Date of this Version
Preliminary experiments were carried out to evaluate in vivo expression of zinc transporter (ZnT) 1 mRNA in a panel of tissues obtained from weaned pigs and to evaluate in vitro changes in Z n T l mRNA in a porcine jejunal epithelial cell line (IPEC-J2) treated with low (40 yM) or high (80 yM) concentrations of zinc sulphate (ZnSO,) or, in a separate experiment, with low (50 yg/ml) or high (1 00 yg/mL) concentrations of antibiotics (as gentamicin; GENT). Lipopolysaccharide (LPS; 10 ng/mL) was included as a negative control in both experiments. Zinc transporter 1 mRNA was detected in all tissues evaluated with the greatest level of expression observed in the tonsil. A treatment X time interaction was not observed for IPEC-J2 cells treated with ZnSO,; however, the addition of high ZnSO, tended (P = 0.08) to increase Z n T l mRNA expression when means were averaged among all time points. Exposure of IPEC-J2 cells to GENT resulted in a significant treatment x time interaction (P < 0.005) with increases in Z n T l mRNA observed at 3 (low GENT) and 6 (low and high GENT) hours post treatment compared to CTL- or LPSt eated cells. This research indicates that Z n T l mRNA is differentially expressed in vivo, in a panel of porcine tissues, and in vitro, in IPEC-J2 cells exposed to low or high concentrations of zinc or antibiotics.