Figure 6.

TGR5 activation is caused by the additive effect of conjugated primary and tertiary bile acids. (A) TGR5 potency was measured for each bile acid (eg, glycolithocholic acid [GLCA]) at increasing concentrations. The concentration that was required to achieve the half-maximal effect of TLCA was calculated. (B) TGR5 potencies of bile acids were expressed as a multiple of cholic acid potency. (C) Formula to calculate the TGR5 activity induced by serum bile acids using the bile acid concentrations and TGR5 potencies (potencies of bile acids). (D) Calculated and measured TGR5 activity correlated closely, N = 66, Spearman correlation rank test. max., maximum.