[Does varied parenteral zinc administration modify interaction between tumor and host? Studies based on an animal model].

Zinc speeds up a lot of metabolic processes because it is essential for a lot of enzymatic reactions. A modification of the zinc pool may influence the tumor growth. We used an animal model where we applied the Yoshida sarkoma intraperitoneally in its ascites form to parenterally fed Sprague-Dawley rats. Four groups with ten tumor bearing (TBR) and ten non-tumor-bearing rats (NTBR) each received different parenteral nutrition. The normocaloric Group 1 and the hypocaloric (reduced to 1/3 energy) Group 2 were fed without zinc. In Groups 3 (normocaloric) and (hypocaloric) high doses of zinc (0.519 mg/500 g Kg/d) were substituted. In Group 3 we found the quantitatively and qualitatively highest proof of tumor mass. The nitrogen content of the ascites wasn't significantly changed within the groups. We found a weight loss of the NTBR with zinc substitution. Zinc improves the synthesis of the tumor and leads to a weight loss of the host in our animal model.