Fig. 3
Effect of very low protein diets supplemented with limiting and branched-chain amino acids higher than recommended levels on mRNA abundance of markers associated with Ca/P absorption in duodenum. (A) parathyroid hormone 1 receptor (PTH1R), (B) calbindin 1 (CALB1), (C) vitamin D receptor (VDR) (D) occludin (OCLN), (E) thyroid hormone receptor alpha (THRA), (F) plasma membrane Ca2+ ATPase 1b (PMCA1b), (G) transient receptor potential cation channel subfamily V member 6 (TRPV6), (H) zonula occludens 1 (ZO1). PC (positive control), standard protein diet; NC (negative control), low protein diet supplemented with limiting amino acids (LAA, i.e., Lys, Met, Thr and Trp); L25, low protein diet supplemented with LAA, 25% more than NRC (2012) requirements; L50: low protein diet supplemented with LAA 50% more than NRC requirements; LB25: low protein diets supplemented with LAA and branched-chain amino acids (BCAA, i.e., Leu, Ile and Val) 25% more than NRC requirements; LB50: low protein diet supplemented with LAA and BCAA 50% more than NRC requirements. a P ≤ 0.05 LB25 vs. PC, d P ≤ 0.05 LB50 vs. NC, f P ≤ 0.05 LB50 vs. L50. $ 0.05 < P ≤ 0.1 LB25 vs. NC, & 0.05 < P ≤ 0.1 LB50 vs. NC, * 0.05 < P ≤ 0.1 LB25 vs. L25, ¥ 0.05 < P ≤ 0.1 LB50 vs. L50. The values are means ± standard error of the mean, n = 8