Cholic acid biosynthesis is defective in individuals with cerebrotendinous xanthomatosis (CTX) and is associated with the excretion of 5β-cholestane-3α,7α, 12α,25-tetrol, an intermediate in the 25-hydroxylation pathway of cholic acid in CTX. To define the enzymatic defect in CTX, two suspected precursors of cholic acid, namely 5β-[7β-3H]cholestane-3α,7α, 12α-triol and 5β-[24-14C]cholestane-3α,7α, 12α,24S,25-pentol were examined by both in vivo and in vitro experiments. A third precursor, 5β-[7β-3H]-cholestane-3α,7α, 12α,25-tetrol, was compared with them in vitro.
Gerald Salen, S. Shefer, F. W. Cheng, B. Dayal, A. K. Batta, G. S. Tint
