Paricalcitol preserves mucosal barrier permeability, attenuates MLCK activation and ameliorates colitis in TNBS colitis model. (A) Mouse body weight changes in four treatment groups following TNBS instillation. *P<0.05, **P<0.01 vs. Ctrl and Paricalcitol; #P<0.05 vs. TNBS+Pari; n=5 in each group. (B) H&E staining of distal colon sections in four treatment groups of mice on day 3. (C) MPO activity in mucosal lysates from four groups of mice on day 3. **P<0.01 vs. the rest; n=5 in each group. (D) Real time RT-PCR quantitation of mucosal pro-inflammatory cytokines and chemokines in the four groups of mice on day 3. *P<0.05; ** P<0.01 vs. the rest; #P<0.05 vs. TNBS; n=5 in each genotype. (E) Transepithelial resistance (TER) of colon mucosa from control mice and mice treated with paricalcitol, TNBS and TNBS+Paricalcitol on day 1. (F) Quantitation of paracellular FITC-dextran passage across mucosal barrier in mice from the four treatment groups. ** P<0.01 vs. the rest. (G and H) Western blot analyses (G) and densitometric quantitation (H) of colonic mucosal lysates from the four treatment groups. *P<0.05, **P<0.01, ***P<0.001 vs. the rest for the same protein; #P<0.05 vs. TNBS; n=3.