The three serum bile pigments in obstructive jaundice and hepatitis.

Many workers have observed that in obstructive jaundice and hepatitis hyperbilirubinaemia is due mainly to a rise in those pigments which give a " direct " reaction in the van den Bergh test. Cole, Lathe, and Billing (1954) have shown that there are two water-soluble pigments which give this reaction. They appear to be chemically related to bilirubin, but their exact structure is still unknown and they have been temporarily called pigment I and pigment II. Pigment II is the more polar of the two and is the principal pigment found in bile. The metabolic relationship between the three pigments is not fully understood and it was hoped that a knowledge of the amounts of pigment I and pigment II in serum might give further information on this subject. Using the method described in the previous paper (Billing, 1955), the sera from 17 jaundiced patients have therefore been analysed for bilirubin, pigment I, and pigment II. The clinical diagnosis of obstructive jaundice does not necessarily mean that the obstruction of the bile ducts is complete and there is also the possibility of some additional liver pathology being present. The effect of bile duct obstruction on bile pigment metabolism can be more easily studied if the obstruction is produced experimentally under standardized conditions. An analysis has therefore been made of the sera from a small series of rats, whose bile ducts were tied, and the results obtained will be compared with those from the pathological