FIG 2.

Response to 1,25(OH)₂D₃ treatment in KO/TG mouse intestine as measured by RT-qPCR. Gene expression in the duodenum (Duo) and colon (Col) of KO/TG1 mice (TG1) (A) or KO/TG2 mice (mice from a second transgenic line [TG2]) (B) treated with vehicle or 1,25(OH)₂D₃ (1 ng/g body weight at 48, 24, and 6 h before termination; TG1+ D or TG2 + D). Results are compared to those from VDR KO mice. n = 6 per experimental group. Gene expression was normalized to Gapdh and expressed as means ± SEMs. +, P < 0.05 compared to vehicle (TG1 or TG2); #, P < 0.05 between 1,25(OH)₂D₃ treated (TG1 or TG2 +D) and VDR KO; *, P < 0.05 between vehicle (TG1 or TG2) and VDR KO. The duodenum was included as a control. Note the lack of responsiveness of the duodenum to 1,25(OH)₂D₃ treatment due to the absence of VDR in the proximal intestine of these transgenic mice. ND, not detected.