Zn is regularly added to TPN solutions, however, requirements are poorly understood. This research investigated whether or not the route of Zn intake (oral vs parenteral) changes Zn concentration in rat tissues. Twenty-four male Fischer-344 rats were equally and randomly assigned to one of four groups (n=6): control (CON), baseline (BS), orally fed (OF), and intravenously fed (IV). After fifteen days of feeding, organs and sera were collected and analyzed for Zn by atomic absorption spectrophotometry. Of the nine tissues analyzed, the Zn concentrations in the liver, kidney, and lung of the IV rats were significantly higher (p<1.l) than those of the CON, BS, and OF rats. Results indicated that rats fed intravenously with Zn displayed increased Zn concentrations in liver, kidney and lung tissues, and that the concentration of Zn in the serum may not reflect tissue Zn levels. This suggests that the route of Zn intake affects tissue Zn concentration.
