Figure 1.

Hepatic mRNA expression levels of several enzymes involved in bile acid biosynthesis are altered in the Cyp27a1^−/− mouse. Relative hepatic RNA levels were determined by Northern analysis from male, mixed-strain, wild-type and Cyp27a1^−/− mice fed a standard rodent diet. The values shown in boxes represent the mean ± SEM of the fold change in mRNA levels (n = 6 mice per genotype). Bile acid intermediates that would be predicted to accumulate upstream of CYP3A11 because of these changes in enzyme levels include the following: 1, 7α-hydroxycholesterol (5-cholesten-3β,7α-diol); 2, 7α-hydroxy-4-cholesten-3-one (4-cholesten-7α-ol-3-one); 3, 5β-cholestan-3α,7α,12α-triol; 4, 4-cholesten-3-one; and 5, cholestanol (5α-cholestan-3β-ol).