Differential effect of MDP treatment on magnesium in rat tissues

Magnesium determinations were performed by atomic absorption spectrophotometry on several tissues of MDP-treated and control rats. Sixteen hours after a single administration of 1 mg of MDP, Mg concentrations were increased in both the liver and the adrenals. After three daily injections of the same MDP doses, statistically significant increases of Mg concentration were observed in the liver, the brain and the adrenals. For the latter, however, the results were significant only when Mg concentrations were referred to the weight of tissue water but not when they were referred to the dry weight. Blood, thymus, spleen, kidneys, cardiac and skeletal muscle Mg determinations were also performed; no significant effect of MDP has been observed under our experimental conditions. The present results show that MDP modifies the distribution of Mg in various compartments of the body and suggest the possible role of Mg in some biological actions of MDP.