Article Figures & Data
Figures
- Fig. 1
Osmotic coefficients of bile acids in aqueous solution. Most naturally occurring bile acids have physical properties that cause them to aggregate in aqueous solution as their concentration increases, referred to as micelle formation. A decrease in osmotic coefficient indicates less water enters via aquaporin 8 and claudin 2 and proportionally more via lecithin-cholesterol vesicle formation. This relationship accounts for the findings in the absence of claudin 2. The decrease in the rate of osmotic equilibration results in an increase in bile acid concentration. Figure reproduced with permission from Carpenter (1969); copyright Springer Nature. C, cholate; CDC, chenodeoxycholate; DC, deoxycholate: GC, glycocholate; GCDC, glycochenodeoxycholate; GDC, glychodeoxycolate; TC, taurocholate; RDC, taurodeoxycholate.
- Fig. 2
Bile flow and erythritol clearance after intravenous infusion of bile acids. Erythritol, a lower molecular weight surrogate for mannitol, is a biomarker for water flow. However, it was found that although erythritol clearance increased in parallel with water flow when TDC was infused, it decreased progressively when taurocholate was infused. Initially the findings were attributed to changes in permeability of the membrane to erythritol caused by the different bile acids. Alternatively, with the recognition of paracellular flow via claudin 2 and the relationship of lecithin-cholesterol vesicle secretion to bile acid micelle formation, it is reasonable to propose that total hepatic bile flow for each bile acid is a composite to transcellular and paracellular flow. Erythritol clearance is a biomarker for paracellular flow. Figure reproduced with permission from Tavoloni (1984); copyright 1984 The American Physiologic Society. CH, cholate; TC, taurocholate; TCDX, taurochenodeoxycholate; TDX, taurodeoxycholate; TUDX, tauroursodeoxycholate.
