engleski

Metal tissue kinetics in regenerating liver, thymus, spleen and submandibular gland after partial hepatectomy in mice

Injury or removal of liver tissue leads to fast growth of liver remnant, involving changes in gene expression, growth factor production and morphological structure. Concomitantly, the breakdown of previously maintained tolerance and the exposure of self antigens lead to the activation of pre-immune and immune repertoire, which participate in surveillance against aberrant cells and re-establishment of previous morphostasis. Since, in these events, important biological function might have tissue minerals which are affecting the structural integrity and enzyme activities, transduction signals, transcription and replication factors during cell proliferation and apoptosis, as well as, the development and maintenance of immune functions and cytokine production, in this study we analyzed tissue dynamics of zinc, iron, magnesium and calcium in the liver, thymus, spleen and submandibular gland in intact and partially hepatectomized (pHx) mice on the 1st, 2nd, 7th and 15th day after 1/3 pHx, using the microwave digestion and inductivity coupled plasma spectrometry. The data have shown that tissue content of Zn++, Fe++, Mg++ and Ca++ is significantly affected by pHx. In early phase of regeneration in the liver significantly increased the concentration of Zn++ and Ca++, while simultaneously, the concentration of Zn++, Ca++ and Mg++ decreased in the thymus and in the spleen. In the latter phase of regeneration (on the 7th and 15th p. o. day), however, a marked accumulation of Zn++, Mg++ and Ca++ was noticed particularly in the thymus. Furthermore, when the mineral content found in estimated organs was, in each mouse, correlated with the intensity of liver regeneration, in early phase of liver growth (24h after pHx) a very high positive correlation was found between the concentration of Zn++ and the concentration of Ca++ in thymus and the index of liver growth (r=0.99 ; p<0.008 and r=0.99 ; p<0.002, respectively). Seven days later, however, liver growth negatively correlated with concentration of Ca++ in the thymus (r = - 0.97 ; r=0.02), while two weeks later, the concentrations of Fe++ in the spleen positively correlated with liver growth (r=0.96 ; p<0.03), in contrast to concentration of Zn++, which was in an inverse relationship with the index of liver growth (r= -0.96 ; p<0.035). Furthermore, in the late phase of liver regeneration the negative correlations were found in submandibular gland between the concentrations of all estimated metals and index of liver growth. The data emphasize that 1/3 pHx in mice is followed by marked changes in tissue dynamics of Zn++, Fe++, Mg++ and Ca++, not only in regenerating liver, but also in the thymus, spleen and submandibular gland, pointing to the regulatory effects of trace metals and metallothioneins in highly interconnected network of growth-factors and cytokine-regulated pathways, activated during liver regeneration.

liver regeneration; metal tissue kinetics; thymus; spleen; submandibular gland

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