolism during acute inflammation: studies on liver and serum copper concentrations in normal and inflamed rats

1 The concentration of copper in serum and liver was determined by atomic absorption spectrophotometry in a study performed on normal rats of either sex and in female rats with carrageenan‐induced pleurisy. 2 In the normal animal, total serum copper concentration is significantly higher in female rats, and appears to be higher in mature animals in females. 3 In normal rats of either sex, liver copper concentration undergoes daily variations which are inversely related to the weight of the organ and which leave constant the total amount of metal in the liver. Moreover a day to day non‐cyclic variability of liver copper concentration and liver weight was observed. 4 This first set of data showed that comparison with time control was essential. 5 In the inflamed rat, a significant rise of total serum copper at 22, 48 and 72 h after the induction of inflammation was observed. From 96 h up to 240 h post‐injection no significant differences were evident. 6 Total liver copper content did not change in the inflamed rats. 7 During acute inflammation in the rat, the copper needed for the increased synthesis of caeruloplasmin is supplied without depletion of liver copper stores.

Carrageenan oedema in copper-deficient rats.

Carrageenan-induced hind paw oedema has been studied in rats deprived of copper for different lengths of time.A common feature observed in normally fed and copper-deficient rats was the rise of serum copper levels coccurring between 10 and 24 h after the injection of the irritant.After 1 month of copper-deficient diet no differences are seen in the oedema developed by controls and copperdeprived animals, while after 3 months the oedema developed by copper-deficient rats was significantly greater compared with the controls.These results are briefly discussed.

Copper and zinc status in rats with acute inflammation: focus on the inflamed area.

Status of copper and zinc in plasma, blood cells, liver and hind paws (sectioned at the tibio-tarsal joint) were evaluated in rats with carrageenan-induced paw-oedema; moreover, concentrations of copper and zinc in the supernatant and cell fractions obtained from exudates pooled from rats with carrageenan-induced pleurisy were also determined.The evaluation of copper and zinc status in the blood and in the liver of rats with carrageenan-induced paw oedema, showed that only minor variations differentiated this experimental pathology from the previously studied carrageenan-induced pleurisy in rat.In inflammatory exudates withdrawn from pleural cavity, copper concentrations were found to be higher than the basal values measured in the whole paw, whereas zinc concentrations were found to be dramatically lower.Thus the induction of the carrageenan paw-oedema determined an increase in copper and a decrease in zinc concentrations in the inflamed paw; however, in the inflamed paw, the total amounts of both copper and zinc were found to be significantly increased.

Copper and zinc status during acute inflammation: studies on blood, liver and kidneys metal levels in normal and inflamed rats

The concentrations of copper and zinc in plasma, blood cells, liver and kidneys were determined in a study performed on normal female rats, and in female rats with carrageenan induced pleurisy. In the normal rat, the total amount of both metals increases, from 51 to 79 days of age, in all the compartments examined. This increase was mostly, and in some case exclusively, dependent upon the growth of the animal, although high individual and day to day variations in both copper and zinc values were observed in all the compartments studied. In the blood of inflamed rats a statistically significant increase in copper was measured during the crucial hours of the experiment (i.e. from 6 to 72 h); over 90% of the increase found was attributable to variations in plasma copper concentration values. In the liver of inflamed rats a statistically significant increase in zinc was measured at 6, 22 and 48 h after the carrageenan injection. The induction of the acute non-infective inflammatory process did not cause quantitative changes of both copper and zinc in all the other compartments considered in the present study. These results seem to suggest that, during acute inflammation, the organism increases its requirement for copper and zinc, and that this demand is fulfilled by enhanced intestinal absorption and/or decreased intestinal excretion of both metals.

Concerning the role of endogenous copper in the acute inflammatory process.

The development of two models of acute inflammation (carrageenan-induced foot oedema and pleurisy) was studied in rats after 1 month of a 0.2 p.p.m. copper-deficient diet and after 5 months of a 0.6–0.8 p.p.m. copper-deficient diet.A ‘pro-inflammatory’ effect of copper deficiency was observed with the 0.2 p.p.m. diet, whilst no effect was evident following the 0.6–0.8 p.p.m. copper-deficient diet.These results are briefly commented upon.

Comparison of the effects of the antimetastatic compound ImH[trans-RuCl4(DMSO)Im] (NAMI-A) on the arthritic rat and on MCa mammary carcinoma in mice.

The effects of the new molecule ImH[trans-RuCl4(DMSO)Im] (NAMI-A), administered orally or intraperitoneally to adjuvant-arthritic rats or orally to mice bearing s.c. or i.m. implants of MCa mammary carcinoma, were studied. NAMI-A was not able to modify the progression of chronic inflammation in the complete Freund-adjuvant injected animals. Histology indicated a significant worsening of the inflammatory process, characterised by an increased infiltration of inflammatory cells, as well as by a remarkable deposition of connective tissue fibres around the blood vessels and alveolar walls. NAMI-A had no effect on primary i.m. implanted MCa mammary carcinoma growth and its lung metastasis formation, but significantly interfered with the cell cycle of primary tumor cells following bolus oral administration. On the contrary, NAMI-A caused a significant inhibition of lung metastasis accompanied by a dramatic deposition of connective tissue fibres around the primary tumor mass, when given as medicated food to mice implanted s.c. with MCa tumor. These data indicated that NAMI-A is well absorbed after oral administration although there is no connection between lung concentration and the antimetastatic activity. Conversely, the marked deposition of connective tissues in NAMI-A treated animals is in agreement with the reported effects of the compund on extracellular matrix and tumor blood vessels.

Copper and zinc status in adjuvant-arthritic rat: studies on blood, liver, kidneys, spleen and inflamed paws

The status of copper and zinc in plasma, blood cells, kidneys, spleen and hind paws was evaluated in tail-injected adjuvant-arthritic rats, during both the asymptomatic (3 and 7 days after the inoculum) and symptomatic (14, 21 and 30 days after the inoculum) phases of the experimental disease. During the symptomatic phase, inflamed rats were studied divided into two groups on the basis of their arthritic scores (low-score L.S. and high-score H.S. arthritic rats).Copper (both in concentration and total amount) was found significantly increased in plasma, blood cells, liver, spleen and arthritic paws, whereas, in the kidneys, it was found to be lower than normal.Zinc was found to be remarkably increased in the liver. In blood, zinc was found to be decreased in plasma, but almost unchanged in the cellular fraction. Zinc total amount (but not concentration) was increased in the spleen, most likely because of a significant increase in spleen weight. As previously described in the case of acute inflammation, zinc concentration was found to be significantly decreased in arthritic paws, whereas the total amount of the metal present in these inflamed tissues was higher than normal.The status of copper and zinc may well differentiate L.S. from H.S. arthritic rats, especially during the latest phase of the experimental disease, and particularly because of a normalization of the considered parameters in the low-score group.Many of the changes observed in the status of both metals were seen prior the appearance of arthritis.The overall accumulation of copper and zinc which is induced in rat by the development of adjuvant arthritis, is suggested to further sustain the hypotesis of increased body requirements for both metals during inflammation.

Serum copper and ceruloplasmin levels in rheumatoid arthritis and degenerative joint disease and their pharmacological implications

Serum copper concentration and ceruloplasmin activity were measured in patients with clinically established rheumatoid arthritis (R.A.) during the active phase, in patients with degenerative joint disease (D.J.D.) and in normal subjects. Copper and ceruloplasmin serum levels are significantly increased (P less than 0.01) in the arthritic group, but not in the degenerative joint disease group. Copper and ceruloplasmin levels are high significantly correlated in all the groups. This parallel enhancement of serum copper and ceruloplasmin in R.A. is commented in view of a possible protective role of endogenous copper and/or ceruloplasmin in inflammation.