Urinary bile alcohol profile in infants with intrahepatic cholestasis: identification of 5β‐cholestane‐3α,7α,24,25‐tetrol

Abstract

Urinary bile acids and bile alcohols were examined in six infants aged between 1 and 6 mo who had intrahepatic cholestasis. Following extraction, hydrolysis and solvolysis, cholanoids were analysed by gas‐liquid chromatography and gas‐liquid chromatography‐mass spectrometry. The relative ratio of the urinary excretion of bile alcohols to bile acids was very low (0.07‐0.22) in three patients with mild to severe cholestasis, whereas the urinary excretion of bile alcohols was 2–4 times greater than that of the total bile acids in three patients with slight cholestasis. The urinary bile alcohol spectrum in infants appears to be quite different from that in adults. Although the major bile alcohol was 27‐nor‐5β‐cholestane‐3α,7α,12α,24,25‐pentol, comprising more than 50% of total urinary bile alcohols in healthy adults, it accounted for only 35% of total urinary bile alcohols in our patients. In addition, bile alcohols carrying chenodeoxycholic acid type nucleus were detected in our patients by comparison of the retention times and mass spectra with those of authentic standards. The presence of 5β‐cholestane‐3α,7α,24,25‐tetrol confirmed for the first time in this study may represent an alternative pathway for chenodeoxycholic acid biosynthesis via a “25‐hydroxylation pathway” in early life.