The importance of total parenteral nutrition-associated tissue zinc distribution in wound healing

It is well known that zinc (Zn), an essential trace element, plays a role in wound healing. Although the importance of Zn supplementation in total parenteral nutrition (TPN) has been recognized, the difference in tissue Zn distribution induced by TPN and whether this difference influences local wound healing remains uncertain. Thus, we conducted a study using 30 Sprague-Dawley rats to investigate the influence of TPN-induced changes in tissue Zn distribution on wound healing at sites of intestinal anastomosis, muscle, and skin sutures. In the ordinary diet group, no significant differences were observed between subgroups with and without supplemental Zn in tissue Zn distribution or in the healing of intestinal, muscular, and cutaneous wounds. In the subgroup given a low-protein diet without supplemental Zn, a gross change in tissue Zn distribution was noted to occur with a concomitant marked decrease in Zn concentration and the tensile strength of wounded skin. These results indicate an association between wound healing and Zn concentration in the respective tissues in TPN-induced Zn deficiency with alternations in tissue Zn distribution. They also provide evidence of the local action of Zn in wound healing.