MALABSORPTION OF ZINC IN RATS WITH ACETIC ACID-INDUCED ENTERITIS AND COLITIS

Acute intestinal inflammation was established in rats by intraluminal administration of acetic acid into loops of distal. ileum, proximal je junum or ascending colon. The study included two control groups of int act (untreated) rats and sham-operated (saline-treated) rats for each intestinal segment. A third group of rats received acetic acid. Histol ogical evaluation demonstrated that acetic acid treatment induced a mi ld inflammatory response. Two days after treatment, zinc absorption wa s measured using ligated 10-cm loops of each segment in which Zn-65 wa s injected intraluminally. Zn-65 absorption by the ileum, jejunum and colon was markedly reduced in those rats in which inflammation was ind uced by acetic acid. The liver showed the highest uptake of radioisoto pe, but the relative tissue distribution generally followed the amount of absorption. The surgical procedure itself seemed to reduce zinc ab sorption. No changes in H-3!leucine absorption were observed between sham-operated and acetic acid-treated controls. There was no significa nt serosal --> luminal secretion of intramuscularly injected Zn-65 in any of the studied segments. Therefore, based upon the data obtained, we conclude that acetic acid-induced intestinal inflammation reduces a bsorption of zinc by the small and large intestine, and that a surgica l procedure (laparotomy) also reduces zinc absorption. The mechanism o f this inflammation is such that malabsorption shows some specificity.