Urinary Elimination of Bile Acid Glucuronides under Severe Cholestatic Situations: Contribution of Hepatic and Renal Glucuronidation Reactions

Figure 3

Kinetic analyses of CDCA-3G (a), CDCA-24G (b), and CA-24G (c) formation by microsomes from human liver and kidney. Human liver (black squares, pool of 50 donors) and kidney (white diamonds; pool of 8 donors) microsomes (10 μg) were incubated in the presence of increasing concentrations (1 to 350 μM) of chenodeoxycholic acid (CDCA, (a) and (b)) or cholic acid (CA, (c)) for 2 hours at 37°C. The formation of CDCA-3G (a), CDCA-24G (b), and CA-24G (c) was analyzed by LC-MS/MS. For each panel, graphs represent the rate of product formation (-axis) versus substrate concentration (-axis) of two experiments performed in triplicate. The listed kinetic parameters were determined as indicated in “Materials and Methods.” : Hill coefficient; : calculated Michaelis constant expressed as μM; : calculated maximal velocity expressed as nmol/h/mg proteins.

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(b)

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