Bile acids: analysis in biological fluids and tissues

in lower vertebrates. Metabolism of cholesterol to bile acids/bile alcohols is of major importance for the maintenance and regulation of cholesterol homeostasis. Depending on their structure, bile acids/bile alcohols can be ligands to nuclear receptors with different regulatory functions in animals, including even Caenorhabditis elegans ( 1 ). Bile acids can be formed in some marine microorganisms ( 2 ). These fi ndings have increased interest in methods for specifi c and sensitive analysis of bile acids.