Fig. 2. Effect of acute administration of Pi on the duodenal and jejunal mRNA expression of Na⁺/Pi-cotransporters. The mRNA expression of NaPi-IIb (A, B), Pit-1 (C, D) and Pit-2 (E, F) was quantified by real-time RT-PCR in samples from duodenum (A, C, E) and jejunum (B, D, F) of rats intragastrically gavaged with saline (NaCl-ig) or with Pi (Pi-ig) as well as of rats intravenously infused with saline (NaCl-iv) or with Pi (Pi-iv). Samples were collected either 40 minutes (40 min) or 4 hours (4 h) post-administration. The expression of each cotransporter was normalized to the abundance of HPRT. Columns represent mean ± the standard error of the mean (SEM); n= 5 for the 40 minutes and n ≥ 8 for the 4 hours groups. Statistical comparisons were performed using one-way ANOVA, followed by the Bonferroni post-test with a confidence interval of 95%. *p<0.05 compared with the corresponding saline value.